Substrate liquid processing apparatus and substrate liquid processing method

Abstract

To provide a technique for confirming that a substrate is properly held by a substrate supporting member while being immersed in processing liquid stored in a processing tank.SOLUTION: A substrate liquid processing apparatus includes a processing tank which has an upper opening for loading and unloading a substrate and stores processing liquid, a substrate support member for supporting a plurality of substrates in a vertical posture while the substrates are arranged side by side to be spaced from one another at predetermined intervals in a horizontal direction, an elevating mechanism for elevating the substrate support member through the upper opening between a processing position in the processing tank and a retracted position above the processing tank, an imaging unit which is provided at a position where the imaging unit can image the plurality of substrates supported by the substrate support member in the processing liquid stored in the processing tank, a substrate position determination unit for determining, on the basis of, image data captured by the imaging unit whether a deviation between actual positions of the plurality of substrates supported by the substrate support member and reference positions where the substrates should be present is within an allowable range, and a control unit for controlling operations of the substrate liquid processing apparatus.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present disclosure relates to a substrate liquid processing apparatus and a substrate liquid processing method. [Background technology]

[0002] The manufacturing process of a semiconductor device includes a silicon nitride film etching process in which a substrate such as a semiconductor wafer is immersed in an aqueous phosphoric acid solution stored in a treatment tank and a silicon nitride film formed on the surface of the substrate is wet-etched. The substrates are immersed in the aqueous phosphoric acid solution while being supported by a substrate support member in a state where the substrates are aligned vertically and equidistantly spaced from one another in the horizontal direction.

[0003] During substrate processing, a flow of processing liquid from the bottom to the liquid surface is formed in the processing tank, and nitrogen gas bubbling is performed to improve processing uniformity. As a result, the substrate receives a force in a direction that causes it to float up from the substrate holder. In the substrate processing apparatus of Patent Document 1, a substrate pressing member that prevents the substrate from being displaced upward is provided on the lid of the processing tank to prevent the substrate from falling off the substrate support member or becoming displaced due to the force applied to the substrate by the processing liquid. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-067995 A Summary of the Invention [Problem to be solved by the invention]

[0005] The present disclosure provides a technique for verifying that a substrate is properly supported by a substrate support member while immersed in a processing liquid stored in a processing bath. [Means for solving the problem]

[0006] According to one embodiment of the present disclosure, there is provided a substrate liquid processing apparatus comprising: a processing tank having an upper opening for loading and unloading substrates and for storing a processing liquid; a substrate support member for supporting a plurality of substrates in a vertical position and arranged at a predetermined interval in the horizontal direction; a lifting mechanism for raising and lowering the substrate support member through the upper opening between a processing position in the processing tank and a retracted position above the processing tank; an imaging unit provided at a position capable of imaging the plurality of substrates supported by the substrate support member in the processing liquid stored in the processing tank; a substrate position determination unit for performing substrate position determination based on image data captured by the imaging unit to determine whether a deviation between the actual positions of the plurality of substrates supported by the substrate support member and a reference position where the substrates should be located is within an acceptable range; and a control unit for controlling the operation of the substrate liquid processing apparatus. Effect of the Invention

[0007] According to the above embodiment, it is possible to confirm that the substrate is appropriately held by the substrate holding member while immersed in the processing liquid stored in the processing tank. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic plan view showing an overall configuration of a substrate liquid processing system. [Diagram 2] 1 is a system diagram showing a configuration of an etching apparatus incorporated in a substrate liquid processing system. [Diagram 3] 1 is a schematic cross-sectional view of a processing tank of an etching apparatus; [Figure 4] FIG. 2 is a schematic longitudinal cross-sectional view of a treatment tank. [Diagram 5] FIG. 2 is a schematic plan view of a treatment tank. [Figure 6] 2 is a transverse longitudinal sectional view of the treatment tank showing in detail only the lid body in the closed position and the surrounding members. FIG. [Figure 7] FIG. [Figure 8] 7 is a transverse longitudinal cross-sectional view showing the cover moved from the closed position shown in FIG. 6 to the open position. [Figure 9] FIG. 1 is a schematic diagram showing a camera and lighting positioned above the treatment vessel. [Figure 10] 1 is a schematic diagram showing a state in which a substrate is properly positioned between a substrate support member and a substrate clamp; [Figure 11] FIG. 2 is a schematic diagram showing an image captured by a camera. [Figure 12] 1 is a graph showing the distribution of grey values; [Figure 13] 1 is a schematic diagram showing a state in which a substrate is improperly positioned (a bridge is formed) between a substrate support member and a substrate clamp; [Figure 14] FIG. 2 is a schematic diagram showing the distribution of grey values ​​when bridging occurs; [Figure 15] 11 is a graph illustrating the rocking motion of a substrate immediately after the substrate is submerged in a processing tank. [Figure 16] FIG. 13 is a schematic diagram showing another arrangement of cameras and lighting. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. First, a substrate liquid processing system 1A incorporating a substrate liquid processing apparatus 1 according to one embodiment of the present invention will be described as a whole.

[0010] As shown in FIG. 1, a substrate liquid processing system 1A includes a carrier loading / unloading section 2, a lot forming section 3, a lot placing section 4, a lot transport section 5, a lot processing section 6, and a control section .

[0011] Of these, the carrier loading / unloading section 2 loads and unloads a carrier 9 that accommodates a plurality of (for example, 25) substrates (silicon wafers) 8 arranged vertically in a horizontal position.

[0012] The carrier loading / unloading section 2 is provided with a carrier stage 10 on which a plurality of carriers 9 are placed, a carrier transport mechanism 11 for transporting the carriers 9, carrier stocks 12 and 13 for temporarily storing the carriers 9, and a carrier placement table 14 on which the carriers 9 are placed. The carrier stock 12 temporarily stores the substrates 8 to be products before they are processed in the lot processing section 6. The carrier stock 13 temporarily stores the substrates 8 to be products after they have been processed in the lot processing section 6.

[0013] The carrier loading / unloading section 2 transports the carrier 9, which has been loaded onto the carrier stage 10 from outside, to the carrier stock 12 or the carrier mounting table 14 using the carrier transport mechanism 11. The carrier loading / unloading section 2 also transports the carrier 9, which has been mounted on the carrier mounting table 14, to the carrier stock 13 or the carrier stage 10 using the carrier transport mechanism 11. The carrier 9 transported to the carrier stage 10 is then unloaded to the outside.

[0014] The lot formation unit 3 combines substrates 8 housed in one or more carriers 9 to form a lot consisting of a plurality of substrates 8 (for example, 50 substrates 8) to be processed simultaneously. When forming a lot, the lots may be formed so that the surfaces on which patterns are formed of every two adjacent substrates 8 face each other, or the lots may be formed so that the surfaces of the substrates 8 on which patterns are formed all face the same direction.

[0015] The lot formation section 3 is provided with a substrate transport mechanism 15 that transports a plurality of substrates 8. The substrate transport mechanism 15 can change the orientation of the substrate 8 from a horizontal orientation to a vertical orientation and from a vertical orientation to a horizontal orientation during transportation of the substrate 8.

[0016] Then, the lot forming section 3 uses the substrate transport mechanism 15 to transport the substrates 8 from the carrier 9 placed on the carrier placement table 14 to the lot placement section 4, and places the substrates 8 forming the substrate lot on the lot placement section 4. The lot forming section 3 also transports the substrates placed on the lot placement section 4 to the carrier 9 placed on the carrier placement table 14 by the substrate transport mechanism 15. The substrate transport mechanism 15 has two types of substrate support sections for supporting a plurality of substrates 8: a pre-processing substrate support section for supporting the substrates 8 before processing (before being transported by the lot transport section 5), and a post-processing substrate support section for supporting the substrates 8 after processing (after being transported by the lot transport section 5). This prevents particles and the like attached to the pre-processing substrates 8 from being transferred to the processed substrates 8.

[0017] The lot placement unit 4 temporarily places (standbys) on the lot placement table 16 a lot that is transferred between the lot formation unit 3 and the lot processing unit 6 by the lot transfer unit 5.

[0018] This lot mounting section 4 is provided with an entrance lot mounting stage 17 on which a lot is mounted before processing (before being transported by the lot transport section 5), and an exit lot mounting stage 18 on which a lot is mounted after processing (after being transported by the lot transport section 5). A plurality of substrates 8 for one lot are mounted in a vertical position, lined up front to back, on the entrance lot mounting stage 17 and the exit lot mounting stage 18.

