JP7347802B2 - wafer processing equipment - Google Patents

Description

The present invention relates to a wafer processing apparatus that performs predetermined processing on wafers using supercritical fluid.

In recent years, patterns formed on the surface of wafers have become increasingly finer, and their aspect ratios have become higher. Therefore, if the pattern is dried while a processing liquid such as an organic solvent used for cleaning the pattern remains on the surface, a problem arises in that the pattern collapses due to the surface tension of the processing liquid. In order to solve this problem, a supercritical fluid may be used for drying processing or the like to remove the processing liquid from the surface of the substrate.

If a processing liquid such as an organic solvent is removed from the pattern surface of a wafer before a drying process using a supercritical fluid or the like is performed, the problem arises that the pattern collapses due to the surface tension of the processing liquid as described above. Therefore, there is a desire to allow a processing liquid such as an organic solvent to remain on the patterned surface of the wafer until a drying process using a supercritical fluid or the like is performed.

For example, if a fluid such as carbon dioxide is injected at high speed onto the pattern surface of the wafer during the pressure raising stage until the pressure reaches a critical pressure, the processing liquid may be blown away by the injection and the pattern may collapse. Therefore, by providing a cutoff plate between the supercritical fluid injection port and the wafer to block the supercritical fluid flowing in from the injection port, it is possible to prevent the supercritical fluid from being directly injected onto the wafer during the pressure increase stage. (For example, see Patent Documents 1 and 2). In addition, in the apparatus described in Patent Document 2, after the pressure in the chamber reaches a critical pressure, supercritical fluid is directly supplied to the wafer, thereby eliminating organic solvents remaining on the wafer. can be effectively removed.

Japanese Patent Application Publication No. 2018-207103 Japanese Patent Application Publication No. 2013-120944

However, in the device described in Patent Document 2, it is necessary to separately provide an injection port for supplying supercritical fluid during pressure increase and an injection port for supplying supercritical fluid after pressure increase, which makes the device complicated. There was a problem.

The present invention has been made to solve the above-mentioned problems, and when a wafer is subjected to a predetermined process using a supercritical fluid, the present invention has a simpler structure, and at the time of starting pressurization, the pattern of the fluid on the wafer can be adjusted. It is an object of the present invention to provide a wafer processing apparatus that can reduce the flow of fluid toward the patterned surface of the wafer, and increase the flow of fluid toward the patterned surface of the wafer after increasing the pressure.

In order to achieve the above object, a wafer processing apparatus according to the present invention includes an upper unit and a lower unit that faces the upper unit and constitutes a housing space for accommodating the wafer. A chamber for processing, an opening/closing means for opening and closing the chamber by vertically moving at least one of the upper and lower units, a support means for supporting the wafer in the accommodation space, and a state in which the chamber is closed, The housing includes a regulating means that restricts vertical movement of at least one of the upper and lower units so that the distance between them does not exceed a predetermined distance in the vertical direction, and a guard provided in the housing space. An inlet for injecting fluid into the space and an outlet for discharging fluid from the accommodation space are provided in at least one of the upper and lower units, respectively, and the guard part is arranged so that the chamber is closed by an opening/closing means. When the volume of the storage space is minimized, the position is such that the flow of fluid injected from the injection port toward the pattern surface of the wafer is reduced, and as the pressure increases due to the injection of fluid into the storage space, When the volume of the storage space is maximized by separating the upper and lower units within the range of regulation by the regulation means, this is a position where the flow of the fluid injected from the injection port to the pattern surface of the wafer is increased. , is a thing.

With this configuration, the positional relationship of the guard part can be changed by changing the distance between the upper and lower units at the beginning of pressurization and after pressurization. The flow of the fluid toward the patterned surface of the wafer can be reduced, and after the pressure is increased, the flow of the fluid injected from the injection port toward the patterned surface of the wafer can be increased. As a result, it is possible to avoid blowing off the processing liquid such as organic solvent from the patterned surface of the wafer when the pressure starts to increase, and it is also possible to efficiently remove the processing liquid from the patterned surface of the wafer after increasing the pressure. Become.

Further, in the wafer processing apparatus according to the present invention, the support means is provided in the lower unit, the injection port is provided on the outer circumferential side of the wafer supported by the support means, and the guard portion is provided on the wafer in a plan view. The lower unit may be provided at a position between the injection port and the injection port.

With this configuration, when the pressure starts to increase, the gap between the guard section provided in the lower unit and the upper unit is small, so that the flow of fluid toward the pattern surface of the wafer is reduced. On the other hand, after increasing the pressure, the distance between the upper and lower units becomes larger, so that the gap between the guard part and the upper unit becomes larger, and the flow of fluid toward the patterned surface of the wafer is increased. As a result, as described above, it is possible to prevent the processing liquid from being blown away from the wafer when the pressure starts to increase, and it becomes possible to efficiently remove the processing liquid after the pressure is increased.

Further, in the wafer processing apparatus according to the present invention, the support means is provided in the lower unit, the injection port is provided on the outer circumferential side of the wafer supported by the support means, and the guard portion is provided on the wafer in a plan view. The lower guard part is installed in the lower unit so that it is located between the wafer and the injection port, and the upper unit is installed in a position that is parallel to the lower guard part and is located between the wafer and the injection port in plan view. The upper guard part has a plurality of holes through which fluid can pass in the horizontal direction, and the vertical position of the plurality of holes in the upper guard part is determined so that the volume of the accommodation space is the minimum. In this case, the position substantially coincides with the vertical position of the lower guard part, and if the volume of the accommodation space is the largest, it may be located above the lower guard part.

With this configuration, when the pressure starts to rise, the plurality of holes in the lower guard part are closed by the upper guard part, so that the flow of fluid toward the patterned surface of the wafer is reduced. On the other hand, after the pressure is increased, the plurality of holes in the lower guard part are no longer blocked by the upper guard part, so that the flow of fluid toward the patterned surface of the wafer is increased. As a result, as described above, it is possible to prevent the processing liquid from being blown away from the wafer when the pressure starts to increase, and it becomes possible to efficiently remove the processing liquid after the pressure is increased.

Further, in the wafer processing apparatus according to the present invention, an inlet may be provided at one end of the accommodation space in plan view, and an outlet may be provided at the other end.

With this configuration, it is possible to generate a flow of supercritical fluid from one end side to the other end side in the processing space, so that efficient processing using supercritical fluid can be performed on wafers. become.

Further, in the wafer processing apparatus according to the present invention, the chamber has a seal portion for sealing between the upper and lower units when the chamber is closed, and the lower unit has a seal portion on the lower side of the seal portion. A groove may be provided along the outer periphery of the accommodation space, and a discharge port may be provided at the bottom of the groove.

With this configuration, particles and dust generated at the contact portion of the upper and lower units can be discharged through the groove, thereby preventing the particles and dust from adhering to the pattern surface of the wafer. can.

