HK1050958A - Method and apparatus for supercritical processing of multiple workpieces - Google Patents

Description

Method and apparatus for supercritical processing of multiple workpieces

Technical Field

The present invention relates to the field of supercritical processing. More particularly, the present invention relates to the field of supercritical processing where multiple workpieces are processed simultaneously.

Background

Semiconductor manufacturing uses photoresist in ion implantation, etching, and other processing steps. During the ion implantation step, the photoresist mask region of the semiconductor substrate is not implanted with dopants. During the etching step, areas of the photoresist mask of the semiconductor body are not etched. Examples of other processing steps include the use of photoresists as a surface protective coating for processed wafers or MEMS (micro-electro-mechanical systems) devices. After the ion implantation step, the photoresist shows a hard crust covering the jelly-like core layer. The hard crust makes it difficult to remove the photoresist. After the etching step, the remaining photoresist exhibits hardening characteristics that make it difficult to remove the photoresist. After the etching step, the residues (photoresist residues mixed with etching residues) cover the sidewalls of the etched features. Depending on the type of etching step and the material being etched, the mixing of photoresist residue with etching residue presents a problematic removal problem, as photoresist residue and etching residue often stick strongly to the sidewalls of the etched features.

Typically, in the prior art, the photoresist and residue are removed by passing them at O₂Plasma ashing followed by wet cleaning bath cleaning. The semiconductor etching and prior art metallization processes are shown in the flow chart of fig. 1. Semiconductor etching and metallization 10 includes a photoresist application step 12, a photoresist exposure step 14, a photoresist development step 16, a dielectric etch step 18, an ashing step 20, a wet clean step 22, and a metal plating step 24. In a photoresist application step 12, photoresist is applied to a wafer having an exposed oxide layerThe above. In the photoresist exposure step 14, the photoresist is exposed to light that is partially blocked by the mask.

Depending on whether the photoresist is a positive or negative photoresist, either the positive or negative photoresist is removed in a photoresist exposure step 16, respectively, and an exposed pattern is left on the oxide layer. In the dielectric etching step 18, the exposed pattern on the oxide layer is etched in an RIE (reactive ion etching) process that etches the exposed pattern on the oxide layer, forming an etched pattern, while partially etching the photoresist. This process produces a residue that covers the sidewalls of the etched features while also hardening the photoresist. In the ashing step 20, O₂The plasma oxidizes and partially removes the photoresist and residues. In the wet wash step 22, the remaining photoresist and residues are removed in a wet wash bath.

In a metal plating step 24, a metal layer is deposited on the wafer, filling the etched pattern and also covering the non-etched areas. In subsequent processing, at least a portion of the metal overlying the non-etched region is removed for forming the line.

U.S. patent No.4,944,837 to Nishikawa et al, published on 31/7/1990, sets forth a prior art method of removing resist using a liquefied or supercritical gas. The substrate with the resist is placed in a pressure vessel that also contains a liquefied or supercritical gas. After a predetermined time has elapsed, the liquefied or supercritical gas rapidly expands, thereby removing the resist.

Nishikawa et al teach supercritical CO₂Can be used as a developer for photoresists. The substrate with the photoresist layer is exposed to light in a pattern, thereby forming a latent image. The substrate with the photoresist layer and latent image is placed in supercritical CO₂Bathe for 30 minutes. Supercritical CO₂Then, the photoresist is shrunk to form a pattern of the photoresist. Nishikawa et al further demonstrated that 0.5% by weight methyl isopropyl ketone (MIBK) can be added to supercritical CO₂In order toIncreasing supercritical CO₂And thus the development time was reduced from 30 minutes to 5 minutes.

Nishikawa et al also teach that the photoresist may use supercritical CO₂And 7% by weight MIBK purge. The substrate with photoresist is placed in supercritical CO₂And MIBK for 30-45 minutes. In supercritical CO₂Upon shrinkage, the photoresist has been removed.

The method described by Nishikawa et al is unsuitable for semiconductor manufacturing lines for a number of reasons. The rapidly expanding liquefied or supercritical gas to clear photoresist from the substrate creates the possibility of substrate fracture. The development treatment with the photoresist for 30 minutes is insufficient. The process of developing or removing the photoresist using MIBK is not preferred because MIBK is toxic and is only used where a more suitable option is not available.

