JP5561137B2 - Liquid processing apparatus, liquid processing method, and storage medium - Google Patents

Description

  The present invention relates to a technique for performing liquid processing on a substrate to be processed using a processing liquid.

  In the manufacturing process of a semiconductor device in which a laminated structure of integrated circuits is formed on the surface of a substrate to be processed, for example, a semiconductor wafer (hereinafter referred to as a wafer), fine dust and natural oxide film on the wafer surface are removed by a processing solution such as a chemical solution For example, a liquid processing step for processing the wafer surface using a liquid is provided.

  The processing liquid supplied to the wafer surface during the liquid processing is removed by, for example, spin-drying that rotates the wafer around the vertical axis and shakes out the processing liquid. However, as the integration of semiconductor devices increases, so-called pattern collapse occurs. The problem is getting bigger. For example, when the liquid that remains on the wafer surface is dried, the liquid that remains on the left and right of the projections and recesses that form the pattern is dried unevenly, for example, and the surface that pulls the projections to the left and right. This is a phenomenon in which the balance of tension collapses and the convex part falls down in the direction in which a large amount of liquid remains.

  As a method for removing the liquid remaining on the wafer surface while suppressing such pattern collapse, a drying method using a fluid in a supercritical state or a subcritical state (hereinafter collectively referred to as a high pressure fluid) is known. Since supercritical fluid and submarine fluid exhibit almost the same effect in the drying process, the following description of an example of supercritical fluid shows that supercritical fluid has a lower viscosity than liquid and has a high ability to dissolve liquid. In addition, there is no interface between the supercritical fluid and the liquid or gas in equilibrium. Therefore, the liquid can be dried without being affected by the surface tension by replacing the wafer on which the liquid is adhered with the supercritical fluid and then changing the state of the supercritical fluid to a gas.

  Therefore, the present inventors have housed the wafer in a processing tank, processed the surface with the wafer immersed in the liquid while changing the type of liquid to be supplied, and then superfluidized the fluid around the wafer from the liquid. By substituting with fluid, we are developing technology for liquid processing while suppressing the occurrence of pattern collapse. In this technique, in order to adjust the flow of the liquid supplied to the wafer surface, it is considered to provide a current plate in the processing tank. However, the current plate is required to promote the mixing of the liquids and uniformly process the wafer surface, or on the contrary, to suppress the mixing of the liquids and to promote efficient replacement. It has been found that selecting a current plate suitable for replacement of one liquid may create a flow state that is not suitable for replacement of another liquid.

  Here, in Patent Document 1, in a one-bus type cleaning apparatus in which a plurality of cleaning steps are performed in the same cleaning tank, an opening larger than the diameter of the semiconductor substrate is provided above the semiconductor substrate vertically held in the cleaning tank. A technique is described in which cleaning is performed while a processing liquid nozzle is provided and a film-like flow of processing liquid is formed on the surface of the semiconductor substrate, but there is no description regarding the current plate.

  Further, in Patent Document 2, when a substrate is disposed in parallel with a flat surface in a flat cleaning processing container and the cleaning liquid is supplied in one direction parallel to the substrate to clean the substrate, a cleaning liquid supply unit is provided. Describes a technique for providing a louver-like rectifying member to make the flow of the cleaning liquid uniform. However, the substrate cleaning apparatus according to Patent Document 2 only describes a technique for rectifying the same type of cleaning liquid, and the configuration of the rectifying member when the liquid to be replaced is switched is not clear.

Japanese Patent No. 3937508: Paragraph 0012, FIG. JP 2002-224627 A: Paragraph 0056, FIG.

  The present invention has been made in view of such circumstances, and an object thereof is a liquid processing apparatus, a liquid processing method, and a liquid processing apparatus capable of adjusting the flow in the processing tank according to the type of liquid to be replaced. To provide a storage medium storing a method.

In the liquid processing apparatus according to the present invention, an opening is formed in the upper part, and a lower port is provided in the lower part for supplying a replacement liquid to be replaced with an internal gas and for discharging the liquid. A treatment tank for performing liquid treatment of the substrate to be treated;
An upper port for supplying liquid into the treatment tank and discharging gas is provided, and a detachable lid portion that hermetically closes the opening;
In order to adjust the flow of the liquid supplied from the upper port, the first rectifier is configured to be detachable between the substrate to be processed and the upper port, each having one or a plurality of holes. A plate and a second baffle plate;
A storage unit for storing the first rectifying plate and the second rectifying plate outside the processing tank;
A transport mechanism for transporting the first current plate or the second current plate between the storage unit and the processing tank;
When replacing the replacement liquid in the processing tank with the processing liquid supplied from the upper port, the first rectifying plate transported from the storage unit is attached to the processing tank, and then the liquid in the processing tank is When replacing with another liquid supplied from the upper port, a control signal is output so that the first current plate is removed from the processing tank and the second current plate conveyed from the storage unit is attached to the processing tank. A control unit;
After supplying the other liquid into the processing tank, the inside of the processing tank is changed to a supercritical or subcritical high-pressure fluid atmosphere, and then the substrate to be processed is dried by reducing the pressure of the high-pressure fluid into a gas. A dry atmosphere forming part for,
Wherein different from each other from the first total opening area of the hole of the total opening area of the hole of the current plate second rectifier plate.

The liquid processing apparatus may have the following characteristics.
(A) The lid portion is divided into a first lid portion configured integrally with the first rectifying plate and a second lid portion configured integrally with the second rectifying plate, The said conveyance mechanism conveys the said 1st cover part or the 2nd cover part between the said storage part and a processing tank.
(B) The first rectifying plate and the second rectifying plate have different total opening areas of the hole portions by changing at least one of the number of holes and the hole diameter.
(C) Of the first rectifying plate and the second rectifying plate, by making the total opening area of the holes of one rectifying plate smaller than the total opening area of the holes of the other rectifying plate, The degree of mixing of the liquids in the treatment tank when the one rectifying plate is attached is increased.

(D) Of the first rectifying plate and the second rectifying plate, by making the total opening area of the holes of one rectifying plate larger than the total opening area of the holes of the other rectifying plate, The liquid is easily replaced by suppressing the mixing of the liquids in the treatment tank during the period in which the one current plate is disposed.
(E) The processing tank is accommodated in a state where the lid is removed, and an external container is provided that performs a process of making the inside of the processing tank an atmosphere of a high-pressure fluid, and the lid is attached to and detached from the processing tank. A moving mechanism for moving the treatment tank between the position where the treatment is performed and the external container is provided.

  According to the present invention, since the first rectifying plate and the second rectifying plate can be exchanged for the processing tank that performs the liquid treatment of the substrate to be processed, the rectification according to the type of liquid to be replaced is possible. The effect can be exhibited.