[0019] In the lot mounting section 4, the lot formed in the lot formation section 3 is mounted on the load-side lot mounting table 17, and the lot is carried into the lot processing section 6 via the lot transport section 5. In the lot mounting section 4, the lot carried out from the lot processing section 6 via the lot transport section 5 is mounted on the load-side lot mounting table 18, and the lot is transported to the lot formation section 3.

[0020] The lot transport section 5 transports lots between the lot placement section 4 and the lot processing section 6 and within the lot processing section 6 .

[0021] This lot transport section 5 is provided with a lot transport mechanism 19 that transports lots. The lot transport mechanism 19 is composed of rails 20 arranged along the lot mounting section 4 and the lot processing section 6, and a movable body 21 that moves along the rails 20 while holding a plurality of substrates 8. A substrate holder 22 that holds a plurality of substrates 8 lined up in a vertical position is provided on the movable body 21 so as to be able to move forward and backward.

[0022] The lot transport section 5 then receives the lot placed on the load-side lot mounting table 17 at the substrate holder 22 of the lot transport mechanism 19, and transfers the lot to the lot processing section 6. The lot transport section 5 also receives the lot processed in the lot processing section 6 at the substrate holder 22 of the lot transport mechanism 19, and transfers the lot to the unload-side lot mounting table 18. Furthermore, the lot transport section 5 transports the lot inside the lot processing section 6 using the lot transport mechanism 19.

[0023] The lot processing section 6 treats a plurality of substrates 8 arranged vertically one behind the other as one lot and performs processes such as etching, cleaning, drying, etc. on each of the lots.

[0024] This lot processing unit 6 is provided with a drying processing unit 23 which performs drying processing on the substrates 8, a substrate holder cleaning processing unit 24 which performs cleaning processing on the substrate holders 22, a cleaning processing unit 25 which performs cleaning processing on the substrates 8, and two etching processing units (substrate liquid processing units) 1 according to the present invention which perform etching processing on the substrates 8, arranged side by side.

[0025] The drying processing device 23 has a processing bath 27 and a substrate lifting mechanism 28 provided in the processing bath 27 so as to be capable of being raised and lowered. A processing gas for drying (IPA (isopropyl alcohol) or the like) is supplied to the processing bath 27. The substrate lifting mechanism 28 holds a plurality of substrates 8 for one lot aligned in a vertical position from front to back. The drying processing device 23 receives the lot from the substrate holder 22 of the lot transport mechanism 19 by the substrate lifting mechanism 28, and raises and lowers the lot by the substrate lifting mechanism 28, thereby drying the substrates 8 with the processing gas for drying supplied to the processing bath 27. The drying processing device 23 also transfers the lot from the substrate lifting mechanism 28 to the substrate holder 22 of the lot transport mechanism 19.

[0026] The substrate holder cleaning processing device 24 has a processing tank 29, and is capable of supplying a cleaning processing liquid and a drying gas to the processing tank 29. After supplying the cleaning processing liquid to the substrate holder 22 of the lot transport mechanism 19, the substrate holder 22 is cleaned by supplying a drying gas.

[0027] The cleaning processing device 25 has a cleaning processing tank 30 and a rinsing processing tank 31, and substrate lifting mechanisms 32, 33 are provided in the processing tanks 30, 31 so as to be capable of moving up and down. A cleaning processing liquid (SC-1, etc.) is stored in the cleaning processing tank 30. A rinsing processing liquid (pure water, etc.) is stored in the rinsing processing tank 31.

[0028] The etching processing apparatus 1 has a processing tank 34 for etching and a processing tank 35 for rinsing, and substrate lifting mechanisms 36, 37 are provided in the processing tanks 34, 35 so as to be capable of moving up and down freely. A processing liquid for etching (aqueous phosphoric acid solution) is stored in the processing tank 34 for etching. A processing liquid for rinsing (pure water, etc.) is stored in the processing tank 35 for rinsing. As described above, the etching processing apparatus 1 is a substrate liquid processing apparatus according to the present invention.

[0029] The cleaning processing device 25 and the etching processing device 1 have the same configuration. Regarding the etching processing device (substrate liquid processing device) 1, a substrate lifting mechanism 36 holds a plurality of substrates 8 for one lot in a vertical posture arranged in front and behind. In the etching processing device 1, the substrate lifting mechanism 36 receives the lot from the substrate holder 22 of the lot transport mechanism 19, and the substrate lifting mechanism 36 raises and lowers the lot to immerse the lot in the etching processing liquid in the processing bath 34, thereby performing the etching processing of the substrates 8. Thereafter, the etching processing device 1 transfers the lot from the substrate lifting mechanism 36 to the substrate holder 22 of the lot transport mechanism 19. In addition, the substrate lifting mechanism 37 receives the lot from the substrate holder 22 of the lot transport mechanism 19, and the substrate lifting mechanism 37 raises and lowers the lot to immerse the lot in the rinsing processing liquid in the processing bath 35, thereby performing the rinsing processing of the substrates 8. Thereafter, the substrate lifting mechanism 37 transfers the lot to the substrate holder 22 of the lot transport mechanism 19.

[0030] The control unit 7 controls the operations of each unit of the substrate liquid processing system 1A (the carrier loading / unloading unit 2, the lot forming unit 3, the lot placing unit 4, the lot transport unit 5, the lot processing unit 6, and the etching processing device 1).

[0031] The control unit 7 is, for example, a computer, and includes a computer-readable M. A program for controlling various processes executed in the substrate liquid processing apparatus 1 is stored in the storage medium 38. The control unit 7 controls the operation of the substrate liquid processing apparatus 1 by reading and executing the program stored in the storage medium 38. The program may be stored in the computer-readable storage medium 38, or may be installed in the storage medium 38 of the control unit 7 from another storage medium. Examples of the computer-readable storage medium 38 include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnet optical disk (MO), and a memory card.

[0032] As described above, in the processing tank 34 of the etching processing apparatus 1, an aqueous solution (aqueous phosphoric acid solution) of a chemical (phosphoric acid) having a predetermined concentration is used as a processing liquid (etching liquid) to perform liquid processing (etching processing) on ​​the substrate 8.

[0033] Next, the schematic configuration and piping system of the etching processing apparatus (substrate liquid processing apparatus) 1 will be described with reference to FIG.

[0034] The etching processing apparatus 1 has the above-mentioned processing tank 34 that stores an aqueous phosphoric acid solution of a predetermined concentration as a processing liquid. The processing tank 34 has an inner tank 34A and an outer tank 34B. The aqueous phosphoric acid solution that overflows from the inner tank 34A flows into the outer tank 34B. The liquid level of the outer tank 34B is maintained lower than the liquid level of the inner tank 34A.

[0035] The upstream end of a circulation line 50 is connected to the bottom of the outer tank 34B. The downstream end of the circulation line 50 is connected to a treatment liquid supply nozzle 49 installed in the inner tank 34A. A pump 51, a heater 52, and a filter 53 are interposed in the circulation line 50, in this order from the upstream side. By driving the pump 51, a circulation flow of the aqueous phosphoric acid solution is formed, which is sent from the outer tank 34B through the circulation line 50 and the treatment liquid supply nozzle 49 into the inner tank 34A, and then flows out again from the inner tank 34A to the outer tank 34B.

[0036] The treatment tank 34, the circulation line 50, and the devices (51, 52, 53, etc.) in the circulation line 50 form a liquid treatment section 39. The treatment tank 34 and the circulation line 50 form a circulation system.

[0037] A gas nozzle 60 for discharging bubbles of an inert gas, such as nitrogen gas, into the aqueous phosphoric acid solution in the inner tank 34A (for bubbling) is provided below the processing liquid supply nozzle 49 in the inner tank 34A. An inert gas, such as nitrogen gas, is supplied to the gas nozzle 60 from a gas supply source 60B via a flow rate regulator 60C composed of an on-off valve, a flow rate control valve, a flow meter, etc.

[0038] The processing tank 34 is provided with the aforementioned substrate lifting mechanism 36. The substrate lifting mechanism 36 can hold a plurality of substrates 8 in a vertically upright position and arranged at intervals in the horizontal direction, and can raise and lower the substrates in this position.

