JP5712902B2 - Substrate processing apparatus, substrate processing method, and storage medium - Google Patents

Description

  The present invention relates to a technique for processing a substrate in a metal processing container using a high-pressure fluid.

  In the manufacturing process of a semiconductor device that forms a laminated structure of an integrated circuit on the surface of a semiconductor wafer (hereinafter referred to as a wafer), which is a substrate, for example, fine dust or a natural oxide film on the wafer surface is removed by a cleaning solution such as a chemical solution. A liquid processing step is provided for processing the wafer surface using a liquid.

  For example, a single wafer spin cleaning apparatus that cleans a wafer uses a nozzle to remove dust and natural oxides on the wafer surface by rotating the wafer while supplying an alkaline or acidic chemical to the wafer surface. . In this case, after the chemical liquid is removed by, for example, rinsing cleaning using pure water or the like, the wafer surface is dried by, for example, shake-off drying in which the remaining liquid is spun off by rotating the wafer.

  However, as semiconductor devices are highly integrated, the problem of so-called pattern collapse is increasing in the process of removing such liquids. Pattern collapse is a phenomenon of surface tension that pulls the convex part left and right when the liquid remaining on the wafer surface is dried. This is a phenomenon in which the protrusion collapses in the direction in which the balance is lost and a lot of liquid remains.

  As a technique for removing the liquid remaining on the wafer surface while suppressing the occurrence of such pattern collapse, a drying method using a supercritical fluid (supercritical fluid) which is a kind of high-pressure fluid is known. The supercritical fluid has a smaller viscosity than the liquid and has a high ability to dissolve the liquid, and there is no interface between the supercritical fluid and the liquid or gas in an equilibrium state. Therefore, if the liquid adhered to the wafer is replaced with a supercritical fluid, and then the state of the supercritical fluid is changed to a gas, the liquid can be dried without being affected by the surface tension.

  The processing of the wafer using the supercritical fluid is performed by supplying a prepared supercritical fluid to a sealed processing container after the wafer is accommodated. At this time, since the inside of the processing container is in a high-pressure atmosphere, a metal container having pressure resistance is used for the processing container.

  On the other hand, since supercritical fluid has high activity, when processing is performed using a metal processing vessel, a metal material exposed to the atmosphere of the supercritical fluid may be eluted into the supercritical fluid.

  The elution of the metal into the supercritical fluid may cause contamination of the wafer to be processed, and it is necessary to reduce the metal concentration in the vicinity of the wafer as much as possible. In order to deal with such a problem, Patent Document 1 discloses that a supercritical fluid is brought into contact with the supercritical fluid in order to suppress metal elution from a processing vessel (cleaning / drying processing chamber) that performs cleaning and drying of the wafer using the supercritical fluid. A processing container having an oxide film formed on the surface is described. However, the applicant has stated that even a supercritical fluid such as IPA (IsoPropyl Alcohol) or carbon dioxide, which is less active than supercritical water, has a trace amount of metal material from a processing vessel in which an oxide film is formed on the inner wall surface. We know that it may not be possible to suppress the elution of.

  Further, Patent Document 2 discloses a processing container (processing chamber) that is in contact with a supercritical fluid in a metal processing container (processing chamber) in which a process for removing a resist remaining on the wafer surface after etching is performed using a supercritical fluid. A technique for coating the inner member with plastic or polymer is described. However, from the viewpoint of reducing the amount of supercritical fluid to be used, the volume of the processing vessel is preferably as small as possible, and the processing space is configured as a narrow space having a height of about several mm to several tens of mm. There is. In such a case, if the coating in the processing container is peeled off, re-coating becomes difficult or time is required, so that maintenance is poor.

JP-A-2006-130418: claim 1, lines 1 to 9 of paragraph 0051, FIG. JP 2008-515235 A: the first to third lines of paragraph 0005, the first to third lines of paragraph 0028, the first and second lines of paragraph 0043, the first and second lines of paragraph 0045, FIG.

  The present invention has been made in view of such circumstances, and an object thereof is to reduce the concentration of metal eluted from a metal processing container around a substrate to be processed with a simple configuration. Another object of the present invention is to provide a substrate processing apparatus, a substrate processing method, and a storage medium storing the method.

