This disclosure relates generally to liquid dispensing in semiconductor manufacturing processes and, more particularly, to a new dispense system having a smart controller for controlling customizable pump operations to meet the diverse needs in the field of semiconductor manufacturing.
There are many applications for which precise control over the amount and/or rate at which a fluid is dispensed by a pumping apparatus is necessary. In semiconductor manufacturing processes, for example, it is important to control the amount and rate at which photochemicals, such as photoresist chemicals, are applied to a semiconductor wafer. A semiconductor manufacturing process refers to a process used to create integrated circuits that are present in everyday electrical and electronic devices. It includes a sequence of photographic and chemical processing steps during which electronic circuits are gradually created on a wafer made of pure semiconducting material. The coatings applied to semiconductor wafers during processing typically require a certain flatness and/or even thickness across the surface of the wafer that is measured in angstroms. The rates at which processing chemicals are applied (i.e., dispensed) onto the wafer have to be controlled carefully to ensure that the processing liquid is applied uniformly.
Photochemicals used in the semiconductor industry can be very expensive. Therefore, it is highly desirable to ensure that a minimum but adequate amount of chemical is used and that the chemical is not damaged by the pumping apparatus. Unfortunately, these desirable qualities can be extremely difficult to achieve in today's pumping systems because of the many interrelated obstacles. For example, due to incoming supply issues, pressure can vary from system to system. Due to fluid dynamics and properties, pressure needs vary from fluid to fluid (e.g., a fluid with higher viscosity requires more pressure). Because these obstacles are interrelated, sometimes solving one many cause many more problems and/or make the matter worse. What is more, different applications have different needs. A pump system that meets the needs of a particular application may not be suitable for a different application.
In semiconductor manufacturing, various pumps may be used to mix chemicals as well as dispensing the mixture of chemicals onto wafers. High performance pumps, such as the Entegris IntelliGen Mini photolithography rolling edge diaphragm pump, can be used to mix and dispense the chemicals directly (Entegris and IntelliGen are trademarks of Entegris, Inc. of Chaska, Minn.). These chemicals may vary from application to application and different applications may have different needs. Thus, a pump system used in dispensing the chemicals must consider a plurality of factors, including size, cost, performance (both speed and accuracy), reliability, adaptability, and so on.
Embodiments disclosed herein can address these needs with a customizable dispense system that is built on modular architecture and that includes a single main controller for controlling components in this versatile, “plug-and-play” dispense system. Within this disclosure, the term “customizable” refers to the fact that embodiments of a dispense system disclosed herein can be easily changed, modified, or otherwise altered to suit various needs. Such a change, modification, or alteration may occur dynamically whenever such a need arises. For example, one embodiment of a customizable dispense system disclosed herein may initially be built with a pneumatic to pneumatic configuration. Pneumatically driven pumps (pneumatic pumps) are generally less expensive than motor-driven pumps (motor pumps) and can provide positive pressure filtration and good throughput, which makes this pneumatic to pneumatic configuration ideal for handling applications such as those for non-critical layers. The pneumatic to pneumatic configuration can be easily changed, modified, or otherwise altered to a motor to motor configuration for critical layer applications. In some embodiments, the single main controller is configured with the necessary intelligence, and hence is referred to herein as a “smart” controller, to automatically recognize a change in the customizable dispense system and operate according to a new configuration and/or a new application.
In some embodiments, the smart controller of a customizable dispense system disclosed herein can be configured to operate a plurality of pumps in semiconductor manufacturing processes that are sensitive to defects in printed patterns. The plurality of pumps may include at least one pneumatic pump and at least one motor pump. The customizable dispense system may further comprise a plurality of lines connecting the smart controller with a track and a variety of devices. In some embodiments, the variety of devices may include filters with radio-frequency identification tags, sensors, and pump heads.
In some embodiments, the smart controller is further configured to, upon switching one of the plurality of lines from communicating with a first pump to a second pump, automatically recognize the second pump and apply a control scheme corresponding to the second pump in order to precisely and accurately control the second pump without minimal, if any, downtime.
In some embodiments, the switching may occur between motor pumps, between pneumatic pumps, or between a mixture of pneumatic pumps and motor pumps. For example, a user may unplug pneumatic pumps and plug in motor pumps to take over certain functions of those pneumatic pumps. Example functions may include chemical feed and dispense. In some embodiments, no physical disconnection/connection may be necessary and the switching is done entirely via software.
