1. Field of the Invention
This invention relates to memory reading and writing apparatus. The invention is more particularly related to memory reading and writing apparatus that utilize operations on single atoms or molecules, and groups of atoms or molecules for performing memory reading and writing.
2. References
This application incorporates by reference, in their entirety, the following documents:
Current technology for high density solid state memory employ various means for storing and reading data.
A summary of previous patent applications in this area are listed in U.S. Pat. No. 5,453,970, entitled “Molecular Memory Medium and Molecular Memory Disk Drive for Storing Information Using a Tunneling Probe” by Thomas F. Rust and Joanne P. Culver.
Current technologies using movement of atoms and molecules (molecular scale technologies) are not practical because my problems exist regarding the efficient reading, writing (including maintaining a high density of storage) on media materials. Further problems with current devices include structures that are difficult or impossible to build using existing tools.
Accordingly, the present invention provides a device capable of reading and/or writing on a substrate by affecting (via movement of molecules/atoms, and/or modification of electrical properties (including any of charges, resistance, capacitance, inductance, and magnetic properties) stored on the media.
The present invention includes a media prepared for storage of data bits in a high density via movement of molecules/atoms on the media and/or the modification of electrical properties on the media.
The present invention, in it's various embodiments, has many distinguishing features, for example:
A molecular memory integrated circuit (IC) is a device for storing very large quantities of information, and is also uniquely capable of providing very high data rates of this information to and from the IC. The molecular memory IC may be manufactured at a cost comparable to current ICs, yet at a fraction of the cost required to achieve the same amount of storage. The molecular memory IC may substitute for many devices which currently are used as a storage medium. The molecular memory IC may be used to replace disk drives in computer systems, the magnetic tape systems in video and audio tape recorders, photographic film used for information storage, and even EEPROM (electrically erasable read only memory), VRAM (video random access memory) and DRAM (dynamic random access memory) where access time is not a high priority. Data transfer rates will depend on the architecture used in the IC, and may involve trade offs between overall memory capacity versus maximum latency. A typical molecular memory IC of 1.6 cm2 will store over 860 Megabytes of data. The molecular IC may replace magnetic tape in camcorders, digital and analog audio tape, video tape, and CD-ROM players. In one embodiment, the present invention has been fabricated using a laser ablated diamond media to produce a Molecular Array Read/write Engine (MARE) IC with the following specifications:
Given:
In accordance with the present invention, there is provided a memory apparatus comprising an input section which comprises one or more fine tip portions, a control means for controlling the input section, whereby high density recording is achieved, an output section, comprising a similar or identical fine tips, and fixed or moving substrate surface or surfaces, comprising sets of molecules, atoms, electrons, or the void left by sets of molecules, atoms, or electrons the position of each set or void or orientation of molecules, atoms, or electrons defining the states of memory regions.
In an alternate embodiment, there is provided a memory apparatus comprising an input section which comprises a source of fine electromagnetic radiation and/or a fine tip, a control means for controlling the input section, whereby high density recording is achieved, an output section, comprising a fine tip and/or electromagnetic radiation sensitive receptor, and fixed or moving substrate surface or surfaces, comprising sets of molecules, atoms, or electrons, or the void left by sets of molecules, atoms, or electrons the position of each set or void of molecules, atoms, or electrons defining the states of memory regions. Magneto-optic effects are also contemplated.
In an alternate embodiment, there is provided a memory apparatus comprising an input section which comprises a fine tip with a ferromagnetic coating, a control means for controlling the input section, whereby high density recording is achieved, an output section, comprising a fine tip with a sensitive magnetic receptor, and fixed or moving substrate surface or surfaces, comprising sets of magnetic domains the position of each set or void of domains defining the states of memory regions.
Generally, the recording of information is performed by the addition, removal or repositioning of atoms, molecules, electrons or magnetic domains from the region either immediately above, on, or immediately below the surface of the molecular media. The removal or repositioning force is either a mechanical force, chemical reaction (as in chemical bond interactions, catalyst, etc.), electrostatic force, electromagnetic radiation, DC or AC magnetic field, electric current, or thermal force. A combination of these above forces come into play to perform writing on the molecular media. The reading of information is performed by one of the methods of one of or a combination of:
One of the techniques for re-write capability involves re-planing of the memory surface, to effect more than a write-once capability.
The medium of a molecular memory surface can be any one of a large class of materials. The present invention describes a number of different materials, and several different techniques for reading and writing the materials. The present invention allows for a large class of materials to be used as the memory surface by virtue of the ability of the read/write head to fly above a relatively uneven surface at very high speeds, and the large range of forces with which to read and write information.
According to the present invention, a molecular memory integrated circuit apparatus comprises one or more stacked systems each comprising a memory element comprising one or more media surfaces, optional servo tracking marks embedded in the media surface, a positioning mechanism for positioning the media surfaces, a control means for controlling the positioning mechanism, an input/output section which comprises at least one head having a fine tip portion faced towards the memory media surface, a positioning mechanism for positioning the head or heads above the memory media surface or surfaces, a control means for controlling the positioning mechanism, a write section which converts an analog or digital signal to write information, a sense section which converts the input section to analog or digital information, an optional sense section which converts position information to analog or digital information, an optional cleaning section which removes unwanted particles, an optional sharpening area where unwanted particles are removed and/or added to the tip, and a fine tip alignment section.
The control section comprises means for bringing the tip portion of the head close to the surface of the memory media to thereby effect positioning, means for allowing the tip portion to scan the memory, means for controlling the distance between the tip and the memory media during scanning, and means for positioning the tip at, above, or below the surface of the memory media. The head or heads have a fine tip portion attached to an oscillating mechanism operating at or near a resonant peak such that when the tip is operated near the memory surface, the phase of the oscillation shifts from its free space value. The amount of this phase shift increases as the distance between the memory and the tip at its closest position to the media decreases. In addition, the state of data bits under the tip may shift the phase of the oscillation above or below the free space value.
According to the present invention, a molecular memory integrated circuit apparatus comprises a memory element comprising one or more media surfaces, an input/output section which comprises at least one head having a fine tip portion faced towards the memory media surface, a positioning mechanism for positioning the head or heads above the memory media surface, a control means for controlling the positioning mechanism, a sense section which converts the input section to analog or digital information, an optional cleaning section which removes unwanted particles, an optional sharpening area where unwanted particles are removed and/or added to the tip, and a fine tip alignment section.
The control section comprises means for bringing the tip portion of the head close to the surface of the memory media to thereby effect positioning, means for allowing the tip portion to scan the memory, means for controlling the distance between the tip and the memory media during scanning, and means for positioning the tip at, above, or below the surface of the memory media. The head or heads have a fine tip portion such that a current flows between the tip portion and the memory surface. The amount of this current indicates the distance between the memory and the tip.
According to the present invention, a molecular memory integrated circuit apparatus comprises a memory element comprising one or more media surfaces, an input/output section which comprises at least one head having a fine tip portion faced towards the memory media surface, a positioning mechanism for positioning the head or heads above the memory media surface, a control means for controlling the positioning mechanism, a sense section which converts the input section to analog or digital information, an optional cleaning section which removes unwanted particles, an optional sharpening area where unwanted particles are removed and/or added to the tip, and a fine tip alignment section.
The control section comprises means for bringing the tip portion of the head close to the surface of the memory media to thereby effect positioning, means for allowing the tip portion to scan the memory, means for controlling the distance between the tip and the memory media during scanning, and means for positioning the tip at, above, or below the surface of the memory media. The head or heads have a fine tip portion which is attached to a cantilever. This cantilever may be vibrating above or such that the tip slightly touches the surface, or the tip may be placed directly on the media surface. The cantilever is connected to a Z axis drive mechanism which is electrostatic and capacitive, or may have a separate capacitive sensor for the Z axis. In the vibrating mode, the change in phase of the resonance of the vibrating cantilever indicates the tip is touching or near the memory surface. In the dragging mode, the deflection of the cantilever by the surface changes the capacitance of the drive electrodes, indicating position.
It is important to note here that individual parts of any of the embodiments described herein may be interchanged to produce a molecular memory device according to the present invention.
The control section comprises means for bringing the head close to the surface of the memory media to thereby effect positioning, means for allowing the head to scan the memory, means for controlling the distance between the head and the memory media during scanning, and means for positioning the head above the surface of the memory media.
Electromagnetic Radiation Source as Fine Tip
In one version, the electromagnetic radiation sources 2320 consists of a source such as a light emitting diode or LASER 2330 which may pass through a polarizing film 2340, then is piped through the waveguide structure consisting of materials 2350, 2360 and optionally 2370. The waveguide focuses the electromagnetic radiation to a fine tip portion 2355 such that a narrow beam emanates from the tip portion, impinges on the memory element 2305, and a modulated version of the electromagnetic radiation, the return electromagnetic radiation, emanates from the memory element. Some versions of the memory media modifies the electromagnetic radiation by altering the polarization of the electromagnetic radiation, such as with magneto-optic materials. The return electromagnetic radiation may again pass through a filtering polarization film 2390 and is then sensed by an electromagnetic radiation receptor such as a photodiode 2380. In some versions one or more of the materials 2350,2360,2370, may be conductive and the tip used in a tunneling mode for sensing, and/or the tip used to modify the memory element using any of the memory modification techniques which use such a tip. The use of the electromagnetic radiation may then be used as a sensor to read the media.