It is a perspective view which shows an example of the liquid processing apparatus and wafer delivery mechanism of this Embodiment. It is a schematic diagram which shows the whole structure of the said liquid processing apparatus. It is a partially broken perspective view of the processing tank provided in the said liquid processing apparatus. It is 1st explanatory drawing which shows the structure of the said processing tank and the external container for supercritical processing. It is 2nd explanatory drawing of the said processing tank and an external container. It is a 1st perspective view which shows the structure of the conveyance mechanism of the baffle plate provided in the said liquid processing apparatus. It is a 2nd perspective view which shows the conveyance mechanism of the said baffle plate. It is a perspective view which shows the external appearance structure of the said baffle plate. It is a top view which shows the position of the hole of a 1st baffle plate. It is a top view which shows the position of the hole of a 2nd baffle plate. It is a 1st explanatory view showing an operation of the liquid treatment device. It is the 2nd explanatory view showing an operation of the liquid treatment device. It is the 3rd explanatory view showing an operation of the liquid treatment device. It is the 4th explanatory view showing an operation of the liquid treatment device. It is a 5th explanatory view showing an operation of the liquid treatment device. It is a 6th explanatory view showing an operation of the liquid treatment device. It is a 7th explanatory view showing an operation of the liquid treatment device. FIG. 10 is an eighth explanatory view showing the operation of the liquid processing apparatus. FIG. 10 is a ninth explanatory view showing the operation of the liquid processing apparatus. It is a 10th explanatory view showing an operation of the liquid processing apparatus. It is an eleventh explanatory view showing the operation of the liquid processing apparatus. It is a twelfth explanatory view showing the operation of the liquid processing apparatus. It is 13th explanatory drawing which shows the effect | action of the said liquid processing apparatus. It is the 14th explanatory view showing an operation of the liquid treatment device. It is a top view which shows the position of the hole of the baffle plate concerning another example. It is a vertical side view which shows the structural example of the conveyance mechanism of the cover part in the liquid processing apparatus in connection with another example. It is a 1st explanatory view showing an operation of a liquid processing apparatus concerning the other example.

  As an example of a system including the liquid processing apparatus of the present invention, a liquid processing apparatus 2 that performs liquid processing by supplying a processing liquid to a wafer W that is a substrate to be processed will be described. FIG. 1 is a partially broken perspective view showing a configuration of a liquid processing apparatus 2 of the present embodiment and a mechanism for carrying a wafer W into the liquid processing apparatus 2. The liquid processing apparatus 2 is disposed on, for example, a floor surface in a housing 101 that can be accessed from a wafer transfer mechanism provided outside, and the liquid processing apparatus 2 and an external space are disposed in an upper space thereof. A delivery mechanism for delivering the wafer W to and from the wafer transfer mechanism is provided. In this example, as the delivery mechanism, a delivery arm 11 that holds and transports the wafer W, and a carry-in / out shelf 12 on which the wafer W before and after carrying in / out of the liquid processing apparatus 2 is placed are provided. In FIG. 1, the direction in which the carry-in / out shelf 12 is provided is described as the front.

  The transfer arm 11 is disposed at a position on the upper side and rear side of the liquid processing apparatus 2 disposed on the bottom of the casing 101, for example, and the wafer W 1 is transferred by a fork 111 provided with a vacuum chuck. For example, a 6-axis articulated arm that can be held one by one. Further, the transfer arm 11 is installed in a space partitioned by the partition plate 105 and the support base 106 so that particles generated by the operation of the transfer arm 41 are less likely to enter the space where the wafer W is transferred. I have to. In the figure, reference numeral 104 denotes an access port for allowing the transfer arm 11 to enter a space where the wafer W is transferred.

  The carry-in / out shelf 12 is provided, for example, at a position on the upper side and the front side of the liquid processing apparatus 2, and is connected to an external wafer transfer mechanism via, for example, three lifting pins that hold the wafers W one by one horizontally. The wafer W can be transferred to and from the transfer arm 11. When the loading / unloading shelf 12 is viewed from the front side, the loading / unloading shelf 12 is disposed at a position closer to the upper side and side of the processing tank 22 opening toward the upper surface. With this arrangement, a transfer path for transferring the wafer W in the vertical direction is secured, and the wafer W can be quickly transferred into and out of the processing tank 22 without interfering with the loading / unloading shelf 12. 1 is not limited to the case where only one carry-in / out shelf 12 is provided as shown in FIG. 1, but two carry-in / out shelves 12 for carrying-in and carrying-out may be provided to suppress recontamination of the wafer W after liquid processing. .

  In FIG. 1, reference numeral 103 denotes a loading / unloading port for loading and unloading the wafers W before and after the liquid processing, and an external wafer transfer mechanism enters the housing 101 through the loading / unloading port 103. Reference numeral 102 denotes an FFU (Fan Filter Unit) for forming a clean air downflow in the casing 101, and 107 denotes an exhaust port for the downflow.

  The liquid processing apparatus 2 provided in the casing 101 uses the high-pressure fluid, for example, a supercritical fluid, to dry the wafer W without forming a gas-liquid interface on the surface after performing the liquid processing. Can do. As shown in FIG. 2, the liquid processing apparatus 2 uses a processing tank 22 in which liquid processing is performed on the wafer W, a lid 23 that seals the processing tank 22 when performing liquid processing, and a supercritical fluid. And an external container 21 that accommodates a processing tank 22 when the wafer W is dried.

  As shown in FIGS. 4 and 5, the outer container 21 is configured as, for example, a rectangular parallelepiped pressure-resistant container that is flat in the vertical direction, and a space capable of accommodating the processing tank 22 is formed therein. Yes. As shown in FIG. 2, the outer container 21 is provided with a heater 212 made of, for example, a resistance heating element. The main body of the outer container 21 is heated by power supply from the power supply unit 213, thereby preventing drying, which will be described later. The liquid can be heated to a supercritical state. A heating mechanism constituted by the heater 212 and the like constitutes a part of the dry atmosphere forming unit of the present embodiment.

  As shown in FIG. 3, the processing tank 22 is a container that can store one or a plurality of wafers W in a vertical direction, and the wafer is immersed in a processing liquid or a liquid for preventing drying described later. W can be held. The processing tank 22 has a shape that is narrower than the internal space of the outer container 21 and is flat in the vertical direction. The outer container 21 can accommodate the processing tank 22 in the space.

  Here, when storing a plurality of wafers W in the processing tank 22, for example, adjacent surfaces of the wafers W are arranged so that the surfaces on which the patterns are formed are opposed to each other. It is good to avoid. In the case where the number of wafers W is an odd number, it is preferable that the remaining one wafer W face the pattern forming surface toward the other wafer W so as not to face the wall surface of the processing bath 22.

As shown in FIG. 3, an opening 222 is provided on the upper surface of the processing tank 22, and the wafer W held by the transfer arm 11 is carried into the processing tank 22 through this opening.
On the other hand, the bottom of the processing tank 22 is curved along the shape of the wafer W, and a wafer holding member 223 for holding the wafer W is provided on the lower side of the space for storing the wafer W. . The wafer holding member 223 has a groove (not shown) formed along the shape of the wafer W, and the wafer W can be held vertically by fitting the peripheral edge of the wafer W into the groove. . Further, the wafer holding member 223 is configured so that even if the liquid supplied to the processing tank 22 is sufficiently in contact with the surface of each wafer W and the fork 111 holding the wafer W enters the processing tank 22, The groove arrangement position and the gap between the grooves are adjusted so that the fork 111 does not interfere with other wafers W and the main body of the processing tank 22.

  As shown in FIG. 3, an opening for supplying DIW (Deion Ized Water), which is a replacement liquid that replaces the gas in the processing tank 22, and discharging various liquids and supercritical fluids is provided on the bottom surface of the processing tank 22. A portion 224 is provided. As shown in FIG. 2, the opening 224 is connected to a supply / discharge line 34 via a fluid supply / discharge port 226. As will be described later, since the processing tank 22 can move in the lateral direction, the supply / discharge line 34 is constituted by, for example, a flexible pipe having pressure resistance, and can be deformed as the processing tank 22 moves. . The supply / discharge port 226 corresponds to the lower port of the present embodiment. Further, in terms of discharging the supercritical fluid and turning the supercritical fluid into a gas by decompression, the supply / discharge port 226 also has a function as a part of the dry atmosphere forming unit.

