JP5609813B2 - Processing equipment - Google Patents

Description

  The present invention relates to a technique for airtightly closing a carry-in / out region of a substrate to be processed when processing the substrate to be processed in a processing container using a high-pressure fluid.

  In a series of processes for forming devices on a substrate to be processed such as a semiconductor wafer (hereinafter referred to as “wafer”), pattern collapse occurs by using a high-pressure fluid such as a supercritical fluid or a subcritical fluid. There is a known process for performing a drying process on a wafer to which a liquid is adhered while preventing it. A processing apparatus that performs this drying process includes, for example, a processing container that stores a wafer therein and performs processing, and a lid that hermetically closes a transfer port (loading / unloading area) into and out of the processing container. Configuration is adopted.

  Between these lids and the processing container, in order to prevent the supercritical fluid from flowing out to the outside, an O-ring (seal member) made of, for example, fluoro rubber or the like is provided so as to surround the periphery of the transfer port. Provided. When processing the wafer, the lid is pressed against the processing container so that the lid does not retract due to the pressure of the supercritical fluid, and the O-ring is crushed to keep the processing container airtight. A technique for preventing the supercritical fluid from flowing out is employed.

  Here, the O-ring provided so as to surround the transfer port of the processing container is disposed at a position in contact with the supercritical fluid to flow out through a slight gap between the processing container and the lid. . When the supercritical fluid comes into contact with the O-ring, depending on the material, the supercritical fluid may penetrate into the O-ring. On the other hand, when the wafer processing is completed, the supercritical fluid is discharged from the processing container, and the inside of the processing container is depressurized. At this time, if the supercritical fluid penetrates into the O-ring, the supercritical fluid expands in the O-ring as the pressure is reduced, which may cause cracks in the O-ring and cause a decrease in strength. is there.

  Supercritical fluids have a high substance extraction capability, so when they come into contact with the O-ring, low polymer components and impurities in the fluororubber are extracted and transported into the processing vessel, where they adhere to the wafer and become contaminated (contaminated). (Nation).

  Here, in Patent Document 1, when a heat-resistant silicone rubber is used as a sealing member for sealing a decompression chamber used in processes such as etching and film formation, a light element such as hydrogen or helium is used as the silicone rubber. It is described that it causes a problem in creating a high vacuum environment. Therefore, Patent Document 1 discloses that an O-ring-shaped silicone rubber is provided with a polyimide film having a thickness of several microns, or a U-shaped cross-section and a ring-shaped polyimide cover member has an O- A seal member having a configuration in which a ring-shaped silicone rubber is fitted is disclosed.

JP-A-11-241155: Paragraph 0006, Paragraphs 0022 to 0023, FIGS.

According to the sealing member described in Patent Document 1, the polyimide film covering the silicone rubber and the cover member can suppress transmission of light elements and suppress a decrease in the vacuum degree of the decompression chamber.
On the other hand, in the above-described processing apparatus, which is the subject of the present invention, the opening / closing operation of the lid occurs each time the substrate to be processed is processed, and the load and the opening of the sealing member are repeated. For this reason, even if the cover member is covered with a coating that does not allow high-pressure fluid to penetrate, a large force is applied to the coating, and the shape change of the sealing member may be repeated, whereby the coating may be cracked or peeled off. In addition, the cover member having a U-shaped cross section may be cracked by repeated deformation, and high-pressure fluid may enter a region where the seal member is fitted through the U-shaped opening. Each of the sealing members described in Patent Document 1 has a difficulty when applied to a processing apparatus using a high-pressure fluid.

  The present invention has been made under such a background, and protects the sealing member interposed between the lid and the processing container from the high-pressure fluid in the processing container, and is used in a clean state for a long period of time. It is an object of the present invention to provide a processing apparatus capable of doing so.

The processing apparatus according to the present invention is a processing apparatus that performs processing using a high-pressure fluid on a substrate to be processed that is carried into a processing container via a carry-in / out region.
A lid that abuts the processing container and hermetically closes the loading / unloading area;
A restricting mechanism for restricting the lid from retreating from the processing container side by the pressure in the processing container;
A seal member provided so as to be interposed between the lid and the processing container so as to surround the carry-in / out area when the lid closes the carry-in / out area;
In order to protect the sealing member from contact with the high-pressure fluid in the processing container, the protective sheet is provided so as to cover the sealing member and is made of a material having corrosion resistance to the high-pressure fluid, and
In order to reduce the displacement of the seal member due to the tensile stress generated in the protective sheet due to the pressure from the high-pressure fluid in the processing container, the protective sheet is attached to the lid or after being attached to the outer surface of the processing vessel, before the processing for the substrate to be processed is started, heating, operation conditioned exposed to pressurized atmosphere is characterized that you have done.