A substrate processing apparatus according to the present invention is a substrate processing apparatus that performs processing on a substrate using a high-pressure fluid.
A metal processing container in which a substrate loading / unloading port is provided and a substrate is processed, and
A fluid supply line connected to the processing vessel for supplying a high-pressure fluid or a raw material fluid that becomes a high-pressure fluid by performing at least one of heating and pressurization, and for discharging the high-pressure fluid in the processing vessel Fluid discharge line,
A substrate holding part disposed inside the processing container in a state where the substrate is held;
A resin cylindrical body provided between the substrate and the inner wall surface of the processing container so as to surround the periphery of the substrate including the plate surface in the substrate held by the substrate holding unit. ,
The substrate holding portion is provided in the lid member for sealing the processing vessel closes the transfer opening, the substrate is Ru is carried on the inside of the tubular body through an opening at one end of the tubular body It is characterized by that.

The above-described substrate processing apparatus may have the following features.
(A) the base end portion of the front Stories substrate holding member, the stopper member is fitted into the opening of the tubular body is provided, further plug is toward the front end side of the substrate holding portion toward the proximal end Have a tapered surface that gradually widens. The surface of this plug should be made of non-fluorine resin.
( B ) The resin forming the cylindrical body is a non-fluorine resin.
( C ) The cylindrical body is molded by seamless processing.
( D ) When an opening on one end side of the cylindrical body is a first opening, a second opening that opens toward the inner wall surface of the processing container is provided on the other end side of the cylindrical body. The end of the cylindrical body constituting the second opening is fitted in a groove formed on the inner wall surface of the processing container. At this time, the inner wall surface of the processing vessel surrounded by the groove is covered with a non-fluorinated resin.
( E ) The cylindrical body is wound around two rod-shaped holder members that are arranged in parallel to each other and extend in a lateral position of the substrate held by the substrate holding portion. A flat space capable of accommodating the substrate held on the substrate is formed.
( F ) The non-fluorine resin is selected from a resin group consisting of polyimide, polyethylene, polypropylene, paraxylene, and polyetheretherketone (PEEK).

( G ) If the space inside the cylindrical body is a first space, a second space is formed between the outer surface of the cylindrical body and the inner wall surface of the processing container, and the fluid supply line is The fluid discharge line is connected to a position for discharging the high-pressure fluid flowing out from the first space toward the second space. Being.
( H ) a fluid supply unit connected to the fluid supply line for supplying high pressure fluid or raw material fluid; a fluid discharge unit connected to the raw material discharge line for discharging high pressure fluid in the processing vessel; and substrate holding Carrying the substrate held in the inside of the cylindrical body, sealing the processing container, and supplying the high-pressure fluid or the raw material fluid from the fluid supply unit toward the first space And processing the substrate with a high-pressure fluid supplied from the fluid supply unit, or a high-pressure fluid obtained by heating or pressurizing a raw material fluid in the processing container, and from the second space, A step of forming a flow of the high-pressure fluid flowing from the first space toward the second space by discharging the high-pressure fluid in the processing container toward the fluid discharge portion. Further comprising a control unit for outputting.

  The present invention surrounds the periphery of a substrate including a plate surface using a resin cylindrical body, and performs processing of the substrate using a high-pressure fluid inside the cylindrical body, so that the inside of the metal processing container is Since the area where the substrate directly faces the wall surface is reduced, the metal eluted from the processing container into the high-pressure fluid is hardly supplied to the substrate, and contamination of the substrate can be suppressed.

1 is a perspective view showing an overall configuration of a wafer processing apparatus according to an embodiment of the present invention. It is a vertical side view of the wafer processing apparatus. It is a disassembled perspective view of the said wafer processing apparatus. It is a perspective view which shows the structure of the cover body and wafer holder which are provided in the said wafer processing apparatus. It is a partially broken perspective view of the cover sleeve provided in the processing container of the wafer processing apparatus. It is an external appearance perspective view which shows a mode that a wafer is carried in in the said cover sleeve. It is the vertical side view which showed typically the arrangement state of the cover sleeve and wafer in the processing container. It is the vertical side view which showed typically the state in the said processing container from another direction. It is the 1st explanatory view showing an operation of the wafer processing device. It is the 2nd explanatory view showing an operation of the wafer processing device. It is the 3rd explanatory view showing an operation of the wafer processing device. It is the 4th explanatory view showing an operation of the wafer processing device. It is a vertical side view of the processing container concerning another example. It is the vertical side view which looked at the processing container concerning the said other example from another direction.