According to the wafer processing apparatus according to the present invention, there is no need to separately provide an injection port for fluid before pressure increase and an injection port for fluid after pressure increase. The flow to the surface can be reduced, and after the pressure is increased, the flow of the fluid injected from the injection port to the patterned surface of the wafer can be increased.

A partially cutaway perspective view showing the configuration of a wafer processing apparatus according to an embodiment of the present invention A sectional view showing a vertical section of a chamber of a wafer processing apparatus according to the same embodiment. A sectional view showing a vertical section of a chamber of a wafer processing apparatus according to the same embodiment. A sectional view showing a vertical section of a chamber of a wafer processing apparatus according to the same embodiment. A perspective view of the upper unit in the same embodiment A plan view of the lower unit in the same embodiment A plan view showing an example of the arrangement of the guard part in the same embodiment. A plan view showing an example of the arrangement of the guard part in the same embodiment. A plan view showing an example of the arrangement of the guard part in the same embodiment. A schematic diagram showing an example of the position of the guard part before and after boosting the voltage in the same embodiment. A sectional view showing a vertical section of a chamber of a wafer processing apparatus according to the same embodiment. A partially enlarged sectional view of the chamber at the start of pressurization in the same embodiment A partially enlarged sectional view of the chamber after pressurization in the same embodiment A partially enlarged sectional view of the chamber in the same embodiment A plan view and a side view showing an example of the lower guard part in the same embodiment. A diagram showing an example of fluid flow in the same embodiment

DESCRIPTION OF THE PREFERRED EMBODIMENTS A wafer processing apparatus according to the present invention will be described below using embodiments. Note that in the following embodiments, constituent elements with the same reference numerals are the same or correspond to each other, and a repeated explanation may be omitted. In the wafer processing apparatus according to the present embodiment, since the positions of the guard portions are different before and after the pressure increase, it is possible to reduce the flow of the fluid injected from the injection port toward the pattern surface of the wafer at the start of the pressure increase, and After the pressure is increased, the flow of the fluid injected from the injection port toward the patterned surface of the wafer can be increased.

FIG. 1 is a partially cutaway perspective view showing the configuration of a wafer processing apparatus 1 according to the present embodiment. 2 to 4 are cross-sectional views showing longitudinal sections of the chamber 11 of the wafer processing apparatus 1. FIG. FIG. 2 shows a state in which the chamber 11 is open, and FIG. 3 shows a state in which the chamber 11 is closed and at the time of starting pressurization. FIG. 4 shows a state in which the chamber 11 is closed and after the pressure is increased. FIG. 5 is a perspective view of the upper unit 21 viewed from the bottom side. FIG. 6 is a plan view of the lower unit 22. 7A to 7C are plan views showing an example of the arrangement of the guard portion 24 provided in the lower unit 22. FIG. FIG. 8 is a schematic diagram showing an example of the position of the guard part 24 before and after boosting the pressure. FIG. 9 is a longitudinal cross-sectional view of the chamber 11 taken along line AA in FIG. FIG. 10 is an enlarged sectional view of the vicinity of the injection port 223a at the start of pressure increase in the longitudinal sectional view of the chamber 11 taken along line AA in FIG. FIG. 11 is an enlarged sectional view of the vicinity of the injection port 223a after pressurization in the longitudinal sectional view of the chamber 11 taken along line AA in FIG. FIG. 12 is an enlarged sectional view of the vicinity of the discharge port 224d of the accommodation space 22c after pressurization in the longitudinal sectional view of the chamber 11 taken along line BB in FIG.

The wafer processing apparatus 1 according to the present embodiment includes a chamber 11 having an upper unit 21 and a lower unit 22, an opening/closing means 12 for opening and closing the upper unit 21 and the lower unit 22 of the chamber 11, and a chamber 11 provided in the chamber 11. In the accommodation space 22c for the wafer 2, the distance between the support means 22a that supports the wafer 2, the guard part 24 provided in the accommodation space 22c, and the upper unit 21 and the lower unit 22 is vertically different when the chamber 11 is closed. In order to prevent the upper unit 21 and the lower unit 22 from moving further than a predetermined distance in the direction, a regulating means 41 is provided for regulating the movement of at least one of the upper unit 21 and the lower unit 22 in the vertical direction.

In the chamber 11, the wafer 2 is subjected to a predetermined process using a supercritical fluid. In this embodiment, a case will be mainly described in which the predetermined process is a drying process of the wafer 2 using a supercritical fluid, but other processes, such as a cleaning process or a cleaning/drying process using a supercritical fluid, will be described. may be performed on the wafer 2. The drying process for the wafer 2 is performed, for example, by removing the processing liquid such as an organic solvent remaining on the surface of the wafer 2 by replacing it with a supercritical fluid, and then drying the supercritical fluid. In this embodiment, the case where the fluid used for processing is carbon dioxide, that is, the case where a supercritical fluid of carbon dioxide is used will be mainly described, but other supercritical fluids may be used.

A support means 21a is provided on the lower surface side of the upper unit 21 to support the wafer 2 carried in in the horizontal direction. Therefore, when the wafer 2 is carried in, the wafer 2 is positioned below the upper unit 21, as shown in FIG. For example, as shown in FIGS. 2 and 5, the supporting means 21a has a substantially L-shaped cross section, and supports the peripheral edge of the wafer 2 carried in at the distal end portion extending in the horizontal direction. Good too. In this embodiment, as shown in FIGS. 5 and 6, a case will be mainly described in which the upper unit 21 is provided with three supporting means 21a, but this need not be the case. The number of supporting means 21a may be, for example, one or two, or four or more. Moreover, the shape of the supporting means 21a is not limited as long as it can support the wafer 2 appropriately.

The lower unit 22 is opposed to the upper unit 21. The upper unit 21 and the lower unit 22 constitute a housing space 22c that accommodates the wafer 2. The accommodation space 22c is usually a substantially cylindrical space. If the volume of the housing space 22c is large, the time required to increase the pressure to bring the fluid to a supercritical state will be long, so it is preferable that the volume of the housing space 22c is small. In addition, although this embodiment mainly describes the case where the accommodation space 22c is formed on the lower unit 22 side, this may not be the case. The accommodation space 22c may be formed by each of the upper unit 21 and the lower unit 22, or may be formed on the upper unit 21 side. Further, the lower unit 22 may be provided with a fluid injection path 221 and a fluid discharge path 222, as shown in FIG. 9 and the like. It is preferable that the fluid injection path 221 and the fluid discharge path 222 be provided in the fixed unit rather than in the movable unit.