[0039] The etching processing device 1 has a phosphoric acid aqueous solution supply unit 40 that supplies a phosphoric acid aqueous solution to the liquid processing device 39, a pure water supply unit 41 that supplies pure water to the liquid processing device 39, a silicon supply unit 42 that supplies a silicon solution to the liquid processing device 39, and a phosphoric acid aqueous solution discharge unit 43 that discharges the phosphoric acid aqueous solution from the liquid processing device 39.

[0040] The phosphoric acid aqueous solution supplying unit 40 supplies a phosphoric acid aqueous solution of a predetermined concentration to any part of the circulation system consisting of the treatment tank 34 and the circulation line 50, i.e., the liquid treatment unit 39, preferably to the outer tank 34B as shown in the figure. The phosphoric acid aqueous solution supplying unit 40 has a phosphoric acid aqueous solution supply source 40A consisting of a tank for storing phosphoric acid aqueous solution, a phosphoric acid aqueous solution supplying line 40B connecting the phosphoric acid aqueous solution supply source 40A and the outer tank 34B, and a flow meter 40C, a flow control valve 40D, and an opening / closing valve 40E interposed in this order from the upstream side on the phosphoric acid aqueous solution supplying line 40B. The phosphoric acid aqueous solution supplying unit 40 can supply the phosphoric acid aqueous solution to the outer tank 34B at a controlled flow rate via the flow meter 40C and the flow control valve 40D.

[0041] The pure water supply unit 41 supplies pure water to replenish the water evaporated by heating the phosphoric acid aqueous solution. The pure water supply unit 41 includes a pure water supply source 41A that supplies pure water at a predetermined temperature, and the pure water supply source 41A is connected to the outer bath 34B via a flow rate regulator 41B. The flow rate regulator 41B can be composed of an on-off valve, a flow rate control valve, a flow meter, etc.

[0042] The silicon supply unit 42 has a silicon supply source 42A consisting of a tank for storing a silicon-containing compound solution, for example, a liquid in which colloidal silicon is dispersed, and a flow rate regulator 42B. The flow rate regulator 42B can be composed of an on-off valve, a flow rate control valve, a flow meter, etc.

[0043] The aqueous phosphoric acid solution discharge part 43 is provided for discharging the aqueous phosphoric acid solution in the circulation system consisting of the liquid treatment part 39 and the circulation line 50, i.e., in the liquid treatment part 39. The aqueous phosphoric acid solution discharge part 43 has a discharge line 43A branching off from the circulation line 50, and a flow meter 43B, a flow control valve 43C, an on-off valve 43D, and a cooling tank 43E provided in this order from the upstream side on the discharge line 43A. The aqueous phosphoric acid solution discharge part 43 can discharge the aqueous phosphoric acid solution at a flow rate controlled via the flow meter 43B and the flow control valve 43C.

[0044] The cooling tank 43E temporarily stores and cools the aqueous phosphoric acid solution that has flowed through the discharge line 43A. The aqueous phosphoric acid solution (see reference symbol 43F) that has flowed out of the cooling tank 43E may be disposed of in a factory waste liquid system (not shown), or may be sent to the aqueous phosphoric acid solution supply source 40A for reuse after silicon contained in the aqueous phosphoric acid solution is removed by a regenerator (not shown).

[0045] In the illustrated example, the discharge line 43A is connected to the circulation line 50 (at the filter drain position in the figure), but is not limited to this and may be connected to another location in the circulation system, for example, the bottom of the inner tank 34A.

[0046] A silicon concentration meter 43G for measuring the silicon concentration in the phosphoric acid aqueous solution is provided in the discharge line 43A. A phosphoric acid concentration meter 55B for measuring the phosphoric acid concentration in the phosphoric acid aqueous solution is provided in a branch line 55A that branches off from the circulation line 50 and is connected to the outer tank 34B. A liquid level meter 44 for detecting the liquid level in the outer tank 34B is provided in the outer tank 34B.

[0047] Next, the configuration of the processing tank 34 of the etching processing apparatus 1 will be described in detail with reference to Figs. 3 to 7. For convenience of explanation, an XYZ orthogonal coordinate system is set and referred to as necessary. Note that the negative X direction may also be called the "front side" or "forward", the positive X direction may also be called the "rear side" or "rear", the negative Y direction may also be called the "right side" or "rightward", and the positive Y direction may also be called the "left side" or "leftward".

[0048] As described above, the treatment tank 34 has an inner tank 34A with an open top and an outer tank 34B with an open top. The inner tank 34A is accommodated inside the outer tank 34B. The aqueous phosphoric acid solution that overflows from the inner tank 34A flows into the outer tank 34B. During the liquid treatment, most of the inner tank 34A, including the bottom, is immersed in the aqueous phosphoric acid solution in the outer tank 34B.

[0049] The outer tank 34B is accommodated inside a liquid receiving container (sink) 80, and a drain space 81 is formed between the outer tank 34B and the liquid receiving container 80. A drain line 82 is connected to the bottom of the drain space 81.

[0050] The processing liquid supply nozzle 49 is formed of a cylindrical body extending in the X direction (horizontal direction) inside the inner tank 34A. The processing liquid supply nozzle 49 discharges the processing liquid from a plurality of discharge ports 49D (see FIGS. 3 and 4) drilled in its peripheral surface toward the substrate 8 held by the substrate lifting mechanism 36. Although two processing liquid supply nozzles 49 are provided in the figure, three or more processing liquid supply nozzles 49 may be provided. The processing liquid (aqueous phosphoric acid solution) is supplied to the processing liquid supply nozzle 49 from a pipe 49A extending in the vertical direction.

[0051] The gas nozzle 60 is a cylindrical body extending in the X direction (horizontal direction) at a height position lower than the processing liquid supply nozzle 49 in the inner tank 34A. The gas nozzle 60 ejects bubbles of an inert gas (e.g., nitrogen gas) from a plurality of ejection ports 60D (see FIGS. 3 and 4) drilled on its circumferential surface. The bubbling of the inert gas can stabilize the boiling state of the phosphoric acid aqueous solution in the inner tank 34A. The gas nozzle 60 is supplied with the processing liquid (phosphoric acid aqueous solution) from a pipe 60A extending in the vertical direction.

[0052] The substrate lifting mechanism 36 has a support plate 36A extending in the vertical direction (Z direction) that is lifted and lowered by a lifting mechanism (not shown), and a pair of substrate support members 36B extending in the horizontal direction (X direction) whose one ends are supported by the support plate 36A (see also FIG. 9). Each substrate support member 36B has a plurality of (e.g., 50 to 52) substrate holding grooves (not shown) arranged at intervals in the horizontal direction (X direction). The peripheral portion of the substrate 8 is inserted into the substrate holding grooves. The substrate lifting mechanism 36 can hold a plurality of (e.g., 50 to 52) substrates 8 in a vertical position with intervals in the horizontal direction (X direction). Such a substrate lifting mechanism 36 is well known in the art, and detailed structural illustration and description will be omitted.

[0053] The treatment tank 34 is provided with a first lid 71 and a second lid 72 for opening and closing the upper opening of the inner tank 34A. The first lid 71 and the second lid 72 are respectively coupled to rotation shafts 71S and 72S extending in the horizontal direction (X direction). The rotation shafts 71S and 72S are connected to a bearing 83 fixed to a liquid receiving container 80 and a rotation actuator 84 (see Figures 4 and 5). By operating the rotation actuator 84, the first lid body 71 and the second lid body 72 can rotate (pivot) about their respective rotation axes extending in the horizontal direction (X direction) between a closed position (position shown in Figures 3 and 6) in which they cover the first area (left half) and the second area (right half) of the upper opening of the inner tank 34A, respectively, and an open position (position shown in Figure 8) in which they are in a generally upright state and open the first area and the second area of ​​the upper opening of the inner tank 34A (see arrows SW1 and SW2 in Figure 3).

[0054] The first lid 71 and the second lid 72 do not cover the area of ​​the upper opening of the inner tank 34A where the support plate 36A and the pipes 49A and 60A are provided.

[0055] During normal operation of the etching processing apparatus 1, the first lid 71 and the second lid 72 are positioned in the closed position except when the substrate 8 held by the substrate lifting mechanism 36 is being loaded / unloaded into the inner tank 34A, thereby preventing a drop in the temperature of the aqueous phosphoric acid solution in the inner tank 34A and suppressing water vapor generated from the boiling aqueous phosphoric acid solution from escaping to the outside of the processing tank 34.