U.S. patent No.5,377,705 to Smith, jr, et al, published 3.1.1995, describes a system for cleaning contaminants from a workpiece. Contaminants include organic, particulate and ionic contaminants. The system comprises a pressurizable purge vessel, liquid CO₂Storage vessels, pumps, solvent delivery systems, separators, condensers, and various valves. Pumping CO₂The gas and solvent are transferred to a purge vessel and CO is introduced₂Pressurizing to supercritical CO₂. Supercritical CO₂And the solvent removes contaminants from the workpiece. Supplementing supercritical CO in the pump₂Simultaneous valving of some supercritical CO with solvent₂And the solvent is drained from the cleaning vessel. Separator secondary supercritical CO₂Separating the solvent. Condenser for CO generation₂Condensed into liquid CO₂So that liquid CO is present₂The storage container can be replenished.

The removal of photoresist and residues using systems such as those described by Smith, jr. The pressurizable cleaning vessel is not configured for semiconductor substrate processing. Supercritical CO during cleaning₂And the discharge of solvent is insufficient. Such systems are not easily adjustableTo fully suit the needs of the semiconductor manufacturing line. Such systems are non-conductive for the safe handling of semiconductor substrates, which is critical to semiconductor manufacturing lines. Such a system is not economical for semiconductor substrate processing.

What is needed is a method for developing photoresist using supercritical carbon dioxide for use in a semiconductor manufacturing line.

What is needed is a method for semiconductor processing lines to remove photoresist using supercritical carbon dioxide.

What is needed is a supercritical processing system configured for processing semiconductor substrates.

What is needed is a supercritical processing system in which supercritical CO is used to generate a fluid flow in the processing chamber₂And the solvent need not be exhausted from the process chamber.

What is needed is a supercritical processing system that is fully suited to the needs of a semiconductor manufacturing line.

What is needed is a supercritical processing system that provides for the safe processing of semiconductor substrates.

What is needed is a supercritical processing system that provides economical processing of semiconductor substrates.

Disclosure of Invention

The invention is an apparatus for supercritical processing of a plurality of workpieces. The apparatus includes a transfer module, first and second supercritical processing modules, and a robot. The transfer assembly includes an inlet. The first and second supercritical processing modules are coupled to the transfer module. The robot is preferably located within the transfer assembly. In operation, the robot transfers a first workpiece from the transfer module entrance to the first supercritical processing module. The robot transfers a second workpiece from the inlet to the second supercritical processing module. After workpiece processing, the robot returns the first and second workpieces to the entrance of the transfer assembly. Alternatively, the apparatus includes an additional supercritical processing module coupled to the transfer module.

Drawings

FIG. 1 shows in a block diagram the production flow of a prior art semiconductor etching and metallization process.

FIG. 2 shows in a block diagram the production flow of the semiconductor etching and metallization process of the present invention.

Figure 3 illustrates in a block diagram a supercritical cleaning process of the present invention.

Figure 4 shows a preferred supercritical processing system of the present invention.

Figure 5 illustrates a preferred supercritical processing module of the present invention.

Figure 6 illustrates a first alternative embodiment of a supercritical processing system of the present invention.

Figure 7 illustrates a second alternative embodiment of the supercritical processing system of the present invention.

Figure 8 illustrates a third alternative embodiment of a supercritical processing system of the present invention.

Figure 9 shows a fourth alternative embodiment of the supercritical processing system of the present invention.

Detailed Description

Fig. 2 illustrates, in block diagram, a semiconductor etching and metallization process of the present invention. The semiconductor etch and metallization process 30 includes a photoresist application step 32, a photoresist exposure step 34, a photoresist development step 36, a dielectric etch step 38, a supercritical removal process 40, and a metallization step 42. In a photoresist application step 32, photoresist is applied to the wafer with the exposed oxide layer. In a photoresist exposure step 34, the photoresist is exposed to light that is partially blocked by the mask.