  As shown in FIG. 2, a switching valve V6 composed of a composite valve or the like is provided at the other end side of the supply / discharge line 34 connected to the supply / discharge port 226. A DIW supply unit 311 that supplies DIW, which is a liquid that is substituted for the gas, and a piping line that continues to, for example, an external detoxification facility or a treatment liquid recovery facility are connected.

  The processing tank 22 is fixed to the thick sealing plate 221 at, for example, a narrow side surface portion. Then, by moving the sealing plate 221 in the lateral direction, a transfer position where the wafer W is transferred to and from the transfer arm 11 and a position where attachment and detachment of the lid 23 described later are performed, and an external container The treatment tank 22 can be moved between the two. Further, as will be described later, in the liquid processing apparatus 2 according to this example, the rectifying plate 27 can be replaced at the transfer position of the wafer W.

  Further, as shown by a broken line in FIG. 2, the sealing plate 221 also plays a role of closing the opening 211 of the external container 21 when the processing tank 12 is accommodated in the external container 21. An O-ring (not shown) is provided around the opening 211 of the outer container 21, and the sealing plate 221 can crush the O-ring to seal the processing space in the outer container 21.

  As shown in FIGS. 4 and 5, the sealing plate 221 is supported by a pedestal portion 26. For example, the pedestal portion 26 has a traveling track 261 cut out from the pedestal portion 26 along the direction in which the treatment tank 22 is moved. Is formed. On the other hand, a traveling member 225 that extends downward toward the traveling track 261 is provided at the lower end of the sealing plate 221. As shown in FIGS. 2 and 4, the traveling member 225 has a ball screw 263 passed along the traveling track 261, and the traveling member 225 and the ball screw 263 constitute a ball screw mechanism. Yes.

  Then, the driving member 262 (FIG. 2) provided at one end of the ball screw 263 rotates the ball screw 263 in either the left or right direction, so that the traveling member 225 travels within the traveling track 261, thereby delivering the wafer W. From the position, the processing tank 22 can be moved to a position below the lid 23 or to the external container 21. On the contrary, by rotating the ball screw 263 in the opposite direction, the processing tank 22 can be moved from the inside of the outer container 21 toward the delivery position. In these viewpoints, the ball screw 263, the traveling member 225, and the driving unit 262 correspond to a moving mechanism of the processing tank 22. However, the moving mechanism for moving the processing tank 22 is not limited to the above-described example of the ball screw mechanism, and for example, a linear motor, a telescopic arm, an air cylinder, or the like may be used.

  Moreover, as shown in FIGS. 1 and 4 to 5, the liquid processing apparatus 2 is provided with a wall portion 24 so as to cover an area in which the sealing plate 221 and the processing tank 22 move from the side surface. The wall portion 24 includes two side wall members 241 extending along the traveling direction of the sealing plate 221 and a front wall member 242 provided so as to face the opening portion 211 of the outer container 21. One end on the far side of the two side wall members 241 is firmly fixed to, for example, the side wall surface of the outer container 21, so that the wall portion 24 is integrated with the outer container 21.

  Further, the liquid processing apparatus 2 faces the sealing plate 221 toward the outer container 21 against the internal pressure received by the sealing plate 221 when drying the wafer W using the supercritical fluid in the outer container 21. A fixing plate 25 is provided for pressing down. The fixing plate 25 does not have a gap between a position where the processing tank 22 and the sealing plate 221 are retracted from the lateral movement region and a position where the sealing plate 221 is pressed toward the external container 21 from the side. It is configured to be movable in the lateral direction by the illustrated driving mechanism.

  On the other hand, the two side wall members 241 are formed with insertion holes 243 through which the fixing plate 25 that moves in the left-right direction can be passed, and waits outside the wall portion 24 (side wall member 241). The fixing plate 25 that has moved can pass through the insertion hole 243 of the side wall member 241 on one side and move to a position where the sealing plate 221 is fixed. In addition, the fixing plate 25 that has moved to the position for fixing the sealing plate 221 is in a state in which both right and left end portions thereof are fitted into the fitting holes 243 of the respective side wall members 241. The sealing plate 221 can be pressed against the pressure in the outer container 21 (see FIG. 5).

  Next, a description will be given of the lid portion 23 for supplying a treatment liquid, a drying prevention liquid, and the like to the treatment tank 22. As shown in FIGS. 1 and 2, the lid 23 is disposed between the transfer position of the wafer W described above and the external container 21, and the processing tank 22 moves laterally between these positions. On the upper side, for example, it is supported by a wall portion 24 (side wall member 241).

  The lid portion 23 functions to hermetically close the opening portion 222 formed on the upper surface of the processing tank 22 to seal the processing tank 22, and is formed by a member elongated in the front-rear direction, for example, in accordance with the shape of the opening portion 222. Has been. A concave portion 233 is formed on the lower surface of the lid portion 23 so as to become deeper from the peripheral portion toward the central portion. The top end of the concave portion 233 penetrates through the member forming the lid portion 23 and enters the treatment tank 22. A supply / discharge port 234 which is an upper port for supplying a fluid and discharging a fluid in the processing tank 22 is opened.

  As shown in FIG. 2, the supply / discharge port 234 is connected to a switching valve V4 composed of a composite valve or the like. The valve V4 is connected to the DIW supply unit 311, the DHF supply unit 312 and the IPA via the liquid supply line 32. A supply unit 313 is connected. The DHF supply unit 312 serves to supply DHF (Diluted Hydro Fluoric acid) as a processing liquid into the processing tank 22 through the supply / discharge port 234.

  The DIW supply unit 311 also has a role of supplying DIW to the processing tank 22 after the processing by the DHF in addition to the supply of the replacement liquid described above. In this case, the DIW is a wafer after the liquid processing is completed. This corresponds to a rinsing liquid for rinsing with W. The IPA supply unit 313 plays a role of supplying IPA, which is a liquid for preventing drying, in order to prevent the wafer W from being dried after the rinse cleaning. Here, V1 to V3 shown in FIG. 2 are open / close valves.

  Further, the above-described switching valve V4 is connected to a discharge line 33 leading to an external detoxification facility, a treatment liquid recovery facility, and the like, and the discharge line 33 and the opening / closing valve V5 provided therein are Are connected to the supply / discharge port 234 side.

  The lid portion 23 having such a configuration is supported by the wall portion 24 via an elevating mechanism 238 as shown in FIG. As a result, the lid 23 is attached to the processing tank 22, and the opening 222 is closed and sealed, and the lid 23 is removed from the processing tank 22 by retreating upward from the sealing position. The lid part 23 can be raised / lowered between the open position and the open position. By removing the lid 23, the processing tank 22 can be moved freely in the lateral direction to transfer the wafer W to / from the transfer arm 11, or to store the processing tank 22 in the external container 21. Is possible.

  As described above, the lid portion 23 is configured to be movable up and down by the elevating mechanism 238. Therefore, the liquid supply line 32 and the discharge line 33 connected to the supply / discharge port 234 are configured by flexible piping or the like. It can be deformed with the movement of. For convenience of illustration, the illustration of the lifting mechanism 238 of the lid portion 23 is omitted in the drawings other than FIG.