A support means 22a for supporting the wafer 2 is provided on the upper surface side of the lower unit 22 (that is, on the bottom surface side of the accommodation space 22c). In this embodiment, when the upper unit 21 and the lower unit 22 are closed with the wafer 2 supported by the support means 21a of the upper unit 21, the wafer 2 is supported by the support means 21a of the upper unit 21. The following will mainly explain the case where the lower unit 22 is no longer supported by the support means 22a of the lower unit 22. In this case, even if the distance between the upper unit 21 and the lower unit 22 changes within the range of regulation by the regulation means 41, the wafer 2 accommodated in the accommodation space 22c will not be able to reach the lower unit. It is preferable that the support means 22a provided at 22 support the support means 22a. That is, even if the distance between the upper unit 21 and the lower unit 22 changes within the range of regulation by the regulation means 41, the surface on which the wafer 2 is placed on the support means 22a is higher than the surface on which the wafer is placed on the support means 21a. It is assumed that it is located on the side. On the other hand, the wafer 2 accommodated in the accommodation space 22c may be supported by a support means 21a provided in the upper unit 21. In either case, even if the distance between the upper unit 21 and the lower unit 22 changes within the range of regulation by the regulating means 41, in the accommodation space 22c, the supporting means 22a on the lower unit 22 side and the upper unit It is preferable that the wafer 2 is supported only by one of the supporting means 21a on the 21 side.

The support means 22a has at least a tapered surface that slopes downward from the outer circumferential side of the substantially cylindrical housing space 22c toward the axis, and a mounting surface that is a horizontal surface connected to the lower end side of the tapered surface. The wafer 2 is positioned by each tapered surface of the plurality of supporting means 22a, and the wafer 2 at a predetermined position in the accommodation space 22c (for example, the center position of the accommodation space 22c in plan view) is supported by the mounting surface. Become so. In this embodiment, as shown in FIG. 6, a case will be mainly described in which the lower unit 22 is provided with three supporting means 22a, but this need not be the case. The number of supporting means 22a may be, for example, one or two, or four or more. Moreover, the shape of the support means 22a is not limited as long as it can support the wafer 2 appropriately.

An injection port for injecting fluid into the housing space 22c and a discharge port for discharging fluid from the housing space 22c are provided in at least one of the upper unit 21 and the lower unit 22, respectively. That is, it is assumed that an inlet is provided in at least one of the upper unit 21 and the lower unit 22, and an outlet is provided in at least one of the upper unit 21 and the lower unit 22. In this embodiment, as shown in FIG. 6, fluid inlets 223a and 223b are provided at one end side (right side in the figure) of the accommodation space 22c, which is circular in plan view, and the fluid inlets 223a and 223b are provided at the other end side. Fluid outlets 224d, 224e, and 224f are provided on the left side in the figure, and fluid outlets 224a, 224b, and 224c are provided between the inlets 223a and 223b and near the center of the accommodation space 22c. We will mainly explain the cases where Note that when the injection ports 223a and 223b are not particularly distinguished, they may be simply referred to as the injection port 223. The same applies to the discharge ports 224a to 224f. As shown in FIG. 6, inlet ports 223a and 223b are provided at one end side of the accommodation space 22c in plan view, and outlet ports 224d, 224e, and 224f are provided at the other end side. , the fluid flows from one end side to the other end side, and it is possible to avoid the fluid from staying on the wafer 2 or the fluid flowing out from the wafer 2 from returning onto the wafer 2. Note that, as shown in FIG. 6, other discharge ports 224a, 224b, and 224c may be provided as long as the fluid flows from one end side to the other end side of the housing space 22c as a whole. Further, other injection ports 223 may be provided.

Further, the arrangement of the inlet 223 and the outlet 224 may be other than that shown in FIG. 6. However, it is preferable that the injection port 223 exists on the outer peripheral side of the wafer 2 accommodated in the accommodation space 22c, that is, on the outer side of the outer edge of the wafer 2 supported in the accommodation space 22c, in plan view. Therefore, for example, in plan view, the inlet 223 may be provided at the periphery of the accommodation space 22c, and the outlet 224 may be provided near the center of the accommodation space 22c. In this embodiment, a case will be mainly described in which both the inlet 223 and the outlet 224 are provided in the lower unit 22; however, the inlet 223 may be provided in the upper unit 21. Note that the discharge port 224 is normally preferably provided in the lower unit 22, but may be provided in the upper unit 21.

The upper unit 21 and the lower unit 22 are preferably made of a pressure-resistant material. The material may be, for example, stainless steel. Further, in order to prevent the generation of particles, a predetermined coating (for example, a coating of a hard film such as DLC (Diamond-Like Carbon), etc.) may be applied to the surface.

Further, the upper unit 21 has an upper heater 21d at a position on the upper surface side of the accommodation space 22c when the chamber 11 is closed, and the lower unit 22 has an upper heater 21d located on the upper surface side of the accommodation space 22c when the chamber 11 is closed. A lower heater 22d is provided at a position on the lower surface side. That is, the upper unit 21 is configured by attaching the upper heater 21d to the upper unit body, and the lower unit 22 is configured by attaching the lower heater 22d to the lower unit body. The upper heater 21d and the lower heater 22d are used to heat the fluid in the accommodation space 22c. This is to bring the fluid into a supercritical state in the accommodation space 22c. When the fluid is carbon dioxide, for example, the carbon dioxide may be heated to 31.1° C. or higher by the upper heater 21d and the lower heater 22d. Note that the spaces 21f and 22f provided in the upper unit 21 and the lower unit 22 are spaces through which wiring for power supply to the upper heater 21d and lower heater 22d passes, respectively. In order to keep the housing space 22c confidential, seals are installed between the upper heater 21d and the main body side of the upper unit 21, and between the lower heater 22d and the main body side of the lower unit 22, as shown in FIG. Parts 21e and 22e may be provided, respectively. This is to keep the accommodation space 22c confidential. Each of the seal portions 21e and 22e may be similar to a seal portion 23 described later.

The chamber 11 may have a seal portion 23 for sealing between the upper unit 21 and the lower unit 22 when the chamber 11 is closed. The seal portion 23 is an annular member, and may be arranged at the annular edge of the opening of the accommodation space 22c in the lower unit 22 or at a portion of the upper unit 21 opposite to the edge. The seal portion 23 may be attached to the lower end side of the upper unit 21, for example, as shown in FIGS. 2 to 4. The seal portion 23 may have a substantially U-shaped cross section, as shown in FIGS. 10 to 12. In that case, when the chamber 11 is closed and the fluid in the accommodation space 22c attempts to flow out to the outside through the seal portion 23, the pressure in the substantially U-shaped inner portion increases and the sealing performance is impaired. This is further improved, and it is possible to effectively prevent the fluid from flowing out of the accommodation space 22c. Further, as shown in FIGS. 10 to 12, the seal portion 23 may be held in its position by being pressed by a seal presser 23a, for example. The seal portion 23 may be made of, for example, a fluororesin such as polytetrafluoroethylene, or a material such as silicon.

