JP7638765B2 - Substrate liquid processing apparatus and substrate liquid processing method - Google Patents

Description

This disclosure relates to a substrate liquid processing apparatus and a substrate liquid processing method.

The manufacturing process for semiconductor devices includes a silicon nitride film etching process in which substrates such as semiconductor wafers are immersed in an aqueous phosphoric acid solution stored in a treatment tank, and the 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 vertical position and arranged at equal intervals in the horizontal direction.

During substrate processing, a flow of processing liquid is formed in the processing tank from the bottom toward the liquid surface, and nitrogen gas bubbling is performed to improve processing uniformity. As a result, the substrate receives a force that tends to lift it up from the substrate holder. In the substrate processing apparatus of Patent Document 1, a substrate pressing member that prevents the substrate from displacing upward is provided on the lid of the processing tank to prevent the substrate from falling off the substrate support member or becoming misaligned due to the force applied to the substrate by the processing liquid.

JP 2019-067995 A

The present disclosure provides a technique for verifying that a substrate is properly held by a substrate support member while immersed in a processing liquid stored in a processing tank.

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 storing a processing liquid; a substrate support member 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 for determining whether or not the deviation between the actual positions of the plurality of substrates supported by the substrate support member and the reference position where the substrates should be located is within an acceptable range based on image data captured by the imaging unit; and a control unit for controlling the operation of the substrate liquid processing apparatus.

According to the above embodiment, it is possible to confirm that the substrate is properly held by the substrate holding member while immersed in the processing liquid stored in the processing tank.

1 is a schematic plan view showing an overall configuration of a substrate liquid processing system. 1 is a system diagram showing a configuration of an etching apparatus incorporated in a substrate liquid processing system. 1 is a schematic cross-sectional view of a processing tank of an etching apparatus; FIG. 2 is a schematic longitudinal cross-sectional view of a treatment tank. FIG. 2 is a schematic plan view of a treatment tank. 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. FIG. 7 is a transverse longitudinal cross-sectional view showing the cover moved from the closed position shown in FIG. 6 to the open position; FIG. FIG. 1 is a schematic diagram showing a camera and lighting positioned above the treatment vessel. 1 is a schematic diagram showing a state in which a substrate is properly positioned between a substrate support member and a substrate clamp; FIG. 2 is a schematic diagram showing an image captured by a camera. 1 is a graph showing the distribution of grey values; 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; FIG. 2 is a schematic diagram showing the distribution of grey values when bridging occurs; 11 is a graph illustrating the rocking motion of a substrate immediately after the substrate is submerged in a processing tank. FIG. 13 is a schematic diagram showing another arrangement of cameras and lighting.

Embodiments of the present invention will now be described with reference to the accompanying drawings. First, an overall substrate liquid processing system 1A incorporating a substrate liquid processing apparatus 1 according to one embodiment of the present invention will be described.

As shown in FIG. 1, the substrate liquid processing system 1A has a carrier loading/unloading section 2, a lot formation section 3, a lot placement section 4, a lot transport section 5, a lot processing section 6, and a control section 7.

The carrier loading/unloading section 2 loads and unloads a carrier 9 that contains multiple (e.g., 25) substrates (silicon wafers) 8 arranged one above the other in a horizontal position.

This carrier loading/unloading section 2 is provided with a carrier stage 10 on which multiple carriers 9 are placed, a carrier transport mechanism 11 that transports the carriers 9, carrier stocks 12 and 13 that temporarily store the carriers 9, and a carrier placement table 14 on which the carriers 9 are placed. Here, the carrier stock 12 temporarily stores the substrates 8 that will become products before they are processed in the lot processing section 6. Also, the carrier stock 13 temporarily stores the substrates 8 that will become products after they have been processed in the lot processing section 6.

Then, the carrier loading/unloading section 2 transports the carrier 9 that 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 that has been placed 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 that has been transported to the carrier stage 10 is then transported to the outside.

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

This lot formation section 3 is provided with a substrate transport mechanism 15 that transports multiple substrates 8. The substrate transport mechanism 15 can change the position of the substrate 8 from a horizontal position to a vertical position and from a vertical position to a horizontal position during transport of the substrate 8.