Depending on whether the photoresist is a positive or negative photoresist, whether it is removed separately in the photoresist exposure step 36, an exposed pattern is formed on the oxide layer. The exposed pattern on the oxide layer is preferably etched in a RIE (reactive ion etching) process that etches the exposed pattern on the oxide layer to form an etched pattern while partially etching the photoresist in a dielectric etching step 38. This process produces a residue that covers the sidewalls of the etched features while also hardening the photoresist.

In the supercritical removal process 40, the etch photoresist and residues are removed using supercritical carbon dioxide and a solvent. In a metal plating step 42, a metal layer is deposited on the wafer, filling the etched pattern and also covering the non-etched areas. In subsequent processing, at least a portion of the metal overlying the non-etched region is removed for forming the line.

Fig. 3 illustrates, in block diagram, a supercritical removal process 40 of the present invention. The supercritical removal process 40 begins by placing the wafer and photoresist and residue thereon in a pressure chamber and sealing the process chamber in a first process step 52. In a second process step 54, the pressure chamber is pressurized with carbon dioxide until the carbon dioxide becomes supercritical carbon dioxide (SCCO)₂). In a third process step 56, supercritical carbon dioxide carrier solvent enters the process chamber. In a fourth process step 58, supercritical carbon dioxide and solvent are maintained in contact with the wafer until the photoresist and residue are removed from the wafer. In a fourth process step 58, the solvent partially dissolves the photoresist and residues. In a fifth process step 60, the pressure chamber is partially evacuated. In a sixth process step 62, the wafer is cleaned. In a seventh process step 64, the supercritical removal process 40 ends with the depressurization of the pressure chamber and the removal of the wafer.

The supercritical removal process 40 is preferably performed on a semiconductor manufacturing line by a preferred supercritical processing system of the present invention, as shown in fig. 4. The preferred supercritical processing system 70 includes a transfer assembly 72, first through fifth supercritical processing assemblies 74-78, a robot 80 and an electronic controller 82. The transfer assembly includes first through fifth processing ports 84-88, and a transfer assembly inlet 90. The transfer assembly inlet 90 includes first and second transfer stations 92 and 94, and first and second inlets 96 and 98.

The first through fifth supercritical processing modules 74-78 are connected to the transfer module 72 through first through fifth processing ports 84-88, respectively. Preferably, the robot 80 is attached to the transfer assembly 72 at the center of the transfer assembly 72. First and second transfer stations 92 and 94 are connected to the transfer assembly by first and second inlets 96 and 98, respectively. An electronic controller 82 is connected to the carriage assembly 72.

Preferably, the transfer assembly 72 operates at atmospheric pressure. Alternatively, the transfer assembly 72 operates at a slightly positive pressure relative to ambient, where the slight positive pressure is created by an inert gas injection device. Inert gas injection device for injecting Ar, CO for example₂Or N₂Is injected into the transfer assembly 72. This ensures a cleaner processing environment in the transfer assembly 72.

Robot 80 preferably includes a robot base 100, a robot arm 102, and an end effector 104. The robot base is connected to a transfer assembly 72. The robotic arm 102 preferably has a two-part robotic arm that can couple the end effector 104 to the robotic base 100. The end effector 104 is configured to pick up and place a workpiece. Preferably, the end effector 104 is configured to pick and place the wafer. Alternatively, the end effector 104 is configured to pick up and place a disk or other substrate. Alternatively, a two-arm robot is used in place of robot 80. Here a two-arm robot comprises two arms and two end effectors.

The first through fifth supercritical processing modules 74-78 preferably include first through fifth gate valves 106-110, respectively. First to fifth gate valves 106 to 110 connect the first to fifth workpiece cavities 112 to 116 of the first to fifth supercritical processing modules 74 to 78 to the first to fifth processing ports 84 to 88, respectively.

Preferably, in operation, the robot 80 transfers the first workpiece 118 from the first transfer station 92 into the first supercritical processing module 74 where the supercritical cleaning process is performed. Thereafter, the robot 80 transfers the second workpiece 120 from the first transfer station 92 to the second supercritical processing module 75 where the supercritical cleaning process is performed. In addition, the robot 80 transfers third through fifth workpieces (not shown) from the first transfer station 92 into the third through fifth supercritical processing modules 76-78, respectively, where the supercritical cleaning process is performed.