The above-described processing apparatus may have the following features.
(A) The thickness of the protective sheet is in the range of 1 μm or more and 1000 μm or less.
( B ) The protective sheet is made of a polyimide material, and the polyimide material is thermoplastic.
( C ) The protective sheet is made of a fluororesin material.
( D ) The protective sheet is made of a fluororesin material, covers the first protective sheet subjected to the habituation operation, and the first protective sheet from the opposite side of the surface in contact with the sealing member, and a polyimide material And a second protective sheet that is not subjected to the habituation operation.
( E ) The cover is separated from the processing container in order to prevent the protective sheet from being peeled off from the surface on which the seal member is provided in association with the operation of opening the carry-in / out region that is airtightly closed. In this case, a pressurized gas supply unit for supplying the pressurized gas to a surface opposite to the surface in contact with the sealing member of the protective sheet is provided.

  Since this invention covers the sealing member provided so that it may interpose between a processing container and its cover body using the protection sheet comprised with the material which has corrosion resistance, the position where the sealing member is arrange | positioned It is difficult for the high-pressure fluid to enter, and the effect of protecting the seal member from contact with the high-pressure fluid is high.

It is a perspective view which shows the whole structure of the processing apparatus concerning embodiment of this invention. It is a vertical side view of the said processing apparatus. It is a disassembled perspective view of the said processing apparatus. It is a perspective view which shows the structure of the cover body and wafer holder which are provided in the said processing apparatus. It is a vertical side view of the said cover body. It is explanatory drawing of habituation operation after attaching a protection sheet to the said cover body. It is 1st operation | movement explanatory drawing of the said processing apparatus. It is 2nd operation | movement explanatory drawing of the said processing apparatus. It is action | operation explanatory drawing of the protection sheet provided in the said cover body. It is operation | movement explanatory drawing at the time of separating a cover body from the processing container of the said processing apparatus. It is explanatory drawing which shows the other example of the attachment position of a protection sheet. It is explanatory drawing which shows the other structural example of a protection sheet. It is explanatory drawing which shows the other example of the attachment method of a protection sheet.

  The configuration of an example of an embodiment of the processing apparatus of the present invention will be described with reference to FIGS. This processing apparatus includes a processing container 1 for performing a drying process on a wafer W using a supercritical fluid that is a high-pressure fluid, and a wafer W transfer port (loading / unloading area) formed on the side surface of the processing container 1. And a lid 3 having a substantially square bar shape that hermetically seals 2. A wafer holder 4, which is a plate-like member for supporting the wafer W from below and carrying it in and out of the processing container 1, is provided on the side surface of the lid 3 that faces the processing container 1. In FIG. 3, drawing of the lid 3 and the wafer holder 4 is omitted, and the processing container 1 is shown with a part thereof cut away.

  The processing container 1 is a generally box-type pressure-resistant container, and a processing region 8 that is a space for storing wafers W horizontally and performing processing is formed therein. Hereinafter, in the loading / unloading direction of the wafer W with respect to the processing container 1 (X direction in FIG. 1), the processing container 1 side and the lid 3 side are referred to as the back side and the near side, respectively. The transfer port 2 described above is formed on the front side surface of the processing container 1 so as to communicate with the processing region 8 so as to extend in the width direction of the processing container 1 (a direction orthogonal to the loading / unloading direction). ing.

For example, when a wafer W having a diameter of 300 mm is processed as a substrate to be processed, the processing region 8 has a height dimension so that the supercritical fluid supplied into the processing region 8 immediately contacts the wafer W. It is about several mm to several tens of mm and the volume is about 300 to 1500 cm ³ .

  As shown in FIG. 2, a high-pressure fluid supply path 221 for supplying a supercritical fluid of, for example, IPA (isopropyl alcohol) into the processing region 8 is connected to the ceiling surface on the back side of the processing region 8. The high-pressure fluid supply path 221 is connected to a high-pressure fluid storage unit 231 in which IPA is stored via a valve V1 and a flow rate adjustment unit M. On the other hand, a high-pressure fluid discharge path 222 is connected to the floor surface of the processing region 8 facing the connection portion of the high-pressure fluid supply path 22, and the high-pressure fluid discharge path 222 is connected to the IPA recovery section 232 via the valve V 2. It is connected to the.