Electromagnetic Radiation Receptor as Fine Tip
In another version, the electromagnetic radiation source 2310 consists of a source such as a light emitting diode or LASER 2380 which may pass through a polarizing film 2390, and emanates as a broad beam. The beam impinges on the memory element 2305, and a modulated version of the electromagnetic radiation, the return electromagnetic radiation, emanates from the memory element. Some versions of the memory media modifies the electromagnetic radiation by altering the polarization of the electromagnetic radiation, such as with magneto-optic materials. The return electromagnetic radiation is piped through the waveguide structure consisting of materials 2350, 2360 and optionally 2370. The wave-guide directs the electromagnetic radiation through an optional filtering polarization film 2340 and is then sensed by an electromagnetic radiation receptor such as a photodiode 2330. In some versions one or more of the materials 2350,2360,2370, may be conductive and the tip used in a tunneling mode for sensing, and/or the tip used to modify the memory element using any of the memory modification techniques which use such a tip. The use of the electromagnetic radiation may then be used as a sensor to read the media.
This version also has an additional advantage in the sensing of large particles, as in
Memory Techniques
In the following descriptions, first the different techniques for reading and writing the memory surface will be discussed, followed by descriptions of apparatus for a molecular memory integrated circuit.
Detailed Description Charge Storage Read/Write Memory System
The following description is for one tip/head. Typically, all platforms and tip/heads are operated simultaneously, with data being multiplexed by time division multiplexing to/from A/Ds and D/As through transmission gate muxes. Alternately, one row of platforms with all tips/heads may be operated simultaneously. Alternately, only one tip/head per platform may be operated simultaneously.
In addition, when power is first applied to the system, a calibration sequence is entered (see calibration).
Note: The X and Y actuators operate in pairs. Normally, only one of the pairs receives an active control signal at any time. For example, to move to the extreme left, the left actuator receives a signal to move to the maximum position (typically 50 u), and the right actuator is left off.
Typical READ Operation:
A Digital Signal Processor takes data of where scan sector/track (X,Y coordinates) is to a start position, and loads parameters which initiate a ramp to the desired coordinates. Normally, this will be to a position near a “sector” mark on the X axis, with Y position being a desired “track”. The media has a series of marks which consist of trenches or raised areas, typically 1 u wide, which do not contain any data, but are used to identify the beginning of blocks of data. In addition, in systems which have moving media, control systems will move the media to a position, normally consisting of one of 9 positions, +/center/− of X and Y.
Once the start position is reached, tip/heads begin oscillating at slightly off resonance and start moving towards media. The oscillations of the tip/heads, in one embodiment, are produced via a thermal heater supplied with current at resonance frequency. The thermal heater is embedded in a cantilever arm attached to the head tip and causes the tip to vibrate. For example, referring to
Other materials may be substituted for the Al. In one embodiment, Ti is used, other substitutes include PolySi, NiCr or other hi-r materials.
A feedback loop of the tip/head will look for phase shifts in the signal coming back from the piezoresistors sensor on the tip/head cantilever, indicating proximity to the media surface. In one embodiment, this feedback signal is generated by changes in the resistance of single crystal (or poly-silicon) doped silicon due to stresses in the film (for example, 4750 of
3) As soon as all tip/heads on a platform have engaged the media, a scan can begin. A DSP optimized control signal, similar to a ramp (the DSP functions to produce a ramp voltage to move the actuators to a new position as opposed to applying the voltage all at once, thereby preventing overshoot of the actuator) is applied to the X actuators. The data returning from each of the tip/heads is manifested in a phase shift from the nominal (or near free space) drive frequency of the Z actuator. In addition, there will be a phase shift due to proximity of the tip to the media surface which is based on the gap at the shortest distance the tip travels towards the media. And in addition to that phase shift the magnitude of the phase shift due to the data will be based on the tip potential and the charge potential of the domain under the tip. These two phase shifts will be used for various purposes. First, a phase shift due to the media surface is used to position the heads relative to the surface initially. The second phase shift is used to acquire data.
As shown in
At the beginning of the scan the cantilever is put in a mode to sense the media data. A guide mark (servo line) made out of a physical trench, typically 1 u wide, which marks the beginning of a track. The interface will sense this as the phase from the piezo electric position sensor will shift towards the free space value. When it shifts back (the sensor is past the trench), the track read will begin (the cantilever changes modes from sensing the surface to sensing the data).
In one embodiment, there will be an initial set of charge domains which, encoded in some form of NRZ, which will encode the track (or Y) position. Once this is read and decoded it will be compared with the desired position. If it is incorrect, the difference information will be used to reposition the platform for a retry. Once the correct track is in scan progress, data can be decoded from the stream of phase shift information.
A fine track position mechanism will be in effect to keep the platform positioned on tracks.
In one embodiment, the tracks for data are optimally laid out such that sequentially positioned (in Y) track data is 90 degrees phase shifted from the previous track. This provides for tight packing of the data. In addition, the phase of the clock embedded in the NRZ encoded data will be flipped 180 degrees after every pair of tracks. This means that the track immediately adjacent to any track will have phases 180 degrees apart. In the sampled data from the cantilevers, should the tip wander off track, data will begin to appear from the adjacent track. The phase of this data, relative to the current track, will indicate which side of the track the tip is wandering in, so that an opposing control signal can be supplied to move the tip back on track.
A Z positioning mechanism will use the average phase shift and the desired average phase shift and move the tip/head up or down to maintain a constant distance of the minimum tip gap point during oscillations while scanning across the surface. Although a resonant scheme is slower than dragging the tip in contact with the surface, the resonant scheme allows for a completely non-contact form of media interaction—thus minimizing tip wear.
A particular track is identified by reading a first few encoded data bits on each track that uniquely identify each track. Only enough bits are utilized to uniquely identify the correct track, alternatively additional bits may also identify a particular sector. In yet another alternative, a minimum number of bits may be used to identify a particular sector. In preparing to read data from the media, the cantilever swings the tip down to acquire the surface of the media (note tip position A,
In one embodiment, a mechanism for determining whether or not the tip is drifting between tracks utilizes a set of sync bits that are set in a predetermined sync bit area set at predetermined intervals among each of the tracks. The sync bits are previously written as shown in the sync bit area of
The sync bits may also be utilized to assure that the tip is positioned a proper height above the media surface. For example, again following along Track 2 and entering the sync bit area, if the tip is vibrating at other than the free space value, it would indicate that the tip is too close and is acquiring the media rather than acquiring bits writ en in the sync bit area. Along the same lines, if at the second bit position within the sync bit area (and therefore over the first darkened circle, high bit, on Track 2 in the sync bit area) and tip were not vibrating at a frequency indicating a data bit having been written, but instead was vibrating at the free space value, this would indicate that the tip is too high above the media surface. Sync bit areas as illustrated in
WRITE Operation:
A write operation is essentially identical to a read except for the following difference:
In one embodiment, when the data portion of the track is reached, each time the tip swings down to its closest point to the media surface, a write pulse of appropriate polarity is applied to the tip. If a charge already exists, an opposite polarity pulse will remove the charge (making the data point a free space value, meaning when the tip passes over the data point, it will vibrate at the free space value). If no charge exists, an appropriate pulse will store the charge. In an alternate mode, the tip may remain in contact with the surface during writing.
Calibration:
After power up, the system will perform a calibration sequence. This involves:
Driving all the Z actuators in free space (well above the media) over a scan range (scan ranges of 70-130 Khz and higher) to determine the resonant frequency of each tip/head/actuator system, and setting the drive frequency tables accordingly.
Moving all platforms to the extreme corner positions, initiating scans, and determining the coordinates of the extreme scan positions, as well as the center positions (in Y, for example), to set the coefficients for ramping the Y position controls. This process is performed in both x and y position controls.
The control system will first perform a scan from left to right, and time the scan from grid mark to grid mark across the extremes of positions. This can be performed at slower than normal speed for increased accuracy. This timing information can be used to adjust the X speed controls, as well as the X position controls. The scans can be performed at different Y positions, and likewise in the Y axis. This will calibrate the X and Y positioning and speed controls.
Thus, by driving the heads and determining timing between servo marks, it can be mathematically calculated how much force (current/voltage) is needed to drive the actuators to place the media and platforms in specific positions. Such information is maintained in tables or other data storage. The DSP utilizes the stored data with respect to driving the x-y actuators and resonant frequencies to determine a ramp to send to the actuators to position the media and platforms.
Each cantilever is tested by the DSP by applying a current at different frequencies to each cantilever to determine resonant frequencies (via amplitude peaks) of each cantilever. The resonant frequencies will be maintained by hardware or software in a table, and utilized in tip operations (reading, for example).
Formatting:
Like any non-volatile memory, the system needs to be formatted. To aid the process of formatting, a set of guide (servo) marks will be etched in the surface of the media. In one embodiment, these marks will consist primarily of 1 u lines, in a grid pattern. Then a series of write tracks will be executed, which write all the tracks with known data and track position information.
Detailed Description Magnetic Read/Write Memory System
The magnetic system is similar in most respects to the charge storage system, with the following differences:
Typical READ Operation:
Same as 1, 2, and 3 above (typical read of charge storage system), except that the phase shift is due to interaction of magnetic material on a coated tip of the cantilever and magnetic domain under the tip and in the media (medium).