In subsequent operation, the robot 80 transfers the first workpiece from the first supercritical processing module 74 to the second transfer station 94. In addition, the robot 80 transfers the second workpiece from the second supercritical processing module 74 to the second transfer station 94. In addition, the robot 80 transfers third through fifth workpieces from the third through fifth supercritical processing modules 76-78 to the second transfer station 94, respectively.

Preferably, the first workpiece 118, the first wafer 120, and the third through fifth workpieces are wafers. Preferably, the wafer is in the first cassette of the first transfer station 92 prior to supercritical processing. Preferably, after supercritical processing, the wafer is placed by robot 80 in the second cassette at the second transfer station 94. Alternatively, the wafer starts and ends in a first cassette at the first transfer station 92, while a second set of wafers starts and ends in a second cassette at the second transfer station 94.

It will be readily apparent to those skilled in the art that additional or no transfer stations may be added to the preferred supercritical processing system 70 for the second transfer station 94. In addition, it will be readily apparent to those skilled in the art that the preferred supercritical processing system 70 can be configured with fewer than the first through fifth supercritical processing assemblies 74-78, or more than the first through fifth supercritical processing assemblies 74-78. In addition, it will be readily apparent to those skilled in the art that the robot 80 may be replaced by a transfer mechanism configured to transfer the first workpiece 118, the second workpiece 120, and the third through fifth workpieces. In addition, it will be readily apparent to those skilled in the art that the first and second cassettes may be front opening unitary containers that employ standard mechanical interface concepts such that the wafers are maintained in a clean environment separate from the ambient environment.

Figure 5 illustrates a first supercritical processing module 74 of the present invention. The first supercritical processing module 74 includes a carbon dioxide supply vessel 132, a carbon dioxide pump 134, a pressure chamber 136, a chemical supply vessel 138, a circulation pump 140, and an exhaust gas collection vessel 144. The carbon dioxide supply vessel 132 is connected to the pressure chamber 136 by a carbon dioxide pump 134 and a carbon dioxide line 146. The carbon dioxide line 146 includes a carbon dioxide heater 148 located between the carbon dioxide pump 134 and the pressure chamber 136. The pressure chamber 136 includes a pressure chamber heater 150. A circulation pump 140 is located on circulation line 152 and is connected to pressure chamber 136 at a circulation inlet 154 and a circulation outlet 156. The chemical supply container 138 is connected to the circulation line 152 through a chemical supply line 158 including a first syringe pump 159. The cleaning agent supply container 160 is connected to the circulation line 152 through a cleaning agent supply line 162 including a second syringe pump 163. The vent gas collection vessel 144 is connected to the pressure chamber 136 by a vent gas line 164.

The carbon dioxide supply container 132, the carbon dioxide pump 134 and the carbon dioxide heater 148 form a carbon dioxide supply device 149. The chemical supply vessel 138, first syringe pump 159, cleaning agent supply vessel 160 and second syringe pump 163 form a chemical and cleaning agent supply 165. Preferably, a carbon dioxide supply 149 and a chemical and cleaning agent supply 165 and an exhaust gas collection vessel 144 are used for the second through fifth supercritical processing modules 75-78 (FIG. 3) and the first supercritical processing module 74. In other words, it is preferred that the first supercritical processing module 74 includes the carbon dioxide supply 149 and the chemical and cleaning agent supply 165 and the exhaust gas collection vessel 144, while the second through fifth supercritical processing modules 75-78 share the carbon dioxide supply 149 and the chemical and cleaning agent supply 165 and the exhaust gas collection vessel 144 of the first supercritical processing module 74.

It will be readily apparent to those skilled in the art that one or more additional carbon dioxide supplies, one or more additional chemical and cleaning agent supplies and one or more additional exhaust gas collection vessels may be provided for the second through fifth supercritical processing modules 75-78. In addition, it will be readily apparent to those skilled in the art that the first supercritical processing assembly 74 includes valves, electronic controllers, filters and general connectors typical of supercritical fluid processing systems. Further, it is easily understood to those skilled in the art that an additional chemical supply container may be connected to the first syringe pump 159, or an additional chemical supply container and an additional syringe pump may be connected to the circulation line 152.