In some embodiments, the smart controller may be configured to, upon interfacing with a newly connected pump, automatically recognize the newly connected pump and apply a control scheme corresponding to the newly connected pump, which may be a motor pump or a pneumatic pump. The smart controller may comprise an onboard database storing information associated with a plurality of pumps.
In some embodiments, the smart controller may be configured to control one or more integrated pumps. In some embodiments, an integrated pump may comprise two or more pneumatic pumps physically combined as a unit. The two or more pneumatic pumps in the unit may operate independent of one another. In some embodiments, the smart controller may be further configured to independently control the two or more pneumatic pumps in the unit.
In some embodiments, a customizable dispense system may include a set of feed pumps and a set of dispense pumps. In some embodiments, a smart controller may be configured to operate the set of feed pumps and the set of dispense pumps which may include one or more integrated pumps.
Software implementing embodiments disclosed herein may be implemented in suitable computer-executable instructions that may reside on one or more non-transitory computer readable medium. Within this disclosure, the term “computer-readable storage medium” encompasses all types of data storage medium that can be read by a processing unit such as a processor or a controller. Examples of computer-readable storage media can include random access memories, read-only memories, hard drives, data cartridges, floppy diskettes, flash memory drives, and the like.
Embodiments disclosed herein can provide many advantages. For example, instead of a fixed number of pumps, a customizable dispense system disclosed herein can support a variable number of different types of pumps over time. This mix and match flexibility allows the system to be tailored to each particular application, reduces the cost of maintaining the system, and provides a way to easily upgrade to a new type of pumps and/or a new system setup.
These, and other, aspects of the disclosure will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following description, while indicating various embodiments of the disclosure and numerous specific details thereof, is given by way of illustration and not of limitation. Many substitutions, modifications, additions and/or rearrangements may be made within the scope of the disclosure without departing from the spirit thereof, and the disclosure includes all such substitutions, modifications, additions and/or rearrangements.
The drawings accompanying and forming part of this specification are included to depict certain aspects of the disclosure. It should be noted that the features illustrated in the drawings are not necessarily drawn to scale. A more complete understanding of the disclosure and the advantages thereof may be acquired by referring to the following description, taken in conjunction with the accompanying drawings in which like reference numbers indicate like features and wherein:
The disclosure and various features and advantageous details thereof are explained more fully with reference to the exemplary, and therefore non-limiting, embodiments illustrated in the accompanying drawings and detailed in the following description. Descriptions of known programming techniques, computer software, hardware, operating platforms and protocols may be omitted so as not to unnecessarily obscure the disclosure in detail. It should be understood, however, that the detailed description and the specific examples, while indicating the preferred embodiments, are given by way of illustration only and not by way of limitation. Various substitutions, modifications, additions and/or rearrangements within the spirit and/or scope of the underlying inventive concept will become apparent to those skilled in the art from this disclosure.
Dispense stage portion 110 can further include a pressure sensor 112 that determines the pressure of fluid at dispense stage 110. The pressure determined by pressure sensor 112 can be used to control the speed of the various pumps as described below. Example pressure sensors include ceramic and polymer piezoresistive and capacitive pressure sensors, including those manufactured by Metallux AG, of Korb, Germany. The face of pressure sensor 112 that contacts the process fluid can be a perfluoropolymer. Pump 100 can include additional pressure sensors, such as a pressure sensor that determines the pressure of fluid at feed stage 105 and/or a pressure sensor to read pressure in feed chamber 155.
Feed stage 105 and dispense stage 110 can include rolling diaphragm pumps to pump fluid in multi-stage pump 100. Feed-stage pump 150 (“feed pump 150”), for example, includes a feed chamber 155 to collect fluid, a feed stage diaphragm 160 to move within feed chamber 155 and displace fluid, a piston 165 to move feed stage diaphragm 160, a lead screw 170 and a stepper motor 175. Lead screw 170 couples to stepper motor 175 through a nut, gear or other mechanism for imparting energy from the motor to lead screw 170. According to one embodiment, feed motor 170 rotates a nut that, in turn, actuates lead screw 170, causing piston 165 to actuate. Dispense-stage pump 180 (“dispense pump 180”) can similarly include a dispense chamber 185, a dispense stage diaphragm 190, a piston 192, a lead screw 195, and a dispense motor 200. Feed stage 105 and dispense stage 110 can each be include a variety of pumps including pneumatically actuated pumps, hydraulic pumps or other pumps. For example, a pneumatically actuated pump may be used for the feed stage and a stepper motor driven hydraulic pump may be used for the dispense stage.