  In the liquid processing apparatus 2 according to the present embodiment having the above-described configuration, the supply / discharge port 234, the processing tank 22, and the like are adjusted in order to adjust the flow of various liquids supplied from the supply / discharge port 234. A rectifying plate 27 is disposed between the two. As described in the background art, the rectifying plate 27 may have different functions depending on the type of liquid to be replaced. However, the liquid processing apparatus 2 according to the present embodiment has a plurality of types of rectifying. By replacing the plates 27a and 27b, flow adjustment (rectifying action) suitable for the type of liquid to be replaced can be performed. Hereinafter, the configuration of the rectifying plates 27a and 27b and the mechanism for replacing them will be described.

  As shown in FIG. 1, the liquid processing apparatus 2 of this example includes a storage shelf 5 corresponding to a storage unit for the current plates 27 a and 27 b and a current plate 27 a and 27 b between the storage shelf 5 and the processing tank 22. And a transport mechanism 4 for transport. The storage shelf 5 is disposed, for example, at the front position on the right hand side of the wall 24 surrounding the processing tank 22 when viewed from the delivery arm 11, and is attached to the side wall surface of the casing 101 that covers the liquid processing apparatus 2. As shown in FIG. 6, the storage shelf 5 includes, for example, two-stage shelf plates 51, and can store the rectifying plates 27 a and 27 b one by one at a predetermined position on each shelf plate 51. A connection portion between the storage shelf 5 and the side wall surface of the housing 101 is opened, and the transport mechanism 4 can access the rectifying plates 27a and 27b through the opening.

  The transfer mechanism 4 is disposed on the same side as the storage shelf 5 at a side position of the wall portion 24, and is provided on both the storage shelf 5 and the processing tank 22 moved to the delivery position of the wafer W. Access is possible (FIG. 1). As shown in FIGS. 6 and 7, the transport mechanism 4 of the present example includes an arm portion 42 having a chuck portion 41 that grips the rectifying plates 27 a and 27 b at the distal end portion, and a support shaft 43 that supports the arm portion 42. And a drive unit 44 that moves the spindle 43 up and down and rotates, and a base unit 45 that supports the drive unit so as to be movable in the lateral direction.

  As shown in FIG. 8, the chuck portion 41 plays a role of gripping and gripping a handle portion 271 provided on the rectifying plate 27 (27a, 27b). Further, the arm portion 42 is bent downward on the tip side where the chuck portion 41 is provided so that the current plates 27 a and 27 b can be attached to the processing tank 22 across the surrounding wall portion 24.

  As shown in FIG. 6, the transport mechanism 4 having the above configuration directs the arm portion 42 toward the storage shelf 5 and enters the chuck portion 41 in accordance with the height position of each shelf plate 51 to make the current plates 27 a and 27 b. Grip. Then, after the drive unit 44 on the base unit 45 is retracted and the support shaft 43 is extended, the direction of the arm unit 42 is changed to rectify to a position above the opening 222 of the processing tank 22 as shown in FIG. The current plates 27a and 27b can be attached to the processing tank 22 by transporting the plates 27a and 27b and lowering the arm part 42.

  The rectifying plates 27 a and 27 b attached to the processing tank 22 serve to disperse the liquid supplied from the supply / discharge port 234 into the recess 233 and supply the liquid into the processing tank 22. The rectifying plates 27a and 27b are constituted by elongated plate-like members corresponding to the shape of the opening 222 so that the rectifying plates 27a and 27b can be fitted into the opening 222 and attached to the processing tank 22. The rectifying plates 27a and 27b are formed with holes 272. By changing the number of holes and the diameter of the holes 272, a rectifying action according to the type of liquid to be replaced can be obtained.

  For example, the rectifying plate 27a shown in FIG. 9 includes a hole 272 designed to exhibit a rectifying action suitable for replacement of DIW as a replacement liquid and DHF as a processing liquid. For example, DHF plays a role of removing a natural oxide film or the like formed on the surface of the wafer W. However, if the concentration of DHF is not uniform in the processing tank 22, unevenness in liquid processing by DHF may occur. There is.

  Therefore, the rectifying plate 27a according to this example has a configuration in which two holes 272 having a diameter of 2 mm are provided in a plane having a short side of about 5 mm and a long side of about 365 mm. By reducing the total opening area of these holes 272, the flow rate of DHF passing through the holes 272 can be increased, and the flow of the DHF can be greatly contracted and expanded. As a result, the mixing of the supply / discharge port 234 and the liquid in the processing tank 22 is promoted, and the replacement of DIW and DHF can be promoted while the concentration of DHF in the processing tank 22 is made uniform.

  In the drawing, a circle indicated by a broken line indicates a position below the opening of the supply / discharge port 234, and each hole 272 is arranged at a position shifted from the position below the opening. As a result, the fluid discharged from the supply / discharge port 234 collides with the rectifying plate 27 and changes its flow direction, and then flows through each hole 272, so that the dispersion action by providing the rectifying plate 27 is reliably exhibited. be able to. In this example, the current plate 27a corresponds to a first current plate.

  On the other hand, FIG. 10 shows a current plate 27b that is attached when the processing of the wafer W by DHF is completed and the inside of the processing tank 22 filled with DIW is replaced with IPA that is a liquid for preventing drying. Yes. DIW and IPA are almost inactive with respect to the wafer W, and there is no inconvenience such as processing unevenness even if the concentration in the processing tank 22 when contacting the wafer W is non-uniform. For this reason, if the flow which extrudes DIW by IPA can be formed in a state where these liquids are separated into two phases while suppressing mixing of DIW and IPA, the replacement of the liquid can be completed in a relatively short time.

  Therefore, the current plate 27b is provided in a plane similar to that of the current plate 27a, for example, ten holes 272 each having a diameter of 1 mm, arranged in two rows in a total of ten. By providing a large number of holes 272 in this manner, the total opening area is increased, and the average flow rate of IPA passing through each hole 272 is reduced. As a result, the disturbance of the IPA flow before and after passing through the hole 272 is reduced, and liquid replacement can be performed in a short time while suppressing mixing of DIW and IPA. The current plate 27b in this example corresponds to a second current plate.

  The liquid processing apparatus 2 having the configuration described above is connected to the control unit 6 as shown in FIG. For example, the control unit 6 includes a computer having a CPU and a storage unit (not shown). The storage unit receives the operation of the liquid processing apparatus 2, that is, receives the wafer W from the outside and carries it into the processing tank 22 for liquid processing. Next, after drying using a supercritical fluid, a program in which a group of steps (commands) related to the operation for delivering the processed wafer W to an external wafer transfer mechanism is recorded is recorded. Yes. 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.

  In particular, the control unit 6 outputs control signals to the various valves V1 to V6, the drive unit 262, the power supply unit 213, and the like as illustrated in FIG. It is possible to switch the supply position and timing of the fluid supplied inside, the type of fluid, the position and timing of discharging the fluid from the processing tank 22, the supply of the fluid, the adjustment of the discharge amount, and the like. Furthermore, the control unit 6 also plays a role of operating the transport mechanism 4 so as to select appropriate rectifying plates 27 a and 27 b and attach them to the processing tank 22 in accordance with the type of liquid to be supplied. The temperature in the external container 21 is also increased or decreased based on the temperature detected by a temperature detection unit (not shown) to increase or decrease the amount of electric power supplied from the power supply unit 213, and the fluid in the processing tank 22 accommodated in the external container 21. Can be heated to a desired temperature.