WRITE Operation:
A write operation is essentially identical to a read except for the following difference:
When the data portion of the track is reached, each time the tip swings down to its closest point to the media surface, a write pulse of appropriate polarity is applied to the write/sense coil. This creates a magnetic field which induces a field in the ferrous coated tip (Co, for example), which then flips the polarity of the domain immediately under the tip. The duration of this pulse must be short enough to prevent driving the tip into the media, yet long enough to flip the domain (which fortunately can be achieved in a short time span). The intensity must be controlled for the same reason. For example,
Alternate Write Operation Technique—Synchronous Write
When the data portion of the track is reached, all of the tips or a block of tips are moved towards the media and positioned at the closest point ONLY if a bit of a certain state is to be written for that bit. If an opposite state is destined for a bit, the tip is moved away from the media. When all the tips of the appropriate state are at their closest point to the media surface, a write pulse of appropriate polarity is applied with an external coil. This creates a magnetic field which induces a field in the Co coated tip, which then flips the polarity of the domain immediately under the tip. A second pass is then initiated to write all the bits of the opposite state. The Z head/tip assemblies may be periodically switched back to a resonant sensing mode to ensure that the assemblies are still tracking the desired tracks correctly (in one embodiment, by reading sync bits).
This technique has the advantage of overcoming the small fields producible by the individual write coils by substituting a large field coil. It has the disadvantage of requiring a slower write time.
Memory Techniques Using Current Flow and Fine Tip
In the previously described techniques, the tip/media interaction operated in the tunneling regime, a distance nominally from 1 to 10 Angstroms between the tip and the media. A larger distance is typically referred to as the field-emission regime. Nominally lower currents flow in this regime and the current is also largely affected by the presence or absence of environmental gases. A smaller distance we will refer to as the purely resistive regime. In this regime, one or more atoms of the tip will be within a range which will allow substantial currents to flow between the tip and the media.
In the field-emissive regime, provided sensitive enough electronics, the sense mechanisms will still operate all the described memory techniques. Provided also that the voltage is raised to a high enough value, the memory element altering mechanisms will also operate for all those techniques which require an electrostatic force to operate.
In the purely resistive regime, the sense electronics need be much less sensitive, providing for much simpler sense electronics. An important consideration in the resistive regime is that the tip generally not move laterally over the media surface while sensing or altering the media in order to reduce tip wear. Here again, the same mechanisms will operate for all those techniques which require an electrostatic force to operate.
In addition to the Memory techniques already described in the previous patent (Rust, et al., U.S. Pat. No. 5,453,970) are the following techniques:
Memory Technique 1
For this technique, an example surface and memory element is doped diamond. The memory altering technique is the same as Technique 6 in the previous application.
In this technique depicted in
When a pulse of greater than 23V is applied of typically 100 ns, the new lattice state of the diamond is in the form of a donut shape 2000 typically 30 nm wide by 10 nm high as shown in
Memory Technique 2
For this technique, an example surface is silicon, the memory element are electrons or depleted electrons (holes) stored on a thin insulator such as silicon dioxide.
In this technique depicted in
The unwritten state is depicted in
To effect a written state in the memory, a head tip 2600 is positioned above or at the plane of the insulator 2610. When it is desired to write a bit of data, a bias voltage is applied between a tip and a memory element 2620. The bias voltage stores a charge in the form of electrons or holes 2630 as the memory element. It is possible to store analog information by using a larger or smaller bias voltage as well.
To read the information stored, the tip is passed over the surface in the same manner as writing. The electronics are put in a read mode. The read electronics discharges the electrons or holes to sense the information. The information is then restored in a subsequent re-write.
A disadvantage of this technique is that it requires re-writing the information after every read.
Memory Technique 3
For this technique shown in
In addition, one of several techniques are used to improve the performance of this structure. In one form, a series of trenches are fabricated in the substrate 2540 and the NO or ONO structure is formed over the surface of the trenches. This has the effect of increasing the effective capacitance of the structure by a large factor causing a larger change in capacitance (stored charge) between a written and non written area of the media. In addition, the preformed structure of trenches serve as guides for the tracking servo mechanism.
In another form, a processing technique is used to etch the NO areas N 2510 and O 2550 into discrete islands. In another technique, in addition to forming the islands, additional doping is injected into the regions between the islands. Both of these techniques have the effect of allowing smaller bits to be formed. In the additional doping technique, the bits tend to have deeper depletion regions as well.
The unwritten state is depicted in
To effect a written state in the memory, a head tip 2500 is positioned above or at the plane of the insulator 2510 at 2520. When it is desired to write a bit of data, a bias voltage exceeding a certain threshold is applied between a tip 2500 and a substrate 2540, creating memory element 2530. The electrons tunnels to/from the substrate material and stores a charge in the form of electrons or holes as the memory element on the insulator 2510. It is possible to store analog information by using a larger or smaller bias voltage as well.
In one embodiment, to read the information stored, the tip is operated on a cantilever operating in a resonant mode. As the tip passes over a region of stored charge, based on the potential of the tip and the potential of the charge, a force will be exerted between the tip and the stored charge which will alter the phase of the cantilever.
In an alternate embodiment, the tip is passed over the surface in the same manner as writing. The electronics are put in a read mode. The existence of a charge forms a depletion layer in the substrate 2540, effectively changing the relative capacitance of the region between the substrate and the surface. A read technique which senses the difference in capacitance of written and unwritten states may be used.
Memory Technique 4
This technique is shown in
The unwritten state is depicted in
To effect a written state in the memory, a head tip 1800/1900 is positioned above or at the plane of the insulator 1820/1920. When it is desired to write a bit of data, a bias voltage exceeding a certain threshold is applied between a tip 1800/1900 and the substrate 1870/1970, creating a memory element under 1820/1920. The electrons tunnel to/from the substrate material 1970 and stores a charge in the form of electrons or holes as the memory element on the insulator 1910. It is possible to store analog information by using a larger or smaller bias voltage as well.
To read the information stored, the tip is passed over the surface in the same manner as writing. The tip is set to a bias voltage for the read mode. A potential is applied between the two electrodes. The existence of a stored charge 1830/1930 forms a depletion layer in the doped region. The existence of the read mode bias adds to the induced field, raising the field enough to create an inversion region in the doped area 1860/1960. The existence of the inversion region will cause a current to flow between the electrodes 1805 and 1815, greater than that which would occur without the tip-induced field.
This greatly simplifies the electronics needed for this type of memory device.
In an alternate embodiment of this technique, the doped regions are formed into narrow channels between sets of two electrodes. The existence of the sets of narrow channels allows the ability to select which regions are to be read or written by selecting the electrodes.
In one embodiment, the molecular memory media (storage medium) is produced by depositing layers similar to those seen in the previous figures (
Memory Technique 5
In an alternate media embodiment, the media consists of structures forming quantum dots. These may be formed using multiple quantum well (MQW) techniques. The media is written by applying a voltage pulse sufficient to change the electron state energy in the trapped quantum well regions.
Memory Technique 6
In this technique, the memory substrate consists of a material such as silicon (Si). The substrate has the property of two or more bonding interface states with the layer of atoms or molecules (memory elements) in the adjoining layer.
This technique is similar to Memory Technique 6 in the previous application, but with several differences in the way the memory elements are read and written.
To effect a written state in the memory, a head tip 1900 is positioned above or at the plane of the memory element layer. When it is desired to write a bit of data, the tip is moved laterally with respect to the memory element layer at a rate TV for tip velocity. At the same time, a periodically fluctuating bias voltage (VBF) of a sufficient amplitude to move the memory elements is applied. The fluctuating bias matches the energy level of the selected media material. The distance between bond center of a substrate-memory element bond, in one of the desired states is DBCS1 (distance bond centers state 1).
VBF will be of such a frequency to be a harmonic relationship of TV/DBCS1. (Alternatively, the TV may match the VBF vs. the lattice structure of the media.) A phase relationship which correctly applies the forces relative to the bond centers may be applied, such that the memory elements are lifted and then forced to fall into the least bonding barrier energy well associated with that state, and so form a structure with that state. This forms a bit in one state B0 (bit value 0).
A VBF with a different frequency and phase is applied to form a bit in another state, where VBF will be of such a frequency to be a harmonic relationship of TV/DBCS2, where DBCS2 (distance bond centers state 2) is another stable state bit value 1 (B1). If there are more than 2 stable states, the memory element may hold more than 1 digital bit.
To read the memory, the tip is passed over the surface using any of several forms of reading where either current or topological information is read back to indicate the positions of the memory elements. The signal indicating data B is applied to any form of filter which distinguishes between the characteristic frequencies of each of the states of the memory elements. For example, in a two state system, a low pass filter with cutoff frequency between the characteristic frequencies of the two states, followed by an integrator and comparator would output one voltage (bit) for one state and another voltage for another state. The use of two bandpass filters, each with their own integrator and comparators, would indicate valid data states and invalid data states.
Memory Technique 7
For this technique, referring to
The unwritten state is depicted in
To effect a written state in the memory, a head tip 4800 is positioned above or at the plane of the insulator 4820. When it is desired to write a bit of data, a bias voltage exceeding a certain threshold is applied between a tip 4800 and a memory element 4820. The electrons tunnel to/from the substrate material 4870 and stores a charge in the form of electrons or holes as the memory element on the insulator 4840 and oppositely doped region 4860 at 4830. It is possible to store analog information by using a larger or smaller bias voltage as well.
To read the information stored, the tip is passed over the surface in the same manner as writing. The tip is set to a bias voltage for the read mode. A potential is applied between the two electrodes. The existence of a stored charge at 4830 forms a depletion layer in the doped region 4860. The existence of the read mode bias adds to the induced field, raising the field enough to create an inversion region in the doped area 4860. The existence of the inversion region will cause a current to flow between the electrodes 4805 and 4815, greater than that which would occur without the tip-induced field. This greatly simplifies the electronics needed for this type of memory device.
In an alternate embodiment of this technique, the doped regions are formed into narrow channels between sets of two electrodes. The existence of the sets of narrow channels allows the ability to select which regions are to be read or written by selecting the electrodes. This technique has the advantage over technique 5 in that the erase times are typically much faster, and programming voltages can be much lower because a single material that is very thin and a potential needed to perform tunneling can be therefore done with a lower voltage.