  On the upper side and the lower side of the region where the lid 3 abuts on the side surface on the front side of the processing container 1, projecting pieces 24 and 24 formed so as to extend horizontally toward the front side are formed. Has been. On the front side of the projecting piece portions 24, 24, substantially rectangular openings 25, 25 are formed. When the transport port 2 of the processing container 1 is closed with the lid 3 (hereinafter simply referred to as “processing container”). 1 is closed by the lid 3), and the lock plate 26 is vertically inserted into the openings 25 and 25 so that the movement of the lid 3 can be restricted from the front side. ing.

  The lock plate 6 serves as a regulating mechanism for regulating the lid 3 from moving to the near side due to the pressure in the processing container 2 (the lid 3 is retracted when viewed from the processing container 1 side). . The lock plate 26 is configured to be movable up and down by a drive unit 27 provided on the lower side of the processing container 1. The openings 25 and 25 have an opening size slightly larger than that of the lock plate 26, and a gap region 28 of, for example, about 0.5 mm is formed between the openings 25 and 25 and the lock plate 26 inserted into the opening 25. Is formed. In FIG. 3, a part of the lock plate 26 is notched. In addition, the restriction mechanism is not limited to being configured by the lock plate 26, and for example, a rod-like member that penetrates the lid 3 and the processing container 1 may be fixed by a lock pin or the like, and the structure of the restriction mechanism can be selected as appropriate. Furthermore, the regulation mechanism is not limited to the case where the movement of the lid 3 is regulated by pressing and locking another member such as the lock plate 26 to the lid 3. For example, when a force for pressing the lid 3 toward the processing container 2 is applied from a driving unit such as a hydraulic cylinder, thereby restricting the movement of the lid 3, the driving unit of the lid 3 functions as a regulating mechanism. Will be combined.

  An upper plate 41 and a lower plate 42 that insulate the processing container 1 are provided on the upper surface side and the lower surface side of the processing container 1, respectively, in order to suppress drying of the wafer W at a delivery position described later. Each of the plates 41 and 42 is formed in substantially the same planar shape as the processing container 1 and is provided with a refrigerant path 43 through which a refrigerant flows. In FIG. 1, the refrigerant path 43 is not shown, and only the refrigerant path 43 of the upper plate 41 is illustrated in FIG. 3. Furthermore, in the longitudinal side view of FIG. 2, FIG. 7, FIG. 8, etc., the description of the upper plate 41 and the lower plate 42 is omitted. In FIG. 3, 44 is a heater for heating the processing region 8 to, for example, 100 to 300 ° C., in this example, 270 ° C., and 441 is a power supply unit that supplies power to these heaters 44. The heaters 44 are provided on the upper and lower surfaces of the processing container 1.

  The lid 3 (specifically, an arm member 50 described later, which is connected to the lid 3 in detail) is fixed to the left and right sides of the front side of the upper plate 41 when the processing container 1 is closed with the lid 3. Lock members 45, 45 are provided respectively. These lock members 45, 45 are configured to be opened and closed (rotated) by a lock cylinder 46 between the locking position of the arm member 50 shown in FIG. 3 and the open position shown in FIG.

  Rails 47 and 47 for moving the wafer holder 4 forward and backward with respect to the processing container 1 are disposed on the left and right sides of the upper surface of the lower plate 42, and the arm member 50 is supported on each rail 47 and 47. In addition, sliders 48 and 48 configured to be movable back and forth along the rails 47 and 47 are provided. In FIG. 3, reference numeral 49 denotes a drive unit such as a rodless cylinder for moving the slider 48. Further, the front side region of the upper plate 41 and the lower plate 42 is formed with a cutout so as not to interfere with the lock plate 26 during the lifting operation.

  As shown in FIG. 1, arm members 50 extending in the horizontal direction toward the processing container 1 side (back side) are connected to the left and right ends of the rectangular bar-shaped lid body 3. The portion on the near side of each arm member 50, 50 forms a locked portion that is locked by the lock members 45, 45 described above. These arm members 50 and 50 are supported from the lower side by the sliders 48 and 48 described above, and by moving the sliders 48 and 48 back and forth along the rails 47 and 47, the lid 3 and the wafer holder 4 are moved. Can be moved.

