Patent Application
20180238961
An electrical system can comprise various electrical hardware components, such as transistors. As more electrical hardware components are added to the electrical system, it can be beneficial to have the electrical system incorporated into a substrate as an integrated circuit. The integrated circuit can be used in a variety of applications, such as personal computers and communications equipment.
In one embodiment, a system, comprises an emission component and a reception component. The emission component can be configured to cause an emission of a radiation set upon an integrated circuit such that the integrated circuit produces a response. The reception component can be configured to receive the response. The response, in view of the radiation set, can indicate a failure state of the integrated circuit. The emission component, the reception component, or a combination thereof can be, at least in part, non-software.
In another embodiment, a system comprises an analysis component and a determination component. The analysis component can be configured to perform an analysis on a response produced by an emission of a radiation upon an integrated circuit. The determination component can be configured to determine a health of the integrated circuit based, at least in part, on a result of the analysis. The report can be outputted that indicates the health. The analysis component, the determination component, or a combination thereof can be implemented, at least in part, by way of hardware
In yet another embodiment, a method can comprise recognizing, by way of a failure test apparatus, a failure of an integrated circuit. The method can additionally comprise determining a radiation frequency subjected upon the integrated circuit. The method can also comprise determining a response voltage of the integrated circuit that is in response to being subjected to the radiation frequency. In addition, the method can comprise propagating an information set onto a database. The information set can reflect the radiation frequency, the response voltage, and the failure.
Incorporated herein are drawings that constitute a part of the specification and illustrate embodiments of the detailed description. The detailed description will now be described further with reference to the accompanying drawings as follows:
Field effect transistors (FETs) can be used as efficient detectors of Terahertz (THz) radiation. In these detectors, non-linearities in the propagation of plasma waves in the two-dimensional electronic fluid of the FET channels produce a direct current voltage from the THz radiation. Such plasmonic detectors could operate at frequencies much higher than their cut-off frequency or maximum frequency of oscillations. FETs operating in the plasmonic regimes can be used as THz detectors, mixers, phase shifters and frequency multipliers at THz. The plasmonic FET detectors can be advantageous because they can detect single THz pulses with enhanced responsivity and can be compatible with integrated circuit technologies, including Si CMOS.
Non-linearities of the electron plasma in FET channels can be used to test integrated circuits, such as a Monolithic Microwave Integrated Circuit (MMIC). Multiple non-linearities in plasma propagation can exist, such as a non-linearity that is proportional to the derivative of the velocity of the electrons and a non-linearity is proportional to a derivative of the current (e.g., velocity times density), as such, low frequencies may not produce a detectable response in at least some circumstances. In addition, to achieve a desirable collective (plasma) oscillation, the signal can be significantly slower than the electron-electron scattering. For the electron plasmas that are typical in VLSI transistor channels, these non-linerities are can be probed with radiation in the THz range. The response of these non-linearities is dependent on the density of the electron plasma within the channel as well as the electrical boundary conditions and parasitic aspects of the transistor, making the response sensitive to many of the parameters that are important for proper transistor operation. A THz overdamped plasmonic response can be used to detect faults in Si CMOS. The polarization dependence of the terahertz response can also be used to increase the effectiveness of this technique. The advantage of this approach to testing MMICs and VLSIs is that the transistors can be tested unbiased (so there is no need to connect them to the sources) or biased and several transistors within the circuit and the entire circuit can be tested.
Increasing complexity and decreasing feature size of integrated circuits brings to the forefront the issues of non-destructive comprehensive and ubiquitous testing. THz imaging can be used for testing Very Large Scale Integration (VLSI), but the image quality is limited by the diffraction limit on the order of tens or even hundreds of microns because of a relatively long wavelength of the sub-THz and THz radiation. Using the laser terahertz emission microscopy for testing VLSI, the resolution could be improved to approximately 3 microns, which still might not be good enough for modern VLSI with feature sizes as small as 7 nm. F
Field effect transistors (FETs) can be used as efficient detectors of the THz radiation using the excitation of propagating or overdamped plasma waves in the two-dimensional electronic fluid in the FET channels. Such plasmonic detectors could operate at frequencies much higher than their cut-off frequency or maximum frequency of oscillations. FETs operating in the plasmonic regimes can also be used as THz detectors, mixers, phase shifters and frequency multipliers at THz. The plasmonic FET detectors have advantages over Schottky diode detectors, such as by detecting single THz pulses with enhanced responsivity and being compatible with integrated circuit technologies, including a silicon (Si) Complementary metal-oxide semiconductor (CMOS). A THz overdamped plasmonic response can be used to detect faults in Si CMOS. Polarization dependence can be added as a part of the terahertz response and can be used to testing a MMIC. The advantage of this approach to testing MMICs and VLSIs is that the transistors can be tested unbiased (e.g., so there is no need to connect them to the sources) or biased and several transistors within the circuit and the entire circuit can be tested.