Memory Technique 8
The memory media consists of a ferromagnetic thin film layer. The tip of the Z cantilever consists of a tip region of a ferromagnetic material which may be surrounded by a hard buffer material which is not ferromagnetic, typically a hard insulator such as silicon nitride. The apparatus is placed in a pulsed magnetic field.
To write a bit, the tip is brought into proximity to the media, then the magnetic field is pulsed. To read a bit, the tip is brought into proximity of the media while vibrating at a resonance frequency. The force of the magnetic attraction or repulsion caused by a written bit will change the resonant frequency and the phase of the oscillation will be shifted.
Drive Apparatus 1
The Z actuators with cantilevers, heads with fine tips, position sensors, and read/write coils are shown in detail in
A cross section of the fingers assembly is in
The tip region 4100 (see
Referring again to the actuator of
Another significant advantage of this actuator over the actuator in
A typical problem with micromechanical devices is stiction. Once components touch, they tend to need a disproportionally large force to separate them. Since, in the embodiment of
The X and Y actuators are shown in more detail in top view
The polarity of the conductors is reversed in the center prong 4220 for M1 and M2. When a voltage potential is applied to the two conductors, an electrostatic force is created which attracts the end prongs to the center prong. As actuation increases, the gap (between prongs) is shortened (4201 and 4202, for example). All of the prongs acting together generate a force which tends to make the actuator compress and reduce all the gaps. Additionally, the arms aligned at an angle to each other and the actuation axis allows for lower spring constant in the opposite axis.
Of each of the pairs of X actuators 3200 and 3210 and Y actuators 3220 and 3230 (
Each platform also contains a set of 8 nub assemblies 3600, 3610, 3620, 3630, 3640, 3650, 3660, and 3670. The nubs are a platform consisting of an array of one or more sharp tips, typically of the same configuration as the tips on the cantilevers. When the media surface is placed over the MARE, if the platform has any bow which causes it to bow towards the media surface, the tips of the nubs will touch the media surface, and thus keep the platform at a fixed distance relative to the media. The very low surface area of the tips reduces the friction between the platform and the media.
A separate media contactor assembly 3100, similar to the above Z actuators with cantilever and head with fine tip, provide a means for electronically controlling a physical and electronic contact with the media. When input pads are given a control voltage of high enough value, the tip is raised into position against the media and electrical connection to the media via a separate input pad is achieved. When no voltage is applied to pads, the Z actuator remains in the off position and the media is electrically isolated from the media biasing voltages as a safety means. This applies only to media which require an electrical connection. More than one contactor may be implemented as backup or to provide more uniform current flow over the media. Alternately, connection to the media may be effected by bonding to the back side of the media wafer.
Each of these cells described above may be integrated into arrays of cells to increase the capacity of the drive. In the simplest form, diodes are placed around each cell to allow each cell to be individually addressed, or addressed by rows and columns selectors. In alternate forms, interface electronics are embedded near each cell.
Alternate Drive Apparatus 2
When a voltage is applied between the inputs 4710 and 4720, the voltage is carried by conductors through the thin flex rods and coupling bars to the moving comb, so the voltage appears between the two combs. In
The notches are staggered in their position to reduce the non-linear effect produced by the difference in gap distance from a notch facing a notch and a notch facing a bar. The electrostatic force pulls the combs together. The force is coupled by the thin flex rods to coupling bars 4630 and 4640, which move at about ½ the speed of the moving comb. This structure has a large rigidity in the Y axis, thus preventing the comb fingers from moving in the Y axis and touching. In addition, a spring action of the thin flex rods and the coupling bars brings the combs and coupling flex rod back to their original positions. The actuation movement is coupled through 4625 to coupling flex rod 4620, the end of which is attached to the platform. This flex rod is designed to be able to bend in the Y axis, when the platform is moved in Y.
Any of the notching techniques described herein may be utilized by any of the electrostatic devices and drivers also described herein.
Alternate Drive Apparatus 3
A cross section of one embodiment of the thermal actuator is shown in
Alternate Drive Apparatus 4
Input pad 60 clock-reset, transfers a 3 state clock and reset signal, buffered by assembly 70 to each of the platform assemblies 40. Separate control signals for the X-Y actuators may optionally be supplied though input pads (not shown in
The data, control, and power information is conveyed to platform assemblies 40 shown in detail in
In another embodiment, a third layer embodies the layer used for carrying the X-Y electrostatic control voltages. The third layer has the advantage of electrical isolation from the other electronics. Typical CMOS devices operate up to 15V. Breakdown voltage of thermal oxide is typically 600V/micron. The third layer metal typically has 1 micron oxide spacing. Therefore a control voltage up to 300V (thus with adequate safety margin) can be applied to this separate layer. As electrostatic force increases by the square of the voltage, higher voltages are a distinct advantage.
In another embodiment, the actuators are thermal bimorphs consisting of a heater (typically poly-silicon resistor), and two materials of different expansion coefficients, patterned with one material on one side and the second on the other side (see
In another embodiment, the spring/actuators are electromagnetically controlled.
In another embodiment, the spring/actuators are controlled by shape memory alloy devices.
All of the embodiments may also use three actuator/spring assemblies instead of four, arranged at typically 120 degrees in a circle around the platform.
On the platform assemblies are control and state engine electronics 220 and one or more Z actuator tip assemblies 230 (in this case 8 assemblies). The Z actuator/tip assemblies are shown in
After post processing, which removes the oxide between electrodes 340 and 330 and under tip assembly 310, the top electrodes, tip, and bridge float above the bottom substrate, anchored at point 350. The bridge 320, typically formed with passivation glass, binds the actuators to the tip assembly. When a potential is applied to the electrodes 330 and 340, electrostatic repulsion pushes the top electrode upwards. The tip assembly is levered upward as well via the bridge.
By extending the tip beyond the edge of the actuators, the tip is leveraged a multiplying height factor approximately based on the number of times the extension is longer than the actuator. As the electrostatic force decreases by the inverse square of the gap, this leverage force is needed to provide a significant motion of the tip.
In an alternate embodiment, the electrostatic actuator and/or tip assembly is folded to conserve space.
In another embodiment, the Z actuators are formed with thermal bimorphs.
In another embodiment, the Z actuators are electromagnetically controlled.
In another embodiment, the Z actuators are controlled by shape memory alloy devices.
The tip region, after fabrication, may have an edge with sufficiently small radius of curvature to be useful as the read/write and sense region for interaction with the media. As a further refinement, a focused ion beam (FIB) deposition machine may be used to deposit a controlled fine tip material, typically tungsten or platinum, to provide a tip region with radius of curvature in the 10 nanometer range.
The FIB machine may also be used to mill down the deposited material in such a way as to form the tip region. Additionally, these machines may be used to subsequently analyze the resulting tip and ensure proper tip fabrication. Alternately, tips may be refined by sputtering of a tip material through an aperture to form a fine tip region. Alternately, the tips may be refined by etching through an aperture above the tip region.
In an alternate Z actuator/tip assembly, an additional piezo resistor, typically made from <100> oriented silicon is inserted in the actuator. This resistor will change resistance depending on the stress induced by the bending of the actuator (see
In an alternate embodiment, the tip can be operated in an AFM mode. In this mode, the tip is set into a resonant vibration mode above the surface of the media. The resonant mode is indicated by a maximum amplitude of travel with a minimum oscillating control voltage amplitude. When a tip approaches the surface, a slight phase shift will occur from a read-back oscillating height sensor amplifier 5010 connected to the tip.
An alternate Z actuator/tip assembly is shown in
The torsion bars are mechanically clamped at points 1550 and 1560. Finally lever 1570 is connected electrically to torsion bar 1530 and tip region 1580. The moving assembly consisting of grid 1500, torsion bars 1520 and 1530, bridge 1540, lever 1570 and tip 1580 form a teeter-totter assembly which rotates about the Y axis formed by the torsion bars 1520 and 1530. An electrostatic potential is applied between conductors 1500 and 1510. The attractive force pulls the grid 1500 downward. An opposite arrangement may be configured on the other side of the fulcrum (not shown) to provide a rising force on the left side of the fulcrum. The net effect is one or two forces, one downward on the right side of
This actuator has the advantage of higher force per area due to the closer proximity and better alignment of the Z force along the Z axis over the actuator of
Alternate Drive Apparatus 5
The media platform in
The Z actuator assemblies shown in
The compensation element 4015, made of the same material as the sensor, contains substantial portions of the element in an axis at right angles to the stress, and are thus not subject to the change in resistance due to the motion. However, both elements resistivity will change due to the thermal temperature change from the heating element, and proportionally to the temperature. Thus the change due to temperature can be removed from the data returned from the sensor.
Each of the masks presented throughout this application are actual masks for making the devices. The masks are negatives.
The servo lines are utilized in calibrating movement of the platform (fine tips) and media. The media and platform are first moved to an extreme position, the tips are set to sense, and then the platform and media are moved back from the extreme position until a first servo line is read by the fine tips. As the fine tips move across servo lines, an amount of force required for the movement mechanisms of the media and platform are calculated.
XY Actuators and Springs
Various actuator and spring configurations are shown in
All of the actuators may optionally contain an additional conductor which may be used either as a driver or as a capacitive sensor for sensing the position of the actuator. An example of the cross section of an embodiment is shown in
It is important to note that in actuators in
An alternate embodiment of a cell is shown in
Alternate Rotating Media Integrated Circuit
An alternate version of the Nanochip is the Nanodisk and Nanodrive device shown in
By operating the radial positioners 1620 and 1630, individual tracks may be selected. Normally, only one of the 6 tips from each platform is operated at a time. In systems where the disk rotation speed is very slow, rotation speed compensation actuators 1600 and 1610 may not be needed. However, normally the disk media speed is much greater (0.1 to 1 m/sec) than the normal speed with which a conventional non-moving media scan is performed (0.03 m/sec).