In the example shown in
Dispense motor 200 can further include an encoder (e.g., a fine line rotary position encoder) for real time feedback of dispense motor 200's position. The use of a position sensor enables accurate and repeatable control of the position of piston 192, which leads to accurate and repeatable control over fluid movements in dispense chamber 185. For, example, using a 2000 line encoder, which may provide 8000 pulses to the DSP, it is possible to accurately measure to and control dispense motor 200's position at 0.045 degrees of rotation. In addition, a PMSM can run at low velocities with little or no vibration. Feed motor 175 can also be a PMSM or a stepper motor. For example, feed motor 175 can be an EAD Motors of Dover, N.H. stepper motor part no. L1LAB-005 and dispense motor 200 can be an EAD Motors brushless DC Motor part no. DA23DBBL-13E17A.
Dispense block 205 can include various external inlets and outlets including, for example, inlet 210 through which the fluid is received, vent outlet 215 for venting fluid during the vent segment, and dispense outlet 220 through which fluid is dispensed during the dispense segment. Dispense block 205, in the example of
Dispense block 205 routes fluid to the feed pump, dispense pump and filter 120. A pump cover 225 can protect feed motor 175 and dispense motor 200 from damage, while piston housing 227 can provide protection for piston 165 and piston 192. In this example, valve plate 230 provides a valve housing for a system of valves (e.g., inlet valve 125, isolation valve 130, barrier valve 135, purge valve 140 and vent valve 145 of
Valve plate 230 includes a valve control inlet for each valve to apply pressure or vacuum to the corresponding diaphragm. For example, inlet 235 corresponds to barrier valve 135, inlet 240 to purge valve 140, inlet 245 to isolation valve 130, inlet 250 to vent valve 145, and inlet 255 to inlet valve 125. By the selective application of pressure or vacuum to the inlets, the corresponding valves are opened and closed. The valves can be opened and closed in various sequences which may vary from application to application. Valve plate 230 can be configured to reduce the hold-up volume of the valves, eliminate volume variations due to vacuum fluctuations, reduce vacuum requirements and reduce stress on the valve diaphragm.
A valve control gas and vacuum are provided to valve plate 230 via valve control supply lines 260, which run from a valve control manifold (covered by manifold cover 263 or housing cover 225), through dispense block 205 to valve plate 230. Valve control gas supply inlet 265 provides a pressurized gas to the valve control manifold and vacuum inlet 270 provides vacuum (or low pressure) to the valve control manifold. The valve control manifold acts as a three way valve to route pressurized gas or vacuum to the appropriate inlets of valve plate 230 via supply lines 260 to actuate the corresponding valve(s).
In
In addition to the examples shown in
Pump 4000 can be similar to one stage, say the dispense stage, of multi-stage pump 100 described above. Pump 4000 can include a pneumatically actuated pump or a rolling diaphragm pump driven by a stepper motor, brushless DC motor, or other motor. Pump 4000 can include a dispense block 4005 that defines various fluid flow paths through pump 4000 and at least partially defines a pump chamber. Dispense pump block 4005 can be a unitary block of PTFE, modified PTFE or other material. Because these materials do not react with or are minimally reactive with many process fluids, the use of these materials allows flow passages and the pump chamber to be machined directly into dispense block 4005 with a minimum of additional hardware. Dispense block 4005 consequently reduces the need for piping by providing an integrated fluid manifold. A pressure sensor can be positioned to read the pressure in the pump chamber.