The opening/closing means 12 opens and closes the chamber 11 by moving at least one of the upper unit 21 and the lower unit 22 in the vertical direction. The upper unit 21 and the lower unit 22 are closed by the opening/closing means 12, and are fitted and integrated to form a housing space 22c for processing the wafer 2. Furthermore, the presence of the seal portions 21e, 22e, and 23 improves the airtightness of the accommodation space 22c. In this embodiment, the opening/closing means 12 is an air cylinder fixed to the base 15, and moves the four corners of the rectangular top plate 16 up and down with respect to the base 15 at the same timing. The case where the unit 21 is moved in the vertical direction will be mainly explained. In addition, in FIG. 1, a part of the opening/closing means 12 is omitted.

The opening/closing means 12 may be constituted by a solenoid other than an air cylinder, a rotational drive means for driving a rack and pinion and a pinion, a rotational drive means for rotating a ball screw and a screw shaft, or the like. Additionally, opening/closing means 12 are provided at one to three of the four corners of the top plate 16, and guide members for vertically guiding the apex portion of the top plate 16 are provided at other locations. may be provided. In this embodiment, a case will be described in which the opening/closing means 12 moves the upper unit 21 in the vertical direction, but this may not be the case. The opening/closing means 12 may move the lower unit 22 in the vertical direction, or may move both the upper unit 21 and the lower unit 22 in opposite directions in the vertical direction.

As will be described later, after the chamber 11 is closed by the opening/closing means 12, the upper unit 21 and the lower unit 22 can be vertically separated within the range of regulation by the regulating means 41. Therefore, after the chamber 11 is closed and the volume of the accommodation space 22c becomes the minimum, the opening/closing means 12 releases the force in the direction of closing the upper unit 21 and the lower unit 22, so that both of them are within the range of restriction by the restriction means 41. It is preferable to be able to move vertically within the interior. Note that the force in the direction of closing the upper unit 21 and the lower unit 22 by the opening/closing means 12 may be released, for example, after the pressure in the accommodation space 22c becomes greater than a predetermined threshold pressure.

The regulating means 41 controls the upper unit 21 and the lower unit 22 in a state in which the chamber 11 is closed, that is, in a state in which the upper unit 21 and the lower unit 22 are fitted in the vertical direction and the internal accommodation space 22c is kept airtight. Movement of at least one of the upper unit 21 and the lower unit 22 in the vertical direction is restricted so that the distance between the two units does not exceed a predetermined distance in the vertical direction. Specifically, the vertical movement of the flange-shaped protrusions 21b and 22b provided on the peripheral edges of the upper unit 21 and the lower unit 22, respectively, is restricted by the recess 41a provided in the regulating means 41. The recess 41a is provided along the circumferential direction on the inner circumferential surface side of the regulating means 41, which is arcuate in plan view, and the length of the recess 41a in the vertical direction is equal to the length of the protrusions 21b and 22b in the vertical direction. is longer than the sum of the lengths. Therefore, even when the protrusions 21b and 22b are inserted into the recess 41a, the upper unit 21 and the lower unit 22 are movable in the vertical direction. However, even if the upper unit 21 and the lower unit 22 move away from each other with the protrusions 21b and 22b inserted into the recess 41a, the chamber 11 does not open. That is, it is assumed that the accommodation space 22c is kept confidential.

The restricting means 41 may be moved by a predetermined moving means between a restricting position where the vertical movement of at least one of the upper unit 21 and the lower unit 22 is restricted and a release position where the restriction is not performed. In this embodiment, the moving means includes a slide rail 43 fixed to the base 15, a slide guide 44 slidably provided on the slide rail 43, a stage 42 fixed to the slide guide 44, and a stage 42. A case will be mainly described in which the device is provided with a drive means (not shown) that moves the slide rail 43 on the slide rail 43. Note that a regulating means 41 is fixed to the upper surface side of the stage 42. Such a moving means allows the regulating means 41 to move in the longitudinal direction of the slide rail 43. The driving means may be, for example, an air cylinder, a solenoid, a rotational driving means for driving a rack and pinion and a pinion, or a rotational driving means for rotating a ball screw and a screw shaft. In this embodiment, as shown in FIG. 1, a case will be mainly described in which the vertical movement of the upper unit 21 and lower unit 22 of the chamber 11 is restricted by three restriction means 41. The number of means 41 may be two, for example, or four or more. The movement of the plurality of restriction means 41 between the restriction position and the release position may be performed independently or in conjunction with each other.

The regulation of vertical movement of the upper unit 21 and lower unit 22 by the regulation means 41 will be explained using FIGS. 2 to 4. Note that in FIGS. 2 to 4, illustrations of the support means 22a, the injection path 221, and the discharge path 222 are omitted. FIG. 2 shows the chamber 11 in an open state, with the restricting means 41 in the released position. Next, after the chamber 11 is closed by the opening/closing means 12 and the volume of the accommodation space 22c becomes the minimum, the plurality of regulating means 41 moves to the regulating position, and the protrusions 21b and 22b When inserted into the recess 41a, the state shown in FIG. 3 is achieved. After that, injection of fluid into the accommodation space 22c is started, and as the pressure in the accommodation space 22c increases, the upper unit 21 and the lower unit 22 are separated in the vertical direction within the range of regulation by the regulation means 41. When the volume of the accommodation space 22c becomes maximum, the state shown in FIG. 4 is reached. A predetermined process using a supercritical fluid will be performed in the state shown in FIG. When the fluid becomes supercritical, the pressure is increased in the accommodation space 22c. Before the pressure increase starts, the volume of the accommodation space 22c is the minimum, and after the pressure increase is completed, the volume of the accommodation space 22c is the maximum. Therefore, during the pressurization process, the volume of the accommodation space 22c changes from the minimum state to the maximum state, but it is more preferable that the changing pressure is close to the pressure after the pressure increase.

The vertical distance between the upper unit 21 and the lower unit 22 when the volume of the housing space 22c is the minimum, and the vertical distance between the upper unit 21 and the lower unit 22 when the volume of the housing space 22c is the maximum. The difference may be, for example, 1 mm or more and 10 mm or less. If the difference between the two distances is large, particles and the like are likely to be generated at the joint between the upper unit 21 and the lower unit 22, so from that point of view, it is preferable that the difference between the two distances is small. Therefore, the difference between both distances may be, for example, 5 mm or less, or 3 mm or less. On the other hand, as will be described later, the flow of fluid in the accommodation space 22c is changed by vertically moving the guard part 24 or components other than the guard part 24 according to the difference between the two distances. , both distances are preferably large. Therefore, the difference between both distances may be, for example, 2 millimeters or more.

The guard portion 24 is provided in the accommodation space 22c. For example, the guard part 24 may be provided in the upper unit 21 and may move in the vertical direction together with the upper unit 21, or may be provided in the lower unit 22 and may move in the vertical direction together with the lower unit 22. . Then, when the volume of the accommodation space 22c becomes the minimum, the guard part 24 is in a position to reduce the flow of the fluid injected from the injection port 223 toward the pattern surface of the wafer 2, and the volume of the accommodation space 22c is reduced. When the maximum value is reached, the position is such that the flow of the fluid injected from the injection port 223 toward the pattern surface of the wafer 2 is increased. That is, the flow of the fluid injected from the injection port 223 toward the pattern surface of the wafer 2 increases when the volume of the accommodation space 22c is the maximum, rather than when the volume is the minimum. The position of the guard portion 24 is the relative position of the guard portion 24 with respect to other components. Therefore, as will be described later, when the distance between the upper unit 21 and the lower unit 22 changes within the range of regulation by the regulation means 41, the guard part 24 itself may move in the vertical direction, or the guard part 24 may move in the vertical direction. The positional relationship of the guard portion 24 with the other components may change by moving the components other than 24 in the vertical direction.