[0056] The first cover 71 has a generally rectangular main body 71A when viewed from directly above, a first splash shielding portion 71B, a second splash shielding portion 71C, and a closing portion 71D extending in the X direction, and a third splash shielding portion 71E extending in the Y direction. Similarly, the second cover 72 has a generally rectangular main body 72A, a first splash shielding portion 72B, a second splash shielding portion 72C, and a closing portion 72D extending in the X direction, and a third splash shielding portion 72E extending in the Y direction.

[0057] A large rectangular recess 71R is formed in the upper surface of the main body 71A. The recess 71R is defined by a bottom wall 711R and four side walls 712R, 713R, 714R, and 715R.

[0058] When the first lid 71 is in the closed position, a gap is provided between the side wall of the inner tank 34A and the adjacent side walls 712R, 713R facing it so as not to prevent overflow (see arrow OF in FIG. 6) of the aqueous phosphoric acid solution from the inner tank 34A to the outer tank 34B. Although not shown, a plurality of V-shaped notches are formed at intervals on the upper ends of the four side walls of the inner tank 34A to facilitate smooth overflow.

[0059] The bottom wall 711R of the first lid body 71 is inclined so as to become higher as it moves away from the second lid body 72 in the Y direction (as it approaches the side wall of the inner tank 34A in the Y direction). This inclination allows the above-mentioned overflow to occur smoothly.

[0060] Since the phosphoric acid aqueous solution in the inner tank 34A is in a boiling state or is being bubbled, splashes of the phosphoric acid aqueous solution fly out of the inner tank 34A together with the phosphoric acid aqueous solution that overflows from the inner tank 34A to the outer tank 34B. The splashes collide with the first splash shielding portion 71B of the first lid 71 in the closed position, fall into the space between the side wall of the inner tank 34A and the side wall of the outer tank 34B, and do not fly outside the outer tank 34B. It is preferable that the lower end of the first splash shielding portion 71B of the first lid 71 in the closed position is at least lower than the upper end of the adjacent side wall of the inner tank 34A.

[0061] When the first lid body 71 is in the open position, the second splash shielding portion 71C plays the same role as the first splash shielding portion 71B when the first lid body 71 is in the closed position. It is preferable that the lower end of the first splash shielding portion 71B of the first lid body 71 in the open position is at least lower than the upper end of the adjacent side wall of the inner tank 34A.

[0062] When the first lid 71 is in the open position (see FIG. 8), the closing part 71D covers the upper part of the area from the rotation axis 71S to the side wall of the outer tub 34B in the gap between the upper end of the side wall of the inner tub 34A and the upper end of the side wall of the outer tub 34B. When the first lid 71 is in the closed position, the closing part 71D guides liquid adhering to the upper surface of the main body part 71A (for example, liquid dropped from a wet substrate when the substrate passes above the processing tank 34) to a drain space 81 between the outer tub 34B and the liquid receiving container 80, preventing the liquid from flowing into the outer tub 34B when the first lid 71 is in the open position. The liquid that has entered the drain space 81 is discarded from a drain line 82.

[0063] The third splash shielding portion 71E is provided so as to extend above the space between the side wall of the inner tank 34A and the side wall of the outer tank 34B on the side farther from the substrate lifting mechanism 36. The third splash shielding portion 71E extends in the Y direction from the rotation axis 71S along the edge of the first lid body 71 over the entire length of the edge. The third splash shielding portion 71E plays a role similar to that of the first splash shielding portion 71B when the first lid body 71 is in the closed position. It is preferable that the lower end of the third splash shielding portion 71E of the first lid body 71 in the open position is at least lower than the upper end of the adjacent side wall of the inner tank 34A.

[0064] It is not necessary to provide a splash shield extending along the edge of the first lid 71 extending in the Y direction on the side closer to the substrate lifting mechanism 36. This is because most of the phosphoric acid aqueous solution splashing in the positive X direction collides with the support plate 36A of the substrate lifting mechanism 36, the pipes 49A and 60A, etc., and does not reach the outer tank 34B.

[0065] The second lid 72 is formed generally in mirror symmetry with respect to the first lid 71, and the first lid 71 and the second lid 72 have generally the same structure. The difference between the two lies in the presence or absence of accessory parts (plate-shaped body 73P, board holder 74) described below. Therefore, the explanation of the configuration and function of the first lid 71 can be used to explain the configuration and function of the second lid 72. The same alphabet is added to the end of the reference numerals of corresponding members of the first lid 71 and the second lid 72 (members in symmetrical positions, members having the same function), and the only difference is whether the first two digits of the reference numerals are "71" or "72".

[0066] 6, when the first cover 71 and the second cover 72 are in the closed position, a side wall 712R extending upward from a bottom wall 711R of the first cover 71 and a side wall 722R extending upward from a bottom wall 721R of the second cover 72 face each other, and a gap G of height H is formed between the both side walls. By providing the recesses 71R and 72R, an increase in the weight of the first cover 71 and the second cover 72 caused by providing a gap of height H can be suppressed.

[0067] 6, when the lower surface (lower surface of bottom wall 711R) of the main body 71A of the first lid 71 and the lower surface (lower surface of bottom wall 721R) of the main body 72A of the second lid 72 are in contact with the liquid level of the treatment liquid in the inner tank 34A, the boiling or bubbling phosphoric acid aqueous solution may splash upward from the gap between the first lid 71 and the second lid and splash around. However, by providing the gap G with height H as described above, the treatment liquid is less likely to splash out from the gap G. To achieve this effect, the height H may be set to, for example, about 5 cm or more.

[0068] When the treatment liquid in the inner tank 34A is a phosphoric acid aqueous solution, at least the main body parts 71A and 72A of the first cover 71 and the second cover 72 are made of a material that is not corroded by the treatment liquid, such as quartz. If the main body parts 71A and 72A are made of quartz, there is a risk that the quartz parts will collide with each other and break or chip. In order to prevent this, it is desirable to provide a gap between the main body parts 71A and 72A so that they do not come into contact with each other when the first cover 71 and the second cover 72 are in the closed position. If a gap is provided between the main body parts 71A and 72A, there is a risk that the phosphoric acid aqueous solution in the treatment tank 34, especially in the inner tank 34A, will splash outward through the gap. However, by providing the gap G with the height H as described above, it is possible to at least significantly suppress the splashing of the phosphoric acid aqueous solution from the gap G.

[0069] In addition, in order to facilitate overflow, when the bottom wall 711R (721R) is inclined as described above and brought into contact with the phosphoric acid aqueous solution in the inner tank 34A, if there is no side wall 712R (722R) extending upward from the bottom wall 711R (721R), the tip of the bottom wall 711R (721R) will be submerged in the phosphoric acid aqueous solution. However, by providing the side wall 712R (722R) extending upward from the bottom wall 711R (721R) as described above, it is possible to make the liquid level of the phosphoric acid aqueous solution lower than the upper end of the side wall 712R (722R).

[0070] As shown in Fig. 6, it is preferable to provide a cover 73 on either the main body 71A of the first lid 71 or the main body 72A of the second lid 72 (main body 71A in this case) that extends to or exceeds the tip of the other (main body 72A in this case) and covers the gap G from above. By providing the cover 73, it is possible to prevent the processing liquid from spilling out upward from the gap G. Note that in Figs. 3 to 5, the cover 73 (and the plate-like body 73P) are not shown in order to avoid complicating the drawings.

[0071] In addition, since the gap G has a height H, the momentum of droplets of the treatment liquid scattered from the liquid surface of the phosphoric acid aqueous solution in the inner tank 34A weakens before colliding with the cover 73. Therefore, the treatment liquid that collided with the cover 73 does not fly out to the side.

[0072] 6, the cover 73 can be provided by attaching a plate-like body 73P having a substantially rectangular cutout portion 73Q that matches the contour of the recess 71R of the first cover body 71 to the upper surface of the main body portion 71A of the first cover body 71. In this case, the cover 73 is formed by the edge portion of the plate-like body 73P.

[0073] 6, when the first lid body 71 and the second lid body 72 are in the closed position, a gap may be provided between the cover 73 and the second lid body 72. Alternatively, when the first lid body 71 and the second lid body 72 are in the closed position, the cover 73 and the second lid body 72 may be in contact with each other. In this case, the cover 73 serves as a seal that closes the upper end of the gap G.

[0074] When the cover 73 is brought into contact with the second lid body 72, it is preferable to form the cover 73 from a resin material that is flexible enough not to cause damage even if it collides with the quartz and not to damage the quartz, and that has relatively high corrosion resistance, such as a fluororesin material such as PTFE or PFA.

