US20040040583A1

US20040040583A1 - Workpiece processing system

Info

Publication number: US20040040583A1
Application number: US10/654,849
Authority: US
Inventors: Ronald Breese; Dana Scranton; Eric Bergman; Michael Bartkoski; Cobby Grove
Original assignee: Semitool Inc
Current assignee: Semitool Inc
Priority date: 1997-05-09
Filing date: 2003-09-04
Publication date: 2004-03-04

Abstract

A workpiece processing system for processing semiconductor wafers and other flat media includes a standalone processing unit having two or more modules vertically stacked on top of one another. A first module includes an ozone generator, a DI water supply, a purge gas/drying gas supply, and optionally includes an ammonium hydroxide generator. A second module is preferably stacked on top of the first module and includes a processing chamber in communication with the devices in the first module. The processing chamber preferably includes a rotor for holding and rotating workpieces, one or more spray manifolds, an ozone destructor, an anti-static generator, and/or any other suitable workpiece-processing devices. The rotor is preferably designed to hold two workpiece-carrying cassettes each capable of holding up to 25 workpieces. A third module is preferably stacked on top of the second module and includes the system electronics and controls.

Description

This Application is a Continuation-In-Part of U.S. patent application Ser. No. 09/621,028, filed Jul. 21, 2000 and now pending, which is a Continuation-in-Part and U.S. National Phase of International Patent Application PCT/US99/08516, filed Apr. 16, 1999, which is a Continuation-in-Part of U.S. patent application Ser. No. 09/061,318, filed Apr. 16, 1998, now abandoned, which is a Continuation-in-Part of U.S. patent application Ser. No. 08/853,649, filed May, 9, 1997, now U.S. Pat. No. 6,240,933. This Application is also a Continuation-in-Part of U.S. patent application Ser. No. 10/315,609, filed Dec. 10, 2002, and now pending. This application also claims priority to U.S. [0001] Provisional Patent Application 60/486,771, filed Jul. 10, 2003. Priority to these Applications is claimed under 35 U.S.C. 119 and 120. These Applications are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The invention relates to surface preparation, cleaning, rinsing and drying of workpieces, such as semiconductor wafers, flat panel displays, glass masks, rigid disk or optical media, thin film heads, or other articles or workpieces formed from a substrate on which microelectronic circuits, data storage elements or layers, or micro-mechanical elements may be formed. These and similar articles are collectively referred to here as a “wafer” or “workpiece”.

The semiconductor manufacturing industry is constantly seeking to improve the processes used to manufacture microelectronic circuits and components, such as the manufacture of integrated circuits from wafers. The objectives of many of these improved processes are decreasing the amount of time required to process a wafer to form the desired integrated circuits; increasing the yield of usable integrated circuits per wafer by, for example, decreasing contamination of the wafer during processing; reducing the number of steps required to create the desired integrated circuits; and reducing the costs of manufacture.

In the processing of wafers, it is often necessary to subject one or both sides of the wafer to a fluid in either liquid, vapor or gaseous form. Such fluids are used to, for example, etch the wafer surface, clean the wafer surface, dry the wafer surface, passivate the wafer surface, deposit films on the wafer surface, etc.

Various systems and methods have been used for carrying out these manufacturing processes. For example, manual or automated wet benches have long been used for various manufacturing process steps. Wet benches typically have a row of immersion tanks, and a mechanism for sequentially immersing a batch a workpieces into each tank. However, these systems have several disadvantages. These disadvantages include relatively large consumption of process chemicals and water, e.g., 30-35 liters for each wet bench tank, with a bath life of for example 2-4 hours. This consumption of process chemicals increases manufacturing costs, which ultimately increases the cost of the final product, such as e.g., computers, cell phones, and virtually all types of consumer, industrial, commercial and military electronic products.

Many chemistries used in processing, such as HF, HCl, H ₂SO₄, and H₂O₂, are toxic, expensive, and/or difficult to handle and dispose of. As a result, complex draining, recycling, and removal systems are often required for effectively handling and disposing of these used processing chemistries. Furthermore, even when proper disposal procedures are followed, there is still a potential for the used processing chemistries to have a negative environmental impact. Accordingly, there is a need for processing machines and methods having less reliance on these types of chemistries.