The patterned surface of the wafer 2 refers to the surface of the wafer 2 on which a pattern is formed. In this embodiment, a case will be mainly described in which the upper surface of the wafer 2 accommodated in the accommodation space 22c is a patterned surface, but the lower surface of the wafer 2 accommodated in the accommodation space 22c may also be a patterned surface. Reducing the flow toward the patterned surface of the wafer 2 may mean that the flow toward the patterned surface of the wafer 2 is eliminated, or that some of the flow reaches the patterned surface of the wafer 2. Good too. The former is ideal, but the latter is usually the case. Even in the latter case, it is preferable that only a flow that does not blow away the processing liquid such as an organic solvent on the pattern surface reaches the pattern surface.

Guard part 24 may be provided at a position between wafer 2 and injection port 223 in plan view. 7A to 7C are diagrams showing the position of the guard portion 24 in the accommodation space 22c in a plan view. The guard part 24 may be provided on a part of the outer periphery of the wafer 2 housed in the accommodation space 22c, as shown in FIGS. It may be provided on substantially the entire outer periphery of the wafer 2. In FIG. 7A, the guard part 24 is provided only in the vicinity of the injection port 223, and in FIG. 7B, the guard part 24 is provided in an area about half the circumference of the wafer 2, including the position of the injection port 223. In either case, it is preferable that the guard portion 24 be disposed outside the outer edge of the wafer 2 and at a position closer to the wafer 2 than the injection port 223 is. Further, the guard portion 24 may be, for example, a member provided independently of the other components, or may be configured integrally with the other components.

Next, with reference to FIG. 8, a description will be given of changing the flow of fluid using the guard portion 24. The left side of FIG. 8 shows a vertical cross section inside the accommodation space 22c in a state where the volume of the accommodation space 22c is the minimum, that is, in a state at the start of pressurization. The right side of FIG. 8 shows a vertical cross section of the inside of the accommodation space 22c in a state where the volume of the accommodation space 22c is maximum, that is, in a state after the pressure is increased. As described above, in the accommodation space 22c, the wafer 2 may be supported by the support means 21a on the upper unit 21 side or by the support means 22a on the lower unit 22 side. In FIGS. 8(a) and 8(b), the wafer 2 is supported by the support means 22a of the lower unit 22, and in FIGS. 8(c) and 8(d), the wafer 2 is supported by the upper unit 21. It is assumed that it is supported by means 21a. Further, in FIGS. 8(a) and 8(c), the guard portion 24 is provided in the lower unit 22, and in FIG. 8(b) and FIG. 8(d), the guard portion 24 is provided in the upper unit 21. shall be provided in. Further, in FIG. 8, it is assumed that the upper unit 21 moves upward within the range of regulation by the regulation means 41 in response to an increase in the pressure in the accommodation space 22c. Further, in FIG. 8, the flow of fluid from the injection port 223 is indicated by arrows. Note that FIG. 8(e) will be described later.

In FIG. 8(a), at the start of pressure increase, as shown on the left side, the gap between the guard part 24 and the upper unit 21 becomes small, and the flow of fluid from the injection port 223 is reduced. , the fluid hardly hits the pattern surface, which is the upper surface of the wafer 2. Therefore, the processing liquid and the like on the pattern surface of the wafer 2 can be prevented from being blown away by the fluid, and the processing liquid can remain on the pattern surface until processing using the supercritical fluid is performed. On the other hand, after increasing the pressure, as shown on the right side, the gap between the guard part 24 and the upper unit 21 becomes larger, and the flow of fluid from the injection port 223 hits the patterned surface of the wafer 2, and the patterned surface is processed. The liquid can be removed efficiently.

In FIG. 8(b), when the pressure starts to increase, the gap between the lower surface of the upper unit 21 and the wafer 2 is closed by the guard part 24 provided in the upper unit 21, as shown on the left side. Fluid flow from the inlet 223 to the patterned surface of the wafer 2 will be reduced. On the other hand, after increasing the pressure, as shown on the right side, the gap between the pattern surface of the wafer 2 and the lower surface of the upper unit 21 becomes larger and is not blocked by the guard part 24, so that the gap from the injection port 223 increases. The flow of fluid comes to hit the patterned surface of the wafer 2, and the processing liquid on the patterned surface can be efficiently removed. In this case, it is preferable that the gap between the periphery of the wafer 2 and the guard portion 24 is small, that is, that the two are close to each other in plan view.

The situation in FIG. 8(c) is the same as the situation in FIG. 8(a), except for whether the wafer 2 rises together with the upper unit 21, so the explanation thereof will be omitted.

In FIG. 8(d), at the start of pressure increase, as shown on the left side, the gap between the guard part 24 and the lower unit 22 is small, and the flow of fluid from the injection port 223 is reduced. , almost no fluid hits the patterned surface of the wafer 2. Therefore, the processing liquid and the like on the wafer 2 can be prevented from being blown away by the fluid, and the processing liquid can be left on the pattern surface until processing using the supercritical fluid is performed. On the other hand, after increasing the pressure, as shown on the right side, the gap between the guard part 24 and the lower unit 22 becomes larger, and the flow of fluid from the injection port 223 hits the patterned surface of the wafer 2, and the patterned surface is processed. The liquid can be removed efficiently.

As shown in FIGS. 8(a) to 8(d), the relative positional relationship between the guard part 24 and the wafer 2, the upper unit 21, the lower unit 22, etc. changes before and after the pressurization of the accommodation space is increased. By doing so, it is possible to reduce the flow of fluid to the patterned surface of the wafer 2 when the pressure starts to increase, and it is possible to increase the flow of fluid to the patterned surface of the wafer 2 after the pressure is increased. As a result, it is possible to prevent the treatment liquid on the pattern surface from being removed due to the fluid before reaching the supercritical state being sprayed onto the pattern surface. It becomes possible to efficiently remove the processing liquid from the surface. Furthermore, since the processing liquid is removed using supercritical fluid, it is possible to prevent the pattern from collapsing.