Dispense block 4005 can include various external inlets and outlets including, for example, inlet 4010 through which the fluid is received, purge/vent outlet 4015 for purging/venting fluid, and dispense outlet 4020 through which fluid is dispensed during the dispense segment. Dispense block 4005, in the example of
Dispense block 4005 routes fluid from the inlet to an inlet valve (e.g., at least partially defined by valve plate 4030), from the inlet valve to the pump chamber, from the pump chamber to a vent/purge valve and from the pump chamber to outlet 4020. A pump cover 4025 can protect a pump motor from damage, while piston housing 4027 can provide protection for a piston. The cover/housing can be formed of polyethylene or other polymer. Valve plate 4030 provides a valve housing for a system of valves (e.g., an inlet valve, and a purge/vent valve) that can be configured to direct fluid flow to various components of pump 4000. Valve plate 4030 and the corresponding valves can be formed similarly to the manner described in conjunction with valve plate 230, discussed above. The purge valve can be the same size as, smaller than, or larger than the inlet valve. Using a smaller purge valve, however, can reduce the holdup volume returned to the chamber as described above. Each of the inlet valve and the purge/vent valve can be partially integrated into valve plate 4030 and can be a diaphragm valve that is either opened or closed depending on whether pressure or vacuum is applied to the corresponding diaphragm. In some implementations, some of the valves may be external to dispense block 4005 or arranged in additional valve plates. As an example, a sheet of PTFE can be sandwiched between valve plate 4030 and dispense block 4005 to form the diaphragms of the various valves. Valve plate 4030 includes a valve control inlet (not shown) for each valve to apply pressure or vacuum to the corresponding diaphragm.
In some embodiments, instead of a fixed number of pumps, a customizable system may support a variable number of pumps over time. The customizable dispense system employs a flexible, modular architecture. Embodiments of a customizable dispense system may also support different types of pumps, including pneumatic and motor, at any given time. For example, in a multi-stage pump system, the first stage pump may be driven pneumatically and the second stage pump may be driven by a motor. This mix and match flexibility allows the system to be customized for each particular application.
As illustrated in
This flexible, modular architecture may provide a dispense system disclosed herein with many advantages. For example, an owner of the system may start with a pneumatic to pneumatic set up. Over time, the owner's needs may change and/or after an evaluation, the pneumatic to pneumatic set up may need an upgrade. One or more of the pneumatic pumps may be readily swapped out and replaced with motor driven pump(s) and/or replacement pneumatic pump(s). The owner would not have to replace the entire dispense system.
This type of plug-n-play modification to the dispense system is possible due at least in part to a versatile, smart controller operable to control various types of pumps automatically and dynamically. For example, one may unplug a first pump, plug in a second pump, plumb the line, and begin or resume the operation. Upon interfacing with the pump head of the second pump, the controller is operable to automatically recognize the second pump and apply a control scheme corresponding to the second pump. In some embodiments, the switching from one pump to another may be done entirely via software, without having to physically unplugging-plugging pumps. For example, a user may want to take Pump A and Pump B off-line and designate Pump C and Pump D to take over and function as new Pump A and new Pump B.
In some embodiments, electronically readable tags or code may be utilized to provide a wide variety of information to the smart controller. In some embodiments, the smart controller may connect to various devices identifiable via electronically readable tags which may or may not be directly affixed on or embedded in those devices/packages. For example, the smart controller may be connected to a smart filter via one of its many ports and information about the smart filter may be provided to the smart controller via an electronically readable tag associated with the smart filter. As another example, the smart controller may be connected to a pack or package and information about the content contained therein may be provided to the smart controller via an electronically readable tag associated with the pack or package. The pack may contain a chemical or substance necessary for a particular application. Other devices/packages can be connected to the smart controller in a similar manner.
In semiconductor manufacturing, different applications often have different requirements for chemical layer thickness and coating area. Correspondingly, a wide array of dispense volumes and rates may be required. Meeting such requirements involves many different size pumps for all the different track sizes as each pump must be able to contain all of the fluid required for an individual dispense. These tracks and pumps may rely on discrete lines for communication, which means each input line and each output line would require a physical wire or cabling. The complexity of wiring adds another layer of challenge to the already complicated fluidic connections in the dispense system.
One way to address these challenges is to provide an input/output (I/O) interface device that can provide serial communications between individual pump controllers and tracks. In this way, individual pump controllers for the same type of pumps can communicate with different tracks through the I/O interface device. More specifically, the I/O interface device can take a signal from a track at the front end and serially communicate that signal to a pump controller at the back end in a format that can be understood by the pump controller.