Reducing consumption of water is also beneficial, especially in areas where clean water is becoming increasingly scarce. Disposing of waste water from manufacturing operations, in environmentally friendly ways, can often be difficult or costly. Accordingly, reducing water consumption in the manufacturing process is important.

Wafers are processed in clean rooms, to reduce potential for contamination resulting in defects in the end products, such as microelectronic or micromechanical devices. Clean rooms are costly and time consuming to build and maintain. Wafer or workpiece processing machines now in use, such as wet benches, often require a large amount of clean room space. This results in higher manufacturing costs and other disadvantages. Accordingly, there is a need for more compact processing machines, which require less clean room space while maintaining or improving on processing speed or throughput.

Overall processing times for large batches of workpieces in existing processing systems are often relatively slow. Wet bench processing can typically take 45 minutes. In some systems, the workpieces may be moved between several processing stations, during a single processing phase or step. This slows total production time. Alternatively, with some processing systems, including spray systems or vapor deposition systems, only a small number of workpieces can be processed at a given time, and/or only a limited number of processing machines or systems can be fit within the clean room. Accordingly, there is a need for workpiece processing systems that are compact but capable of processing large batches of workpieces in a relatively short amount of time.

For certain processing steps, ozone is introduced into the processing chamber. Ozone is typically introduced with water, sometimes containing dilute amounts of chemical. The ozone is then removed from the processing chamber (optionally along with other chemicals, such as acid vapors) and then exhausted to the atmosphere.

However, ozone is a highly chemically reactive gas. In high concentrations, it can become toxic to humans. The exhaust mixture of ozone can therefore be both toxic, and highly corrosive. Consequently, handling the gas exhaust from a processing chamber generally requires special procedures. For example, components such as ducts, etc. generally must be made of PVDF or other plastics which resist corrosion. Leak detectors may also be employed to detect any leaks in the pipes or ducts carrying the exhaust gases from the processing chamber to the outside.

Ozone converters or destructors have been used to convert ozone in an exhaust flow into oxygen. These converters or destructors typically use catalysts, such as maganese dioxide. The catalyst, however, lose efficiency or ability to catalyze, when they become saturated with condensation. It is also important to prevent stray catalyst particles from moving into the processing chamber, where they can cause contamination.

Accordingly, it is a further object of the invention to provide an improved ozone destructor for destroying ozone, by converting ozone into oxygen.

SUMMARY OF THE INVENTION

Processing systems or machines, and methods, have now been invented to overcome the disadvantages described above. These new systems and methods provide for rapid and efficient wafer processing, and at a reduced cost. In addition, these systems and methods avoid the need for using large amounts of various costly or toxic chemistries. The invention therefore provides for significant advances in the technology of manufacturing semiconductor wafers and similar workpieces. The invention is directed to a system for processing workpieces preferably in a standalone processing apparatus having vertically stacked modules. The vertically stacked modules advantageously contain the system components used in processing the workpieces.

In a first aspect, a system for processing a workpiece includes a first module including an ozone generator. A second module is attached to the first module and includes a processing chamber for processing a workpiece. The ozone generator provides ozone to the processing chamber. A third module, which includes a system controller, is attached to at least one of the first and second modules. The system is highly compact and requires a minimum amount of floor space in a clean room. This reduces both initial and follow on operating costs, and allows for higher throughput or manufacturing speed, via more systems within the clean room. In comparison to a typical wet bench system which may require 150 square feet of clean room floor space, the present system occupies less than 10 or even less than 8 square feet, while having an increased throughput. Moreover, the present system uses only a small fraction of the volume of process chemistries required by wet bench systems. In addition, the initial cost of the present system is less than wet bench systems.

In another aspect, a rotor in the processing chamber for holding and rotating a plurality of workpieces is rotatable about an axis that is inclined from horizontal. The rotor is preferably configured to hold at least two workpiece-carrying cassettes, with each cassette preferably holding up to 25 workpieces. As a result, processing speeds are increased while use of de-ionized (DI) water per wafer processed, are reduced. In comparison to wet bench processing requiring e.g., 45 minutes, the present system requires only e.g., 15 minutes.