  The operation of the liquid processing apparatus 2 having the configuration described above will be described with reference to FIGS. First, when an external wafer transfer mechanism enters the housing 101 via the loading / unloading port 103 and transfers the wafer W to the lifting pins of the loading / unloading shelf 12, the transfer arm 11 is located below the wafer W supported by the lifting pins. The fork 111 is inserted into the fork 111 and then the lift pins are lowered to receive the wafer W on the fork 111. At this time, the processing tank 22 into which the wafer W can be loaded is waiting at the delivery position in an empty state where the liquid is not filled therein.

  The transfer arm 11 that has received the wafer W from the loading / unloading shelf 12 raises the wafer W vertically and rotates each rotation shaft so that the tip of the fork 111 faces the opening of the processing tank 22. As shown, the fork 111 is lowered to carry the wafer W into the processing tank 22 (however, the description of the fork 111 is omitted in FIG. 11). When a predetermined number of wafers W are thus stored in the processing tank 22, the fork 111 is retracted from the processing tank 22.

  When the wafer W is accommodated in the processing tank, the arm portion 42 of the transfer mechanism 4 is moved to take out the rectifying plate 27a from the storage shelf 5 and transferred to a position above the opening 222 of the processing tank 22 as shown in FIG. Then, the flow regulating plate 27a is attached by being fitted into the opening 222. When the attachment of the current plate 27a is completed, the processing tank 22 is moved to a position where the lid portion 23 is attached. For convenience of illustration, the description of the handle portion 271 of each of the rectifying plates 27a and 27b is omitted except for FIG. 8, FIG. 12, and FIG.

  As shown in FIG. 13, when the processing tank 22 arrives at the mounting position of the lid 23, the lid 23 that has been waiting in the open position is lowered, and the lid 23 is placed on the processing tank 22 to open it. The part 222 is airtightly closed, and the inside of the processing tank 22 is sealed. At this time, the switching valves V4 and V6 are in a closed state with respect to any line, for example (indicated by “S” in FIG. 13 and the same in other drawings), and the processing tank 22 However, no fluid is supplied or discharged.

  When the lid portion 23 is attached, the valve portion connected to the DIW supply portion 311 of the lower switching valve V6 is opened as shown in FIG. 14 (the symbol “O” is attached in FIG. 14). While the DIW is received, the upper switching valve V4 opens the valve connected to the discharge line 33, and discharges the gas in the processing tank 22. By this operation, the inside of the sealed processing tank 22 is gradually replaced with DIW which is a liquid from the lower side toward the upper side. By supplying DIW from the supply / discharge port 226 on the lower side in this manner, it is difficult for splashes and bubbles to be formed in the processing tank 22, and the wafer W is brought into the DIW while the bubbles remain attached to the surface. Generation | occurrence | production of the state of being immersed can be suppressed.

  When the inside of the concave portion 233 of the processing tank 22 and the lid portion 23 is replaced with DIW, as shown in FIG. 15, the valve portion connected to the liquid supply line 32 of the upper switching valve V4 is opened. Then, DIW is caused to flow from the DIW supply unit 311 toward the discharge line 33 from the liquid supply line 32. By this operation, the DIW replaces the gas remaining in the liquid supply line 32 upstream of the supply / discharge port 234, the switching valve V4, and the system on the discharge line 33 side of the supply / discharge port 234. Further, it is possible to suppress re-entry of gas into the processing tank 22 during the supply operation of DHF or the like at the subsequent stage. At this time, the switching valve V6 on the lower side may be fully closed so that DIW and bubbles flowing toward the discharge line 33 do not flow into the processing tank 22 side.

  When the inside of the processing tank 22, the concave portion 233 of the lid portion 23, the supply / discharge port 234, the upstream liquid supply line 32, and the downstream discharge line 33 are replaced with DIW, as shown in FIG. In the side switching valve V4, the valve connected to the discharge line 33 is closed, and the liquid supply line 32 side is left open. On the other hand, the lower switching valve V6 opens a valve portion connected to a piping line for discharging the liquid in the processing tank 22 to the outside. In this way, while the liquid in the processing tank 22 is drained from the lower supply / discharge port 226, the upper supply / discharge port 234 supplies, for example, DHF, which is the same amount of processing liquid, from the DHF supply unit 312.

  As a result, the DHF supplied from the supply / discharge port 234 on the upper side passes through the hole 272 of the rectifying plate 27a and is distributedly supplied into the processing tank 22, so that the concentration of hydrogen fluoride in the processing tank 22 increases. Unnecessary natural oxide films formed on the surface of the wafer W are removed. At this time, since there are only two holes 272 provided in the rectifying plate 27a and the total opening area is relatively small, the flow velocity of DHF flowing through the holes 272 is increased, and the DHF The flow also contracts and expands greatly. As a result, the disturbance of the DHF flow is increased, DIW and DHF are mixed in the processing tank 22, and the wafer W liquid processing can be performed in a more uniform state. Here, the supply amount per unit time of DHF supplied from the supply / discharge port 234 is, for example, within the range that can be adjusted by a flow rate control valve (not shown) provided in the DHF supply unit 312, and the processing unevenness is the smallest. It is advisable to determine the supply amount by a preliminary experiment or the like.

  At this time, since the inside of the treatment tank 22 is filled with DIW in advance, even if DHF is supplied from the supply / discharge port 234 on the upper side, splashing and bubbles are unlikely to occur. Also, DIW filled in the processing tank 22 in advance is supplied from the supply / discharge port 226 on the lower side, and since there are few bubbles adhering to the surface of the wafer W, DHF spreads over the surface of the wafer W evenly. The occurrence of processing unevenness is suppressed.

  Then, by forming a flow of DHF flowing from the upper side toward the lower side in the processing tank 22, it is possible to prevent particles from being rolled up in the processing tank 22, and to prevent particles from being reattached to the wafer W from the processing tank 22. Can be discharged. The effect of suppressing the reattachment of particles by forming a flow from the upper side to the lower side is also exhibited in the replacement operation with the rinsing liquid (DIW) or the drying prevention liquid (IPA) at the subsequent stage. .

  When DIW in the processing tank 22 is replaced with DHF and liquid processing is performed for a preset time, the liquid supplied to the upper supply / discharge port 234 is switched from DHF to DIW as shown in FIG. Then, the inside of the processing tank 22 is replaced with DIW. At this time, the DIW supplied into the processing tank 22 serves as a rinsing liquid for removing DHF from the surface of the wafer W, and the liquid processing of the wafer W is stopped by replacing DHF with DIW.

  At this time, the flow of DIW passing through the hole 272 is disturbed and the mixing of DHF and DIW is promoted, so that the concentration of the mixed fluid of DIW and DHF is more uniform over the entire surface of the wafer W. Thus, the liquid processing can be stopped while suppressing the occurrence of processing unevenness.

  When the DHF in the processing tank 22 is replaced with DIW, the valves V4 and V6 are closed, the lid 23 is raised to the open position, and the processing tank 22 is moved to the delivery position where the rectifying plates 27a and 27b are replaced. (FIG. 18). Here, when the lid 23 is removed, the DIW filled in the recess 233 flows down. However, a receiving tray is provided on the lower side of the processing tank 22 at the position where the lid 23 is removed, and the drained DIW is discharged to the outside. You may make it do.