  An example of an embodiment of the substrate processing apparatus of the present invention will be described with reference to FIGS. The substrate processing apparatus is configured as a wafer processing apparatus that performs a drying process on a wafer W using a supercritical fluid that is a high-pressure fluid. As shown in FIGS. 1 to 3, the processing container 1 and the processing container 1 A lid 3 having a substantially square bar shape that hermetically closes the loading / unloading port 2 of the wafer W formed on the side surface side. 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 flat, generally box-shaped pressure-resistant container made of a metal such as aluminum or stainless steel, for example, and a processing space 8 that is a space for storing wafers W horizontally and performing processing therein. Is formed. 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.

For example, when processing a wafer W having a diameter of 300 mm as a substrate, the processing space 8 has a height dimension so that the supercritical fluid supplied into the processing space 8 can quickly contact the wafer W. Is a flat space having a size of about several mm to several tens of mm and a volume of about 300 to 1500 cm ³ .

  As shown in FIG. 2, the processing space 8 extends in the front-rear direction of the flat processing container 1 and opens on the front side surface and the back side surface of the processing container. Among these, the opening on the near side constitutes the loading / unloading port 2 for the wafer W, and is formed so as to spread in the width direction of the processing container 1 (direction perpendicular to the loading / unloading direction). The held wafer holder 4 can be passed.

  On the other hand, the opening on the rear end side is closed by a rear cover 11 which is a metal plate material. The rear cover 11 is connected to an IPA supply line 231 that supplies a supercritical fluid (supercritical IPA in this example) into the processing space 8 and an IPA discharge line 291 that discharges the supercritical fluid from the processing space 8. Yes. 3 and 5, 112 is a supply hole for supplying supercritical IPA toward the processing space 8, and 111 is a discharge hole for discharging the supercritical IPA after processing. Since the opening positions of the discharge hole 111 and the supply hole 112 in the rear cover 11 are specified according to the configuration of the cover sleeve 6 described later, it will be described in accordance with the description of the cover sleeve 6. Reference numeral 110 shown in FIG. 2 and the like denotes an O-ring for keeping the inside of the processing container 1 airtight.

  The IPA supply line 231 is connected to an IPA supply unit 23 for supplying supercritical IPA into the processing container 1 (processing space 8). The IPA supply unit 23 includes a supply tank that heats and stores the IPA in a supercritical state, a flow rate adjustment unit that adjusts the supply amount of the supercritical fluid, and the like. In FIG. 2, V1 provided on the IPA supply line 231 is an on-off valve, and the IPA supply unit 23 and the on-off valve V1 constitute a fluid supply unit of the present embodiment.

  On the other hand, the IPA discharge line 291 is connected to an IPA recovery unit 29 for recovering the supercritical IPA discharged from the processing container 1 (processing space 8). The IPA recovery unit 29 includes a cooler that cools the supercritical IPA and gas IPA discharged from the processing container 1 to form liquid IPA, a recovery tank that stores the recovered liquid IPA, and the like. In FIG. 2, V2 interposed on the IPA discharge line 291 is an on-off valve, and the IPA recovery part 29 and the on-off valve V2 constitute a fluid discharge part of the present embodiment.

  Protruding pieces 24 and 24 formed to extend in the horizontal direction toward the front side are provided 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. It has been. Each of the projecting pieces 24, 24 is formed with a substantially rectangular opening 25, 25 in an area on the front side thereof, and when the loading / unloading port 2 of the processing container 1 is closed by the lid 3 (simply “processing”). The container 1 is also referred to as “closing the container 1 with the lid 3”), and the movement of the lid 3 can be restricted from the front side by inserting the lock plate 26 vertically into the openings 25, 25.

  The lock plate 26 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 that is slightly larger than that of the lock plate 26, and a gap 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 done. In FIG. 3, a part of the lock plate 26 is notched.