  The wafer holder 4 is housed together with the wafer W in the processing container 1, and the processing position at which the transfer port 2 of the processing container 1 is closed hermetically by the lid 3, and the outside of the processing container 1 (front side). Side) is moved forward and backward from the transfer position where the wafer W is transferred to the wafer holder 4 by a transfer arm (not shown).

  As shown in FIG. 1, an IPA nozzle 51 for supplying IPA to the wafer W held by the wafer holder 4 is provided above the wafer holder 4 at the delivery position. Further, on the lower side of the wafer holder 4 at the delivery position, for example, a cooling mechanism 52 having a substantially disc-shaped cooling plate that blows clean air for cooling upward is used to cool the wafer holder 4. Is provided. Outside the cooling mechanism 52, a drain tray 53 is provided for receiving and discharging IPA that has flowed down from the surface of the wafer W.

  In the processing apparatus having the above-described configuration, the lid 3 has a seal for preventing the supercritical fluid from flowing out of the processing container 1 on the side surface on the back side facing the transfer port 2 of the processing container 1. A member 12 is provided. Further, the seal member 12 is protected by a protective sheet 13 so as not to come into contact with the supercritical fluid in the processing container 1. As shown in FIGS. 4 and 5, the seal member 12 is an O-ring made of an elastic material such as fluoro rubber, and the cross section has a reverse wedge shape so as to surround the connection portion between the lid 3 and the wafer holder 4. It is stored in the formed groove 121.

  As shown in the cross-sectional view of FIG. 5, a part of the surface of the seal member 12 that faces the processing container 1 protrudes from the groove portion 121, and the sealing member 12 is crushed by pressing the protruding portion, whereby the processing container 1. It closely adheres to the side surface of the plate and plays a role of preventing the outflow of the high-pressure fluid (see FIG. 9).

  Thus, the sealing member 12 surrounding the transport port 2 is disposed at a position where the seal member 12 can come into contact with the supercritical fluid flowing out from the transport port 2. When the sealing member 12 made of fluoro rubber or the like comes into contact with the supercritical fluid, as explained in the background art, the penetration of the supercritical fluid into the sealing member 12, the generation of cracks due to repeated expansion during decompression, the supercriticality Contamination is caused by the extraction of low polymerization components and impurities in the fluid.

  Therefore, in order to protect the sealing member 12 from contact with the supercritical fluid, the processing apparatus according to the present embodiment is in a state where the sealing member 12 is covered with the protective sheet 13 as shown in FIGS. Yes. The protective sheet 13 is made of, for example, polyimide (for example, Kapton (registered trademark), midfil (registered trademark)) or fluororesin (for example, PTFE: polytetrafluoroethylene, PFA: perfluoroalkoxy fluororesin, PCTFE, polychlorotrifluoroethylene trifluoride). A material having resistance to a supercritical fluid, such as an ethylene-based resin.

  The protective sheet 13 is attached so as to cover the entire abutting portion where the processing container 1 and the lid 3 come into contact with each other when the transfer port 2 of the processing container 1 is closed, and from the contact with the supercritical fluid. The seal member 12 is protected. Further, the seal member 12 is in close contact with the side surface of the processing container 1 via the protective sheet 13 so that the function of preventing the supercritical fluid from flowing out is not lost.

  In this way, by covering the entire side surface of the lid 3 in contact with the processing container 1 with the protective sheet 13, only a part of the seal member 12 is covered with a cover member or the like (see Patent Document 1 of the background art). Thus, the seal member 12 can be reliably protected from contact with the supercritical fluid. 4 and 5, reference numeral 14 denotes screws for fixing the protective sheet 13 to the lid 3. These screws 14 contact the lid 3 with the processing container 1 as shown in FIG. 9, for example. It is arranged at a position that does not get in the way of keeping the airtightness in the processing container 1 when it is made to move.

  The thickness of the protective sheet 13 is preferably in the range of 1 to 1000 μm. If the thickness is less than 1 μm, sufficient mechanical strength cannot be secured, and the protective sheet 13 may be broken during the opening / closing operation of the lid 3. There is a risk. On the other hand, if the thickness of the protective sheet 13 exceeds 1000 μm, the elastic force of the sealing member 3 cannot be sufficiently transmitted to the processing container 1 side. As a result, the processing container 1 must be pressed down with a stronger force. The inner airtightness cannot be maintained, and the drive mechanism (rodless cylinder 49) of the lid 3 is increased in size.