In one embodiment, a product manufacturer can obtain pre-fabricated integrated circuits from an outside party. In one example, a medical manufacturer can obtain an integrated circuit from a chip manufacturer. The medical manufacturer can incorporate the integrated circuit into a medical device, such as a monitor, a defibrillator, or a breathing machine. The medical device can be complex and, in turn, the integrated circuit can be complex with a vast number of transistors and other electrical hardware components.
With the integrated circuit being incorporated in the medical device, failure of the integrated circuit could be catastrophic. In one example, if the integrated circuit is incorporated in the defibrillator and the integrated circuit fails, then the defibrillator could fail to function and a patient may die. Since the medical manufacturer is not manufacturing the integrated circuit, the medical manufacturer should place in a control mechanism to determine if the integrated circuit is properly functioning before integration.
The control mechanism can subject the integrated circuit to a radiation at a specific frequency. When functioning properly, the integrated circuit can have an anticipated response to the specific radiation frequency. When subjecting the integrated circuit to the specific radiation frequency an actual response can be measured. Comparing the actual response against the anticipated response can result in determining if the integrated circuit is properly functioning or failing. If the actual response matches the anticipated response, such as within a tolerance, then the integrated circuit can be considered to be properly functioning and can be used by the medical device. If the actual response does not match the anticipated response, then the integrated circuit can be considered to be failing and can be discarded.
The following includes definitions of selected terms employed herein. The definitions include various examples. The examples are not intended to be limiting.
“One embodiment”, “an embodiment”, “one example”, “an example”, and so on, indicate that the embodiment(s) or example(s) can include a particular feature, structure, characteristic, property, or element, but that not every embodiment or example necessarily includes that particular feature, structure, characteristic, property, or element. Furthermore, repeated use of the phrase “in one embodiment” may or may not refer to the same embodiment.
“Computer-readable medium”, as used herein, refers to a medium that stores signals, instructions and/or data. Examples of a computer-readable medium include, but are not limited to, non-volatile media and volatile media. Non-volatile media may include, for example, optical disks, magnetic disks, and so on. Volatile media may include, for example, semiconductor memories, dynamic memory, and so on. Common forms of a computer-readable medium may include, but are not limited to, a floppy disk, a flexible disk, a hard disk, a magnetic tape, other magnetic medium, other optical medium, a Random Access Memory (RAM), a Read-Only Memory (ROM), a memory chip or card, a memory stick, and other media from which a computer, a processor or other electronic device can read. In one embodiment, the computer-readable medium is a non-transitory computer-readable medium.
“Component”, as used herein, includes but is not limited to hardware, firmware, software stored on a computer-readable medium or in execution on a machine, and/or combinations of each to perform a function(s) or an action(s), and/or to cause a function or action from another component, method, and/or system. Component may include a software controlled microprocessor, a discrete component, an analog circuit, a digital circuit, a programmed logic device, a memory device containing instructions, and so on. Where multiple components are described, it may be possible to incorporate the multiple components into one physical component or conversely, where a single component is described, it may be possible to distribute that single component between multiple components.
“Software”, as used herein, includes but is not limited to, one or more executable instructions stored on a computer-readable medium that cause a computer, processor, or other electronic device to perform functions, actions and/or behave in a desired manner. The instructions may be embodied in various forms including routines, algorithms, modules, methods, threads, and/or programs, including separate applications or code from dynamically linked libraries.
“Frequency”, when referring to the frequency of terahertz emission, the frequency can refer to part of an electro-magnetic emission that contributes to a measured response (e.g., a significant amount of the measured response).
The response 150 can be considered a measurement from the radiation set 130. In one example, the measurement is done under a predetermined series of bias voltages of the integrated circuit 140. In one example, the measurement is done under a predetermined series of the modulated integrated circuit bias voltages and the response 150 compared with the etalon as functions of the modulation frequencies for a comparison result. The response 150 can be used in a number of manners. In one example, the response 150 is used to determine a manufacturer of the integrated circuit 140.
The response 150 can be transmitted to a data processing unit (e.g., wirelessly transmitted to the data processing unit). The data processing unit can process the response 150 in accordance with big data processing techniques.
The emission of the radiation set 150 can be composed of a narrow band of frequencies around a center frequency, such as a narrow band produced by a THz laser, or can be a broad band of frequencies around a center frequency, such as a broad band produced by a short THz pulse. The emission of the radiation set 150 can have multiple peaks, frequency aspects that do not significantly impact the measured response, and/or aspects that introduce unwanted features to the measured response (e.g., noise).