Referring to fig. 3, 4 and 5, the supercritical fluid removal method 40 is performed beginning with a first processing step 52 in which a wafer having photoresist or residue (or both) is inserted through a first processing port and placed in the first wafer cavity 112 of the pressure chamber 136 by the robot 80, and then the pressure chamber 136 is sealed by closing the gate valve 106. In the second process step 54, the pressure chamber 136 is pressurized with carbon dioxide from the carbon dioxide supply vessel 132 by the carbon dioxide pump 134. In a second process step 54, the carbon dioxide is heated by a carbon dioxide heater 148 while the pressure chamber 136 is heated by a pressure chamber heater 150 to ensure that the temperature of the carbon dioxide in the pressure chamber 136 is above the critical temperature. The critical temperature for carbon dioxide is 31 ℃. Preferably, the temperature of the carbon dioxide in the pressure chamber 136 is in the range of 45 ℃ to 75 ℃. Alternatively, the temperature of the carbon dioxide in the pressure chamber 136 is maintained in the range of 31 ℃ to about 100 ℃.

Upon reaching the initial supercritical state, the first syringe pump 159 pumps the solvent from the chemical supply vessel 138 through the recycle line 152 into the pressure chamber 136 while the carbon dioxide pump further pressurizes the supercritical carbon dioxide in the third step 56. At the beginning of the solvent injection, the pressure in the pressure chamber 136 is about 1100-1200 psi. Once the desired amount of solvent has been pumped into the pressure chamber 136 and the desired supercritical state has been reached, the carbon dioxide pump 134 stops pressurizing the pressure chamber 136, the first syringe pump 159 stops pumping solvent into the pressure chamber 136, and the circulation pump 140 begins circulating supercritical carbon dioxide and solvent in the fourth step 58. Preferably, the pressure is about 2700 to 2800psi at this point. The supercritical carbon dioxide maintains the solvent in contact with the wafer by circulating the supercritical carbon dioxide and the solvent. Additionally, by circulating supercritical carbon dioxide and solvent, the fluid flow enhances the removal of photoresist or residue from the wafer.

Preferably, the wafer is held stationary in the pressure chamber 136 in the fourth step 58. Alternatively, the wafer is rotated in the pressure chamber 136 in a fourth step 58.

After the photoresist or residue is removed from the wafer, the pressure chamber 136 is partially depressurized by venting some of the supercritical carbon dioxide, solvent, removed photoresist, and removed residue to a drain collection vessel 144 in order to return the state of the pressure chamber 136 to an initial supercritical state near the fifth process step 60. Preferably, the pressure in the pressure chamber 136 is cycled at least once by raising the pressure and then partially venting the pressure chamber 136 at this point. This may increase the cleanliness of the pressure chamber 136. In a fifth step 60, the pressure chamber is preferably maintained above the critical temperature and critical pressure. The critical pressure for carbon dioxide is 1070 psi.

In a sixth step 62, the second syringe pump 163 pumps cleaning agent from the cleaning agent supply vessel 160 into the pressure chamber 136 through the circulation line while the carbon dioxide pump 134 pressurizes the pressure chamber 136 close to the desired supercritical state, and then the circulation pump 140 circulates the supercritical carbon dioxide and cleaning agent in order to clean the wafer. Preferably, the cleaning agent is selected from the group consisting of water, alcohol, acetone, and mixtures thereof. More preferably, the cleaning agent is a mixture of ethanol and water. Preferably, the alcohol is selected from the group consisting of isopropanol, ethanol and other low molecular weight alcohols, more preferably, the alcohol is selected from the group consisting of isopropanol and ethanol, and most preferably, the alcohol is ethanol.

Preferably, the wafer is held stationary in the pressure chamber 136 during the sixth step 62. Alternatively, the wafer is rotated in the pressure chamber 136 in a sixth step 62.

In a seventh step 64, the pressure chamber 136 is depressurized by venting the pressure chamber 136 to the exhaust gas collection container 144, the gate valve 106 is opened, and the wafer is removed from the pressure chamber 136 by the robot 80.