  Thus, the protective sheet 13 that covers the sealing member 12 is a member that directly contacts the processing container 1 when the lid 3 is brought into contact therewith and is pressed strongly toward the processing container 1 side. For this reason, an adhesion force may be generated between the protective sheet 13 and the constituent members of the processing container 1 for some reason while the processing container 1 is sealed. When an adhesion force is generated between the processing container 1 and the protective sheet 13, the protective sheet 13 is peeled off from a position covering the sealing member 12 when the lid 3 is moved after releasing the sealing, In some cases, the processing container 1 may not be kept sufficiently airtight.

  Therefore, the processing apparatus of this example is provided with a pressurized gas supply path 223 so as to branch from the above-described high-pressure fluid supply path 221 as shown in FIG. The pressurized gas supply path 221 is connected to the pressurized gas supply unit 233 via the valve V3. The pressurized gas supply unit 233 supplies a gas having a pressure higher than atmospheric pressure (for example, an inert gas such as nitrogen gas or clean air) into the processing container 1 when the lid 3 is separated from the processing container 1. By this, it plays the role which assists isolation | separation with the protection sheet 13 and the processing container 1 which are closely_contact | adhered.

  The processing apparatus having the configuration described above is connected to the control unit 60. For example, the control unit 60 includes a computer having a CPU and a storage unit (not shown), and the processing unit, that is, a wafer W that has been cleaned, is loaded into the processing container 1 and supplied with a supercritical fluid. A program in which a group of steps (commands) for control from the process of removing the liquid adhering to the wafer W to the unloading of the wafer W is recorded. This program is stored in a storage medium such as a hard disk, a compact disk, a magnetic optical disk, or a memory card, and installed in the computer therefrom.

  Before explaining the operation of the processing apparatus of this example, the acclimation operation to be performed before the wafer W is processed after the protective sheet 13 is attached to the lid 3 will be described. As shown in FIG. 9, during the processing of the wafer W, the pressure of the supercritical fluid is applied to the protective sheet from the processing container 1 (processing region 8) side. At this time, when a material having low flexibility such as polyimide is used as the material of the protective sheet 13, the pressure applied to the protective sheet 13 causes the sealing member 12 to move inside the processing container 1 (on the conveyance port 2 side). It is converted into tensile stress that is going to be pulled into. As a result, when the displacement of the seal member 12 occurs, it causes the leakage of the supercritical fluid from the processing container 1.

  Therefore, in the processing apparatus of this example, after the protective sheet 13 is attached to the lid 3 as shown in FIG. 4 (P1 in FIG. 6), before the processing of the wafer W is started, the processing container 1 is held by the lid 3. For example, by supplying a supercritical fluid into the processing region 8 in the closed state, temperature and pressure are applied to the protective sheet 13 to perform a habituation operation to adjust to the processing atmosphere (P2 in FIG. 6). The temperature and pressure applied to the protective sheet 13 vary depending on the material of the protective sheet 13 and the design temperature and design pressure of the processing container 1, but are preferably performed at a temperature of 100 ° C. or higher and a pressure of 1 MPa or higher, for example.

  By performing a habituation operation under conditions of high temperature and high pressure, the protective sheet 13 is stretched, and the tensile stress applied to the seal member 12 during processing of the wafer W is reduced by being in close contact with the lid 3 and the seal member 12. It is thought that it is. As a material that causes elongation when heated or pressurized as described above, a thermoplastic material is preferable. For example, many fluororesins have thermoplasticity, but some polyimides have no (small) thermoplasticity. Therefore, when polyimide is used, it is preferable to use thermoplastics. Further, in the case where the protective sheet 13 is made of a polymer material, it is preferable that the acclimation operation is performed under a temperature condition lower than the glass transition temperature of the polymer material so as not to lose the flexibility of the polymer material. .

The time for the habituation operation (time for heating and pressurizing) may be determined by a preliminary experiment or the like for a sufficient operation time during which no leakage of the supercritical fluid occurs during the processing. The necessity of the habituation operation also depends on the processing conditions of the wafer W. If the tensile stress applied to the seal member 12 during the processing of the wafer W is not large enough to cause a leak, the habituation operation is not necessarily performed. Also good.
When the acclimatization operation is performed and the protective sheet 13 is sufficiently accustomed to the lid 3 and the seal member 12, the processing of the wafer W is started (P3 in FIG. 6).