  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. 3, the description of the refrigerant path 43 of the lower plate 42 is omitted. 2 and 3, 44 is a heater for heating the processing space 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. 2, 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 accommodated inside the processing container 1 together with the wafer W, and the processing position where the loading / unloading port 2 of the processing container 1 is hermetically closed by the lid 3 and the outside (front side) of the processing container 1. In FIG. 2, the transfer arm moves 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 FIGS. 2 and 4, an O-ring 31 is provided on the surface of the lid 3 on which the wafer holder 4 is attached so as to surround the base end portion of the wafer holder 4. The O-ring 31 plays a role of maintaining airtightness in the processing container 1 when the processing container 1 is closed with the lid 3.

  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. On the other hand, on the lower side of the wafer holder 4 at the delivery position, a cooling mechanism 52 having a substantially disc-shaped cooling plate that blows clean air for cooling upward, for example, 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.

  The wafer processing apparatus having the above-described configuration is provided with the cover sleeve 6 that is a cylindrical body for protecting the wafer W from the elution of metal from the processing container 1 to the supercritical IPA, which has been described in the background art. (FIGS. 5 to 8). The cover sleeve 6 is a resin thin plate or film formed into a cylindrical shape by seamless (seamless) processing, and a space capable of accommodating the wafer W is formed inside thereof. 7 to 12 are exaggerated in the vertical direction in order to clarify the positional relationship between the wafer holder 4, the wafer W held on the processing space 8, and the cover sleeve 6 in the processing space 8. It is. In addition, in order to avoid that a figure becomes complicated, description of the cover sleeve 6 is abbreviate | omitted in FIG.

  The resin constituting the cover sleeve 6 is selected in consideration of corrosion resistance to the supercritical fluid, heat resistance to the temperature of the supercritical fluid atmosphere, mechanical strength, and the like. In addition, since it is not preferable that the semiconductor device be processed in an environment where fluorine atoms exist, a non-fluorine resin is selected. Specific examples of such non-fluorine resins include polyimide, polyethylene, polypropylene, paraxylene polyetheretherketone (PEEK), and the like. Further, the reason for adopting a seamless process is to avoid elution of the adhesive used in the seam into the supercritical fluid.

  In this example, the cover sleeve 6 is a polyimide film having a thickness of 5 to 500 μm, preferably about 70 to 200 μm, formed into a cylindrical shape by seamless processing, so that the wafer W can be accommodated therein. Furthermore, the length from the opening (first opening) on one end side of the cylinder to the opening (second opening) on the other end side is 300 mm or more.

  As shown in FIGS. 5 and 8, the cover sleeve 6 is wound inside the processing container 1 in a state of being wound around two holder members 61 extending from the side wall surface of the rear cover 11 toward the front side of the processing container 1 (processing It is arranged in the space 8). For example, the holder member 61 is a member having a C-shaped cross section formed by dividing an elongated rod-shaped polyimide circular tube into two in the axial direction. The two holder members 61 are arranged in parallel so that the surfaces corresponding to the C-shaped notches face inward so as to face each other and are aligned in the horizontal direction when viewed from the front side (loading outlet 2 side). ing.

  As shown in FIG. 8, the cover sleeve 6 wound around the holder member 61 forms a cylindrical space having a flat longitudinal section viewed from the front side, and has an opening (first opening) on one end side. ) Toward the loading / unloading port 2. As a result, as shown in FIG. 6, the wafer 3 held in the wafer holder 4 is carried into and out of the space inside the cover sleeve 6 by the forward and backward movement of the lid 3. Hereinafter, the space inside the cover sleeve 6 is referred to as a first space 601, and the space between the outer surface of the cover sleeve 6 and the inner wall surface of the processing container 1 is referred to as a second space 602.

  Further, as shown in FIG. 7, the opening (second opening) on the other end side of the cover sleeve 6 opens toward the inner wall surface of the rear cover 11, and the cover sleeve constituting the second opening is formed. 6 is fitted and fixed in a groove 113 formed on the inner wall surface of the rear cover 11. As shown in FIG. 5, the supply hole 112 for supplying the supercritical IPA is opened in a region surrounded by the groove 113, and the supercritical IPA is placed in the first space 601 containing the wafer W. It comes to be supplied.