[0075] The cover 73 may be formed integrally with the first lid 71. Also, the cover 73 does not have to be provided. When the cover 73 is not provided, it is preferable to make the height H higher than when the cover is provided.

[0076] Further, a substrate holder 74 is provided on either the main body 71A of the first cover 71 or the main body 72A of the second cover 72 (the tip of the main body 72A of the second cover 72 in the illustrated example). A plurality of substrate holding grooves 74G are formed on the lower surface of the substrate holder 74 along the arrangement direction (X direction) of the substrates 8, and are arranged at the same pitch and in the same X direction positions as the substrate holding grooves 36BG (see FIG. 10) of the substrate support member 36B (see FIG. 7 and FIG. 10). Each of the substrate holding grooves 74G accommodates the peripheral portion of one substrate 8. Note that although the lower end portion of the substrate holder 74 (the portion where the substrate holding grooves 74G are formed) is visible in the perspective view of FIG. 7, it is actually hidden by the bottom wall 721R of the recess 72R and cannot be seen.

[0077] In the illustrated embodiment, the substrate holder 74 is an elongated plate-like body formed separately from the second cover 72, and is fixed to the main body 72A of the second cover 72 by screws. Alternatively, the substrate holder 74 may be formed integrally with the second cover 72. In either case, the substrate holder 74 constitutes a part of the side wall 722R of the main body 72A of the second cover 72.

[0078] When the substrate 8 is being processed, the substrate presser 74 provided on the second lid 72 in the closed position engages with the substrate 8 supported by the substrate support member 36B, preventing or suppressing the upward displacement of the substrate 8. Therefore, even if the processing liquid is discharged at a high flow rate from the processing liquid supply nozzle 49, or even if the boiling level of the processing liquid in the inner tank 34A becomes high, or even if nitrogen gas bubbling is performed vigorously, there is no risk of the substrate 8 falling off the substrate support member 36B.

[0079] As shown generally in Fig. 9, a camera 90 and lighting 92 are provided above the processing tank 34. If an image required for image processing, which will be described later, can be acquired, it is possible to omit the lighting 92 dedicated to the camera 90. An image signal is output from the camera 90 via wired or wireless communication to a substrate position determination unit 94 having an image processing function. The substrate position determination unit 94 may be a part of the control unit 7, or may be a separate arithmetic processing unit.

[0080] The camera 90 can be disposed directly above the upper opening of the inner bath 34A and above the upper limit position of the substrate 8 supported by the substrate support member 36B (the height position at which the substrate 8 is transferred between the substrate support member 36B of the substrate lifting mechanism 36 and the substrate holder 22 of the lot transport mechanism 19). Alternatively, the camera 90 may be provided at a lower position (a height position close to the upper opening of the inner bath 34A) and a moving mechanism may be provided to move the camera 90 between a position directly above the inner bath 34A and a position away from directly above the inner bath 34A. The camera 90 may be provided at a position other than the above as long as it can acquire an image required for substrate position determination, which will be described later.

[0081] A fan filter unit (FFU) 100 is disposed further above the camera 90. Clean air is blown downward from the fan filter unit 100. Due to this downflow of clean air, even if gas or mist originating from the processing liquid (chemical liquid) that may fog the lens of the camera 90 or corrode the camera 90 rises from the processing tank 34, such gas or mist will not reach the camera 90.

[0082] The camera 90 may be protected from gas or mist originating from the processing liquid by providing a cover (not shown) surrounding the camera 90 and flowing an appropriate shielding gas (clean air or inert gas) inside the cover.

[0083] When the processing liquid stored in processing tank 34 is phosphoric acid, the gas rising above processing tank 34 is substantially water vapor, and the effect on camera 90 is small.

[0084] Next, a description will be given of the operation of the etching processing apparatus 1. First, the phosphoric acid aqueous solution supply unit 40 supplies the phosphoric acid aqueous solution to the outer tank 34B of the liquid processing unit 39. When a predetermined time has elapsed after the start of the supply of the phosphoric acid aqueous solution, the pump 51 of the circulation line 50 is operated, and a circulation flow circulating in the above-mentioned circulation system is formed.

[0085] Furthermore, the heater 52 of the circulation line 50 is operated to heat the phosphoric acid aqueous solution in the inner tank 34A to a predetermined temperature (for example, 160°C). The first lid 71 and the second lid 72 are placed in the closed position at the latest by the time when heating by the heater 52 starts. The phosphoric acid aqueous solution at 160°C is in a boiling state (preferably a slight boiling state). When the phosphoric acid concentration meter 55B detects that the phosphoric acid concentration has exceeded a predetermined upper limit due to evaporation of water caused by boiling, pure water is supplied from the pure water supply unit 41.

[0086] Before one lot of substrates 8 is put into the phosphoric acid aqueous solution in the inner tank 34A, the silicon concentration (which affects the etching selectivity of a silicon nitride film to a silicon oxide film) in the phosphoric acid aqueous solution present in the circulation system (including the inner tank 34A, the outer tank 34B, and the circulation line 50) is adjusted. The silicon concentration can be adjusted by immersing a dummy substrate in the phosphoric acid aqueous solution in the inner tank 34A, or by supplying a silicon-containing compound solution from a silicon supply unit 42 to the outer tank 34B. In order to confirm that the silicon concentration in the phosphoric acid aqueous solution present in the circulation system is within a predetermined range, the phosphoric acid aqueous solution may be flowed into the discharge line 43A and the silicon concentration may be measured by a silicon concentration meter 43G.

[0087] After the silicon concentration adjustment is completed, the first lid 71 and the second lid 72 are moved to the open position. At this time, above the processing bath 34, the substrate support member 36B of the substrate lifting mechanism 36, which has received the substrate 8 from the substrate holder 22 of the moving body 21 of the lot transport mechanism 19, is waiting. The substrate support member 36B properly supports a plurality of substrates 8, i.e., a plurality of substrates 8, for example, 50 substrates, which form one lot (also called a processing lot or batch). "Properly supported" means that, as shown in the lower half of the schematic diagram of FIG. 10, the lower peripheral portion of the substrate 8 fits into each substrate holding groove 36BG of the substrate support member 36B one by one, and the substrates 8 are arranged in a vertical position and horizontally at a predetermined arrangement pitch (for example, about 5 mm). Next, the substrate support member 36B is lowered, and the substrates 8 supported by the substrate support member 36B are submerged in the phosphoric acid aqueous solution in the inner bath 34A. At this time, it is preferable to stop bubbling in order to prevent the substrate 8 from floating up from the substrate support member 36B.

[0088] When a predetermined time (e.g., about 5 seconds) has elapsed since the substrates 8 were submerged in the phosphoric acid aqueous solution in the inner tank 34A, the second lid body 72 is moved to the closed position. The substrate holder 74 provided on the second lid body 72 engages with the upper peripheral edge of the substrate 8 to restrain the substrate 8. Next, the substrate 8 is imaged by the camera 90. Based on the image result, it is determined whether all the substrates 8 are in appropriate positions (particularly whether the substrate holder 74 is appropriately engaged with the substrate 8) (hereinafter referred to as "substrate position determination"). The method of this determination will be described later. When it is determined that all the substrates 8 are in appropriate positions, the first lid body 71 is moved to the closed position.

[0089] Next, bubbling is started by discharging nitrogen gas from the gas nozzle 60. The substrate 8 is immersed in the phosphoric acid aqueous solution for a predetermined period of time, whereby the substrate 8 is subjected to a wet etching process (liquid process).

[0090] By keeping the first lid 71 and the second lid 72 in the closed position during the etching process of the substrate 8, a decrease in temperature near the liquid surface of the aqueous phosphoric acid solution in the inner tank 34A is suppressed, and thus the temperature distribution of the aqueous phosphoric acid solution in the inner tank 34A can be kept small. In addition, since the inner tank 34A is immersed in the aqueous phosphoric acid solution in the outer tank 34B, a decrease in temperature of the aqueous phosphoric acid solution in the inner tank 34A due to heat radiation from the wall of the inner tank 34A is suppressed, and the temperature distribution of the aqueous phosphoric acid solution in the inner tank 34A can be kept small. Therefore, the in-plane and inter-plane uniformity of the etching amount of the substrate 8 can be maintained at a high level.