Embodiments of a smart controller disclosed herein can provide another viable solution. In some embodiments, the smart controller may comprise a plurality of communication ports for physical connections to a track and a variety of devices. In some embodiments, the smart controller may have 24 communication ports for motor pumps, pneumatic pumps, filters, sensors, etc., each of which may be plugged into any one of the 24 ports and be automatically recognized by the smart controller, utilizing an onboard database. The communication lines between the smart controller and the devices may be software configurable. In some embodiments, each type of device may be assigned to a particular port of the smart controller.
In some embodiments, the smart controller may comprise different types of interfaces to communicate serial, parallel, or analog signals/data to and from various devices, including a track, pumps, valves, sensors, tag readers, pump heads, and other components. In some embodiments, the interface to the track may utilize a proprietary protocol or an industry standard protocol. As another example, an interface to the track may be a Controller Area Network (CAN) interface with DeviceNet, an industry standard Ethernet, or some other industry standard protocol. For example, the smart controller may utilize the Transmission Control Protocol/Internet Protocol (TCP/IP) to communicate with the track. Other interfaces of the smart controller may be used to communicate with a variety of devices, including individual pump heads, in one or more protocols. In some embodiments, the variety of devices may include CAN devices. In some embodiments, the interfaces to the variety of devices may include stripped down simple proprietary interfaces.
In many tracks, Ethernet and DeviceNet or something similar may be utilized to control the I/O signals of the pumps. For example, a track would send a DeviceNet command to a DeviceNet parallel I/O board to set some signals and those signals would go through connectors and cables to a special pump interface module. This kind of connection architecture requires delicate and complicated hardware arrangement in addition to software programming.
In some embodiments, the smart controller may implement a proprietary communications protocol for interfacing/communicating with the pumps. In some embodiments, the smart controller may implement a track interface to take the place of a parallel I/O that is normally used to trigger the pump and get basic status. In some embodiments, pumps may be implemented as the same parallel device type and the smart controller may be operable to interpret the protocol directly. This would eliminate the need for parallel signals on the pump as well as the track hardware board and cabling while providing virtually the same programming functions that many tracks currently use. Following the above example, the track could send the same DeviceNet command to the pump through the smart controller and not require additional hardware. Those skilled in the art will appreciate that this is just one possible example. In some embodiments, an existing Entegris Networking Protocol may be used to communicate to the smart controller or pumps.
In some prior dispense systems, a master controller may be connected to multiple pumps and each pump may have a dedicated pump controller coupled thereto. The functionality of this type of dedicated pump controller may be categorized into two levels: high and low. High level control functions may include functions required to run a dispense pump. Low level control functions may include simple functions such as moving a motor from Point A to Point B. These pump controllers have a lot of processing power. Unfortunately, prior dispense systems do not utilize the processing powers of such pump controllers in an efficient manner. For example, in a dispense system with multiple pumps, say 30-40, there may be up to three pumps that are operating at the same time and the rest of the pumps sit idle. This inefficiency can be costly.
Another drawback of a prior dispense system is in its fixed architecture that cannot be readily modified. The master controller is generally programmed with a control scheme corresponding to the type of pump controllers connected thereto. Since the control scheme is specific to the type of pumps, if a pneumatic pump is pulled out and replaced with a motor pump, the master controller will not recognize the motor pump, nor will the master controller know how to control the motor pump.
Embodiments of a smart controller disclosed herein can take the high level functionality out of the pump controllers so they can share the processing power smartly in order to reduce idle time and corresponding cost. The low level functionality stays at the pump head. The distinction between high level functions and low level functions may be software configurable to customize the dispense system for a particular implementation. For example, in some embodiments, the smart controller may send a simple ‘DISPENSE’ command to a pump head and the pump head has sufficient intelligence to execute the command and report to the smart controller when the task is complete. As another example, the smart controller may give the pump controller (at or local to the pump) a generic command “DISPENSE RECIPE 4” and the pump controller having been configured to dispense this particular recipe, performs the task as instructed. In some embodiments, the pump head may have only rudimentary or basic functions sufficient to drive a pump coupled thereto and the smart controller may provide specific instructions to the pump head in order to perform the task at hand.