In another aspect, an ozone destructor or converter is connected with the processing chamber. Ozone gas used in processing in the processing chamber is exhausted to the ozone destructor where it is converted to oxygen. This ozone conversion is performed within the system. The potential for release of toxic ozone gas is reduced. The ozone destructor advantageously uses catalyst to convert ozone to oxygen. Saturation of the catalyst with condensation is reduced or avoided by novel design and arrangement of the ozone destructor.

Other features and advantages of the invention will be apparent to persons knowledgeable in this technology, from the following description taken together with the accompanying drawings. While the drawings show a single embodiment of the invention, various changes, modifications and substitutions can of course be made within the scope of the invention. The invention resides as well in sub-combinations of the features described and in the individual components.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, wherein the same reference number denotes the same element throughout the several views: [0019]
FIG. 1 is a front perspective view of a workpiece processing system according to a preferred embodiment, with various covers removed for purpose of illustration. [0020]
FIG. 2 is rear perspective view of the processing system of FIG. 1. [0021]
FIG. 3 is a perspective view of a processing chamber assembly according to a preferred embodiment. [0022]
FIG. 4 is a perspective view of a rotor that may be used in the processing chamber assembly of FIG. 3. [0023]
FIG. 5 is a schematic diagram of a preferred processing method. [0024]
FIG. 6 is a schematic diagram of an alternative preferred processing method. [0025]
FIG. 7 is an exploded perspective view of the ozone destructor shown in FIGS. 1 and 2. [0026]
FIG. 8 is a section view of a preferred ozone destructor as shown in FIGS. [0027] 5-6.