  When the processing tank 22 filled with DIW reaches the delivery position, the transport mechanism 4 is operated to remove the rectifying plate 27a and return it to the storage shelf 5. Then, after the rectifying plate 27b for replacement with IPA is taken out and attached to the opening 222 of the processing tank 22 as shown in FIG. 19, the processing tank 22 is moved, and the lid portion 23 is mounted again.

  When the lid portion 23 is mounted, first, the valve portion connected to the DIW supply portion 311 of the lower side switching valve V6 and the discharge side valve portion of the upper side switching valve V4 are opened to supply DIW and the lid The gas in the recess 233 of the part 23 is expelled (not shown). After that, as shown in FIG. 20, the valve section connected to the IPA supply section 313 of the upper switching valve V4 and the valve section connected to the discharge line 33 of the lower switching valve V6 are opened, and the processing tank Replace DIW in 22 with IPA. This IPA plays a role of preventing drying of the wafer W after the liquid processing and preventing the occurrence of pattern collapse, and in the subsequent processing of drying the wafer W using the supercritical fluid, Become.

  At this time, the rectifying plate 27b is provided with a total of ten holes 272, and the total opening area is relatively large, so that the flow rate of the IPA flowing through the holes 272 is reduced. IPA can be dissolved in DIW. However, if IPA is slowly supplied from the upper side while removing DIW from the lower side, the difference in specific gravity between IPA and DIW causes the two liquids as shown in FIG. The inventors have grasped that it is possible to efficiently replace the DIW in the treatment tank 22 while maintaining the state where the phases are substantially separated. The supply amount of IPA per unit time from the supply / discharge port 234 that can be replaced while maintaining the state where the IPA and DIW are substantially separated may be grasped by preliminary experiments.

  When the inside of the processing tank 22 is replaced with IPA, the upper and lower switching valves V4 and V6 are all closed to stop the supply and discharge of the liquid in the processing tank 22, and then the lid 23 is moved to the open position. The lid 23 is removed from the treatment tank 22 by raising (FIG. 21). At this time, IPA may flow down from the recess 233 of the lid 23, but the IPA may be discharged to the outside or collected via a tray provided on the lower side of the processing tank 22.

  When the lid portion 23 is removed, the processing tank 22 is moved to the delivery position, the flow regulating plate 27b is removed by the transport mechanism 4 (not shown), and then the processing tank 22 is moved into the external container 21 (FIG. 22). . Then, the fixing plate 25 is moved, the sealing plate 221 is pressed from the side, the power supply unit 213 is turned on as shown in FIG. 23, power is supplied to the heater 212, and the inside of the processing tank 22 is, for example, 100 ° C. Heat to 270 ° C in the range of ~ 300 ° C. Here, the processing tank 22 may be carried into the external container 21 with the rectifying plate 27b attached, and a heater is provided so that the evaporation of IPA is started as soon as the processing tank 22 is accommodated in the external container 21. 212 may always be in a heated state.

  When the processing tank 22 is heated, the opening 211 of the external container 21 is sealed with the sealing plate 221 and all the switching valves V6 downstream of the supply / discharge port 226 are also closed. When the IPA in the inside evaporates into a gas, the pressure in the external container 21 (treatment tank 22) increases with the expansion of the IPA volume. Furthermore, when the heating in the sealed atmosphere is continued and the temperature and pressure of the IPA are increased and increased, the temperature and pressure of the IPA reach the critical point, and the inside of the treatment tank 22 is filled with the supercritical IPA. It becomes.

  As a result, the surface of the wafer W is replaced with the IPA in the supercritical state from the liquid IPA. However, since no interface is formed between the liquid and the supercritical fluid in the equilibrium state, the pattern collapses. The fluid on the surface of the wafer W can be replaced with the supercritical fluid without any problem. In this way, when a predetermined time has elapsed since the start of heating of the IPA, and the IPA in the treatment tank 22 changes from a liquid to a supercritical fluid to become a supercritical fluid atmosphere, as shown in FIG. The valve part connected to is opened, IPA is discharged, and the supercritical atmosphere in the outer container 21 (treatment tank 22) is decompressed.

At this time, by maintaining the inside of the outer container 21 at or above the condensation temperature of the IPA, the IPA can be discharged while preventing liquefaction again, and the wafer W can be dried while preventing the pattern collapse. .
When the drying of the wafer W is completed, the fixing plate 25 is moved to release the fixing of the sealing plate 221, the processing tank 22 is moved to the delivery position, the wafer W is taken out in the reverse order of loading, and the external transfer is performed. The dried wafer W is delivered to the means and the liquid processing is finished.

  The liquid processing apparatus 2 according to the present embodiment has the following effects. The first rectifying plate (rectifying plate 27a) and the second rectifying plate (rectifying plate 27b) can be attached to the processing tank 22 for performing the liquid processing of the wafer W in an exchangeable manner. As a result, depending on the type of the liquid to be replaced, the mixing of the fluid is promoted to perform the replacement while maintaining the liquid concentration in the processing tank 22 to be uniform, or on the contrary, the mixing of the liquids is suppressed. Replacement can be performed in a short time.

Further, after the liquid processing is performed, drying of the wafer W with the supercritical fluid is started in a state where the processing tank 22 is filled with the liquid for preventing drying, so that the wafer W is not exposed to the gas atmosphere and the pattern collapses. Occurrence is suppressed.
In addition, there are only two pipes connected to the lower supply / discharge port 226: the DIW supply unit 311 and the piping line connected to the outside, while the upper supply / discharge port 234 is supplied with DIW. The unit 311, the DHF supply unit 312, the IPA supply unit 313, and four piping lines to the outside are connected. Thus, by reducing the number of piping lines connected to the supply / discharge ports 226 accommodated in the external container 21 that is in a high-pressure atmosphere, for example, the piping that requires a pressure-resistant structure is shortened, thereby increasing the device cost. Can be suppressed.

  The rectifying plates 27a and 27b replaced by the liquid processing apparatus 2 are not limited to two, and three or more rectifying plates 27 may be replaced based on the liquid to be replaced and the combination of the liquid to be replaced. . For example, FIG. 25 shows a rectifying plate 27c that is attached when replacing the liquid in the processing tank 22 from DHF to DIW after the liquid processing by DHF is completed. For example, if an unnecessary natural oxide film or the like is sufficiently removed by DHF, processing unevenness may not occur on the wafer W even if the DHF concentration changes abruptly. In this case, it may be preferable to replace DHF and DIW quickly to shorten the processing time of the entire liquid processing apparatus 2.

  Therefore, in order to perform replacement while suppressing the mixing of liquids, it is conceivable to employ a method of increasing the total opening area of the holes 272 arranged in the rectifying plate 27c. At this time, compared with the above-described replacement of DIW with IPA, DIW and DHF are close in specific gravity, so that the liquids are easily mixed with each other. Therefore, the current plate 27c of this example is provided with, for example, 17 holes 272 each having a diameter of 1 mm, for a total of 34 holes, as shown in FIG. Is even larger.

  As a result, the flow rate of DIW flowing out from the hole 272 can be further reduced, and the liquid can be replaced from DHW to DIW while suppressing mutual mixing. Therefore, in this example, the current plate 27a is attached in the first replacement from DIW to DHF, and the current plate 27c is attached in the replacement from DHF to DIW. When the DIW is replaced with the IPA, the rectifying plate 27b is attached and the rectifying effect corresponding to each liquid is exhibited. At this time, when viewed from the rectifying plate 27a (first rectifying plate) attached during the liquid treatment, both of the rectifying plates 27c and 27b correspond to the second rectifying plate. The total opening area of the hole 272 can be changed by changing at least one of the number of holes and the hole diameter.