In some embodiments, the operation of a pump is controlled by the smart controller using information about a filter that is connected to the pump. In some embodiments, the filter is a removable filter disposed in a fluid flow path between a pump inlet and a pump outlet. The removable filter may implement a quick change or quick connect mechanism to connect to the pump. In some embodiments, the smart controller is configured to receive filter information, receive process fluid information such as a chemical type, access a library of operating routines (control schemes) based on the filter information and the process fluid information to select an operating routine for the pump and operate the pump according to the selected operating routine. The selected operating routine can include a priming routine, a dispense cycle, selected segments of a dispense cycle of other routine.
The smart controller may provide proprietary or internally standardized communication lines to communicate with a variety of devices, including pneumatic pumps, motor pumps, filters, etc. In communicating with these devices, the smart controller may identify each type of device upon connection, look up a corresponding control scheme, and proceed accordingly. For example, to switch from communicating with one pump to another, the smart controller may access an internal or local database for information, including a control scheme associated with the newly connected pump, and apply the control scheme accordingly.
In some embodiments, the smart controller may connect to filters having electronically readable filter information tags containing filter information. Some examples of electronically readable filter information tags may implement the Radio-frequency identification (RFID) technology. These filters may be of a removable type implementing a quick change or quick connect mechanism. In some embodiments, the filter information tags can be an active or passive RFID tags, bar code or other optically readable code.
Radio-frequency identification (RFID) generally has two parts: readers and tags. Using radio waves, some RFID tags can be read from several meters away and beyond the line of sight of an RFID reader. In some embodiments, the range of suitable RFID tags is intentionally shortened to reduce cross talk of adjacent pumps reading each other's tags. As an example, in one embodiment, the range of RFID tags is reduced to about an inch. Other ranges are also possible, depending upon the distance and/or arrangement of RFID reader(s) and tag(s).
Examples of filter information may include, but are not limited to, part number, design style, membrane type, retention rating, generation of the filter, configuration of the filter membrane, lot number, serial number, a device flow, membrane thickness, membrane bubble point, particle quality, filter manufacturer quality information or other information. The design style indicates the type of pump for which the filter is designed, the capacity/size of the filter, amount of membrane material in the filter or other information about the design of the filter. The membrane type indicates the material and/or thickness of the membrane. The retention rating indicates the size of particles that can be removed with a particular efficiency by the membrane. The generation of the filter indicates whether the filter is a first, second, third or other generation of the filter design. The configuration of the filter membrane indicates whether the filter is pleated, the type of pleating or other information regarding the design of the membrane. The serial number provides the serial number of the individual filter. The lot number can specify the manufacturing lot of the filter or membrane. The device flow indicates the flow rate the filter can handle while still producing good dispenses. The device flow can be determined during manufacture for the individual filter. The membrane bubble point provides another measure of the flow rates/pressure the filter can handle and still produce good dispenses. The membrane bubble point can also be determined during manufacture for the individual filter. The above examples are provided by way of explanation are not limiting of the information that can be contained in the filter information.
The part number contained in the filter information can convey a variety of information. For example, each letter in the example part number format “Aabcdefgh” can convey a different piece of information. Table 1 below provides an example of information conveyed by the part number:
Using the example of Table 1, the part number A2AT2RMR1 for an Impact pump filter would indicate that the connectology of the filter, the filter is designed for an IntelliGen2 Pump (Impact and IntelliGen are trademarks of Entegris, Inc. of Chaska, Minn.), the membrane is thin UPE, has a retention rating of 10 nm, the filter is a version 2 filter, the filter includes an RFID tag, the filter membrane has an M-pleat, the filter is O-ringless and there is one filter per box. The use of a part number to convey information, however, is provided by way of example and filter information can be conveyed in other manners.
Other suitable filters may also be connected to the smart controller for various purposes. For example, an earlier version of a smart filter may need to be swapped out and replaced with a newer version. This may be done as simple as pulling the old smart filter out and plugging in the replacement in its place. A set of rules can be applied to the filter information to determine if the filter is appropriate. The rules for determining whether a filter is appropriate can depend on the filter information and other factors, such as the process fluid, environmental properties, required cycle time or other factors. For example, a rule may be applied such that, if the process fluid has a certain viscosity, a filter will only be considered appropriate if it has a specific part number or certain part number and bubble point. Thus, the rules applied can depend on multiple pieces of filter information and other information. If the filter is not an appropriate filter, a corresponding action can be taken. Otherwise, operation of the pump can proceed.