For example, in
The tip is then operated in the same manner as described in the previous application, or in a manner described in this application with regard to different types of tips and media. When the maximum travel of the compensator has been reached, the tips are retracted, the compensators moved to the opposite extreme position, and the process repeated.
In an alternate version, there are multiple tip assemblies arrayed around the disk equally spaced and multiple sets of tips designed to access the same tracks. This allows the access time to any location on the disk to be reduced by a factor n where n is the number of sets of tips for each track. Or the rotation speed may be slowed to the point where the rotation speed compensators are not needed. The number of tips also could be smaller near the hub of the disk, as the linear velocity is slower near the hub.
An alternate embodiment is shown in
Alternately, drive electronics may be integrated for each platform. Eliminating the need for active electronics on the MARE greatly reduces the number of steps to fabricate the MARE, thus reducing the cost and time to manufacture. Although only one column may be driven at any instant, the inherent capacitance of the system, plus the inertia of the components, allows each section to be multiplexed. Alternately all platforms can be connected electrically to a common set of X and Y controls, with the disadvantage that feedback for each platform is not possible, thus reducing accuracy and thus bit density.
Groups of actuators along a column have a common Z drive connection (ZDcolm). Sets of controls along rows provide the other Z drive connection (ZDrown). Applying a large differential voltage between Zdcolm and ZDrown effectively enables the Z actuation of the intersecting row and column controls on the actuators. Alternately, if all actuators along a single column are enabled with one column drive and all row drives on, all Z actuators on that column will be enabled. Each individual Z drive may have slightly different values to accommodate differing height controls.
Tips of the actuators are also connected in common in sets along rows. When used in tunneling or resistive mode, the data under tips along a column may be read out via the resistance between the tip and the substrate. So all tips under a column may be read or written simultaneously and individually.
In an alternate embodiment, the set of X and Y controls may be split into multiple banks, to allow simultaneous access to multiple blocks of data. The row and column arrangement may be maintained, or additional and separate sets of rows and columns for each bank provided.
In an alternate embodiment, the column enables are connected such that one “column” enable only enables one tip from each actuator platform, and the enable is spread over multiple platforms such that effectively a large number of tips are accessed simultaneously. The advantage of this embodiment is most pronounced when the Z actuators are used in an oscillating AFM mode, where the Z cantilevers are vibrating at a high frequency. This allows only one cantilever vibrating per platform to be operating, reducing problems associated with mechanical coupling between cantilevers.
Performing a Write Operation on Apparatus
To perform a write operation, a control voltage positioning signal is applied either through the I/O pads 10 or separate actuator control input pads. The control voltage is enabled for input by enabling input enable 20 and disabling output enable 30. Four (or three) sets of control voltages, one for each spring/actuator, generate a force which creates a motion of the springs/actuators and subsequently the suspended platform.
This motion is typically designed to first move the platform to a start scan position, nominally an extreme in X or Y. For this discussion, we will use extreme left in X for start position. The Y position will determine the track to be written. A control set is then applied to move the platform, nominally at maximum acceleration, to get the platform up to the nominal scan speed (typically somewhat lower than maximum velocity). Once nominal velocity is achieved (for example, 3×10-2 m/sec), the tip actuator assemblies are instructed to raise the tip assemblies towards the media surface. While in this mode, the tip is in a read mode, sensing track, sector, and data information.
When the correct track with optional sector position has been reached, as determined by the tip in read mode, the operation of the tip is switched to write mode. When in write mode, the tip bias voltage is alternated between a sense read mode, where the bias voltage is of a low enough value that no change is effected to the memory surface, and a write mode, where the bias voltage is of sufficient intensity to effect a change to the memory surface.
During the sense read mode state, the current between the tip and the memory is measured. If the current has increased, this indicates the tip is closer to the memory surface. Conversely, if the current drops, this indicates the tip is further from the memory surface. This information is processed by the computer and fed to the Z axis positioner to raise or lower the tip to maintain the height required by a particular memory technique described below. The current information in one embodiment is measured via a simple 2 CMOS transistor amplifier, with typical Beta of 50. In the current sensing mode, the tip is first biased at a nominal input voltage such that the output voltage of the amplifier is in a mid-range between + and − supplies.
As the small current starts to flow, depending on the bias of the media, the output of the sense amplifier will begin to rise or fall. This indicates the tip is approaching the media. In an alternate media embodiment, the information is stored as an electronic charge. When the tip approaches the media, the charge is transferred to the tip capacitance. This charge is amplified by the sense amplifier transistors and is indicated by a sudden change in the output voltage of the amplifier, indicating the charge has been transferred to the tip and that the tip is in proximity to the media.
The data portion of the memory is written with an alternating control voltage such that the data pattern will never match a track or sector pattern, and additionally always alternates from one state to another within several data bit states. An example of such a pattern form is non-return to zero, referred to as NRZ. This form also has the advantage of supplying self clocking information when in read mode (the NRZ format has transitions at regular intervals which is utilized for clocking). Also, the state is guaranteed to return to a read sense state often enough to obtain necessary surface height information.
In the capacitive charge storage media method, the above method destroys the data during read, thus requires a subsequent re-write.
In an alternate embodiment, data is stored as an electronic charge on a nitride-oxide-substrate (or NOS) structure. In this embodiment, charge is written by positioning the tip near or on the media (nitride) surface. A voltage pulse of sufficient amplitude to tunnel through the nitride is applied to the tip. A subsequent charge is then stored on the oxide, which then forms a depletion layer in the substrate region. This depletion region modifies the effective capacitance of the area below the tip in effect lowering the capacitiance. To read this change in capacitance, a sensitive capacitance measuring circuit is employed. This embodiment has the advantage of not requiring that data bits be re-written after each read.
Many of the media forms can be improved with an additional set of processing steps which effectively alter the shape of the media surface from a continuous sheet to a 2 dimensional array of discrete, small regions. This can be created by use of interference patterns from a laser beam which is reflected back on itself, which effectively creates a grid of spacing ½ the wavelength of the laser source. In one axis this forms spaced lines. Formed at right angles to the first set a grid pattern is formed. This can be used to expose a thin resist, which can then be used to subsequently pattern the media. Use of excimer lasers with wavelengths of 157 nm yields a pattern of 78 nm spacing as an example.
Alternately, this can be achieved by first depositing a thin layer of a metal such as gold on the media surface. The media is then slowly heated to cause the thin metal to form beaded regions with no metal in between the beads. These beads then effectively form a mask. An anisotropic etch, typically with reactive ion etching (RIE) or similar dry etching technique, removes the material in the open areas between the beads.
In an alternate media embodiment, the media consists of structures forming quantum dots. These may be formed using multiple quantum well (MQW) techniques. The media is written by applying a voltage pulse sufficient to change the electron state energy in the trapped quantum well regions.
Manufacturing Techniques
The apparatus described herein are primarily designed to be fabricated with semiconductor processing techniques. A typical apparatus would be first fabricated with a CMOS or BiCMOS fabrication process. Then, the wafer or die would be placed in a silicon etchant and released by a post process etch using wet chemicals such as KOH (potassium hydroxide) or TMAH (tetra-methyl ammonium hydroxide) or dry etching using RIE or plasma etching in an isotropic mode such that etching proceeds under the moving structures.
Alternately, the devices can be released by etching in a vapor of XeF2 (xenon diflouride) or RIE in SF6 (sulfur hexaflouride). Active electronics would be protected by glass or oxide layers. The tips may be fashioned from the single crystal Si in the substrate, or from a low temperature deposited silicon, then protected by a thin coating impervious to the final release etchant. In another alternative, the tips may be fabricated by FIB techniques.
However, in the past, most Micro Electric Mechanical Systems (MEMS) structures have been fabricated with polysilicon or single crystal silicon. These have a high Young's modulus and tend to have lower residual biases in the thin film layers than materials such as oxide and aluminum. Most of the spring structures described herein may be fabricated from silicon or polysilicon, given oxide completely surrounding all structures, and using a final silicon etch.
However, materials such as aluminum and oxide for the MEMS structures, as these have lower Youngs's modulus by a wide margin (69×109 instead of 170×109), aluminum has much lower resistance, and the micromechanical structures can be fabricated out of the same steps which are normally used for the metal interconnects and intermetal dielectrics. Unfortunately, most processes tend to leave quite large residual biases in these materials. But fortunately, the direction of the biases for different layers tend to be different. By careful tailoring of multi-layer films and their biases, and one or more additional process steps, the sum of the residual stresses can be reduced to a very low value.
If one layer has negative stress T− and the other layer has positive stress T+, and T++T−<0, by thinning T+, the total stress can be reduced to near zero. The thinning may be performed isotropically or anisotropically, depending on which layers need to be affected. With 3 or more layer films, such as in
As an example, typically 2110, 2120, 2140, 2160, 2180 would be oxide, 2100,2130,2150,2170 would be aluminum. By etching the oxide with HF or Buffered HF, the results of thinning would look like 22a-c. Alternately, the total stress bias may be reduced by a post annealing step.
Compensation for Service Defects
The present invention may use any of the techniques previously described in the previous patent application for compensating for surface defects. Additionally, by virtue of the large number of tips, the media may be scanned in a much shorter time than might normally be available in a single head system.