Alternative supercritical removal processes of the present invention are described in the following patent applications, all referenced below: U.S. application filed on 25/10/2000 (attorney docket No. ssi-001103); U.S. patent application Ser. No.09/389,788, filed 3.9.1999; U.S. patent application Ser. No.09/085,391, on 27/3/1998; U.S. provisional patent application No.60/047,739, 1997, 3, 27.

FIG. 6 illustrates a first alternative embodiment of a supercritical processing system of the present invention. The first selective supercritical processing system 170 adds first through fifth vestibule chambers 172-176, and first through fifth vestibule robots 178-182 to the preferred supercritical processing system 70. In operation, the first through fifth front cavities 172-176 operate from about atmospheric pressure to some elevated pressure. This allows the first through fifth wafer cavities 112-116 to operate between an elevated pressure and a supercritical pressure, thereby improving throughput. Alternatively, in the first alternative supercritical processing system 170, the first through fifth front cavity robots 178-182 are replaced by first through fifth magnetic linkages, or first through fifth hydraulic drive mechanisms, or first through fifth pneumatic mechanisms.

Figure 7 illustrates a second alternative embodiment of a supercritical processing system of the present invention. The second alternative supercritical processing system 190 replaces the first and second transfer stations 92 and 94 of the preferred supercritical processing system 70 with first and second carrier clamps 192 and 194. In operation, the transfer assembly operates at the second elevated pressure and thus increases throughput.

Figure 8 illustrates a third alternative embodiment of a supercritical processing system of the present invention. The third alternative supercritical processing system 200 includes an optional transfer assembly 202 and a robot track 204.

FIG. 9 illustrates a fourth alternative embodiment of a supercritical processing system of the present invention. The fourth alternative supercritical processing system 210 preferably replaces the third supercritical processing module 76 of the preferred supercritical processing system 70 with a third transfer station 212 and adds a second transfer module 214, a second robot 216, and an additional supercritical processing module 218. In the fourth alternative supercritical processing system 210, the third transfer station 212 couples the transfer module 72 to the second transfer module 214. The second robot 216 is preferably located in the second transfer assembly 214. An additional supercritical processing module 218 is coupled to the second transfer module 214. Thus, the fourth alternative supercritical processing system 210 allows for more supercritical processing components than the preferred supercritical processing system 70.

The fifth alternative embodiment of the supercritical processing system of the present invention eliminates the transfer assembly 72 of the preferred supercritical processing system 70. In the fifth alternative supercritical processing system, the robot 80 is configured to move the workpieces between the first and second transfer stations 92 and 94 and the first through fifth supercritical processing modules 74-78 without benefiting from the coverage provided by the transfer module 72.

A sixth alternative embodiment of the supercritical processing system of the present invention adds a detection station to the preferred supercritical processing system 70. In the sixth alternative supercritical processing system, the first workpiece 118, the second workpiece 120, and the third through fifth workpieces are transferred to the inspection station before being transferred to the second transfer station 94. At the inspection station, the workpiece is inspected to ensure that the photoresist and residue are removed from the workpiece. Preferably, the inspection station inspects the workpiece using spectroscopy.

A seventh alternate embodiment of the supercritical processing system of the present invention adds a front end robot to the preferred supercritical processing system 70. In the seventh alternative supercritical processing system, the front end robot is located outside the entrance of the transfer assembly 72 and the first and second cassettes are located remotely from the first and second transfer stations 92 and 94. The front end robot is preferably configured to move the wafer from the first cassette into the first transfer station 92 and is also preferably configured to move the wafer from the second transfer station 94 into the second cassette.

An eighth alternative embodiment of the supercritical processing system of the present invention adds a wafer orientation apparatus to the preferred supercritical processing system 70. The wafer orientation device orients the wafer according to a flat, notched, or other orientation indicator. Preferably, the wafer is directed at the first transfer station 92. Alternatively, the wafer is directed at the second transfer station 94.

A first alternative embodiment of the supercritical processing module of the present invention replaces the pressure chamber 136 and gate valve 106 with an alternative pressure chamber. The selectable pressure chamber includes a chamber housing and a hydraulically driven thin platen. The chamber housing includes a cylindrical cavity open at its bottom. The hydraulically driven thin platen is configured to seal with the chamber housing outside of the cylindrical cavity. The thin platen is then hydraulically driven to move upward and seal with the chamber housing. Once the wafer is processed, the thin platen is hydraulically driven down and the wafer is removed.