DETAILED DESCRIPTION OF THE DRAWINGS

The terms workpiece, wafer, or semiconductor wafer, as used here, mean any flat media, including semiconductor wafers and other substrates or wafers, glass, mask, and memory media, MEMS substrates, or any other workpiece having micro-electronic, micro-mechanical, or micro electro-mechanical devices. [0028]
Turning now in detail to the drawings, as shown in FIGS. 1 and 2, a [0029] workpiece processing system 10 preferably includes a first module 12, a second module 14, and a third module 16. More or less modules may be included in the processing system 10, but three modules are preferred. Each module houses a variety of processing system components.
The [0030] processing system 10 may be used to process workpieces of various sizes, but is typically configured to process workpieces of one size, such as 200 or 300 mm diameter semiconductor wafers. The area that the processing system 10 occupies on a clean room floor, or the system's “footprint,” is preferably minimized to increase the amount of space available for additional processing systems and/or other clean room equipment. In the standalone processing system 10, which uses a modular construction to be as compact as possible, the size of the workpieces to be processed generally dictates the minimum possible size of the system footprint, as well as the minimum height of the system. Thus, with certain limitations, the smaller the size of the workpieces that are processed in the processing system 10, the smaller the system footprint and height may be.
When processing 200 mm semiconductor wafers, the footprint of the [0031] third module 16, or the bottom module, is preferably 19 to 23 inches wide by 47 to 53 inches long, more preferably 20 to 21 inches wide by 49 to 51 inches long. For processing larger workpieces, such as 300 mm semiconductor wafers, the third module 16 is preferably 24 to 28 inches wide by 47 to 53 inches long, more preferably 26 to 27 inches wide by 49 to 51 inches long. The first and second modules 12, 14 preferably have similar cross-sectional areas to the third module 16, and may be slightly smaller, as illustrated in FIGS. 1 and 2.
When configured for processing 200 mm semiconductor wafers, the first, second, and [0032] third modules 12, 14, 16 preferably have a combined height of 58 to 62 inches, more preferably 60 inches. For processing larger workpieces, such as 300 mm semiconductor wafers, the first, second, and third modules 12, 14, 16 preferably have a combined height of 62 to 66 inches, more preferably 64 inches. Accordingly, the footprint and height of the standalone workpiece processing system 10 are generally significantly smaller than those of typical existing processing systems. Thus, the processing system 10 is compact, and takes up relatively little space in a clean room environment.
The [0033] first module 12 preferably includes a system controller, which includes a control panel and display 18 at the front of the first module 12 for controlling and monitoring operation of the system. The first module 12 also preferably includes a system power supply and any other electrical or electronic devices required for performing the various system operations.
The [0034] second module 14 includes a processing chamber assembly 20, as illustrated in FIGS. 2 and 3. The processing chamber assembly 20 includes a substantially cylindrical processing chamber 22 or bowl that is mounted to the second module 14 via support mounts 23. The support mounts 23 are preferably attached to support beams or another suitable base structure in the second module 14 via bolts or fasteners.
The [0035] second module 14 further includes a door 64 to provide access into the processing chamber 22. The door 64 preferably forms a seal with a front end 24 of the processing chamber 22. A window 66 is preferably located in the door 64 for allowing visual inspection into the processing chamber 22.
The [0036] processing chamber 22 may be oriented horizontally but is preferably inclined upwardly at an angle of, for example, 5-30°, and preferably about 10°, so that the front end 24 of the processing chamber 22 is at a higher elevation than the back end 26 of the processing chamber 22. Examples of such a processing chamber 22 and chamber assembly 20 are described in U.S. Pat. No. 6,418,945, incorporated by reference.
A [0037] rotor 40, as illustrated in FIG. 4, is preferably rotatably supported within the processing chamber 22. A drive shaft 42 extends from the back of the rotor 40 into a motor 44 located at the back end 26 of the processing chamber 22. Power cables extending from the system controller in the first module 12 preferably provide electrical power and control to the motor 44 via connectors 46. The back end 26 of the processing chamber 22 is preferably sealed with a suitable seal assembly 27.
The [0038] rotor 40 preferably incorporates a dual-cassette design including a first or back cassette position 50, and a second or front cassette position 52. As a result, the rotor 40 can hold two carriers or cassettes, a first cassette 54, and a second cassette 56. Workpieces 55 are held within slots or wafer positions within each cassette 54, 56. Typically, the cassettes hold, for example, up to 25 wafers, although other cassette sizes may be used. The workpieces 55 are spaced apart from each other within the cassette, to allow processing fluids and/or gases to contact all surfaces of the workpieces 55.