The radiation set 130 can be a plasmon emission that comprises one or more frequencies. In one example, the emission component 110 emits a first frequency at 0.2 terahertz and a second frequency at 0.6 terahertz. The values of the first frequency and the second frequency can be above (including equal to) about 0.2 terahertz and below (including equal to) about 40 terahertz. The emission component 110 can emit the first frequency and the reception component 120 can collect the response 150 from this emission. After the emission component 110 emits the first frequency, the emission component 110 can emit the second frequency such that the first frequency and second frequency are emitted in series and therefore frequencies of the radiation set 130 do not interfere with one another.
The radiation set 130 can be a beam set upon an area of several integrated circuits 140 forming a system and the response 150 can be compared with responses of identical and fully functional integrated circuits (e.g., etalon responses). With this, an impinging radiation beam can be scanned over the area of the integrated circuits and multiple responses can be recorded as a function of scanning beam position with comparisons of the etalon responses (e.g., at the same scanning beam position). In one example, the radiation set 130 can be modulated as a function of time or frequency and the response 150 can be recorded as a function of frequency or modulation frequency. Further, a temperature of the integrated circuit 140 can be modulated as a function of time and the response 150 can be recorded as a function of temperature and/or the modulation frequency. In one example, the modulation frequency of radiation can be between 1 Hz and 1 THz while a modulation frequency of temperature can be between 1 Hz and 1 MHz. In one embodiment, the radiation set 130 is used to measure a low frequency noise spectral density (e.g., that is the response 150) and the comparison can be with an etalon noise spectral density, such as when the noise is measured in the bandwidth between 0.01 Hz and 10 MHz. The radiation set 130 can be a radiation pattern.
The response 150 of the integrated circuit 140 to the radiation set 130 can be a voltage. In one example, a transistor set of the integrated circuit 140 can be biased with a substrate of the integrated circuit 140. The radiation set 130 can cause the transistor set of the integrated circuit 140 to respond by producing voltage due to this biasing. The reception component 120 can be physically coupled to a pin set of the integrated circuit 140. By way of this physical coupling to the pin set, the reception component 120 can sense the voltage that is the response 150 to the radiation set 130.
In one embodiment, the emission of the radiation set 130 upon the integrated circuit 140 occurs wirelessly. In another embodiment, the emission component 110 can physically couple to the integrated circuit 140 and the emission component 110 can emit the radiation set 130 by way of a waveform generator. The integrated circuit 140 can comprise the transistor set, such as a transistor set of at least about 1000 transistors and therefore be considered a very large-scale integrated circuit. The integrated circuit 140 can be packaged or unpackaged, be under bias or unbiased, as well as being independent or installed in a system.
The emission component 110 and the reception component 120 can be considered a system to test the integrated circuit 140 under bias by measuring the response 150 to the radiation set 130. The radiation set 130 can be, for example, a radio frequency (about three gigahertz to about three-hundred gigahertz), a sub-terahertz frequency (over about three-hundred gigahertz to under about one terahertz), or terahertz frequency (above about one terahertz). The response 150 can be between pins of the integrated circuit 140 when the integrated circuit 140 is illuminated by the radiation set 130. The response 150 can be, for example, a function of frequency, radiation intensity, position of a scanning radiation beam on a surface of the integrated circuit 140, or a combination thereof.
In one example, the integrated circuit 140 can be silicon and under bias. The integrated circuit 140 can comprise a transistor set of field effect transistors. The response 150 of the integrated circuit 140 to the radiation set 130 can be by way of an excited decaying plasma wave. Example detection of the response 150 from the integrated circuit 140 can comprises gate leakage current measurement, parasitic resistance measurement, channel mobility measurement, channel saturation velocity measurement, channel transport measurement, threshold voltage measurement, or a combination thereof.
In one embodiment, the system 100 can function for period and/or constant monitoring of the integrated circuit 140. As part of this, the system 100 can comprise a component that transmits a visual and/or audio signal indicating a failure or potential failure of the integrated circuit 140. Additional fail safes can be implemented, such as shutting down an operation of a system that include the integrated circuit 140 when the failure is detected or switching to another system that is not indicated as having a failure on its integrated circuit 140.
In one example, before beginning operation, multiple integrated circuits 140 can be available. The emission component 110 and the reception component 120 can function upon the individual integrated circuits 140 (e.g., each integrated into identical systems). A best performing integrated circuit 140 (e.g., an integrated circuit 140 with fewest failures) can be chosen. In one example, the reception component 120 determines a placement of the individual integrated circuits 140 within a accuracy range (e.g., 1% to 100%), and chooses a highest placing integrated circuit for initial usage.
In one example, physical characteristics for the integrated circuit 140 can be inputted into a graphical user interface. These physical characteristics can be an example of the feature set. Based on these physical characteristics, the selection component 210 can select the radiation value. One type of integrated circuit can have little response to low frequencies, such as a frequency of about 0.2 terahertz, and therefore low frequencies can be skipped and testing can occur at a higher frequency. Conversely, the integrated circuit 140 can be highly delicate. Therefore, subjecting the integrated circuit 140 to high frequencies, such as a frequency of about 40 terahertz, can cause damage to the integrated circuit 140. Therefore, the selection component 210 can select a frequency that is not anticipated to cause damage (unless causing such damage is desired).