Fine Tip Sharpening
Similarly, fine tip sharpening techniques, such as those described in Rust et al, U.S. Pat. No. 5,453,970, may additionally be used to keep the fine tips clear of debris.
Media
Any one of the media described in the previous application may be used with the current apparatus when used in the current mode of operating the tip. In one embodiment of the re-writable media, a charge is stored on an insulator above a conductor. This is preferably an insulator with a high dielectric coefficient, and extremely low leakage. Examples of dielectrics are silicon dioxide, titanium dioxide, and piezoelectric materials such as PZT. Alternately the charge may be stored in a region below the surface, such as with NOS materials such as silicon nitride over silicon oxide on silicon substrate.
In an alternate capacitive media such as NOS, an alternate read technique is to use a capacitive bridge amplifier which senses the small difference in capacitance on one of the legs of a bridge (the capacitor being the NOS data bit). This has the advantage of not destroying the data bit during read. Unfortunately, the sense electronics are considerably more complicated.
Method for Data Compression
Mare as Lithography Apparatus
The current contenders for production scale lithography for the under 0.25 u regime are X-ray—costly and still limited to perhaps 0.1 u, and ion beam projection—a still experimental system again with probable limits of 0.1 u. Both of these systems also are for exposure only—they have no inherent metrology capability for analyzing the results. The MARE portion of the Nanochip is itself a high speed lithography instrument with up to 10 nm resolution. The Nanochips inherent parallelism will allow the patterning of a 6″ wafer in approx. 8 minutes (5×5 cm Nanochip, 1 Mhz/tip data rate, 30 nm line width).
In addition, the Nanochip lithography instrument will allow the patterning to be checked for accuracy by the same instrument. This can be used to identify particle defects and used as a gauge to eliminate unnecessary processing. Also, the data for the mask remains digitally represented—there is no need for an intermediate mask to be generated.
Additionally, by scanning the tip in the presence of a bistable gas or liquid medium which changes to a solid state when in the field of the voltage/current spike produced by the tip region, materials may be deposited on a surface a layer at a time and built up to construct three dimensional geometries. STMs have been used to pattern photoresist and form very fine geometries (10 nm lines), additionally silicon dioxide has been formed in silicon, which can then be used as a mask for additional semiconductor processing steps.
The MARE and molecular media technologies in this application will also be a primary enabling force for flat-panel display fabrication for field emission displays. The diamond media forms donut shaped hillocks of extremely fine dimension. These can be used as field emitters for field-emission based flat panel displays.
In one embodiment, the media is constructed of a base from any material having charge storage capability. For example, any material that stores electrons when a charge is applied. The charge storage capabilities are then enhanced by augmentation of grain boundaries of the media material. This augmentation is performed by applying material coating (texture coating, PMMA, for example) to the surface of the media material, and then removing the coating. Pit markings remain that augment the grain boundaries of the media material, and enhance the charge storage capabilities of the media. Examples of the augmented grain boundaries can be seen in the photographs of
Portions of the present invention may be conveniently implemented using a conventional general purpose or a specialized digital computer or microprocessor programmed according to the teachings of the present disclosure, as will be apparent to those skilled in the computer art.
Appropriate software coding can readily be prepared by skilled programmers based on the teachings of the present disclosure, as will be apparent to those skilled in the software art. Portions of the invention may also be implemented by the preparation of application specific integrated circuits or by interconnecting an appropriate network of conventional component circuits, as will be readily apparent to those skilled in the art.
The present invention includes a computer program product which is a storage medium (media) having instructions stored thereon/in which can be used to program a computer to perform any of the processes of the present invention.
Stored on any one of the computer readable medium (media), the present invention includes software for controlling both the hardware of the general purpose/specialized computer or microprocessor, and for enabling the computer or microprocessor to interact with a human user or other mechanism utilizing the results of the present invention. Such software may include, but is not limited to, device drivers, operating systems, and user applications. Ultimately, such computer readable media further includes software supporting and controlling devices and mechanisms according to the present invention, as described herein.
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings.
This application is a Continuation of U.S. application Ser. No. 09/465,592 entitled “Molecular Memory Medium and Molecular Memory Integrated Circuit,” by Culver et el. filed Dec. 17, 1999 now U.S. Pat. No. 7,260,051 which claims the benefit of United States Provisional Application entitled “Molecular Memory Medium and Molecular Memory Integrated Circuit,” Culver et al, filed Dec. 18, 1998, and having a U.S. Application No. of 60/112,787.
Number | Name | Date | Kind |
---|---|---|---|
4300350 | Becker | Nov 1981 | A |
4340953 | Iwamura et al. | Jul 1982 | A |
4575822 | Quate | Mar 1986 | A |
4710899 | Young et al. | Dec 1987 | A |
4719594 | Young et al. | Jan 1988 | A |
4737934 | Ross et al. | Apr 1988 | A |
4744055 | Hennessey | May 1988 | A |
4769338 | Ovshinsky | Sep 1988 | A |
4769682 | Yang et al. | Sep 1988 | A |
4775425 | Guha et al. | Oct 1988 | A |
4792501 | Allred et al. | Dec 1988 | A |
4820394 | Young et al. | Apr 1989 | A |
4829507 | Kazan et al. | May 1989 | A |
4831614 | Duerig et al. | May 1989 | A |
4843443 | Ovshinsky et al. | Jun 1989 | A |
4845533 | Pryor et al. | Jul 1989 | A |
4868616 | Johnson et al. | Sep 1989 | A |
4876667 | Ross et al. | Oct 1989 | A |
4882295 | Czubatyj et al. | Nov 1989 | A |
4883686 | Doehler et al. | Nov 1989 | A |
4891330 | Guha et al. | Jan 1990 | A |
4916002 | Carver | Apr 1990 | A |
4916688 | Foster et al. | Apr 1990 | A |
4924436 | Strand | May 1990 | A |
4943719 | Akamine et al. | Jul 1990 | A |
4945515 | Ooumi et al. | Jul 1990 | A |
4962480 | Ooumi et al. | Oct 1990 | A |
4968585 | Albrecht et al. | Nov 1990 | A |
4987312 | Eigler | Jan 1991 | A |
5008617 | Czubatyj et al. | Apr 1991 | A |
5038322 | Van Loenen | Aug 1991 | A |
5043577 | Pohl et al. | Aug 1991 | A |
5043578 | Guthner et al. | Aug 1991 | A |
5051977 | Goldberg | Sep 1991 | A |
5091880 | Isono et al. | Feb 1992 | A |
5095479 | Harigaya et al. | Mar 1992 | A |
5097443 | Kaneko et al. | Mar 1992 | A |
5103284 | Ovshinsky et al. | Apr 1992 | A |
5126635 | Doehler et al. | Jun 1992 | A |
5128099 | Strand et al. | Jul 1992 | A |