The cassettes are generally standard components available from various manufacturers, although the size, shape, and features of different types of cassettes may vary. The [0039] rotor 40 may be adapted to hold a specific cassette (model number) from a specific manufacturer. Thus, the features and dimensions of the rotor 40 are adapted to the specific size, shape, and features of the cassettes selected for use in the processing system 10. Specific examples of rotors and cassettes that may be used in the processing chamber 22 are described in detail in U.S. Pat. No. 6,418,945.
For ease of design, manufacture, and use, the first cassette [0040] 54 is preferably of the same design as the second cassette 56, so that the first and second cassettes positions 50, 52 within the rotor 40 may be the same. Although the invention contemplates any rotor having positions for first and second cassettes, regardless of whether the cassettes are of the same design, using two of the same cassettes: (a) allows the first and second cassette positions 50, 52 to be the same; (b) allows the rotor to be generally symmetrical; and (c) makes the loading sequence of the cassettes 54, 56 irrelevant.
Depending upon the chemicals to be used in the [0041] processing system 10, the rotor 40 and the processing chamber 22, as well as other components exposed to the chemicals, may be made of stainless steel, or alternatively the rotor and processing chamber material may be Teflon® (i.e., fluorine containing resins), or another suitable material. In a preferred embodiment, harsh chemicals, such as acids and solvents (e.g., HF, HCl, H₂SO₄, and H₂O₂), are not used in the processing system 10, so that a stainless steel processing chamber 22 and rotor 40 may be used, and so that any negative impact on the environment is substantially minimized.
As illustrated in FIG. 4, spray manifolds [0042] 60 for delivering processing fluid and/or rinse water preferably extend substantially along the entire length of the processing chamber 22. The manifolds 60 have spray nozzles or other openings directed into the processing chamber 22 for spraying liquids or gases into the processing chamber 22. The spray system in the chamber 22 is preferably designed as described in U.S. patent application Ser. No. 10/199,998, filed Jul. 19, 2002, and incorporated herein by reference. A vent 62 is preferably included to exhaust gases or vapors from the processing chamber 22, as well as a drain 47 to remove liquids from the processing chamber 22.
The [0043] processing chamber 22 may further include various other components to enhance processing of the workpieces 55. For example, the processing chamber 22 may include: (a) an anti-static generator to reduce static electricity within the chamber 22; (b) one or more heaters to heat the workpieces 55 and/or the processing and or rinsing fluids; (c) an ozone destructor 45 to convert ozone into oxygen.
The [0044] third module 16 preferably serves as a process fluid storage compartment. The third module 16 preferably contains an ozone generator 70 in communication with or connecting with the processing chamber 22 for providing ozone gas into the processing chamber 22. The ozone generator 70 is preferably connected to a gas spray manifold 61 in the processing chamber 22 via one or more ozone delivery lines (not shown). In a preferred embodiment, the ozone generator 70 is a high capacity ozone generator that may generate up to 240 g/cubic meter of ozone, or approximately 90 g/hour of ozone. If needed, separate cooling water lines may be routed to the ozone generator.
A DI water supply is preferably in communication with the [0045] processing chamber 22 for supplying DI water into the processing chamber 22. The DI water may be supplied from a DI water reservoir located in the third module 16, or may be supplied from an external source via one or more fluid delivery lines or other suitable fluid delivery means. One or more heaters may be located in the third module 16, or in another suitable location, for heating the DI water before it enters the processing chamber 22.
The [0046] third module 16 may house additional processing fluid supplies, such as an ammonium hydroxide (NH₄OH) supply, and/or any other suitable processing fluid supplies. Any fluid supplies used in the processing system 10 preferably communicate with the processing chamber 22 via one or more fluid delivery lines. A purge gas and/or drying gas (e.g., N₂) and/or clean dry air (CDA) if used, are typically supplied provided to the system from the fab or facility.
The [0047] third module 16 may further include pumps, filters, and/or other components for effectively providing the processing fluids and/or gases into the processing chamber 22. Additionally, the third module 16 may include alarms, sensors, and other monitoring devices to detect processing fluid levels in the processing chamber and to alert an operator when a problem may exist within the processing chamber. One or more of these devices may alternatively be located in the first or second modules 12, 14.
Referring to FIGS. 7 and 8, a [0048] preferred ozone destructor 45 has an upper end 151 and a lower end 153. The exhaust line 52 from the process chamber 22 connects at an inlet 174 at or near the upper end 151 of the ozone destructor 45. As shown with the arrows E in FIG. 8, exhaust from the process chamber flows down within the ozone destructor 45, reverses direction, and then flows up through a catalyst 164 and then out of the ozone destructor 45 through an outlet to the system or enclosure exhaust line 63. The drain line is either valved or trapped to prevent ozone flow to the drain.