  Hereinafter, the operation of the processing apparatus will be described. First, on the surface of the wafer W to be processed, a pattern composed of a concave portion and a convex portion constituting the semiconductor device is formed. In the preceding cleaning process, for example, an SC1 solution (ammonia and peroxide) that is an alkaline chemical solution. Removal of particles and organic contaminants using a mixture of hydrogen water), removal of natural oxide film using dilute hydrofluoric acid (DHF), which is an acidic chemical, and DIW (DeIonized Water) Rinse cleaning was performed. Finally, IPA for preventing drying is supplied to the surface of the wafer W, and the wafer W in a state where the IPA is accumulated is transferred to the processing apparatus by an external transfer arm (not shown).

  On the other hand, the processing apparatus stands by with the wafer holder 4 moved to the delivery position, and the transfer arm places the wafer W on the wafer holder 4. Next, after the transfer arm is retracted from the upper side of the wafer holder 4, IPA is supplied from the IPA nozzle 51 to the surface of the wafer W, and IPA liquid is filled again.

  At this time, electric power is supplied from the power supply unit 441 to the heater 44 of the processing container 1, and the temperature in the processing region 8 is adjusted to, for example, 270 ° C. by a temperature controller (not shown). Then, the wafer W is accommodated in the processing container 1 (processing region 8) by sliding the arm member 50 on the rail 47 and moving the wafer holder 4 and the lid 3 toward the processing container 1 side.

  As a result, the lid 3 comes into contact with the processing container 1 via the seal member 12 and the protective sheet 13, and the transport port 2 of the processing container 1 is airtightly closed by the lid 3. Subsequently, the lock member 45 is rotated to lock the front side portion of the arm member 50, and as shown in FIG. 7, the lock plate 26 is raised to restrict the movement of the lid 3 from the front side. .

  When the wafer W is loaded into the processing region 8 and the lid 3 is regulated by the lock plate 26, the valve V1 of the high-pressure fluid supply path 221 is opened before the IPA accumulated in the wafer W is dried, for example, IPA in a critical state (critical temperature: 235 ° C., temperature of critical pressure: 4.8 MPa (absolute pressure) or higher, pressure state) is supplied to the processing region (FIG. 8).

  When IPA in a supercritical state is supplied into the processing region 8 heated to a temperature atmosphere higher than the critical temperature (270 ° C. in this example) by the heater 44, the IPA accumulated on the wafer W is suddenly integrated with the supercritical IPA. Eventually, the liquid IPA also enters a supercritical state. As a result, the surface of the wafer W is replaced with the supercritical fluid from the liquid IPA. However, since an interface is not formed between the liquid IPA and the supercritical fluid in the equilibrium state, the pattern collapses. The fluid on the surface of the wafer W can be replaced with a supercritical fluid.

  When the processing region 8 is filled with the supercritical fluid in this way, the pressure of the supercritical fluid is also applied to the side of the lid 3 exposed toward the processing region 8 through the transport port 2 as shown in FIG. At this time, the supercritical fluid enters the gap between the lid 3 and the processing container 1, but the seal member 12 is covered with the protective sheet 13 and protected from the supercritical fluid. Neither permeation of the critical fluid into the seal member 12 nor extraction of low polymerization components, impurities, etc. from the seal member 12 occurs. Further, since the protective sheet 13 has corrosion resistance to the supercritical fluid, the above-described penetration and extraction phenomenon which causes a problem even when contacting with the fluid does not occur.

  Further, at this time, pressure is applied to the protective sheet 13 around the transport port 2, and a tensile stress is applied to pull the seal member 12 inward as indicated by the arrow attached to the seal member 12 shown in FIG. 9. Even in such a case, since the acclimation operation is performed in advance so as to reduce the tensile stress, it is possible to suppress the deviation amount of the seal member 12 to the extent that the leakage of the supercritical fluid does not occur. it can.