5132934 | Quate et al. | Jul 1992 | A |
5144148 | Eigler | Sep 1992 | A |
5144581 | Toda et al. | Sep 1992 | A |
5159661 | Ovshinsky et al. | Oct 1992 | A |
5166758 | Ovshinsky et al. | Nov 1992 | A |
5166919 | Eigler et al. | Nov 1992 | A |
5177567 | Klersy et al. | Jan 1993 | A |
5180686 | Banerjee et al. | Jan 1993 | A |
5180690 | Czubatyj et al. | Jan 1993 | A |
5182724 | Yanagisawa et al. | Jan 1993 | A |
5187367 | Miyazaki et al. | Feb 1993 | A |
5196701 | Foster et al. | Mar 1993 | A |
5210714 | Pohl et al. | May 1993 | A |
5216631 | Sliwa, Jr. | Jun 1993 | A |
5222060 | Kuroda et al. | Jun 1993 | A |
5223308 | Doehler | Jun 1993 | A |
5231047 | Ovshinsky et al. | Jul 1993 | A |
5233582 | Tanno et al. | Aug 1993 | A |
5251200 | Hatanaka et al. | Oct 1993 | A |
5260567 | Kuroda et al. | Nov 1993 | A |
5262981 | Rabe et al. | Nov 1993 | A |
5264876 | Kawade et al. | Nov 1993 | A |
5265046 | Fuchs et al. | Nov 1993 | A |
5268571 | Yamamoto et al. | Dec 1993 | A |
5283442 | Martin et al. | Feb 1994 | A |
5289455 | Kuroda et al. | Feb 1994 | A |
5296716 | Ovshinsky et al. | Mar 1994 | A |
5307311 | Sliwa, Jr. | Apr 1994 | A |
5323375 | Ihara et al. | Jun 1994 | A |
5324553 | Ovshinsky et al. | Jun 1994 | A |
5329122 | Sakai et al. | Jul 1994 | A |
5329514 | Eguchi et al. | Jul 1994 | A |
5330630 | Klersy et al. | Jul 1994 | A |
5331589 | Gambino et al. | Jul 1994 | A |
5335197 | Kaneko et al. | Aug 1994 | A |
5341328 | Ovshinsky et al. | Aug 1994 | A |
5343042 | Fuchs et al. | Aug 1994 | A |
5359205 | Ovshinsky et al. | Oct 1994 | A |
5373494 | Kawagishi et al. | Dec 1994 | A |
5389475 | Yanagisawa et al. | Feb 1995 | A |
5390161 | Kurihara et al. | Feb 1995 | A |
5396453 | Kawada et al. | Mar 1995 | A |
5396483 | Matsuda et al. | Mar 1995 | A |
5398229 | Nakayama et al. | Mar 1995 | A |
5406509 | Ovshinsky et al. | Apr 1995 | A |
5411591 | Izu et al. | May 1995 | A |
5412597 | Miyazaki et al. | May 1995 | A |
5414271 | Ovshinsky et al. | May 1995 | A |
5416331 | Ichikawa et al. | May 1995 | A |
5426092 | Ovshinsky et al. | Jun 1995 | A |
5432771 | Shido et al. | Jul 1995 | A |
5439777 | Kawada et al. | Aug 1995 | A |
5444191 | Yamamoto et al. | Aug 1995 | A |
5446684 | Kaneko et al. | Aug 1995 | A |
5453970 | Rust et al. | Sep 1995 | A |
5471064 | Koyanagi et al. | Nov 1995 | A |
5471458 | Oguchi et al. | Nov 1995 | A |
5475318 | Marcus et al. | Dec 1995 | A |
5481528 | Eguchi et al. | Jan 1996 | A |
5526334 | Yamano et al. | Jun 1996 | A |
5534711 | Ovshinsky et al. | Jul 1996 | A |
5534712 | Ovshinsky et al. | Jul 1996 | A |
5536947 | Klersy et al. | Jul 1996 | A |
5537372 | Albrecht et al. | Jul 1996 | A |
5543737 | Ovshinsky et al. | Aug 1996 | A |
5547774 | Gimzewski et al. | Aug 1996 | A |
5557596 | Gibson et al. | Sep 1996 | A |
5561300 | Wada et al. | Oct 1996 | A |
5562776 | Sapru et al. | Oct 1996 | A |
5567241 | Tsu et al. | Oct 1996 | A |
5591501 | Ovshinsky et al. | Jan 1997 | A |
5596522 | Ovshinsky et al. | Jan 1997 | A |
5597411 | Fritzsche et al. | Jan 1997 | A |
5606162 | Buser et al. | Feb 1997 | A |
5615143 | MacDonald et al. | Mar 1997 | A |
5623295 | Kishi et al. | Apr 1997 | A |
5623476 | Eguchi et al. | Apr 1997 | A |
5670224 | Izu et al. | Sep 1997 | A |
5679952 | Lutwyche et al. | Oct 1997 | A |
5687112 | Ovshinsky et al. | Nov 1997 | A |
5689494 | Ichikawa et al. | Nov 1997 | A |
5694054 | Ovshinsky et al. | Dec 1997 | A |
5694146 | Ovshinsky et al. | Dec 1997 | A |
5714768 | Ovshinsky et al. | Feb 1998 | A |
5721721 | Yanagisawa et al. | Feb 1998 | A |
5751685 | Yi | May 1998 | A |
5757446 | Ovshinsky et al. | May 1998 | A |
5777977 | Fujiwara et al. | Jul 1998 | A |
5778134 | Sakai et al. | Jul 1998 | A |
5793743 | Duerig et al. | Aug 1998 | A |
5801472 | Wada et al. | Sep 1998 | A |
5804710 | Mamin et al. | Sep 1998 | A |
5808973 | Tanaka | Sep 1998 | A |
5812516 | Nose et al. | Sep 1998 | A |
5822285 | Rugar et al. | Oct 1998 | A |
5825046 | Czubatyj | Oct 1998 | A |
5835477 | Binnig et al. | Nov 1998 | A |
5848077 | Kamae et al. | Dec 1998 | A |
5851902 | Sakai et al. | Dec 1998 | A |
5856672 | Ried | Jan 1999 | A |
5856967 | Mamin et al. | Jan 1999 | A |
5861754 | Ueno et al. | Jan 1999 | A |
5877497 | Binnig et al. | Mar 1999 | A |
5886922 | Saito et al. | Mar 1999 | A |
5912839 | Ovshinsky et al. | Jun 1999 | A |
5929438 | Suzuki et al. | Jul 1999 | A |
5933365 | Klersky et al. | Aug 1999 | A |
5935339 | Henderson et al. | Aug 1999 | A |
5953306 | Yi | Sep 1999 | A |
5962949 | Dhuler et al. | Oct 1999 | A |
6000021 | Saito et al. | Dec 1999 | A |
6000047 | Kamae et al. | Dec 1999 | A |
6001519 | Yang et al. | Dec 1999 | A |
6017618 | Gupta et al. | Jan 2000 | A |
6027951 | MacDonald et al. | Feb 2000 | A |
6028393 | Izu | Feb 2000 | A |
RE36603 | Pohl et al. | Mar 2000 | E |
6038916 | Cleveland et al. | Mar 2000 | A |
6054745 | Nakos et al. | Apr 2000 | A |
6075719 | Lowrey | Jun 2000 | A |
6084849 | Durig et al. | Jul 2000 | A |
6087580 | Ovshinsky | Jul 2000 | A |
6087674 | Ovshinsky | Jul 2000 | A |
6088320 | Bayer et al. | Jul 2000 | A |
6101164 | Kado | Aug 2000 | A |
6124663 | Haake et al. | Sep 2000 | A |
6141241 | Ovshinsky | Oct 2000 | A |
6186090 | Dotter, II | Feb 2001 | B1 |
6196061 | Adderton et al. | Mar 2001 | B1 |
6236589 | Gupta et al. | May 2001 | B1 |
6245280 | Tan et al. | Jun 2001 | B1 |
6249747 | Binnig et al. | Jun 2001 | B1 |
6252226 | Kley | Jun 2001 | B1 |
RE37259 | Ovshinsky | Jul 2001 | E |
6275410 | Morford | Aug 2001 | B1 |
6305788 | Silverbrook | Oct 2001 | B1 |
6314014 | Lowrey | Nov 2001 | B1 |
6339217 | Kley | Jan 2002 | B1 |
6359755 | Dietzel et al. | Mar 2002 | B1 |
6366340 | Ishibashi et al. | Apr 2002 | B1 |
6369400 | Haeberle et al. | Apr 2002 | B1 |
6370306 | Sato | Apr 2002 | B1 |
6411589 | Hoen et al. | Jun 2002 | B1 |
6452891 | Hennessey | Sep 2002 | B1 |
6463874 | Dotter, II et al. | Oct 2002 | B1 |
6480438 | Park | Nov 2002 | B1 |
6487113 | Park | Nov 2002 | B1 |
6501210 | Ueno et al. | Dec 2002 | B1 |
6507552 | Gibson | Jan 2003 | B2 |
6511862 | Hudgens | Jan 2003 | B2 |
6511867 | Lowrey | Jan 2003 | B2 |
6515898 | Baumeister et al. | Feb 2003 | B2 |
6515957 | Newns | Feb 2003 | B1 |
6521921 | Lim et al. | Feb 2003 | B2 |
6522566 | Carter | Feb 2003 | B2 |
6531373 | Gill | Mar 2003 | B2 |
6534781 | Dennison | Mar 2003 | B2 |
6542400 | Chen et al. | Apr 2003 | B2 |
6545907 | Lowrey et al. | Apr 2003 | B1 |
6563164 | Lowrey et al. | May 2003 | B2 |
6566700 | Xu | May 2003 | B2 |
6567293 | Lowrey et al. | May 2003 | B1 |
6567296 | Casagrande et al. | May 2003 | B1 |
6570784 | Lowrey | May 2003 | B2 |
6589714 | Maimon | Jul 2003 | B2 |
6593176 | Dennison | Jul 2003 | B2 |
6597639 | Hamann | Jul 2003 | B1 |
6608773 | Lowrey | Aug 2003 | B2 |
6611033 | Hsu et al. | Aug 2003 | B2 |
6611140 | Bloechl et al. | Aug 2003 | B1 |
6613604 | Maimon | Sep 2003 | B2 |
6617192 | Lowrey | Sep 2003 | B1 |
6617569 | Narita et al. | Sep 2003 | B2 |
6621095 | Chiang | Sep 2003 | B2 |
6628452 | Haeberle | Sep 2003 | B2 |
6646297 | Dennison | Nov 2003 | B2 |
6647766 | Despont et al. | Nov 2003 | B2 |
6665258 | Dietzel et al. | Dec 2003 | B1 |
6667900 | Lowrey | Dec 2003 | B2 |
6671710 | Ovshinsky | Dec 2003 | B2 |
6673700 | Dennison | Jan 2004 | B2 |
6680808 | Allenspach et al. | Jan 2004 | B2 |
6692145 | Gianchandani et al. | Feb 2004 | B2 |
6696355 | Dennison | Feb 2004 | B2 |
6723421 | Ovshinsky | Apr 2004 | B2 |