Smart filters may play an important role in various semiconductor manufacturing processes that are sensitive to defects in printed patterns, especially those processes involving very small, microscopic or submicron feature sizes. Some existing dispense systems filter at a negative pressure. Some existing dispense systems are able to monitor and perhaps passively maintain the pressure needed for the filtration. However, prior dispense systems are not known to have the ability to accurately and precisely control the pressure needed for the filtration.
Some embodiments disclosed herein may control and maintain a positive pressure in a pump head at the inlet of the pump on the dispense side to reduce defect-causing bubbles. For a motor pump, this positive pressure can be controlled by motor movements and by a feedback loop to a pressure transducer. For example, to provide a 5 psi positive pressure, an upstream electronic regulator may be set to provide 10 psi in the first stage and a downstream electronic regulator may be set to provide 5 psi in the second stage. This pressure differential pushes the fluid across the filter to the dispense side.
In a pneumatic pump set up, a pressure transducer is placed in the fluid path to detect the actual fluid pressure. Based on information from the smart filters, the smart controller can infer what the actual filtration rate is for a particular filter and control that filtration rate accordingly. This allows a user to set a desired filtration rate, in addition to setting the downstream pressure. The upstream pressure can be adjusted to get the desired target rate across the filter.
As an example, a filtration rate for a pneumatic to pneumatic pump set up can be calculated as follows:
As a specific example, a user may desire a filtration rate of 1.5 cc per sec. and a downstream pressure of 4 psi on the dispense pump for filtering a fluid having a viscosity of 3 Centipoise (cps). Suppose R=1.55, UFR=10.98 psi. If the pressure regulator for the feed pump is set at 10.98 psi and the pressure regulator for the dispense pump is set at 4 psi, the movement of fluid is caused by the differential pressure across the filter which in this example causes the fluid to move from the feed side to the dispense side at a flow rate of 1.5 cc per sec through the filter. That flow rate will continue until it does not need any more fluid. At that time, the dispense pump diaphragm will bottom out and the pressure regulator for the dispense pump will no longer be able to maintain the 4 psi setpoint. The pressure at the second stage then begins to drift towards the 10.98 psi setpoint. Once that drift begins to occur, it signifies the end of filtration and the dispense pump can move away from filtration and go to the next step in the cycle. One reason that this is possible is because a pressure transducer is placed in the fluid path. If the pressure transducer is only placed in the pneumatic path, a change in the fluid pressure may not be detected.
The dispense nozzle is generally at atmosphere. Preferably, the level of pressure at the dispense nozzle remains undisturbed—no high pressure, no vacuum, no spikes. Placing the pressure transducer in the fluid path in a pneumatic to pneumatic set up may ensure that the inlet of the dispense pump has a positive pressure and that the positive pressure is accurately controlled at all time, without having to make any assumptions. A pressure transducer is a type of sensor that can generate a signal as a function of the pressure imposed. Many suitable pressure transducers may be used in this set up. In some embodiments, the positive pressure may be in the range of 0 to about 12 psi. In some embodiments, the positive pressure may be in the range of about 2 to 10 psi.
Filter 950a can have tag 952a. In operation, a tag reader (not shown) can read filter information from tag 952a and communicates the filter information to the smart controller (see
The smart controller can also use the filter information to correlate good or bad operations to filter characteristics. During operation, the smart controller can track a variety of operational data for customizable dispense system 1000. The information tracked by the smart controller can include any operational parameters made available to the smart controller and any information calculated by the smart controller. Some non-limiting examples of operational data may include pressure, parameters related to valve operations, motor positions, motor speeds, hydraulic pressure or other parameters (such as temperature if the pump includes temperature sensors). This information can be used to determine whether a dispense is/was a good dispense. This can be done after the dispense has occurred or in real time during the dispense cycle.
The operational data can be correlated to the filter information so that the effect of the various filter parameters on dispense quality can be identified. As an example, the smart controller can record the lot number of a filter so that operational data of customizable dispense system 1000 can be correlated to that lot. This information can be used to identify whether a particular lot of filters produced better or worse results compared to another lot of filters of the same design. Similarly, the serial number can be used to track operational data versus individual filter to help determine if an individual filter was the cause of bad coatings. As yet another example, operational data can be correlated to membrane bubble points to determine if filters having the same part number but different membrane bubble points had different dispense results. Recording information from tag 952a and tracking information about dispenses can optimize selection and even manufacture of filters.