In one embodiment, the analysis can be voltage-based. The response 150 can be a voltage. The analysis can comprise comparing the voltage against a voltage standard (e.g., a voltage from an etalon circuit considered a fully operational circuit). With this, a radiation emitted upon the integrated circuit 140 can be known and therefore an expected response from the integrated circuit 140 can be known. The expected response can be particular to a specific radiation. This expected response can be the voltage standard. If the response does not match the expected response, such as match within a defined tolerance, then the determination can be that the integrated circuit 140 is failing and not healthy. Therefore, the determination component 320 can determine the health based, at least in part on if the comparison results such that the voltage meets the voltage standard. In this, the determination component 320 can establish from a difference that results from the comparison the present or absence of one or more failures of the integrated circuit and/or the nature of such failure(s).
This voltage-based analysis can function on a pin-by-pin level. In one example, the integrated circuit 140 can comprise thirty-two pins. The individual pins can have expected voltage responses of different values from one another. Thirty-one pins can have expected responses while one pin can have a voltage that does not meet the expected response. This can be considered as the integrated circuit 140 failing since one pin does not meet the expected response. However, a configuration can be used where one pin not meeting the expected response does not place the health of the integrated circuit 140 as failing.
As part of the voltage-based analysis, the determination component 320 can determine health based on power supplied. The radiation set 130 of
Returning to the example above, the integrated circuit 140 can have thirty-two pins. Thirty-one of these pins can return an expected voltage while one pin can return with an unexpected voltage. While the determination component 320 can output a report of the failure, such as that the integrated circuit 140 fails or highlight the pin that fails, the identification component 410 can identify the failure itself.
In one example, a higher than expected voltage can indicate a first failure while a lower than expected voltage can indicate a second failure. The first failure can be a physical failure of one hardware portion of the integrated circuit 140 while the second failure can be a physical failure of another, different hardware portion. In one example, the integrated circuit 140 is a Monolithic Microwave Integrated Circuit.
The database can be built or updated by way of this propagation. In one example, a customer can purchase a large number of integrated circuits—this purchase can include multiple orders at different times to different physical locations. As information is learned about the integrated circuits, this information can be aggregated into the database. Users at different physical locations can use the database to diagnose, and potentially correct, failures. Additionally, information in the database can be forwarded to an integrated circuit manufacturer so that their product can be improved and/or aspects disclosed herein can be used by the integrated circuit manufacturer for quality control purposes.
The method 800 can end after processing the failure. In one example, a first radiation and a second radiation (e.g., the first being higher than the second) can be scheduled to be emitted. The first radiation can ultimately cause a determination that the integrated circuit 140 of
While aspects disclosed herein relate to a clear pass/fail evaluation of the integrated circuit 140 of
While the methods disclosed herein are shown and described as a series of blocks, it is to be appreciated by one of ordinary skill in the art that the methods are not restricted by the order of the blocks, as some blocks can take place in different orders. Similarly, a block can operate concurrently with at least one other block.
As can be seen, the two circuits have different shapes and amplitudes of the response. The shape of the dependences is in qualitative agreement with the analytical theory of the overdamped plasmonic detection. As seen from
In one embodiment, polarization dependences of the response compared with the cosine response can be as expected for a straight interconnect conductor. This shape of the polarization response is consistent with THz radiation coupling via bonding connections. The polarization response could be also used as a part of the test vector for identifying the circuit faults.
Aspects disclosed herein can be used for frequency dependence of the response as a part of the defect signature. The responsivity of FETs is a strong function of frequency and the device feature size. A crude estimate of the peak response frequency, fpeak, can be given by fpeak, ˜α/L, where L is the gate length and α ˜15 THz/nm, α ˜130 THz/nm, and α ˜45 THz/nm for Si, InGaAs and GaN FETs, respectively. At lower frequencies, the response can drop approximately as 1/f2 and, at frequencies higher than the peak frequency it drops approximately as 1/f0.5. Hence, this technique could work in fairly broad frequency range.
Practicing aspects disclosed herein can be used in resolving a single transistor defect in an integrated circuit. The ultimate resolution can be even higher, since the transistor response strongly depends on the boundary conditions at the gate edges, on the leakage current, and on parasitic resistances. A response to the THz radiation measured between the pins or contact pads of an integrated circuit allows to establish and identify the integrated circuit faults using the response bias and polarization dependences. This allows for the ability to identify individual transistor defects.
The innovation described herein may be manufactured, used, imported, sold, and licensed by or for the Government of the United States of America without the payment of any royalty thereon or therefor.