6733956 | Maimon | May 2004 | B2 |
6762402 | Choi et al. | Jul 2004 | B2 |
6784475 | Hong et al. | Aug 2004 | B2 |
6800865 | Nakayama et al. | Oct 2004 | B2 |
6819587 | Sharma et al. | Nov 2004 | B1 |
6819588 | Baumeister et al. | Nov 2004 | B2 |
6841220 | Onoe | Jan 2005 | B2 |
6854648 | Hong et al. | Feb 2005 | B2 |
6862206 | Carter et al. | Mar 2005 | B1 |
6912193 | Cho | Jun 2005 | B2 |
6930368 | Hartwell et al. | Aug 2005 | B2 |
6942914 | Onoe | Sep 2005 | B2 |
6982898 | Rust | Jan 2006 | B2 |
6985377 | Rust | Jan 2006 | B2 |
7020064 | Kim et al. | Mar 2006 | B2 |
7026676 | Ahner et al. | Apr 2006 | B2 |
7027364 | Hong et al. | Apr 2006 | B2 |
7041394 | Weller et al. | May 2006 | B2 |
7065033 | Onoe | Jun 2006 | B2 |
7071031 | Pogge et al. | Jul 2006 | B2 |
7149180 | Onoe | Dec 2006 | B2 |
7151739 | Cho | Dec 2006 | B2 |
7212484 | Maeda | May 2007 | B2 |
7218600 | Cho | May 2007 | B2 |
7221639 | Onoe | May 2007 | B2 |
7227830 | Cho | Jul 2007 | B2 |
7242661 | Cho | Jul 2007 | B2 |
7260051 | Rust et al. | Aug 2007 | B1 |
7265937 | Erden | Sep 2007 | B1 |
7276173 | Onoe | Oct 2007 | B2 |
7283453 | Onoe | Oct 2007 | B2 |
20010045530 | Haeberle et al. | Nov 2001 | A1 |
20020021139 | Jackson | Feb 2002 | A1 |
20020037438 | Takami | Mar 2002 | A1 |
20020101573 | Ishibashi et al. | Aug 2002 | A1 |
20020110074 | Gibson | Aug 2002 | A1 |
20020135917 | Davidson | Sep 2002 | A1 |
20020173153 | Lee et al. | Nov 2002 | A1 |
20030007443 | Nickel | Jan 2003 | A1 |
20030020725 | Trivedi | Jan 2003 | A1 |
20030032290 | Lee et al. | Feb 2003 | A1 |
20030081527 | Gibson et al. | May 2003 | A1 |
20030081532 | Gibson | May 2003 | A1 |
20030108777 | Gunsel et al. | Jun 2003 | A1 |
20030128494 | Birecki et al. | Jul 2003 | A1 |
20030133324 | Baumeister et al. | Jul 2003 | A1 |
20030185139 | Ives | Oct 2003 | A1 |
20030189200 | Lee et al. | Oct 2003 | A1 |
20030218960 | Albrecht et al. | Nov 2003 | A1 |
20040027935 | Cho | Feb 2004 | A1 |
20040042351 | Onoe | Mar 2004 | A1 |
20040047275 | Cherubini et al. | Mar 2004 | A1 |
20040071021 | Binnig et al. | Apr 2004 | A1 |
20040076047 | Cho | Apr 2004 | A1 |
20040077123 | Lee et al. | Apr 2004 | A1 |
20040090823 | Brocklin et al. | May 2004 | A1 |
20040095868 | Birecki et al. | May 2004 | A1 |
20040097002 | Pogge et al. | May 2004 | A1 |
20040105323 | Giovanni et al. | Jun 2004 | A1 |
20040107770 | Despont et al. | Jun 2004 | A1 |
20040113641 | Birecki et al. | Jun 2004 | A1 |
20040114490 | Antonkaopoulos et al. | Jun 2004 | A1 |
20040136277 | Binnig et al. | Jul 2004 | A1 |
20040145941 | Rust | Jul 2004 | A1 |
20040150472 | Rust et al. | Aug 2004 | A1 |
20040168527 | Nakayama et al. | Sep 2004 | A1 |
20040218507 | Binnig et al. | Nov 2004 | A1 |
20040233817 | Antonkapoulos et al. | Nov 2004 | A1 |
20040245462 | Binning | Dec 2004 | A1 |
20040245547 | Stipe | Dec 2004 | A1 |
20040252553 | Sharma | Dec 2004 | A1 |
20040252590 | Sharma | Dec 2004 | A1 |
20040252621 | Cho | Dec 2004 | A1 |
20040257887 | Binnig et al. | Dec 2004 | A1 |
20050013230 | Adelmann | Jan 2005 | A1 |
20050018588 | Duerig et al. | Jan 2005 | A1 |
20050025034 | Gibson | Feb 2005 | A1 |
20050029920 | Birecki et al. | Feb 2005 | A1 |
20050036428 | Adelmann | Feb 2005 | A1 |
20050037560 | Duerig et al. | Feb 2005 | A1 |
20050038950 | Adelmann | Feb 2005 | A1 |
20050047288 | Maeda | Mar 2005 | A1 |
20050047307 | Frommer et al. | Mar 2005 | A1 |
20050050258 | Frommer et al. | Mar 2005 | A1 |
20050055170 | Gibson et al. | Mar 2005 | A1 |
20050066107 | Bachtold et al. | Mar 2005 | A1 |
20050082598 | Liao et al. | Apr 2005 | A1 |
20050088873 | Tran et al. | Apr 2005 | A1 |
20050095389 | Newns | May 2005 | A1 |
20050099430 | Nauka | May 2005 | A1 |
20050099895 | Maeda | May 2005 | A1 |
20050122786 | Antonakopoulos et al. | Jun 2005 | A1 |
20050122886 | Takahashi | Jun 2005 | A1 |
20050128616 | Johns et al. | Jun 2005 | A1 |
20050128927 | Milligan et al. | Jun 2005 | A1 |
20050128928 | Takahashi | Jun 2005 | A1 |
20050135199 | Mejia et al. | Jun 2005 | A1 |
20050135200 | Mejia et al. | Jun 2005 | A1 |
20050135203 | Mejia et al. | Jun 2005 | A1 |
20050135224 | Mejia et al. | Jun 2005 | A1 |
20050139883 | Sharma | Jun 2005 | A1 |
20050147017 | Gibson | Jul 2005 | A1 |
20050152175 | Ashton | Jul 2005 | A1 |
20050156271 | Lam et al. | Jul 2005 | A1 |
20050157562 | Smith et al. | Jul 2005 | A1 |
20050157575 | Binnig et al. | Jul 2005 | A1 |
20050169063 | Cherubini et al. | Aug 2005 | A1 |
20050185567 | Adelmann | Aug 2005 | A1 |
20050190684 | Kley | Sep 2005 | A1 |
20050201255 | Champion et al. | Sep 2005 | A1 |
20050201256 | Champion et al. | Sep 2005 | A1 |
20050201257 | Champion et al. | Sep 2005 | A1 |
20050201258 | Champion et al. | Sep 2005 | A1 |
20050207234 | Baechtold et al. | Sep 2005 | A1 |
20050226117 | Champion et al. | Oct 2005 | A1 |
20050232004 | Rust et al. | Oct 2005 | A1 |
20050232061 | Rust et al. | Oct 2005 | A1 |
20050233596 | Chen et al. | Oct 2005 | A1 |
20050237906 | Gibson | Oct 2005 | A1 |
20050243592 | Rust et al. | Nov 2005 | A1 |
20050243659 | Rust et al. | Nov 2005 | A1 |
20050243660 | Rust et al. | Nov 2005 | A1 |
20050247873 | Hilton | Nov 2005 | A1 |
20050259366 | Champion et al. | Nov 2005 | A1 |
20050259503 | Hilton | Nov 2005 | A1 |
20050281075 | Chen et al. | Dec 2005 | A1 |
20050281174 | Gotsmann et al. | Dec 2005 | A1 |
20050286321 | Adelmann | Dec 2005 | A1 |
20060003493 | Milligan et al. | Jan 2006 | A1 |
20060006471 | Rossel et al. | Jan 2006 | A1 |
20060023606 | Lutwyche | Feb 2006 | A1 |
20060023612 | Hilton et al. | Feb 2006 | A1 |
20060023613 | Mejia et al. | Feb 2006 | A1 |
20060028964 | Mejia et al. | Feb 2006 | A1 |
20060028965 | Fasen et al. | Feb 2006 | A1 |
20060039250 | Cherubini et al. | Feb 2006 | A1 |
20060043288 | Binnig et al. | Mar 2006 | A1 |
20060064624 | Albrecht | Mar 2006 | A1 |
20060072420 | Albrecht | Apr 2006 | A1 |
20060083152 | Albrecht | Apr 2006 | A1 |
20060182004 | Maeda | Aug 2006 | A1 |
20060187803 | Baechtold | Aug 2006 | A1 |
20060211154 | Buehlman | Sep 2006 | A1 |
20060219655 | Cho | Oct 2006 | A1 |
20060238185 | Kozicki | Oct 2006 | A1 |
20060239129 | Kley | Oct 2006 | A1 |
20060245312 | Maeda | Nov 2006 | A1 |
20060291364 | Kozicki | Dec 2006 | A1 |
20070014047 | Cho | Jan 2007 | A1 |
20070041233 | Roelofs | Feb 2007 | A1 |
20070047427 | Cherubini | Mar 2007 | A1 |
20070125961 | Despont | Jun 2007 | A1 |
20070152253 | Lee | Jul 2007 | A1 |
20070158731 | Bae | Jul 2007 | A1 |
20070195682 | Duerig | Aug 2007 | A1 |
20070196645 | Duerig | Aug 2007 | A1 |
20070210812 | Yoo | Sep 2007 | A1 |
20070253314 | Jones | Nov 2007 | A1 |
20070254383 | Buehlmann | Nov 2007 | A1 |
20070296101 | DiPietro | Dec 2007 | A1 |
20070296500 | Yang | Dec 2007 | A1 |
20080013437 | Albrecht | Jan 2008 | A1 |
20080017609 | Takahashi | Jan 2008 | A1 |
20080020489 | Im | Jan 2008 | A1 |
Number | Date | Country |
---|---|---|
0 438 256 | Jul 1991 | EP |
0 734 017 | Sep 1996 | EP |
0 788 149 | Jun 1997 | EP |
3295043 | Dec 1991 | JP |
3295044 | Dec 1991 | JP |
4159636 | Jun 1992 | JP |
9198726 | Jul 1997 | JP |
WO 9611472 | Apr 1996 | WO |
WO 9705610 | Feb 1997 | WO |
WO 0237488 | May 2002 | WO |
Number | Date | Country | |
---|---|---|---|
20070165444 A1 | Jul 2007 | US |
Number | Date | Country | |
---|---|---|---|
60112787 | Dec 1998 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 09465592 | Dec 1999 | US |
Child | 11670941 | US |