  On the other hand, the discharge hole 111 through which the supercritical IPA in the processing space 8 is discharged is disposed in a region outside the discharge hole 111. At this time, as described above, the end of the cover sleeve 6 constituting the second opening is fitted into the groove 113, so that the supply hole 112 extends to the discharge hole 111 along the inner wall surface of the rear cover 11. The formation of a flowing bypass flow is impeded. As shown in FIGS. 3 and 5, two discharge holes 111 are provided in the outer region of the groove 113, and each discharge hole 111 is provided in the IPA discharge line 291. In FIG. 2, the discharge line 291 is generally shown as a single line for convenience.

  On the other hand, the opening (first opening) on one end side of the cover sleeve 6 facing the loading / unloading port 2 of the processing container 1 is an area through which the wafer holder 4 holding the wafer W passes. As shown in FIG. 7, a taper surface 401 that gradually spreads from the distal end side to the proximal end side of the wafer holder is formed at the proximal end portion of the wafer holder 4 supported by the lid 3.

  The polyimide film constituting the cover sleeve 6 has flexibility, and when the base end portion is inserted into the first opening, the end portion of the cover sleeve 6 is pushed and widened by the taper surface 401. The opening is closed. In this respect, the base end portion of the wafer holder 4 on which the tapered surface 401 is formed constitutes a plug that closes the first opening. However, the shape of the base end portion of the wafer holder 4 constituting the stopper is not limited to the case where the tapered surface 401 is provided, and other shapes may be selected as long as the first opening can be closed.

  When supercritical IPA is supplied from the discharge hole 111 to the first space 601, the first opening closed at the base end of the wafer holder 4 is further expanded by the internal pressure of the supercritical IPA. Thus, a flow path for allowing the supercritical IPA to flow out from the first space 601 to the second space 602 is formed.

  Furthermore, the wafer holder 4 accommodated in the first space 601 is formed by, for example, coating a metal main body with a non-fluorine resin such as polyimide, or a non-fluorine resin or quartz molding. The metal does not elute even when exposed to a supercritical IPA atmosphere.

Also, as shown in FIG. 7, the inner wall surface of the rear cover 11 exposed to the atmosphere in the first space 601 (the region surrounded by the groove 113 in FIG. 5) is also covered with a coating film 114 of non-fluorine resin such as polyimide. This prevents the elution of metal from the rear cover 11 to the first space 601.
Since the wafer holder 4 can be taken out from the processing container 1 and the rear cover 11 can also be removed from the processing container 1, the problem of maintainability when the coating is peeled is less than when the entire inner surface of the processing container 1 is coated. small.

  The wafer processing apparatus having the configuration described above is connected to the control unit 7 as shown in FIG. For example, the control unit 7 includes a computer having a CPU and a storage unit (not shown). The operation of the wafer processing apparatus, that is, the cleaned wafer W is loaded into the processing container 1 and supplied with a supercritical fluid. In addition, 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.

  Hereinafter, the operation of the wafer 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 a wafer processing apparatus by an external transfer arm (not shown).

  On the other hand, the wafer 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 space 8 is adjusted to 270 ° C. by a temperature controller (not shown). Then, the wafer W is accommodated in the processing container 1 (processing space 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 (FIG. 9). ).

  As a result, the lid 3 comes into contact with the processing container 1 via the O-ring 31, and 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. 9, the lock plate 26 is raised to restrict the movement of the lid 3 from the front side. .

  The wafer W loaded into the processing container 1 enters the inside of the cover sleeve 6 through the first opening that opens toward the loading / unloading port 2 and is accommodated in the first space 601 ( FIG. 7). At this time, the first opening is closed by the base end of the wafer holder 4.

  When the wafer W is accommodated in the first space 601 and the lid 3 is regulated by the lock plate 26, the IPA supply line 231 as shown in FIG. Open and close the open / close valve V1 (indicated by the symbol “O” in the figure) and set the supercritical IPA (critical temperature 235 ° C., critical pressure 4.8 MPa (absolute pressure) or higher, pressure state) Supply to the processing area (FIG. 8).

  When supercritical IPA is supplied from the supply hole 112 provided at a position facing the first space 601, the supercritical IPA spreads into the first space 601 and the pressure in the first space 601 increases. . As a result, the first opening closed at the base end of the wafer holder 4 is expanded, and the supercritical IPA in the first space 601 flows out toward the second space 602.