While FIG. 8 shows the [0049] ozone destructor 45 in a vertically upright position, with exhaust gas flowing vertically up through the catalyst 164, the ozone destructor 45 may also have a different position or orientation, so long as there is a vertical component to the flow direction through the catalyst.
Referring still to FIG. 8, by having the exhaust gas enter and exit at or adjacent to the top of the [0050] ozone destructor 45, and flow upwardly through the catalyst 164, the catalyst 164 is better isolated from the chamber exhaust line 52 and the process chambers. Consequently, potential for catalyst particles to move into the chamber exhaust line or process chambers is reduced, as catalyst particles would have to move against both gravity and exhaust flow to move into the chamber exhaust line 52. As exhaust also flows up through the catalyst, any condensation within the catalyst can run down, via gravity and drain out. This helps to prevent loss of catalytic action due to saturation of the catalyst. Ozone in exhaust flow moving through the catalyst 164 is converted into oxygen, which can then be vented out through the system exhaust 63.
Referring still to FIGS. 7 and 8, the following additional detailed description relates to a preferred ozone destructor design, without individually describing any single essential elements of the invention. The [0051] ozone destructor 45 has an outer container 152 which may be supported on or in an enclosure with a mounting bracket 155. A lid 166 is supported and attached to a flange 158 of the outer container 152. An o-ring or seal 156 seals the lid 166 to the outer container 152. Lid bolts or fasteners 170 secure the lid 166 to the outer container 152. An inner container or canister 160 contains the catalyst 164, typically a manganese dioxide-based catalyst suitable for decomposing ozone into oxygen. A perforated plate 162 at the lower end of the canister 160 holds the catalyst 164 (typically beads of solid material) within the canister 160. The perforated plate 162 has openings allowing exhaust gas to enter at the bottom, with the openings forming canister inlets 165. A canister collar 163 is attached at the top or upper end of the canister or inner container 160. Canister mounting bolts 168 attach the canister 160 via the canister collar 163 to the lid 166. A canister o-ring 172 seals the canister collar 163 against the lid 166. A lid bushing 176 extends through an opening in the lid and into the canister collar 163, connecting with the canister outlet 175, at the top or upper end of the canister 160. A pipe nipple 178 connects an aspirator 180 with the. canister outlet 175 through the lid bushing 176. A clean dry air supply line 182 connects to the inlet side of the aspirator 180. The outlet side of the aspirator 180 connects, directly or indirectly to the system exhaust line 63. The aspirator 180 may be replaced by an air amplifier. The inlet 174 provides an entry flow path into the ozone destructor 45, through the lid 166.
Referring to FIG. 8, the canister or [0052] inner container 160 containing the catalyst 164 is preferably suspended within the outer container 152. As shown in FIG. 7, the outer container 152 and inner container 160 are preferably cylindrical, although other cross section shapes may also be used. Referring to FIG. 8, an annular flow path extends from the inlet 174 down within the ozone destructor 45, between the outside walls of the inner container 160 and the inside walls of the outer container 152 to the canister inlets 165. Of course, other types of ozone destructors may also be used, including thermal, UV, and catalytic devices, or other equivalents which can convert, neutralize or destroy ozone.
In use, [0053] workpieces 55 are loaded into cassettes 54, 56 either manually or via a robot or other automated device. The door 64 on the second module 14 is opened, preferably manually by an operator, to provide access into the processing chamber 22. The first cassette 54 is lifted and placed into the rotor 40, as described in U.S. Pat. No. 6,418,945. The first cassette 54 is moved toward the back of the rotor 40 until it can be moved no farther. As the rotor 40 is preferably positioned at an inclined angle, as shown in FIGS. 2 and 3, the first cassette 54 moves down into and is seated into the first cassette position 50 within the rotor 40 with some assistance by gravity.
With the first cassette [0054] 54 installed within the rotor 40, the operator loads the second cassette 56 into the rotor 40, following the same procedure. The second cassette 56 is moved into the rotor 40 until it contacts the first cassette 50, such that it can be moved no farther toward the back of the rotor 40.
The operator then closes the [0055] door 64. A processing sequence can be preprogrammed into the system controller, or can be set up or selected by the operator using the control panel and display 18. In a typical application, as illustrated in the schematic diagram of FIG. 5, ozone gas is sprayed into the processing chamber 22 via manifolds 60 while the motor 44 spins the rotor 40. As the rotor 40 begins to rotate, the workpieces 55 are held within their respective cassettes 54, 56 by retainer bars or other retaining mechanisms, as described in U.S. Pat. No. 6,418,945.