Next, a more detailed configuration will be described in which the wafer 2 is supported by the support means 22a of the lower unit 22 and the guard portion 24 is provided on the lower unit 22 side. FIG. 9 is a longitudinal cross-sectional view of the chamber 11 taken along line AA in FIG. In FIG. 9, the wafer 2 accommodated in the accommodation space 22c is supported by a support means 22a provided in the lower unit 22. FIG. 10 is an enlarged sectional view of the vicinity of the right side of the accommodation space 22c in FIG. 9. As shown in FIG. In FIG. 10, the guard portion 24 is provided continuously on the peripheral edge of the lower heater 22d. Further, a gap exists on the lower surface side of the lower heater 22d, and fluid can move through the gap. Further, a gap exists on the upper surface side of the upper heater 21d, and the fluid can move through the gap. At the start of pressure increase, the upper end of the guard part 24 and the lower surface of the upper heater 21d are close to each other in the vertical direction, and the fluid injected from the injection port 223a via the injection path 221 is directed toward the upper surface of the wafer 2. entry is prevented. Therefore, the processing liquid on the patterned surface of the wafer 2 is not removed. For example, when starting the supply of carbon dioxide to the accommodation space 22c, carbon dioxide of about 5 MPa is supplied from a cylinder to the accommodation space 22c of about 0.1 MPa (1 atm). When such high-pressure carbon dioxide directly hits the patterned surface of the wafer 2, the processing liquid on the patterned surface is easily blown away, causing the pattern to collapse. On the other hand, as shown in FIG. 10, when the gap between the guard part 24 and the upper heater 21d is narrow, it becomes difficult for the carbon dioxide injected from the injection port 223a to reach the pattern surface of the wafer 2. Since the processing liquid on the pattern surface is not blown away, collapse of the pattern can be avoided.

As shown in FIG. 10, carbon dioxide injected from the injection port 223 passes through the upper surface side of the upper heater 21d and the lower surface side of the lower heater 22d, and fills the accommodation space 22c. Then, shortly after the supply of carbon dioxide is started, the pressure in the accommodation space 22c becomes approximately 5 MPa. After that, carbon dioxide pressurized using a pressure increasing mechanism such as a pressurizing pump is supplied to the accommodation space 22c. By injecting the pressurized carbon dioxide, the pressure in the accommodation space 22c increases. The upper unit 21 moves upward in accordance with the rise in pressure in the accommodation space 22c. Note that after the start of supply of carbon dioxide using the pressurization mechanism, carbon dioxide is no longer supplied vigorously from the injection port 223. Therefore, it is preferable that the upper unit 21 starts to rise after the supply of carbon dioxide using the pressure increasing mechanism is started. It is assumed that the volume of the accommodation space 22c becomes the maximum in this way. FIG. 11 is an enlarged sectional view showing this state. Note that a pressure regulating valve is connected to the discharge path 222 connected to the discharge port 224, and when the pressure in the accommodation space 22c exceeds a predetermined value, the fluid is discharged. In this way, the pressure in the accommodation space 22c is maintained at a predetermined value.

As shown in FIG. 11, when the upper unit 21 moves upward, the gap between the upper end of the guard part 24 and the lower surface of the upper heater 21d becomes larger. As a result, the fluid from the injection port 223a comes to flow to the upper surface of the wafer 2, and the processing liquid such as an organic solvent remaining on the patterned surface of the wafer 2 is dissolved in the supercritical fluid and flows from the discharge port 224. be discharged. Note that the fluid flowing on the lower surface side of the lower heater 22d is discharged from discharge ports 224b and 224c provided on the lower surface of the accommodation space 22c. Further, the fluid flowing on the pattern surface of the wafer 2 also falls from the end of the wafer 2 to the lower heater 22d side, flows to the lower surface side of the lower heater 22d via the hole 22h, and is discharged from the discharge ports 224b and 224c. Ru. Due to the presence of the hole 22h, the flow rate of the fluid flowing between the lower surface of the wafer 2 and the upper surface of the lower heater 22d can be reduced, and it is possible to suppress the wafer 2 from flapping. A plurality of holes 22h may be provided all around the lower heater 22d at an angle such that the fluid from the wafer 2 flows toward the discharge port 224 without backflowing. On the other hand, the fluid flowing on the upper surface side of the upper heater 21d is discharged from discharge ports 224a, 224d, 224e, and 224f provided at the periphery of the accommodation space 22c. Note that, as shown in FIG. 11, as the gap between the upper end of the guard portion 24 and the lower surface of the upper heater 21d becomes larger, the air can pass between the main body side of the lower unit 22 and the upper heater 21d. The flow rate of the fluid flowing above the upper heater 21d is reduced.

FIG. 12 is an enlarged sectional view of the vicinity of the discharge port 224d in the longitudinal sectional view of the chamber 11 taken along line BB in FIG. As shown in FIGS. 10 to 12, the lower unit 22 is provided with a groove 22g along the outer periphery of the accommodation space 22c. As shown in FIGS. 10 to 12, the groove portion 22g is provided at a position below the seal portion 23 so as to open upward when the chamber 11 is in a closed state. Therefore, particles 17 generated at the seal portion 23 and the joint portion between the upper unit 21 and the lower unit 22 can be efficiently received. Further, it is preferable that the fluid passing through the upper surface side of the upper heater 21d is also received by the groove portion 22g. Therefore, the gap between the upper heater 21d and the main body side of the lower unit 22 is preferably narrower than the flow path from the upper surface side of the upper heater 21d to the groove portion 22g. Further, discharge ports 224a, 224d, 224e, and 224f are provided at the bottom of the groove 22g. Therefore, the particles 17 etc. received in the groove 22g can be discharged without being diffused to the wafer 2 side, reducing the possibility that the particles 17 etc. received in the groove 22g will adhere to the pattern surface of the wafer 2. can do. Further, the fluid that has passed through the upper surface of the wafer 2 is discharged from the discharge ports 224b and 224c near the center of the accommodation space 22c via the lower surface side of the lower heater 22d.

Next, the guard part 24 having the lower guard part 241 and the upper guard part 242 will be explained using FIG. 8(e) and FIG. 13. 13(a) is a plan view showing an example of the upper guard part 242, and FIG. 13(b) is a side view showing an example of the upper guard part 242. In FIG. 8E, it is assumed that the wafer 2 is supported by the support means 22a of the lower unit 22. Further, it is assumed that the lower guard part 241 is provided in the lower unit 22 and the upper guard part 242 is provided in the upper unit 21. The lower guard part 241 is provided at a position between the wafer 2 and the injection port 223 in plan view. Further, the upper guard part 242 is also provided at a position between the wafer 2 and the injection port 223 in plan view, and has a plurality of holes 242a through which fluid can pass in the horizontal direction. Further, it is assumed that the lower guard part 241 and the upper guard part 242 are provided in parallel on the outer peripheral side of the wafer 2 in plan view. In this embodiment, a case will be mainly described in which the lower guard part 241 is on the inside and the upper guard part 242 is on the outside, but the reverse may be possible. Furthermore, when the volume of the accommodation space 22c is at its minimum, that is, at the start of pressurization, the vertical position of the plurality of holes 242a of the upper guard part 242 substantially coincides with the vertical position of the lower guard part 241, and the accommodation space 22c When the volume is at its maximum, that is, after the pressure is increased, it is assumed to be above the lower guard part 241. More specifically, at the start of pressure increase, the upper ends of the plurality of holes 242a are preferably located below the upper end of the lower guard part 241, and after the pressure increase, the lower ends of the plurality of holes 242a are It is preferable that the lower guard portion 241 be located above the upper end of the lower guard portion 241 . By doing so, as shown in FIG. 8(e), when the pressure starts to increase, the plurality of holes 242a are blocked by the lower guard part 241, so that the fluid from the injection port 223 can flow to the pattern surface of the wafer 2. This will reduce the flow to. On the other hand, after the pressure is increased, the plurality of holes 242a are no longer blocked by the lower guard part 241, so that the flow of fluid from the injection port 223 to the pattern surface via the plurality of holes 242a is increased. Note that although the case where the upper guard portion 242 has a plurality of holes 242a has been described here, this may not be the case. The upper guard part 242 does not need to have the plurality of holes 242a. In that case, it is preferable that the supercritical fluid flows from the injection port 223 to the pattern surface of the wafer 2 through the lower side of the upper guard part 242 and the upper side of the lower guard part 241 after increasing the pressure. It is.