  Further, the configurations of the transport mechanism 4 and the storage shelf 5 are not limited to the examples illustrated in FIGS. 6 and 7, and other configurations may be adopted. For example, in the liquid processing apparatus 2a shown in FIGS. 26 and 27, the lid portions 23a and 23b (first and second lid portions) and the rectifying plates 27a and 27b (first and second rectifying plates) are integrated. The rectifying plates 27a and 27b are replaced by changing the lid portions 23a and 23b that are configured and attached to the processing tank 22.

  As shown in FIG. 26, the lids 23a and 23b are supported from above by elevating mechanisms 238a and 238b for raising and lowering the lids 23a and 23b. Then, the elevating mechanisms 238a and 238b are moved laterally on the traveling rail 28 by a drive unit (not shown), thereby processing the rectifying plates 27a and 27b and the lid portions 23a and 23b formed integrally therewith. It can be made to face the opening 222 of the tank 22.

  When the lids 23a, 23b and the current plates 27a, 27b reach the position above the opening 222 of the processing tank 22, the lifting mechanisms 238a, 238b are operated to lower the lids 23a, 23b as shown in FIG. In addition, by closing the opening 222 in an airtight manner, the attachment of the lids 23a and 23b and the attachment of the rectifying plates 27a and 27b are performed simultaneously.

For example, a DIW supply unit 311 and a DHF supply unit 312 are connected to the supply / discharge port 234a of the lid portion 23a configured integrally with the rectifying plate 27a, and from the DIW as a replacement liquid in a state where the lid portion 23a is mounted. Replacement with DHF and replacement with DHF to DIW are performed. On the other hand, an IPA supply unit 313 is connected to the supply / discharge port 234b of the lid part 23b that is formed integrally with the rectifying plate 27b. The lid 23b is attached to the processing tank 22 to replace DIW with IPA. Done.
In the example of the liquid processing apparatus 2a shown in FIGS. 26 and 27, the elevating mechanisms 238a and 238b, the travel rail 28, and the drive unit (not shown) that moves the elevating mechanisms 238a and 238b on the travel rail 28 are used as the transport mechanism. Correspondingly, the space above the processing tank 22 corresponds to the storage part of the rectifying plates 27a, 27b.

  The formation of the supercritical fluid atmosphere is not limited to the case where the processing tank 22 is accommodated in the external container 21. For example, the processing tank 22 and the lid portion 23 are strongly fastened to each other as a pressure-resistant structure, a heater is provided in the processing tank 22 and the lid portion 23 to heat the internal IPA, and the inside of the processing tank 22 is set as a supercritical fluid atmosphere. You may dry. Also in this case, the present invention in which the rectifying plates 27a and 27b are replaced at the time of liquid replacement can be applied.

  Further, the dry atmosphere forming unit is not limited to the case where the IPA in the treatment tank 22 is heated to form a supercritical fluid atmosphere. For example, a high-pressure fluid supply unit composed of a container storing carbon dioxide supercritical fluid is connected to the treatment tank 22 and the external container 21, and a liquid for preventing drying (such as IPA) is discharged while supplying the supercritical fluid from the outside. By doing so, the inside of the processing tank 22 may be a supercritical fluid atmosphere. Thereafter, the wafer W is dried by reducing the pressure in the processing tank 22. At this time, for example, a configuration in which a supercritical fluid supply port is provided in the external container 21 and a supercritical fluid is supplied from an external high-pressure fluid supply unit through the supercritical fluid supply port can be considered.

  Thus, the method of forming the supercritical fluid atmosphere by supplying the supercritical fluid from the high-pressure fluid supply unit 54 connected to the processing tank 22 is performed when the processing tank 22 is accommodated in the external container 21. However, the present invention can be applied to the case where the wafer W is dried with the supercritical fluid while the lid 23 is attached to the processing tank 22 as exemplified above.

  The various liquid processing apparatuses 2 and 2a for drying the wafer W using the supercritical fluid after performing the liquid processing on the wafer W have been described above. However, the processing liquid for processing the wafer W is limited to DHF. It is not a thing. For example, the present invention is also applied to liquid processing using other types of processing liquids such as SC1 liquid (mixed liquid of ammonia and hydrogen peroxide) for removing particles and organic contaminants attached to the wafer W. it can. Further, in the various liquid processing apparatuses 2 described above, an example of the processing tank 22 that holds the wafer W in a vertically placed state is shown, but the present invention is also applied to the processing tank 22 that holds the wafer W in a horizontally placed state. be able to.

  In each of the above-described embodiments, the second rectifying plate (rectifying plates 27b and 27c) has a larger total opening area of the hole 272 than the first rectifying plate (rectifying plate 27a). showed that. However, a configuration in which the total opening area of the first rectifying plate is larger than that of the second rectifying plate may be adopted depending on the type and properties of the liquid to be replaced, such as the processing liquid to be selected Of course. The high-pressure fluid atmosphere for drying the wafer W is not limited to the supercritical fluid atmosphere, and may be a subcritical fluid atmosphere.

  In each example described above, the liquid in the treatment tank 22 is replaced in the order of replacement with gas by DIW (substitution liquid) → liquid treatment with DHF → rinse cleaning with DIW → preventing drying by IPA, and finally high pressure fluid ( An example in which the wafer W is dried using a supercritical fluid or a subcritical fluid) has been described. However, when the liquid in the processing tank 22 containing the wafer W is replaced and liquid processing is performed, the technology of selecting the rectifying plate 27 having an appropriate opening area in accordance with the liquid to be replaced and the type of liquid to be replaced. The effectiveness is not limited to application to liquid processing involving drying of the wafer W using a high-pressure fluid. For example, the liquid in the treatment tank 22 is replaced in the order of DIW (replacement liquid) → DHF (treatment liquid) → DIW (rinse liquid) → SC1 (treatment liquid) → DIW (which also serves as a rinse liquid and an anti-drying liquid). The present invention can be applied even when the wafer W is pulled up and dried in an IPA vapor atmosphere after the processing. Also in this case, an appropriate rectifying plate 27 is selected according to the combination of the liquid to be replaced and the liquid to be replaced.

Using the rectifying plates 27a to 27c shown in FIG. 9, FIG. 10, and FIG.
A. Experimental conditions
The rectifying plate 27a shown in FIG. 9 is called “rectifying plate 1”, the rectifying plate 27b shown in FIG. 10 is called “rectifying plate 2”, and the rectifying plate 27c shown in FIG.
(Experiment 1)
A processing tank 22 having a capacity of 350 cc containing one wafer W (diameter 300 mm) and attached with any of the rectifying plates 1 to 3 was previously filled with DIW, and DHF (49 wt% hydrofluoric acid: DIW = 1: 200) was supplied at 1 L / min for 150 seconds to examine the in-plane uniformity of the natural oxide film removal.
(Experiment 2)
In (Experiment 1), the liquid to be filled in advance was changed to DHF having the same concentration as in (Experiment 1), the liquid to be replaced was changed to DIW, and the change in the specific resistance of the liquid flowing out from the treatment tank 22 was measured.
(Experiment 3)
In (Experiment 1), the liquid to be replaced was changed to IPA, and the IPA concentration in the liquid flowing out of the treatment tank 22 was measured. However, in this experiment, no experiment was performed on the current plate 3.