  Further, when the sealing member 12 made of, for example, an O-ring is covered with a polyimide coating, when the sealing member 12 is brought into close contact with the processing container 1, the coating is subjected to stress associated with the deformation of the sealing member 12 being crushed. Join repeatedly. As a result, cracks or the like are likely to occur in the coating, and the protective effect of the sealing member 12 is not high. In contrast, when the protective sheet 13 is used, the amount of deformation that occurs when the sealing member 12 is brought into close contact with the processing container 1 is smaller than in the case of the above-described coating. For this reason, even if the lid 3 is repeatedly opened and closed, the seal member 12 can be used for a longer period of time.

  Further, as shown in FIG. 9, when the protective sheet 13 is attached to the lid 3 with the screw 14, the supercritical fluid enters between the lower surface of the protective sheet 13 and the lid 3, and the sealing member There is also a concern of reaching 12. However, it is confirmed that the intrusion of the supercritical fluid from the lower surface side of the protective sheet 13 can be suppressed by performing a habituation operation before starting the processing and sufficiently attaching the protective sheet 13 to the lid 3. doing. Further, as shown in FIG. 13 to be described later, instead of using the screw 14, the end of the protective sheet 13 is fixed so as to be embedded in the inside of the lid 3, and the entry of the supercritical fluid from the lower surface side is suppressed. May be.

  In this way, when a predetermined time has elapsed since the supercritical fluid was supplied to the processing region 8 and the surface of the wafer W has been replaced with the supercritical fluid, the valve V1 of the high-pressure fluid supply path 221 is closed. Then, the valve V2 of the high-pressure fluid discharge passage 222 is opened to discharge the supercritical fluid from the processing region 8. As a result, the pressure in the processing container 1 gradually decreases, and the supercritical fluid is discharged while changing into a gas. However, since the processing container 1 is heated to 270 ° C. above the dew point of IPA, IPA can be discharged while avoiding dew condensation.

  At this time, since the supercritical fluid does not permeate the seal member 12, there is no generation of cracks due to expansion of the supercritical fluid inside the seal member 12 even if the inside of the processing container 1 is depressurized.

  When the IPA in the processing area 8 is discharged, the operation of moving the lid 3 and the wafer holder 4 to the delivery position and unloading the wafer W from the processing container 1 is started. At this time, as described above, when an adhesion force is generated between the protective sheet 13 attached to the lid 3 and the side wall surface of the processing container 1, the lid 3 is protected when it is moved as described above. This causes the sheet 13 to float from the lid 3 or torn.

  Therefore, in the processing apparatus of this example, after discharging IPA, the valve V2 of the high-pressure fluid discharge path 222 is closed, and then the valve V3 of the pressurized gas supply path 223 is opened to pressurize from the pressurized gas supply unit 233. Gas is supplied and the inside of the processing container is pressurized. Thereafter, the lock plate 26 is moved downward to release the regulation of the lid 3, and the lid 3 and the wafer holder 4 are moved to the wafer W delivery position.

At this time, as shown in FIG. 10, the force of separating the protective sheet 13 from the processing container 1 acts as the pressurized gas in the processing container 1 flows out between the protective sheet 13 and the processing container 1. To do. As a result, even if an adhesion force is generated between the protective sheet 13 and the processing container 1, the sealing member 12 and the lid 3 are covered with the protective sheet 13 by separating the two using the force of the pressurized gas. The lid 3 can be moved while maintaining the state. On the other hand, when the wafer W is unloaded, the supply of the pressurized gas from the pressurized gas supply unit 233 is stopped.
When the wafer holder 4 is moved to the delivery position in this way, the liquid IPA is removed, the dried wafer W is delivered to the external transfer arm, a series of operations are completed, and the next wafer W is waited for being carried in. .

  The processing apparatus according to this embodiment has the following effects. Since the protective sheet 13 made of a material having corrosion resistance is used to cover the sealing member 12 provided so as to be interposed between the processing container 1 and the lid 3, the sealing member 12 is disposed. It becomes difficult for the supercritical fluid to enter the position. As a result, the seal member 12 is protected from the supercritical fluid, the occurrence of cracks can be prevented, and contamination of the wafer W due to the extraction of low polymerization components and impurities can be suppressed.

  Here, the sealing member 12 and the protective sheet 13 are not limited to being provided on the lid 3. For example, as shown in FIG. 11, a seal member 12 and a protective sheet 13 may be provided around the transport port 2 on the processing container 1 side.

  Further, the number of protective sheets 13 that protect the sealing member 12 is not limited to one, and two or more protective sheets may be provided. In FIG. 12, a fluororesin first protective sheet 13a is attached so as to cover the seal member 12, and the surface of the first protective sheet 13a opposite to the surface in contact with the seal member 12 is further made of polyimide. This is an example in which two protective sheets 13a and 13b are overlapped by being covered with the second protective sheet 13b.