A second alternative embodiment of the supercritical processing module of the present invention provides for the circulation line 152 to enter the wafer cavity 112 with an optional inlet at the periphery of the wafer cavity and an optional outlet at the top center of the wafer cavity 112. The optional inlet is preferably configured to inject supercritical carbon dioxide in the plane defined by the wafer cavity 112. Preferably, the selectable inlet is angled relative to a radius of the wafer cavity 112 such that, in operation, the selectable inlet and the selectable outlet create a vortex within the wafer cavity 112.

It will be readily apparent to those skilled in the art that various other modifications may be made to the preferred embodiment without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (33)

1. An apparatus for supercritical processing of first and second workpieces, comprising:

a. a transfer assembly having an inlet;

b. first and second supercritical processing modules coupled to the transfer module; and

c. a transfer mechanism coupled to the transfer assembly, the transfer mechanism configured to move the first workpiece between the inlet and the first supercritical processing assembly, the transfer mechanism configured to move the second workpiece between the inlet and the second supercritical processing assembly.

2. The apparatus of claim 1, wherein the transfer module operates at about atmospheric pressure.

3. The apparatus of claim 1, wherein the transfer module further comprises means for maintaining a slight positive pressure in the transfer module relative to the ambient environment.

4. The apparatus of claim 3 wherein the means for maintaining a slight positive pressure in the transfer module comprises an inert gas injection means.

5. The apparatus of claim 2, wherein the entrance of the transfer module comprises a transfer station.

6. The apparatus of claim 5, wherein the entrance of the transfer module further comprises an additional transfer station.

7. The apparatus of claim 1, wherein the transfer module operates at an elevated pressure and the inlet of the transfer module comprises a load-bearing jaw.

8. The apparatus of claim 7, wherein the entrance of the transfer module further comprises an additional carrier clamp.

9. The apparatus of claim 1, wherein the transfer mechanism comprises a robot.

10. The apparatus of claim 9, wherein the transfer assembly comprises a circulation structure.

11. The apparatus of claim 10, wherein the robot comprises a central robot, the central robot occupying a center of the loop structure.

12. The apparatus of claim 9, wherein the transfer assembly comprises a track structure.

13. The apparatus of claim 12, wherein the robot comprises an orbital robot, the orbital robot comprising the robot coupled to a track such that the robot moves along the track to reach the first and second processing components located along the track.

14. The apparatus of claim 13 further comprising third and fourth supercritical processing modules, the third and fourth supercritical processing modules located along the track, the third and fourth supercritical processing modules located opposite the first and second supercritical processing modules relative to the track.

15. The apparatus of claim 9, wherein the robot comprises an extendable arm and an end effector.

16. The apparatus of claim 15, wherein the robot further comprises an additional arm and an additional end effector.

17. The apparatus of claim 1, wherein the first supercritical processing module comprises a first pressure vessel and the second supercritical processing module comprises a second pressure vessel.

18. The apparatus of claim 17, wherein:

a. the first pressure vessel including a first workpiece cavity that holds the first workpiece during supercritical processing and a first pressure vessel inlet that provides for ingress and egress of the first workpiece; and

b. the second pressure vessel includes a second workpiece cavity that holds the second workpiece during supercritical processing and a second pressure vessel inlet that provides for ingress and egress of the first workpiece.

19. The apparatus of claim 18, wherein the transfer mechanism is configured to place the first and second workpieces in the first and second workpiece cavities, respectively.

20. The apparatus of claim 19, wherein the transfer module and the supercritical processing module are configured to operate in a supercritical state.

21. The apparatus of claim 19 further comprising first and second gate valves, the first gate valve being coupled to the transfer assembly and the first supercritical processing assembly, the second gate valve being coupled to the transfer assembly and the second supercritical processing assembly.

22. The apparatus of claim 18 further comprising first and second vestibules, the first vestibule being coupled to the transfer module and the first supercritical processing module, the second vestibule being coupled to the transfer module and the second supercritical processing module.