Heated DI water (provided by a [0056] heater 43 in the system or separately supplied) is concurrently sprayed into the processing chamber 22 in order to form a heated liquid boundary layer, through which the ozone gas may diffuse, on the surface of each of the workpieces 55. The DI water is preferably heated to a temperature of 30 to 110° C., more preferably 40, 50, 60, 70, 80 or 90 to 100° C. The ozone diffuses through the heated boundary layer, which accelerates diffusion-reaction kinetics, to react at the surface of the workpiece, as described in U.S. Pat. No. 6,267,125, and U.S. Pat. No. 6,497,768, incorporated by reference.
In an alternative embodiment, as illustrated in FIG. 6, ammonium hydroxide (NH[0057] ₄OH) from a source or tank 49 may be mixed with (or injected via a pump 51) into heated DI water before the DI water enters the processing vessel 22, in order to enhance the cleaning process. The concentration of NH₄OH in the DI water is preferably very low, on the order of approximately 500-5000:1 or 1000-3000 or about 2000:1 parts DI water to NH₄OH. The addition of NH₄OH is particularly effective in photoresist removal applications, as it generally increases the removal rate of photoresist layers. NH₄OH mixed with heated DI water may also be supplied to the processing chamber as a separate step after first performing the steps of delivering ozone and DI water into the processing chamber 22. Use of ammonium hydroxide provides improved particle performance, cleaning efficiency of SiN particles, and removal of anti-reflective coatings.
After the cleaning and/or stripping steps are performed, the [0058] workpieces 55 are typically rinsed using DI water that is sprayed from the manifolds 60, and then dried with a drying gas, such as N₂gas. A purge gas, such as N₂gas, may be used between the rinsing and drying steps, or between other processing steps, to remove excess fluids from the processing chamber. Exhaust vapors and gases flow out of the chamber through the exhaust port 62 and into the ozone destructor 45. Ozone in the ozone destructor is converted in oxygen gas which flows out of the system enclosure via an exhaust gas duct 63, along with other exhaust gases or vapors. The various processing steps may be repeated one or more times to enhance the cleaning or stripping processes, as desired.
Referring to FIG. 8, the exhaust gas moves into the ozone destructor at or near the [0059] upper end 151 and moves downwardly, as shown by the arrows E. The exhaust flow E moves to the lower end 153 of the ozone destructor 45, reverses direction, and flows upwardly through the perforated plate 162 and into the canister 160. As the exhaust flows through the catalyst 164 within the canister 160, ozone within the exhaust gas E is converted into oxygen. The aspirator or air amplifier 180 helps to draw exhaust gas flow through the ozone destructor 45, thereby eliminating any back pressure on the process chamber. Oxygen converted by the catalyst 164, and any other exhaust gas components, move upwardly through the canister outlet 175, through the aspirator 180, and out via the system exhaust line 63.
If water vapor condenses within the [0060] catalyst 164, the liquid water drains out downwardly through the perforated plate 162 and collects at the lower end 153 of the outer container 152, where it can be removed by the liquid drain line 184. Consequently, saturation of the catalyst 164 with condensation is avoided. As the exhaust flow inlet into the ozone destructor 45 is at or near the upper end 151, the potential for catalyst particles getting into the chamber exhaust line 52 or the process chambers is greatly reduced. Similarly, the potential for condensed liquid to block the exhaust line 52 is reduced or eliminated. Preferably, the components of the ozone destructor 50 coming in contact with exhaust gas are made of stainless steel having a PFA coating to better resist corrosion by chemical vapors in the exhaust flow.
In general, when processing 200 mm workpieces, the [0061] processing system 10 has a throughput of approximately 200 workpieces/hour. When processing 300 mm workpieces, the processing system 10 has a throughput of approximately 100 workpieces/hour. The actual throughput will depend on the type of workpiece-processing application that is performed, the number of workpieces processed at one time, and the number of processing steps that are repeated.
The [0062] processing system 10 and methods described herein may be used in several different workpiece-processing applications, such as the following: (1) post-ash cleaning; (2) photoresist stripping; (3) organic material cleaning (4) photo reworking/reclaiming; (5) post-etch cleaning; and any other suitable processing applications.
The [0063] processing system 10 provides several advantages over existing processing systems. First, the system 10 is extremely compact so it does not take up significant space in a clean room environment. Due to the limited number of components and processing stations required, the processing system 10 is also relatively inexpensive. The processing system 10 uses relatively mild processing chemicals, such as ozone gas and DI water, so there is minimal, if any, negative impact on the environment. Additionally, larger batches of workpieces can be processed in a relatively short amount of time in the processing system 10.
While embodiments and applications of the present invention have been shown and described, it will be apparent to one skilled in the art that other modifications are possible without departing from the inventive concepts herein. The invention, therefore, is not to be restricted except by the following claims and their equivalents. [0064]