In a mix and match system, the bottle drawer may utilize motor pump(s) to pull the fluid(s) from the bottle(s). A negative pressure may be applied (via an upstream electronic regulator) to pull the fluid(s) from the bottle(s) into the fluid reservoir in the first stage. Using a motor pump may have the benefit of a finer level of controls with respect to rate of the fluid and pressure. In some embodiments, a pneumatic pump may be utilized at a lower cost. Thus, in some embodiments, the positive pressure control scheme described above is not limited to a pneumatic to pneumatic set up and may be implemented in a motor to motor set up or a motor to pneumatic set up. The bottle could also be pressurized, and the feed stage used to control the rate at which chemical fills, and also determine when the fill is complete.
In addition to the dispense cycle, the smart controller may be configured to perform other operations. For example, when a new filter is connected to a pump, the filter should be primed so that the filter membrane is fully wetted prior to running a dispense cycle. An example priming routine may be as follows. First, fluid is introduced into the dispense chamber. The filter can be vented for a period of time to remove air bubbles from the upstream portion of the filter. Next, a recirculating purge segment may occur. An example recirculating purge sequence 1300 is shown in
The pumps in a customizable dispense system may be primed based on the type of filter and process fluid used. Thus, while the foregoing provides an example priming routine, other priming routines can be used as would be understood by those of ordinary skill in the art. A suitable priming routine can involve any number of different steps and to ensure that the filter membrane is fully wetted. Some non-limiting examples of sequences of segments that can be used in a priming routine include, but are not limited to: I) a fill segment, a vent segment; ii) a fill segment, a purge-to-vent segment, a filtration segment, a vent segment, a purge-to-inlet segment; iii) a dispense segment, a fill segment, a filtration segment and a purge segment.
As discuss above, in some embodiments, a customizable dispense system may include one or more units of physically connected pumps. With the help of a PCB, the smart controller can communicate with these pumps via a single line/port/physical interface per unit. However, since the pumps are not physically integrated, each of the pumps still requires a full set of tubing and parts. In some embodiments, a customizable dispense system disclosed herein may include integrated pumps with simplified wiring/tubing requirements.
As those skilled in the art can appreciate, the number of pumps as well as the type of pumps that can be combined in this way is not limited to what is shown in the drawings accompanying this disclosure. For example, motor driven pumps may also be combined: by forming two or more bore holes—one for each pump—in a single block, by bolting together two or more rolling diaphragm pumps with a single control board, etc. In some cases, practical considerations such as complexity involved in combining the pumps and benefits that may be provided by such a combination may influence the number of pumps to be combined. For example, using two separate pumps in a dispense system may cost X and combining two pumps may cost a fraction of X. Coming four pumps, however, may increase that fraction of X. As the number of pumps to be combined continues to increase, so does the challenges, which diminishes the value in combining them. There may be a point where that fraction of X is sufficiently close to X so as to render negligible the saving from combining the pumps.
Combining pumps that may be operated independently can provide many advantages. For example, the integrated pumps may require a smaller foot print than the total foot print of separate pumps. Additionally, the integrated pumps may simplify wiring/cabling, thereby reducing the installation/configuration/maintenance time. Furthermore, the integrated pumps may reduce the cost of the overall system, at least due to the sharing of materials in each unit of the integrated pumps.
Although embodiments of a modular, flexible, smart, cost-effective, and high-performance dispense system have been described in this disclosure, one of ordinary skill in the art can appreciate that various modifications and changes can be made without departing from the spirit and scope of the specific embodiments disclosed herein. Those skilled in the art will appreciate that features and aspects disclosed herein may be independently implemented or in various combinations. Accordingly, the specification and figures disclosed herein, including in the accompanying appendices, are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of this disclosure. Therefore, the scope of the present disclosure should be determined by the following claims and their legal equivalents.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US11/42018 | 6/27/2011 | WO | 00 | 12/19/2012 |
Number | Date | Country | |
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61359239 | Jun 2010 | US |