13(a) is a plan view of the upper guard part 242, and FIG. 13(b) is a side view of the upper guard part 242. When the upper guard part 242 is arranged at the position of the guard part 24 shown in FIG. 7B, the plurality of holes 242a are arranged in the upper guard part 24 as shown in FIGS. 242 may be provided in a direction perpendicular to the surface. FIG. 14 is a diagram showing how supercritical fluid is supplied to the patterned surface of the wafer 2 through the plurality of holes 242a of the upper guard part 242 shown in FIG. As shown in FIG. 14, the supercritical fluid injected from the injection port 223 is supplied to the pattern surface of the wafer 2 through the plurality of holes 242a of the upper guard part 242, and a portion is discharged to the discharge port 224a. However, most of it is discharged to the discharge ports 224d, 224e, and 224f. Therefore, as a whole, the supercritical fluid flows from the right side to the left side in the figure, and a more uniform flow can be realized. Therefore, the processing liquid dissolved in the supercritical fluid does not remain on the pattern surface of the wafer 2 and is appropriately discharged.

Next, the operation of the wafer processing apparatus 1 according to this embodiment will be specifically explained. First, as shown in FIG. 1, it is assumed that the regulating means 41 is moved to the release position, the chamber 11 is opened by the opening/closing means 12, and the upper unit 21 and lower unit 22 are separated in the vertical direction. . In this state, the wafer 2, which has been cleaned with a cleaning agent such as IPA (isopropyl alcohol) in the cleaning device of the previous process, is conveyed by a conveyance robot and loaded onto the lower surface side of the upper unit 21. The loaded wafer 2 is supported by the supporting means 21a so that the pattern surface is the upper surface (FIG. 2).

Thereafter, the chamber 11 is closed by lowering the top plate 16 by the opening/closing means 12. Note that in the accommodation space 22c, the wafer 2 is supported by the support means 22a of the lower unit 22. Further, by moving the stage 42 toward the axis of the chamber 11, the regulating means 41 is moved to a regulating position where it regulates the vertical movement of at least one of the upper unit 21 and the lower unit 22 (Fig. 3).

Then, the injection valve connected to the carbon dioxide injection path 221 is opened, and carbon dioxide is injected into the accommodation space 22c of the chamber 11. At this point, the volume of the accommodation space 22c is the minimum, and the flow of carbon dioxide injected from the injection port 223 toward the pattern surface of the wafer 2 is reduced by the upper guard part 242, so that It is possible to prevent IPA and the like from being blown away by the injected carbon dioxide (FIG. 10). For example, carbon dioxide is pressurized using a pressure increasing mechanism such as a pressurizing pump and then injected into the accommodation space 22c. Further, the injected carbon dioxide is heated by the upper heater 21d and the lower heater 22d.

The injected carbon dioxide becomes a supercritical state when the pressure in the accommodation space 22c reaches a critical pressure of 7.38 MPa or higher and the temperature reaches a critical temperature of 31.1° C. or higher, and the IPA and the like on the wafer 2 become supercritical carbon dioxide. Dissolved in carbon. In addition, the pressure in the accommodation space 22c increases due to the injection of carbon dioxide, and in accordance with the increase in pressure, the upper unit 21 and the lower unit 22 are separated within the range of regulation by the regulation means 41 (FIG. 4). As a result, more of the injected supercritical carbon dioxide flows to the patterned surface of the wafer 2, and IPA and the like on the patterned surface are efficiently dissolved into the supercritical carbon dioxide.

When the pressure of supercritical carbon dioxide (supercritical fluid) in the accommodation space 22c exceeds a certain value, a discharge valve (pressure adjustment valve) connected to the discharge path 222 releases the supercritical carbon dioxide (supercritical fluid) while maintaining the pressure in the accommodation space 22c. The critical fluid is gradually drained. In this way, the supercritical fluid in which IPA and the like adhering to the patterned surface of the wafer 2 have been dissolved is discharged, and IPA and the like are removed from the wafer 2 in the accommodation space 22c.

Note that the accommodation space 22c is preferably maintained at a pressure and temperature at which carbon dioxide becomes supercritical at least until discharge of IPA and the like is completed. Preferably, the pressure of the accommodation space 22c is maintained at 7.4 to 15 MPa, and the temperature is maintained at 31 to 50° C. by the upper heater 21d and the lower heater 22d, for example.

Since the injection of carbon dioxide into the accommodation space 22c continues, the injection of the supercritical carbon dioxide fluid and the discharge of the supercritical carbon dioxide fluid in which IPA and the like are dissolved are performed in parallel. When the discharge of the supercritical fluid in which IPA and the like are dissolved is completed, the injection valve is closed, the pressure in the accommodation space 22c is lowered by the discharge valve, and the phase of the supercritical fluid is converted into a gas before being discharged. The exhaust valve is then closed. Heating of the accommodation space 22c may be stopped and may be maintained at a temperature of 31 to 50°C. Note that whether or not the supercritical fluid has finished discharging IPA or the like may be confirmed by, for example, detecting IPA or the like in the accommodation space 22c using a sensor that detects IPA or the like. The sensor that detects IPA or the like may be, for example, an alcohol detection sensor.

Thereafter, the restricting means 41 is moved to the release position. Moreover, the chamber 11 is opened by lifting the upper surface plate 16 by the opening/closing means 12, and the upper unit 21 and the lower unit 22 are separated. By separating the upper unit 21 and the lower unit 22, the wafer 2 changes from being supported by the supporting means 22a of the lower unit 22 to being supported by the supporting means 21a of the upper unit 21, and the wafer 2 is moved away from the upper unit 21. move upward together. The wafer 2 dried using the supercritical fluid is then carried out by the transfer robot, and the series of drying processes is completed.