  When attaching these protective sheets 13a and 13b, the second protective sheet 13b is attached after performing the habituation operation on the first protective sheet 13a, and the habituation operation is not performed on the second protective sheet 13b. It may be. In the case where the habituation operation is not performed, the protection effect of the sealing member 12 is enhanced because it is not thermoplastic but can employ a polyimide that is stronger and hard to break. On the other hand, since the supercritical fluid pressurizes these protective sheets 13a and 13b and pulls in the sealing member 12 is absorbed by the first protective sheet 13a having higher flexibility, The amount of displacement does not increase and the effect of preventing the supercritical fluid from flowing out is not lost.

  Further, in the examples shown in FIGS. 4 and 9, the protective sheet 13 is fixed to the lid 3 with screws 14, so that the screws 14 avoid the contact portion between the lid 3 and the processing container 1. Is arranged. As a result, the entire contact portion is covered with the protective sheet 13, but it is not always necessary to cover the entire contact portion with the protective sheet 13. For example, when the protective sheet 13 can be fixed without interfering with the processing container 1 by embedding the end of the protective sheet 13 in the members of the lids 3a and 3b as shown in FIG. The region exposed to the transport port 2 and the entire seal member 12 are covered with the protective sheet 13, whereby the seal member 12 can be protected from the supercritical fluid.

As the high-pressure fluid, instead of the supercritical IPA, for example, a supercritical fluid such as HFE (Hydro Fluoro Ether) or carbon dioxide (CO ₂ ) may be used, or a subcritical fluid of these substances may be used. It may be used. For example, in the case of IPA, the subcritical state is a state in which the temperature and pressure are in the range of about 100 to 300 ° C. and about 1 to 3 MPa, respectively. As described above, the present invention can be widely applied when processing is performed on the wafer W using a high-pressure fluid (supercritical fluid or subcritical fluid).
In addition to the above-described drying process, the process performed in the processing apparatus may be, for example, a resist film removal (dissolution) process from the surface of the wafer W.

W Wafer 1 Processing container 12 Seal member 13 Protective sheet 2 Transport port 26 Lock plate 3 Lid 60 Control unit 8 Processing area

Claims (7)

In a processing apparatus that performs processing using a high-pressure fluid on a substrate to be processed that is carried into a processing container via a carry-in / out region,
A lid that abuts the processing container and hermetically closes the loading / unloading area;
A restricting mechanism for restricting the lid from retreating from the processing container side by the pressure in the processing container;
A seal member provided so as to be interposed between the lid and the processing container so as to surround the carry-in / out area when the lid closes the carry-in / out area;
In order to protect the sealing member from contact with the high-pressure fluid in the processing container, the protective sheet is provided so as to cover the sealing member and is made of a material having corrosion resistance to the high-pressure fluid, and
In order to reduce the displacement of the seal member due to the tensile stress generated in the protective sheet due to the pressure from the high-pressure fluid in the processing container, the protective sheet is attached to the lid or after being attached to the outer surface of the processing vessel, before the processing for the substrate to be processed is started, heat, process characterized that you have been made conditioned operation exposed to pressurized atmosphere device.   The processing apparatus according to claim 1, wherein a thickness of the protective sheet is in a range of 1 μm to 1000 μm. The protective sheet processing apparatus according to claim 1 or 2, characterized in that it consists of a polyimide material. The processing apparatus according to claim 3 , wherein the polyimide material is thermoplastic. The protective sheet processing apparatus according to claim 1 or 2, characterized in that a fluorine resin material. The protective sheet is made of a fluororesin material, covers the first protective sheet subjected to the habituation operation, and the first protective sheet from the opposite side of the surface in contact with the seal member, and is made of a polyimide material. The processing apparatus according to claim 1 , further comprising: a second protective sheet that is not subjected to the habituation operation. When the lid is separated from the processing container in order to prevent the protective sheet from being peeled off from the surface on which the seal member is provided in association with the operation of opening the carry-in / out region that is airtightly closed. the processing according to any one of claims 1 to 6, characterized in that it comprises a pressurized gas supply unit for supplying a pressurized gas to the surface opposite to the surface contacting with the sealing member of the protective sheet apparatus.

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