[0091] During the processing of one lot of substrates 8, silicon is eluted from the substrates 8, and the silicon concentration in the phosphoric acid aqueous solution present in the circulating system increases. In order to maintain or intentionally change the silicon concentration in the phosphoric acid aqueous solution present in the circulating system during the processing of one lot of substrates 8, the phosphoric acid aqueous solution can be supplied by the phosphoric acid aqueous solution supply unit 40 while the phosphoric acid aqueous solution in the circulating system is discharged by the phosphoric acid aqueous solution discharge unit 43.

[0092] When the processing of one lot of substrates 8 is completed as described above, the first lid body 71 and the second lid body 72 are moved to the open position, and the substrate support member 36B is then raised to unload the substrates 8 from the inner tank 34A.

[0093] After the processing of the substrate 8 is completed and before the substrate 8 is removed from the inner tank 34A, the first lid 71 may be moved to the open position while the second lid 72 is kept in the closed position, and the substrate position may be determined in this state. By doing so, it is possible to detect any positional deviation of the substrate 8 that may occur during processing (although the probability of this occurring is very low).

[0094] Thereafter, the first lid 71 and the second lid 72 are moved to the closed position again, and the temperature, phosphoric acid concentration, and silicon concentration of the phosphoric acid aqueous solution in the circulating system are adjusted, and then another lot of substrates 8 is processed in the same manner as described above.

[0095] Next, an embodiment of substrate position determination will be described. Prior to substrate position determination, a plurality of substrates 8 (e.g., 50 substrates) supported by substrate support members 36B are submerged in the processing liquid stored in inner tank 34A. At this time, the entirety of each substrate 8 is located below the liquid surface of the processing liquid. After a predetermined time (e.g., 5 seconds) has elapsed, second cover 72 with substrate holder 74 is moved to the closed position while first cover 71 is kept in the open position (shown by the dashed line in FIG. 9). Next, substrate position determination is performed.

[0096] When the substrate position determination is performed, the illumination 92 is turned on, and in this state, an image of the substrate 8 is captured by the camera 90 (imaging unit). At this time, the illumination light reaches the substrate 8 through the area of ​​the upper opening of the inner tank 34A that is not closed by the first lid body 71, and the reflected light (object light) from the substrate 8 reaches the camera 90. As a result, the camera 90 acquires an image with sufficient clarity to perform the substrate position determination described below without any problems. In this image, essentially only the APEX (the outermost edge of the substrate) and its vicinity out of the entire surface of each substrate 8 are visible, and the substrate surface (device formation surface) and back surface are not visible (see the schematic diagram of FIG. 11). It is preferable that the illumination 92 irradiates the illumination light from a position where the APEX of each substrate 8 is most brightly captured.

[0097] The substrate position determination unit 94 cuts out a region AR of the image so as to include a portion of each substrate 8 close to the liquid surface (see the schematic diagram in FIG. 11). The region AR may be, for example, a rectangular region whose longitudinal direction is the arrangement direction of the substrates 8. In the image of the region AR, the APEX of each substrate 8 visible in FIG. 11 (particularly the portion perpendicular to the optical axis of the illumination light) reflects the illumination light well, and therefore has the highest brightness in the image.

[0098] The substrate position determination unit 94 determines the distribution of gray values ​​(values ​​corresponding to the brightness of the image) along the arrangement direction of the substrates 8 within the region AR (this is the direction along the arrow XS parallel to the X-axis in FIG. 11).

[0099] The distribution of gray values ​​can be a distribution along a line having a width of a plurality of pixels (for example, a Y-directional width of the number of pixels equivalent to the width of the region AR) extending along the arrangement direction (X-directional) of the substrate 8. In this case, the average value of gray values ​​calculated based on signals from a plurality of pixels aligned in the Y-directional direction at the same X-directional position may be treated as the gray value at a certain X-directional position. This can improve the detection accuracy.

[0100] Alternatively, the distribution of gray values ​​may be a distribution along a line having a width of one pixel (width in the Y direction) extending along the direction of the arrow XS. In this case, a line sensor may be used as the imaging unit instead of the camera 90. The line sensor may be provided, for example, in the first cover 71 or the second cover 72. If the first cover 71 or the second cover 72 is transparent, the line sensor may be provided, for example, inside the recesses 71R, 72R. In this case, the line sensor receives the object light transmitted through the first cover 71 or the second cover 72.

[0101] FIG. 12 shows an example of the distribution of gray values ​​along the arrow XS in FIG. 11. The brightness of the image portion corresponding to the APEX of each substrate 8 is the highest, and the gray value is at its peak. The gray value of the image portion corresponding to the gap between adjacent substrates 8 is at its bottom. If the deviation between the actual position (X coordinate) of each substrate 8 and the reference position where the substrate 8 should be located is within the allowable range for all substrates 8, the peaks are arranged at a predetermined arrangement interval (for example, 5 mm ± the amount of deviation within the allowable range) of the substrates 8, and the bottom is between the adjacent peaks. At this time, as shown in FIG. 10, the lower peripheral portion of each substrate 8 is fitted into each substrate holding groove 36BG of the substrate support member 36B, and the upper peripheral portion of each substrate 8 is fitted into each substrate holding groove 74G of the substrate presser 74. This is also called the "appropriate substrate holding state."

[0102] Fig. 13 shows the cause of an inappropriate substrate holding state. As shown on the left side of Fig. 13, when the upper peripheral portion of one substrate 8 approaches the upper peripheral portion of an adjacent substrate 8, the second cover 72 is closed and the substrate presser 74 is brought closer to the substrate 8, a phenomenon occurs in which the upper peripheral portions of the adjacent substrates 8 come into contact with each other and get stuck in the same substrate holding groove 74G. This is called a "bridge (wafer bridge)". Since the flow of the processing liquid is poor between the two substrates 8 where the bridge occurs, there is a possibility that the intended substrate processing results will not be obtained (for example, deterioration of in-plane uniformity).

[0103] FIG. 12 shows an example of a gray value distribution obtained for 50 substrates 8. In FIG. 12, the interval between adjacent gray value peaks is wider at the end of the substrate array. This is due to the occurrence of the above-mentioned bridge. In other words, when a bridge occurs as shown on the right side of FIG. 13, the gray value peaks of the APEX images of two adjacent substrates 8 are detected as a single inseparable peak, as shown by the dashed line in FIG. 14. The distance between the adjacent peaks also becomes larger. Using this, the occurrence of a bridge can be detected. In FIG. 14, the solid line is a curve obtained when the substrates are held in an appropriate state.

[0104] The determination as to whether or not a bridge has occurred is included in the determination as to whether or not the deviation between the actual position and the reference position of at least one substrate 8 is within an allowable range.

[0105] Immediately after closing the second lid 72 with the substrate holder 74, the substrate position is determined. If it is confirmed that no bridges have occurred (i.e., all substrates 8 are properly held), bubbling of nitrogen gas is started and the first lid 71 is closed, allowing the liquid processing (e.g., wet etching processing) to proceed.

[0106] If a bridge has occurred, the second lid 72 is opened and then closed again (retry). At this time, it is not necessary to open the second lid 72 to the fully open state (i.e., move it to the open position), and it is sufficient if the substrate holder 74 is once separated from the substrate 8. While the substrate holder 74 is separated from the substrate 8, the substrate support member 36B may be moved slightly up and down to shake the substrate 8. After the second lid 72 is closed, the substrate position is determined again. When it is confirmed that the substrate 8 is in the appropriate position (i.e., no bridge has occurred), nitrogen gas is discharged from the gas nozzle 60 (see Figures 2 to 4) to start bubbling, and the first lid 71 is closed to continue the process.

[0107] If the bridge is not eliminated despite the above operations, the opening and closing of the second lid 72 and the substrate position determination may be repeated until the bridge is eliminated. Alternatively, after the opening and closing of the second lid 72 and the substrate position determination are performed a predetermined number of times, bubbling may be started and the first lid 71 may be closed to continue the liquid processing, regardless of whether the bridge has been eliminated or not. Alternatively, even if a bridge has occurred when the second lid 72 is closed for the first time, bubbling may be started and the first lid 71 may be closed to continue the liquid processing.

[0108] Nitrogen gas bubbling is performed for the purpose of improving the in-plane and inter-plane uniformity of the processing of the substrate 8. For this reason, it is not preferable to continue immersing the substrate 8 in the processing liquid without bubbling. From this point of view, it is preferable to set a limit on the number of attempts to open and close the second lid 72 and to determine the substrate position. However, depending on the type of processing, the above-mentioned problems may not occur, so there is no need to set a limit on the number of retries.