23. The apparatus of claim 1 further comprising means for pressurizing the first and second supercritical processing modules.

24. The apparatus of claim 23, wherein the means for pressurizing comprises a CO₂A pressurizing structure including a CO connected to a pump₂A supply vessel, the pump connected to the first and second supercritical processing modules such that the CO is₂The pressurizing structure is independent ofThe second supercritical processing module pressurizes the first supercritical processing module and causes CO to be introduced₂A pressurization structure pressurizes the second supercritical processing module independently of the first supercritical processing module.

25. The apparatus of claim 18 further comprising first and second means for sealing, the first means for sealing operable to seal the first pressure vessel inlet, the second means for sealing operable to seal the second pressure vessel inlet.

26. The apparatus of claim 1 further comprising means for controlling such that the means for controlling controls the transfer mechanism to move the first and second workpieces between the transfer module entrance and the first and second supercritical processing modules, respectively, and further such that the means for controlling controls the first supercritical processing module independently of the second supercritical processing module.

27. A method of supercritical processing first and second workpieces, comprising the steps of:

a. transferring the first workpiece from the transfer module inlet to the first supercritical processing module;

b. transferring the second workpiece from the transfer module inlet to the second supercritical processing module;

c. processing the first and second workpieces in the first and second supercritical processing modules, respectively;

d. transferring the first workpiece from the first supercritical processing module to the transfer module inlet; and

e. the second workpiece is transferred from the second supercritical processing module to the transfer module inlet.

28. The apparatus of claim 27, wherein the entrance of the transfer module comprises a transfer station.

29. The apparatus of claim 28, wherein the entrance of the transfer module further comprises an additional transfer station.

30. An apparatus for supercritical processing of first and second workpieces comprising:

a. means for conveying the first and second workpieces;

b. the first means for supercritical processing is configured such that in operation the means for transferring transfers the first workpiece from a transfer assembly inlet to the first means for supercritical processing and further such that in operation the first means for supercritical processing processes the first workpiece; and

c. the second means for supercritical processing is configured such that in operation the means for transferring transfers the second workpiece from the transfer assembly inlet to the second means for supercritical processing, and also such that in operation the second means for supercritical processing processes the second workpiece.

31. An apparatus for supercritical processing comprising:

a. a transfer assembly having an inlet;

b. an inert gas injection means connected to the transfer assembly such that in operation the inert gas injection means maintains a slight positive pressure in the transfer assembly relative to the ambient environment;

c. a first front chamber coupled to the transfer assembly;

d. a first supercritical processing module coupled to the first vestibule;

e. first means for moving a first semiconductor substrate between the first vestibule and the first supercritical processing module;

f. a second front cavity connected to the transfer assembly;

g. a second supercritical processing module coupled to the second vestibule;

h. second means for moving a second semiconductor substrate between the second vestibule and the second supercritical processing module;

i. a transfer mechanism is coupled to the transfer assembly such that, in operation, the transfer mechanism transfers the first and second semiconductor substrates between the first and second vestibules and the transfer assembly inlet, respectively.

32. An apparatus for supercritical processing comprising:

a. a transfer assembly having an inlet;

b. an inert gas injection means connected to the transfer assembly such that in operation the inert gas injection means maintains a slight positive pressure in the transfer assembly relative to the ambient environment;

c. a first supercritical processing module coupled to the transfer module, the first supercritical processing module including first means for sealing the first supercritical processing module;

d. a second supercritical processing module coupled to the transfer module, the second supercritical processing module including second means for sealing the second supercritical processing module;

e. a transfer mechanism coupled to the transfer assembly such that, in operation, the transfer mechanism transfers the first and second semiconductor substrates between the first and second supercritical processing modules and the transfer module inlet, respectively.

33. An apparatus for supercritical processing of first and second workpieces comprising:

a. a transfer station;

b. first and second supercritical processing modules connected to the transfer station; and

c. a transfer mechanism coupled to the transfer station, the transfer mechanism coupled to the first and second supercritical processing modules, the transfer mechanism configured to move the first workpiece between the transfer station and the first supercritical processing module, the transfer mechanism configured to move the second workpiece between the transfer station and the second supercritical processing module.