  When a predetermined amount of supercritical IPA is supplied to the processing space 8, the supercritical IPA pushes the first opening until the pressure in the second space 602 balances with the pressure in the first space 601. It spreads and flows out into the second space 602. When a predetermined amount of supercritical IPA is supplied, the opening / closing valve V1 of the IPA supply line 231 is closed (indicated by “S” in the figure), and the supply of supercritical IPA is stopped.

  Thus, when IPA in a supercritical state is supplied into the processing space 8 (the first space 601 and the second space 602) heated to a temperature atmosphere higher than the critical temperature (270 ° C. in this example) by the heater 44. Then, the IPA accumulated on the wafer W is united with the supercritical IPA, and the liquid IPA eventually becomes a supercritical state (FIG. 11). As a result, the surface of the wafer W is replaced with the supercritical IPA from the liquid IPA. However, since no interface is formed between the liquid IPA and the supercritical IPA in the equilibrium state, the pattern collapses. The fluid on the surface of the wafer W can be replaced with supercritical IPA.

  On the other hand, since the polyimide cover sleeve 6 is provided between the wafer W to be processed and the inner wall surface of the processing container 1, the metal eluted in the supercritical IPA of the second space 602 is the wafer W. It is difficult to reach the surface. The first opening on the front end side of the cover sleeve 6 is closed by the base end (plug) of the wafer holder 4, and the second opening on the rear end side is fitted in the groove 113 of the rear cover 11. Therefore, the concentration of the eluted metal in the vicinity of the surface of the wafer W can also be suppressed by making it difficult for the supercritical IPA to enter from these openings.

  At this time, the base end portion of the wafer holder 4 is fitted into the first opening of the cover sleeve 6, and the polyimide film constituting the cover sleeve 6 has flexibility, so that for some reason. Even if the pressure on the second space 602 side becomes higher than the pressure on the first space 601 side, the cover sleeve 6 is only pressed against the tapered surface 401 of the base end portion. Therefore, a channel through which the supercritical IPA in the second space 602 flows into the first space 601 is not formed, and the concentration of the eluted metal in the vicinity of the surface of the wafer W can be kept low.

  Thus, when a preset time has elapsed since the supply of the supercritical IPA to the processing space 8 and the surface of the wafer W has been replaced with the supercritical IPA, the opening / closing valve V2 of the IPA discharge line 291 is opened, The supercritical fluid is discharged from the processing space 8 toward the IPA recovery unit 29. At this time, since the discharge hole 111 is provided at a position facing the second space 602, the supercritical IPA in the second space 602 is discharged first, and the pressure in the second space 602 decreases.

  As a result, since the pressure in the first space 601 is relatively higher than the pressure in the second space 602, the supercritical IPA in the first space 601 pushes the first opening. Then, a flow path is formed and flows into the second space 602. In this way, a supercritical IPA flow from the first space 601 to the second space 602 through the first opening is formed in the processing container 1 as shown in FIG. 12, and both the spaces 601 and 602 are formed. The supercritical IPA will be discharged.

  At this time, since the flow from the first space 601 to the second space 602 is formed, the supercritical IPA including the eluted metal flows into the first space 601 on which the wafer W is placed. Without being discharged from the processing container 1. By forming such a flow, the metal concentration near the surface of the wafer W can be kept low.

  If the supercritical IPA is continuously discharged in this manner, the pressure in the processing container 1 gradually decreases and the supercritical fluid is discharged while changing to a gas. However, the processing container 1 is heated to 270 ° C. above the dew point of IPA. Therefore, IPA can be discharged while avoiding condensation on the surface of the wafer W. Further, when the IPA in the processing space 8 is discharged and the pressure in the processing space 8 becomes atmospheric pressure, a purge nitrogen gas is supplied from the supply hole 112 to the first space 601 to discharge the remaining IPA. May be.

  When the IPA in the processing space 8 is discharged, the lid 3 and the wafer holder 4 are moved to the delivery position and the wafer W is unloaded from the processing container 1. When the wafer holder 4 is moved to the delivery position, 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 wafer processing apparatus according to the present embodiment has the following effects. The periphery of the wafer W including the plate surface is surrounded by a cover sleeve 6 made of resin, for example, polyimide, which is a non-fluorine-based resin, and the wafer W is processed using supercritical IPA inside the cylindrical body. As a result, the area where the wafer W directly faces the inner wall surface of the metal processing container is reduced, so that the metal eluted from the processing container into the high-pressure fluid is hardly supplied to the wafer W, and contamination of the wafer W can be suppressed.