[0109] If the substrate 8 is not held down by the substrate presser 74, bubbling may cause the substrate 8 to float up from the substrate support member 36B, and the lower peripheral edge of the substrate 8 may come out of the substrate holding groove of the substrate support member 36B. For this reason, whatever the procedure for processing, it is preferable to perform bubbling with the second lid 72 in the closed position.

[0110] Software marking may be applied to the substrate 8 on which a bridge has occurred. Software marking means, for example, storing in the storage medium 38 of the control unit 7, for example, "when wet etching was performed on the substrate 8 of lot M (M is the ID of the lot) in the processing bath 34, a bridge occurred on the Nth substrate 8 and the N+1th substrate 8." Based on the software marking, in a later process, a thorough inspection may be performed on the substrate 8 on which a bridge has occurred or a semiconductor device obtained from the substrate 8. All substrates 8 on which a bridge has occurred even once may be subject to software marking. Alternatively, only substrates 8 on which a bridge has occurred a predetermined number of times or more may be subject to software marking. Alternatively, only substrates 8 on which a liquid processing was performed while a bridge was occurring may be subject to software marking.

[0111] If a bridge occurs in the initial substrate position determination, the process may proceed without performing the opening / closing operation (retry) of second lid body 72. In this case, software marking is applied to the substrate 8 on which the bridge occurs. The operator may be able to set whether or not to perform the opening / closing operation of second lid body 72 after the bridge occurs in the initial substrate position determination via a user interface (keyboard, touch panel, etc.) (not shown) of substrate liquid processing system 1A.

[0112] When the occurrence of a bridge is detected, an alarm may be issued to an operator via a user interface (not shown) of the substrate liquid processing system 1A (display, alarm lamp, alarm buzzer, etc.).

[0113] The timing of closing the second cover 72 with the substrate holder 74 can also be determined using the substrate position determination. In the process of submerging the substrates 8 in the processing liquid stored in the inner tank 34A while being held vertically and equidistantly in the horizontal direction by the substrate support members 36B, the substrates 8 sway due to the influence of Laplace pressure, and the distance between the upper edges of adjacent substrates 8 varies. FIG. 15 shows the change over time in the distance between several pairs of adjacent substrates 8, with the moment when the substrates 8 are submerged in the processing liquid as a reference (0 seconds). From the graph in FIG. 15, it can be seen that the substrate swaying converges after a certain amount of time (for example, about 5 seconds) has passed since the substrates 8 were submerged in the processing liquid. When the substrate 8 swaying decreases to a level that does not cause problems, the second cover 72 with the substrate holder 74 may be closed.

[0114] It has been confirmed by experiments that the time (e.g., about 5 seconds) from when the substrate 8 is submerged in the processing solution in the inner bath 34A until the shaking of the substrate 8 becomes sufficiently small is almost constant. For this reason, when a predetermined time (e.g., about 6 seconds to allow for a small safety margin) has elapsed since the substrate 8 was placed in the inner bath 34A, the second lid 72 may be closed without determining the substrate position. Even in this case, the problem of bridging hardly occurs. Even if bridging occurs, the occurrence of bridging can be detected by determining the substrate position after the second lid 72 is closed, and measures can be taken as necessary.

[0115] Alternatively, the substrate position may be determined based on images acquired, for example, 5 seconds, 6 seconds, or 7 seconds after the substrate 8 is submerged in the processing solution, and the second lid 72 may be closed when it is confirmed that the deviation (position deviation) of the actual position of the substrate 8 from the reference position of the substrate 8 is stable and falls within a predetermined range. In this case, the occurrence of bridges can be more reliably prevented.

[0116] According to the above embodiment, batch processing can be performed with the substrate 8 firmly held in an appropriate position (reference position) by the substrate support member 36B and the substrate presser 74. If bridging occurs, there is a risk that the in-plane and inter-plane uniformity of the processing result (e.g., etching amount) of the substrate 8 will decrease, but this does not happen according to the present embodiment.

[0117] In the above embodiment, only the presence or absence of a bridge is considered in the substrate position determination, but this is not limited to the above. In the substrate position determination, the deviation between the reference X coordinate and the actual X coordinate of each substrate 8 may be determined individually. The reference X coordinate of each substrate 8 is equal to the X coordinate of the substrate holding groove 36BG of the substrate support member 36B with which the substrate 8 should be engaged (or the X coordinate of the substrate holding groove 74G of the substrate presser 74). The deviation between the reference X coordinate and the actual X coordinate of each substrate 8 may be obtained, and if the deviation exceeds a predetermined threshold value for one or more substrates 8, it may be determined that an inappropriate substrate holding state is occurring.

[0118] In the above embodiment, all the substrates 8 are imaged and the positions of all the substrates 8 are determined, but only some of the substrates 8 may be imaged and the positions of only some of the substrates 8 may be determined. Depending on the arrangement of the inner tank 34A and the nozzles, positional deviation may occur only in the substrates 8 located in a specific location. In such a case, images may be captured and the substrate positions may be determined for only some of the substrates. For this purpose, a function may be provided that automatically adjusts the imaging range of the camera 90 based on past substrate position determinations. In this way, the burden of calculation processing can be reduced and the accuracy of substrate position determination can be improved.

[0119] In the above embodiment, the camera is disposed above the upper opening of the inner tank 34A, and the substrate 8 is photographed with the first lid 71 in the open position. That is, the object light emitted from the object (light from the light source 92 reflected by the substrate 8 and directed toward the camera 90) enters the camera 90 without passing through the components of the processing tank 34 or the lids 71 ​​and 72. That is, the object light is only disturbed when it passes through the processing liquid and when it passes through the liquid surface (gas-liquid interface) of the processing liquid. As is clear from the illustrated configuration of the above embodiment, the distance from the portion of the substrate 8 involved in the substrate position determination (upper periphery) to the liquid surface of the processing liquid is relatively small. Therefore, the camera 90 can capture an image with a clarity that allows the substrate position determination to be performed without any problems.

[0120] 3, if the first lid body 71 is in close contact with the surface of the processing liquid when the first lid body 71 is in the closed position and is made of a transparent material such as quartz, it may be possible for the camera 90 to capture an image with sufficient clarity to perform substrate position determination without hindrance even when the first lid body 71 is in the closed position. In such a case, the substrate position determination may be performed based on an image obtained with the first lid body 71 in the closed position.

[0121] If the processing tank 34 is transparent, the substrate 8 may be imaged from below the processing tank 34. In this case, the presence or absence of a jump slot in the substrate support member 36B can be determined. The jump slot here means that, for example, when the substrate is forcefully submerged in the processing liquid, an upward force is applied to the substrate 8, causing the lower peripheral portion of the substrate 8 to come out of the substrate holding groove 36BG of the substrate support member 36B, and the substrate 8 to move to an inappropriate position. Note that, in general, a liquid supply line, a drainage line, and various devices attached to these lines are provided in the space below the processing tank 34, but it is preferable to arrange these lines and devices so as not to interfere with imaging.

[0122] Furthermore, if the processing tank 34 is transparent (for example, if the processing tank is made of quartz), the camera 90 may capture an image of the substrate 8 from the side of the inner tank 34A. In this case, from the viewpoint of obtaining a clearer image, a processing tank in which the outer tank (34B) surrounds only the upper part of the inner tank (34A) may be used, as shown in FIG. 16. In this case, the camera 90 may be provided so that the camera lens is in close contact with the side of the inner tank 34A. Note that, if an image having sufficient clarity to perform substrate position determination without any problems can be obtained, an image of the substrate 8 may be captured through the outer tank (34B) and the inner tank (34A).

[0123] There is also a type of substrate liquid processing apparatus in which the substrate is processed while being supported only from below by the substrate support member (36B) without using a substrate presser (74) for holding the substrate 8. In this case, when the processing liquid is boiled vigorously or when gas is discharged vigorously for bubbling, the substrate may float up from the substrate support member, resulting in a jump slot. The occurrence of such a jump slot can also be detected by performing the same substrate position determination as above based on an image captured by a camera installed to the side or below the processing tank 34.

[0124] A camera may also be provided to confirm the position of the substrate 8 held by the substrate support member 36B that has been pulled up from the liquid. This makes it possible to detect any misalignment of the substrate that occurs during the processing of the substrate or when the substrate is pulled up from the processing liquid.