As described above, according to the wafer processing apparatus 1 according to the present embodiment, even when the chamber 11 is closed, the upper unit 21 and the lower unit 22 are relatively fixed within the range of regulation by the regulation means 41. It is movable in the vertical direction. In addition, as the pressure increases due to the injection of fluid into the accommodation space 22c, the relative positional relationship between the guard portion 24 provided in the accommodation space 22c and other components changes, so that the injected fluid increases. The flow toward the patterned surface of the wafer 2 can be reduced at the start of boosting the pressure, and can be increased after boosting the pressure. As a result, it is possible to prevent the pattern from collapsing due to the treatment liquid such as IPA being blown away from the pattern surface by the fluid other than the supercritical fluid when the pressure increase starts. Furthermore, this can be achieved with a simple configuration without providing separate injection ports for before pressure increase and after pressure increase. Moreover, after the pressure is increased, the processing liquid such as IPA on the pattern surface can be efficiently removed by the supercritical fluid, and the processing time can be shortened.

Furthermore, when the inlet 223 is provided at one end of the accommodation space 22c in plan view, and the outlet 224 is provided at the other end, the supercritical gas flows in one direction on the pattern surface of the wafer 2. The fluid flows, and it is possible to prevent the supercritical fluid containing the processing liquid such as IPA from staying on the wafer 2 and the supercritical fluid containing the processing liquid from returning to the wafer 2 . As a result, the processing liquid can be removed efficiently.

Further, a groove 22g is provided on the outer peripheral side of the housing space 22c and below the seal portion 23, and a discharge port 224 is provided at the bottom of the groove 22g. Particles generated at the contact portion between the wafer 21 and the lower unit 22 can be discharged from the groove 22g, and particles can be prevented from diffusing toward the wafer 2 and adhering to the pattern surface.

In addition, although this Embodiment demonstrated the case where the vertical movement of the upper unit 21 and the lower unit 22 is restricted by the restriction means 41 similar to a clamp, this is not necessary. The restricting means is, for example, a rod-shaped member provided on the base 15 side, and is located between a restricting position where the upward movement of the upper unit 21 and the top plate 16 is restricted and a release position where the restriction is released. may be moved. Further, the regulating means may have any other configuration as long as it can regulate the movement of the upper unit 21 and the lower unit 22 in the vertical direction.

Further, in FIGS. 10 and 11 of the present embodiment, a case has been described in which the guard portion 24 is configured integrally with the lower heater 22d, but this may not be the case. For example, the guard part 24 may be provided integrally with a structure different from the upper unit 21 and the lower heater 22d of the lower unit 22, or may be an independent member fixed to the upper unit 21 or the lower unit 22. There may be.

Further, in this embodiment, a case has been described in which the upper unit 21 has the upper heater 21d and the lower unit 22 has the lower heater 22d, but this may not be the case. The upper unit 21 does not need to have the upper heater 21d, and the lower unit 22 does not need to have the lower heater 22d.

Further, in this embodiment, a case has been described in which the annular groove portion 22g is provided so as to surround the wafer 2 housed on the outer peripheral side of the housing space 22c, but this may not be the case. The groove portion 22g may not be provided in the accommodation space 22c.

Further, in the present embodiment, a case has been described in which the fluid is not discharged until the pressure in the accommodation space 22c reaches a predetermined level, but this may not be the case. When a fluid such as carbon dioxide is started to be supplied from the cylinder to the accommodation space 22c, it is exhausted through the exhaust port 224 for a predetermined period (for example, about several seconds), and then the exhaust is finished and the accommodation space 22c is The pressure may be increased. By doing so, particles, dust, etc. remaining in the accommodation space 22c at the start of pressure increase can be discharged from the accommodation space 22c.

Furthermore, it goes without saying that the present invention is not limited to the above-described embodiments, and that various modifications can be made, and these are also included within the scope of the present invention.

As described above, according to the wafer processing apparatus according to the present invention, it is possible to reduce the flow of fluid from the injection port toward the pattern surface of the wafer at the start of pressure increase, and to increase it after the pressure increase. The present invention is useful as a wafer processing apparatus that performs predetermined processing on wafers using supercritical fluid.

1 Wafer processing device 2 Wafer 11 Chamber 12 Opening/closing means 21 Upper unit 21a, 22a Supporting means 22 Lower unit 22c Accommodating space 22g Groove 23 Seal portion 24 Guard portion 41 Regulating means 223, 223a, 233b Inlet 224, 224a to 224f Discharge port 241 Lower guard part 242 Upper guard part

Claims (5)

a chamber for performing a predetermined process on the wafer using a supercritical fluid, the chamber having an upper unit and a lower unit opposing the upper unit and forming a housing space for accommodating a wafer;
opening/closing means for opening and closing the chamber by moving at least one of the upper and lower units in the vertical direction;
Supporting means for supporting the wafer in the accommodation space;
regulating means for regulating vertical movement of at least one of the upper and lower units in a state in which the chamber is closed, so that the distance between the two does not exceed a predetermined distance in the vertical direction;
A guard part provided in the accommodation space,
An injection port for injecting fluid into the accommodation space and an outlet for discharging fluid from the accommodation space are each provided in at least one of the upper and lower units,
The guard portion is located at a position that reduces the flow of fluid injected from the injection port toward the pattern surface of the wafer when the chamber is closed by the opening/closing means and the volume of the accommodation space is minimized. Then, when the upper and lower units are separated within the range of regulation by the regulating means in response to an increase in pressure due to the injection of fluid into the accommodation space, and the volume of the accommodation space becomes maximum, A wafer processing apparatus configured to increase the flow of fluid injected from the inlet toward a patterned surface of the wafer. The support means is provided in the lower unit,
The injection port is provided on the outer peripheral side of the wafer supported by the support means,
The wafer processing apparatus according to claim 1, wherein the guard portion is provided in the lower unit so as to be located between the wafer and the injection port in plan view. The support means is provided in the lower unit,
The injection port is provided on the outer peripheral side of the wafer supported by the support means,
The guard portion is
a lower guard part provided in the lower unit so as to be located between the wafer and the injection port in plan view;
an upper guard provided in the upper unit so as to be located between the wafer and the injection port in plan view and parallel to the lower guard part, and having a plurality of holes through which fluid can pass in a horizontal direction; It has a section and a
The vertical positions of the plurality of holes in the upper guard section substantially match the vertical positions of the lower guard section when the volume of the accommodation space is the minimum, and when the volume of the accommodation space is the maximum. 2. The wafer processing apparatus according to claim 1, wherein the lower guard portion is located above the lower guard portion. The wafer processing apparatus according to any one of claims 1 to 3, wherein the injection port is provided at one end of the accommodation space in plan view, and the discharge port is provided at the other end. The chamber has a seal portion for sealing between the upper and lower units when the chamber is closed,
The lower unit is provided with a groove portion below the seal portion along the outer periphery of the accommodation space,
The wafer processing apparatus according to any one of claims 1 to 4, wherein the discharge port is provided at the bottom of the groove.

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