  In addition, the processing space 8 in the processing container 1 is partitioned into a first space 601 and a second space 602 by the cover sleeve 6, and the supercritical IPA supplied from the IPA supply line 231 stores the wafer W. , And then flows into the second space 602 surrounded by the wall surface of the processing vessel 1 and the cover sleeve 6 to form a flow in which supercritical IPA is discharged from the IPA discharge line 291. The concentration of the eluted metal in the vicinity can be greatly reduced.

  Here, in the above-described embodiment, as shown in FIGS. 5 and 8, the example in which the cover sleeve 6 is held by the holder member 61 is shown. However, the provision of the holder member 61 is not an essential requirement. For example, as shown in FIGS. 13 and 14, a cover sleeve 6 a having a size suitable for the inner wall surface shape of the processing container 1 is inserted into the processing space 8, and the cover sleeve 6 is brought into contact with the inner wall surface of the processing container 1. You may make it cover. The cover sleeve 6a used in this case is selected to have a rigidity sufficient to maintain a space for accommodating the wafer W while being supported by the inner wall surface of the processing container 1.

  In this example, unlike the case where a polyimide film is applied using an adhesive or the like, the cover sleeve 6a that has been seamlessly processed in this example is merely inserted into the processing space 8, so that the coating is peeled off or the adhesive is used. There is no risk of component elution. Further, at the time of replacement or the like, it is only necessary to pull out the cover sleeve 6a. However, it is not an essential requirement to provide the cover sleeves 6 and 6a that are processed without a seam. If there is no fear of elution of the adhesive, the cover sleeves 6 and 6a having seams may be used.

  Furthermore, among the various configurations described with reference to FIGS. 5 to 8, (1) the base end portion of the wafer holder 4 is configured as a plug that closes the first opening, and (2) the second The end of the cover sleeve 6 that constitutes the opening of the processing chamber 1 is embedded in the groove 113 of the inner wall surface (rear cover 11) of the processing container 1, and (3) the inner wall surface of the rear cover 11 exposed to the atmosphere in the first space 601. A coating film 114 made of non-fluorine resin, (4) coating the wafer holder 4 with a non-fluorine resin, or forming a molded body of this kind of resin, and (5) a cover sleeve 6. Disposing the supply hole 112 and the discharge hole 111 at a position where the flow of the supercritical IPA is formed from the first space 601 formed by dividing the processing space 8 to the second space 602, Necessarily required No. These configurations may be appropriately selected and combined according to the concentration of the eluted metal in the supercritical IPA allowed for the wafer W to be processed.

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 200 to 240 ° C. and 3 to 5 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).

  And the raw material supplied to the processing container 1 is not limited to what is previously a high-pressure state (a supercritical state or a subcritical state). For example, after the high-pressure fluid source fluid is supplied to the processing container 1 in a liquid or gaseous state, the source fluid may be heated and pressurized to be in a supercritical state in the processing container 1.

  In addition to this, the processing performed in the processing apparatus may be, for example, a resist film removal (dissolution) process from the surface of the wafer W in addition to the above-described drying process.

W Wafer 1 Processing container 111 Discharge hole 112 Supply hole 113 Groove 114 Coating film 23 IPA supply part 29 IPA recovery part 401 Tapered surface 6, 6a Cover sleeve 601 First space 602 Second space 61 Holder member 8 Processing space

Claims (14)