B. Experimental result
The results of (Experiments 1-3) are shown in (Table 1).
(Table 1)

  According to the results of (Experiment 1) shown in Table 1, the in-plane uniformity of the liquid treatment by DHF is the best in the “rectifier plate 1”, while the in-plane uniformity of the “rectifier plate 3” is It was the worst. The “rectifier plate 2” had the in-plane uniformity between the rectifier plates 1 and 3. This is because, when the supply amount of DHF is constant, the total opening area of the holes 272 is reduced, thereby disturbing the flow of DHF in the treatment tank 22 and promoting the mixing of the liquid. This is a consistent result.

  On the other hand, in the result of (Experiment 2), the liquid replacement from DHF to DIW is executed in the shortest time (about 10 minutes to the target specific resistance value) in the “rectifying plate 3” (the rate of increase in specific resistance). In the “rectifying plate 1”, the time required for the liquid replacement was the longest (55 minutes or more until the target value). The time required for replacement of the liquid in the “rectifying plate 2” was intermediate between the rectifying plates 1 and 3 (approximately 12 minutes to the target value). Also in this case, when the supply amount of DIW is constant, by increasing the total opening area of the holes 272, mixing of DIW in the processing tank 22 is suppressed, and liquid replacement proceeds in a shorter time. Results consistent with the action were obtained.

  And, as shown in (Experiment 3), in the DIW and IPA where the specific gravity difference of the liquid to be replaced is large, the opening area of the “rectifying plate 2” has a sufficiently short time (for example, less than 100 seconds) in the treatment tank 22. Of the liquid could be replaced with nearly 100% IPA. In Table 1, the result of (Experiment 3) is indicated as “Δ” when another experiment was performed in which the supply amount of IPA per unit time was gradually reduced from 1 L / min. This is because it has been confirmed that even the “rectifying plate 1” can be replaced with IPA within the target time.

V1-V3, V5
On-off valve V4, V6 switching valve W Wafer 2, 2a Liquid processing apparatus 21, 21A
External container 211 Opening 212 Heater 22 Processing tank 221 Sealing plate 222 Opening 23, 23a-23b
Lid 234 Supply / discharge port 238 Lifting mechanism 27, 27 a to 27 c
Current plate 311 DIW supply unit 312 DHF supply unit 313 IPA supply unit 34 Supply / discharge line 4 Transport mechanism 41 Chuck unit 5 Storage shelf 6 Control unit

Claims (10)

An opening is formed in the upper part, and a lower port is provided in the lower part for supplying a replacement liquid to be substituted for the internal gas and discharging the liquid, and for performing liquid processing on the substrate to be processed accommodated therein. A treatment tank for performing,
An upper port for supplying liquid into the treatment tank and discharging gas is provided, and a detachable lid portion that hermetically closes the opening;
In order to adjust the flow of the liquid supplied from the upper port, the first rectifier is configured to be detachable between the substrate to be processed and the upper port, each having one or a plurality of holes. A plate and a second baffle plate;
A storage unit for storing the first rectifying plate and the second rectifying plate outside the processing tank;
A transport mechanism for transporting the first current plate or the second current plate between the storage unit and the processing tank;
When replacing the replacement liquid in the processing tank with the processing liquid supplied from the upper port, the first rectifying plate transported from the storage unit is attached to the processing tank, and then the liquid in the processing tank is When replacing with another liquid supplied from the upper port, a control signal is output so that the first current plate is removed from the processing tank and the second current plate conveyed from the storage unit is attached to the processing tank. A control unit;
After supplying the other liquid into the processing tank, the inside of the processing tank is changed to a supercritical or subcritical high-pressure fluid atmosphere, and then the substrate to be processed is dried by reducing the pressure of the high-pressure fluid into a gas. A dry atmosphere forming part for,
Liquid processing apparatus according to claim mutually different from said first total opening area of the hole of the total opening area and the second rectifier plate hole portion of the current plate.   The lid portion is divided into a first lid portion integrated with the first rectifying plate and a second lid portion integrally formed with the second rectifying plate, and the transport mechanism The liquid processing apparatus according to claim 1, wherein the first lid portion or the second lid portion is transported between the storage unit and the treatment tank. The total opening area of the holes is made different between the first rectifying plate and the second rectifying plate by changing at least one of the number of holes and the hole diameter. The liquid processing apparatus as described. Of the first rectifying plate and the second rectifying plate, the total opening area of the holes of one rectifying plate is made smaller than the total opening area of the holes of the other rectifying plate. The liquid processing apparatus according to claim 1, wherein a degree of mixing of liquids in the processing tank when the current plate is attached is increased. Of the first rectifying plate and the second rectifying plate, by making the total opening area of the holes of one rectifying plate larger than the total opening area of the holes of the other rectifying plate, The liquid replacement in the processing tank is suppressed during the period in which the current plate is arranged to facilitate the replacement of the liquid. Liquid processing equipment.   A processing tank is accommodated in a state where the lid is removed, and an external container is provided for performing a process for making the inside of the processing tank an atmosphere of a high-pressure fluid, and the processing tank is attached to and detached from the position where the lid is attached. A liquid processing apparatus according to claim 1, further comprising a moving mechanism that moves the processing tank between the first and second outer containers. A process of storing a substrate to be processed in a processing tank provided with a lower port in which an opening is formed in the upper part and a lower port for supplying a replacement liquid that replaces the internal gas and discharging the liquid is provided in the lower part; ,
A first rectifying plate having one or a plurality of holes is attached to a processing tank containing a substrate to be processed, and an upper port is provided for supplying liquid into the processing tank and discharging gas. A step of airtightly closing the opening of the treatment tank with the lid portion,
Supplying a processing liquid from the upper port, and replacing the processing liquid in the processing tank with the processing liquid while adjusting the flow of the processing liquid with the first rectifying plate;
Next, the first rectifying plate is removed from the processing tank, and the second rectifying plate having one or a plurality of holes formed therein, which has a total opening area different from that of the first rectifying plate, is attached to the processing tank. Airtightly closing the opening with the lid,
Thereafter, another liquid is supplied from the upper port, and the liquid in the treatment tank after the treatment with the treatment liquid is replaced with the other liquid while the flow of the other liquid is adjusted by the second rectifying plate. And a process of
After supplying the other liquid into the processing tank, the inside of the processing tank is changed to a supercritical or subcritical high-pressure fluid atmosphere, and then the substrate to be processed is dried by reducing the pressure of the high-pressure fluid into a gas. A liquid processing method comprising: a step.   The lid portion is divided into a first lid portion configured integrally with the first rectifying plate and a second lid portion configured integrally with the second rectifying plate. When the current plate is attached to the treatment tank, the opening is closed by the first lid, and when the second current plate is attached to the treatment tank, the opening is closed by the second lid. The liquid treatment method according to claim 7.   After filling the inside of the processing tank with another liquid, the process includes removing the lid and carrying the processing tank into an external container. The liquid treatment method according to claim 7, wherein the liquid treatment method is carried out after being carried into an external container. A storage medium storing a computer program used in a liquid processing apparatus for processing a substrate to be processed with a processing liquid,
A storage medium, wherein the program has steps for executing the liquid processing method according to any one of claims 7 to 9.

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