Claims

What is claimed is:

1. A system for processing a workpiece, comprising:

a first module including an ozone generator;

a second module attached to the first module, the second module including a processing chamber for processing a workpiece, wherein the ozone generator is connected to supply ozone gas to the processing chamber; and

a rotor rotatably supported within the processing chamber.

2. The system of claim 1 wherein the rotor is adapted to hold a first cassette and a second cassette, with each cassette holding a batch of workpieces.

3. The system of claim 1 wherein the ozone generator produces ozone gas at a rate of at least 90 grams/hour.

4. The system of claim 1 wherein the first, second, and third modules all have approximately the same width and length.

5. The system of claim 1 further comprising a source of NH4OH connecting into the processing chamber.

6. The system of claim 1 further comprising a manually operated door moveable from an open position, for loading and unloading workpieces into the rotor, to a closed position, for processing.

7. The system of claim 1 further comprising an ozone destructor connecting with the processing chamber for converting ozone in exhaust gases flowing out from the processing chamber into oxygen.

8. The system of claim 1 wherein the ozone destructor includes:

an inlet and an outlet adjacent to the upper end;

a chamber exhaust line connecting from the processing chamber to the inlet of the ozone destructor; and

a system exhaust line connecting to the outlet of the ozone destructor.

9. The system of claim 7 wherein the ozone destructor contains a catalyst.

10. The system of claim 1 further comprising at least one spray manifold in the processing chamber for spraying a process liquid onto the workpieces.

11. The system of claim 1 further comprising a DI water supply in the first module connecting into the processing chamber.

12. The system of claim 11 further comprising a heater in the first module for heating the DI water.

13. The system of claim 1 further comprising an anti-static generator in the processing chamber.

14. The system of claim 1 further comprising a purge gas generator in the first module, with the purge gas generator connecting into the processing chamber.

15. The system of claim 14 wherein the purge gas generator comprises an N₂gas generator.

16. The system of claim 1 further comprising a compressed dry air supply in the first module connecting into the processing chamber.

17. A standalone system for processing a workpiece, comprising:

a first module including a processing fluid supply;

a second module on top of and attached to the first module, the second module including a processing chamber for processing a workpiece, wherein the processing fluid supply is in communication with the processing chamber; and

a third module on top of and attached to the second module.

18. The system of claim 17 wherein the first module has a footprint of 6-12 square feet.

19. The system of claim 17 wherein the height of the system is more than double the width of the system.

20. The system of claim 17 with the third module including a system controller.

21. The system of claim 17 wherein the processing fluid supply comprises an ozone generator for supplying ozone gas into the processing chamber.

22. A method for processing a wafer comprising the steps of:

loading a first cassette of wafers into a rotor in a process chamber;

loading a second cassette of wafers into the rotor;

wetting the wafers with water heated to 30-95 degrees C.;

rotating the rotor;

introducing ozone gas into the process chamber, with ozone gas diffusing through a layer of the heated water on;

purging the ozone gas from the chamber; and

drying the wafers.

23. The method of claim 22 further comprising the step of rinsing the wafers.

24. A system for processing articles, comprising:

support means for supporting a batch of articles within a process chamber;

liquid supply means for supplying a heated liquid onto the articles;

ozone supply means for supplying ozone into the process chamber; and

rotation means for rotating the articles within the chamber.

25. The system of claim 24 further comprising a device for destroying ozone, including:

a container having an upper end and a lower end;

a container inlet in the container, adjacent to the upper end of the container;

a container outlet in the container, adjacent to the upper end of the container;

a canister within the container, with the canister having an upper end and a lower end;

a canister inlet adjacent to the lower end of the canister;

a canister outlet adjacent to the upper end of the canister, with the canister outlet leading into the container outlet; and

a catalyst within the canister, above the canister inlet and below the canister outlet.