In a substrate processing apparatus for processing a substrate using a high pressure fluid,
A metal processing container in which a substrate loading / unloading port is provided and a substrate is processed, and
A fluid supply line connected to the processing vessel for supplying a high-pressure fluid or a raw material fluid that becomes a high-pressure fluid by performing at least one of heating and pressurization, and for discharging the high-pressure fluid in the processing vessel Fluid discharge line,
A substrate holding part disposed inside the processing container in a state where the substrate is held;
A resin cylindrical body provided between the substrate and the inner wall surface of the processing container so as to surround the periphery of the substrate including the plate surface in the substrate held by the substrate holding unit. ,
The substrate holding portion is provided in the lid member for sealing the processing vessel closes the transfer opening, the substrate is Ru is carried on the inside of the tubular body through an opening at one end of the tubular body A substrate processing apparatus. Wherein the proximal end portion of the substrate holding member, the substrate processing apparatus according to claim 1, characterized in that the plug body is fitted into the opening of the tubular body is provided. The resin substrate processing apparatus according to claim 1 or 2 characterized in that it is a non-fluorinated resin. The tubular body is a substrate processing apparatus according to any one of claims 1 to 3, characterized in that it is molded by a seamless process. The substrate processing apparatus according to claim 2 , wherein the stopper includes a tapered surface that gradually spreads from a distal end side to a proximal end side of the substrate holding portion. Surface of the plug body, the substrate processing apparatus according to claim 2 or 5, characterized in that it is made of a non-fluorinated resin. When the opening on one end of the cylindrical body is the first opening, a second opening that opens toward the inner wall surface of the processing container is formed on the other end of the cylindrical body. , the ends of the tubular body constituting the second opening, to one of the claims 1 to 6, characterized in that it is fitted into a groove formed on the inner wall surface of the processing container The substrate processing apparatus as described. The substrate processing apparatus according to claim 7 , wherein an inner wall surface of the processing vessel surrounded by the groove is covered with a non-fluorine resin. The cylindrical body is held in the substrate holding portion by being wound around two rod-shaped holder members that are arranged in parallel to each other and extend in the lateral position of the substrate held in the substrate holding portion. the substrate processing apparatus according to any one of claims 1 to 8, wherein the forming can accommodate flat space substrate. The non-fluorine-based resin, polyimide, polyethylene, polypropylene, paraxylene, a substrate processing apparatus according to claim 3, 6, 8, characterized in that it is selected from the resin group consisting of polyetheretherketone . Assuming that the space inside the cylindrical body is the first space, a second space is formed between the outer surface of the cylindrical body and the inner wall surface of the processing container, and the fluid supply line includes the first space. The high pressure fluid or the raw material fluid is connected to a position where the high pressure fluid is supplied to the space, and the fluid discharge line is connected to a position where the high pressure fluid flowing out from the first space toward the second space is discharged. the substrate processing apparatus according to any one of claims 1 to 10, wherein. A fluid supply unit connected to the fluid supply line for supplying high-pressure fluid or raw material fluid;
A fluid discharge unit connected to the raw material discharge line and from which the high-pressure fluid in the processing vessel is discharged;
A step of carrying the substrate held by the substrate holding unit into the cylindrical body and sealing the processing container, and supplying a high-pressure fluid or a raw material fluid from the fluid supply unit toward the first space A step of processing the substrate with a high-pressure fluid obtained by heating or pressurizing a high-pressure fluid supplied from the fluid supply unit or a raw material fluid in the processing container; and from the second space Forming a flow of the high-pressure fluid flowing from the first space toward the second space by discharging the high-pressure fluid in the processing container toward the fluid discharge portion. The substrate processing apparatus according to claim 11 , further comprising: a control unit that outputs. In a substrate processing method for processing a substrate using a high-pressure fluid,
In the substrate held by the substrate holder, the periphery of the substrate including the plate surface is surrounded by the resin cylindrical body provided inside the metal processing container in which the substrate is processed. A step of carrying the substrate held in the substrate holding part inside the cylindrical body and sealing the processing container;
Supplying a high-pressure fluid or a raw material fluid that becomes a high-pressure fluid by performing at least one of heating or pressurization to a first space that is an inner space of the cylindrical body;
Processing the substrate with a high-pressure fluid or a high-pressure fluid obtained by heating or pressurizing a raw material fluid in the processing vessel; and
By discharging the high-pressure fluid in the processing container from the second space that is a space between the outer surface of the cylindrical body and the inner wall surface of the processing container, the first space is directed to the second space. Forming a flow of a flowing high-pressure fluid. A substrate processing method comprising: A storage medium storing a computer program used in a substrate processing apparatus for processing a substrate using a high-pressure fluid,
14. A storage medium characterized in that the program includes steps for executing the substrate processing method according to claim 13 .

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