[0125] In the above embodiment, the treatment liquid is a phosphoric acid aqueous solution, but the present invention is not limited thereto. For example, a treatment liquid obtained by mixing an additive such as acetic acid with SC1 or a phosphoric acid aqueous solution may be used. In the above embodiment, the film to be etched is a silicon nitride film, but the present invention is not limited thereto. The film to be etched may be any other film. The treatment performed on the substrate in the treatment tank may not include an etching process, and may include only a cleaning process. That is, the present invention is applicable when the treatment is performed under conditions in which splashes are generated from the surface of the treatment liquid in the treatment tank. The substrate is not limited to a semiconductor wafer, and may be a substrate made of other materials such as glass or ceramic.

[0126] Please note that ordinal numbers such as "first" or "second" placed before parts in the specification do not necessarily match the ordinal numbers placed before components described in the claims (for example, "cover body"). [Explanation of symbols]

[0127] 34, 34A Treatment tank 36B Substrate support member 36 Lifting mechanism 90 Imaging section 94 Board position determination section 7 Control section

Claims

1. A substrate liquid processing apparatus, comprising: a processing tank having an upper opening for loading and unloading a substrate and storing a processing liquid; a substrate support member that supports a plurality of substrates in a vertical position and arranged at predetermined intervals in the horizontal direction; a lifting mechanism for lifting the substrate support member between a processing position in the processing tank and a retreat position above the processing tank through the upper opening; an imaging unit provided at a position capable of imaging the plurality of substrates supported by the substrate support member at the processing position in the processing liquid stored in the processing tank; a substrate position determination unit that performs substrate position determination to determine whether or not a deviation between an actual position of the plurality of substrates supported by the substrate support member in the processing liquid stored in the processing tank and a reference position where the substrate should be located is within an allowable range, based on image data obtained by imaging the plurality of substrates supported by the substrate support member at the processing position in the processing liquid stored in the processing tank with the imaging unit; A control unit for controlling an operation of the substrate liquid processing apparatus; A substrate liquid processing apparatus comprising:

2. the substrate support member is configured to support a peripheral portion of a lower half of each of the substrates from below so that each of the substrates is displaceable upward; The substrate liquid processing apparatus includes: A first cover capable of closing at least a portion of the upper opening; a first cover opening / closing mechanism for opening and closing the first cover; a substrate pressing member provided on the first lid, the substrate pressing member engaging with a peripheral portion of an upper half of each of the substrates supported by the substrate support member when the substrate support member supporting the substrates is positioned at the processing position and the first lid is positioned at the closed position, thereby preventing the substrates from being displaced upward and also in the horizontal direction; The substrate liquid processing apparatus of claim 1 further comprising:

3. The control unit is a first timing after the substrate support member supporting the plurality of substrates is submerged in the processing liquid stored in the processing tank and before the first lid is closed; and a second timing after the substrate support member supporting the plurality of substrates is submerged in the processing liquid stored in the processing tank and after the first lid is closed; The substrate liquid processing apparatus according to claim 2 , wherein the substrate position determining section determines the substrate position based on image data of the substrate captured at least at one of the timings of:

4. 4. The substrate liquid processing apparatus of claim 3, wherein the substrate position determination unit determines the substrate position based on image data of the substrate imaged at the first timing, and when the substrate position determination unit determines that the deviation is within the allowable range, the control unit moves the first lid to a closed position by the first lid opening / closing mechanism.

5. 5. The substrate liquid processing apparatus of claim 3, wherein the substrate position determination unit determines the substrate position based on image data of the substrate imaged at the second timing, and when the substrate position determination unit determines that the deviation is not within the allowable range, the control unit causes the first lid opening and closing mechanism to perform an opening and closing operation of opening the first lid and then moving the first lid to a closed position again.

6. 6. The substrate liquid processing apparatus of claim 5, wherein the control unit causes the first lid opening / closing mechanism to repeatedly perform the opening / closing operation up to a predetermined number of times depending on a result of the substrate position determination, until the deviation after the first lid was last moved to the closed position falls within the allowable range.

7. 7. The substrate liquid processing apparatus according to claim 5, wherein the control unit raises and lowers the substrate support member using the lifting mechanism to rock the substrate supported by the substrate support member after the first lid body is opened and before the first lid body is moved to a closed position again.

8. a gas nozzle provided in the processing tank below the substrate support member at the processing position and configured to eject a bubbling gas; a gas supply mechanism for supplying gas to the gas nozzle; Further equipped with 7. The substrate liquid processing apparatus of claim 5, wherein the control unit controls the gas supply mechanism to stop ejection of bubbling gas from the gas nozzle between the time when the first lid body is opened and the time when the first lid body is moved to a closed position again.

9. the upper opening is composed of a first region and a second region, and the first lid is provided so as to be able to close the first region; The substrate liquid processing apparatus includes: a second cover provided so as to be able to close the second region; a second cover opening / closing mechanism for opening and closing the second cover; Further equipped with 6. The substrate liquid processing apparatus of claim 5, wherein when imaging the substrate at the second timing, the control unit causes the second lid to be in an open state using the second lid opening / closing mechanism, and images of the substrate are captured through the second region of the upper opening.

10. a gas nozzle provided in the processing tank below the substrate support member at the processing position and configured to eject a bubbling gas; a gas supply mechanism for supplying gas to the gas nozzle; Further equipped with 3. The substrate liquid processing apparatus of claim 2, wherein the control unit controls the gas supply mechanism to stop ejecting bubbling gas from the gas nozzle until the first lid body is moved to a closed position after the plurality of substrates supported by the substrate support member are submerged in the processing liquid stored in the processing tank, and to eject bubbling gas from the gas nozzle after the first lid body is moved to the closed position.

11. The substrate liquid processing apparatus of claim 2, wherein the substrate position determination unit determines, in the substrate position determination, that the deviation is not within an acceptable range when the distance between at least two adjacent substrates among the plurality of substrates supported by the substrate support member is smaller than a predetermined threshold value, and determines that the deviation is not within an acceptable range.

12. 3. The substrate liquid processing apparatus of claim 2, wherein the substrate position determination unit, in determining the substrate position, individually determines the deviation between the reference position and the actual position for each substrate supported by the substrate support member, and determines whether the deviation is within an acceptable range for each substrate individually.

13. A substrate liquid processing apparatus as described in any one of claims 1 to 12, wherein the imaging unit is positioned to photograph the multiple substrates from a direction such that substantially only APEXes of the multiple substrates held by the substrate support member at the processing position appear on the image.

14. The substrate liquid processing apparatus of claim 13, further comprising an illumination unit that irradiates illumination light necessary for the imaging section to image the substrate, the illumination unit being positioned at a position where it can irradiate the illumination light so that the APEX is imaged as brightly as possible.

15. The substrate liquid processing apparatus of claim 13 or 14, wherein the substrate position determination unit is configured to determine the substrate position by regarding the APEX of each substrate as being present at a position in the image acquired by the imaging unit that exhibits a brightness peak, and by regarding the position of each peak as the actual position of each substrate.

16. A substrate liquid processing apparatus as described in any one of claims 1 to 15, wherein the imaging unit includes one or more cameras, and the one or more cameras are provided at one or more positions including a position above the processing tank, a position to the side of the processing tank, and a position below the processing tank.

17. The substrate liquid processing apparatus according to claim 1 , wherein the imaging section includes a linear image sensor having an imaging element arranged along an arrangement direction of the plurality of substrates supported by the substrate support member.

18. A substrate liquid processing apparatus as described in any one of claims 1 to 17, wherein when the substrate position determination unit determines that two adjacent substrates have come into contact, the control unit stores each of the two substrates as a substrate that has had a history of contact with another substrate.

19. A substrate liquid processing method using a substrate liquid processing apparatus comprising: a processing tank having an upper opening for loading and unloading a substrate and storing a processing liquid; a substrate support member supporting a plurality of substrates in a vertical position and arranged at predetermined intervals in a horizontal direction; and a lifting mechanism for lifting and lowering the substrate support member through the upper opening between a processing position in the processing tank and a retreat position above the processing tank, capturing images of the substrates supported by the substrate support member in the processing liquid stored in the processing tank by an imaging unit; a substrate position determination unit performs substrate position determination to determine whether or not a deviation between an actual position of the plurality of substrates supported by the substrate support member and a reference position where the substrate should be located is within an allowable range based on image data captured by the imaging unit; controlling an operation of the substrate liquid processing apparatus by a control unit according to a result of the substrate position determination; A substrate liquid processing method comprising the steps of:

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