Then, the lot forming section 3 uses the substrate transport mechanism 15 to transport the substrate 8 from the carrier 9 placed on the carrier placement table 14 to the lot placement section 4, and places the substrate 8 forming the lot on the lot placement section 4. The lot forming section 3 also transports the lot 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 multiple substrates 8: a pre-processing substrate support section that supports the substrate 8 before processing (before being transported by the lot transport section 5), and a post-processing substrate support section that supports the substrate 8 after processing (after being transported by the lot transport section 5). This prevents particles and the like attached to the pre-processing substrate 8 from transferring to the processed substrate 8.

The lot placement unit 4 temporarily places (stands by) the lots being transported between the lot formation unit 3 and the lot processing unit 6 by the lot transport unit 5 on the lot placement table 16.

This lot placement section 4 is provided with an entrance lot placement table 17 on which lots are placed before processing (before being transported by the lot transport section 5), and an exit lot placement table 18 on which lots are placed after processing (after being transported by the lot transport section 5). On the entrance lot placement table 17 and the exit lot placement table 18, multiple substrates 8 for one lot are placed in a vertical position, lined up front to back.

In the lot placement section 4, the lot formed in the lot formation section 3 is placed on the load-side lot placement table 17, and the lot is carried into the lot processing section 6 via the lot transport section 5. In addition, in the lot placement section 4, the lot carried out from the lot processing section 6 via the lot transport section 5 is placed on the load-side lot placement table 18, and the lot is transported to the lot formation section 3.

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.

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 placement section 4 and the lot processing section 6, and a moving body 21 that moves along the rails 20 while holding multiple substrates 8. The moving body 21 is provided with a substrate holder 22 that holds multiple substrates 8 lined up in a vertical position and can move forward and backward.

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

The lot processing unit 6 treats multiple substrates 8 arranged vertically one behind the other as one lot and performs processes such as etching, cleaning, and drying.

In this lot processing section 6, a drying processing device 23 for drying the substrates 8, a substrate holder cleaning processing device 24 for cleaning the substrate holders 22, a cleaning processing device 25 for cleaning the substrates 8, and two etching processing devices (substrate liquid processing devices) 1 according to the present invention for etching the substrates 8 are arranged side by side.

The drying processing device 23 has a processing tank 27 and a substrate lifting mechanism 28 that is provided in the processing tank 27 so that it can be raised and lowered. A drying processing gas (IPA (isopropyl alcohol) or the like) is supplied to the processing tank 27. The substrate lifting mechanism 28 holds a number of substrates 8 for one lot in a vertical position, arranged front to back. The drying processing device 23 receives the lot from the substrate holder 22 of the lot transport mechanism 19 with the substrate lifting mechanism 28, and raises and lowers the lot with the substrate lifting mechanism 28, thereby drying the substrates 8 with the drying processing gas supplied to the processing tank 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.

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 the drying gas.

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 each processing tank 30, 31 so that they can be raised and lowered freely. A cleaning processing liquid (such as SC-1) is stored in the cleaning processing tank 30. A rinsing processing liquid (such as pure water) is stored in the rinsing processing tank 31.

The etching processing apparatus 1 has a processing tank 34 for etching and a processing tank 35 for rinsing, and each processing tank 34, 35 is provided with a substrate lifting mechanism 36, 37 that can be raised and lowered freely. The processing tank 34 for etching stores a processing liquid for etching (aqueous phosphoric acid solution). The processing tank 35 for rinsing stores a processing liquid for rinsing (pure water, etc.). As described above, the etching processing apparatus 1 is a substrate liquid processing apparatus according to the present invention.

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, the substrate lifting mechanism 36 holds a plurality of substrates 8 for one lot in a vertical position, arranged front to back. 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 tank 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 tank 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.

The control unit 7 controls the operation of each part of the substrate liquid processing system 1A (the carrier loading/unloading unit 2, the lot formation unit 3, the lot placement unit 4, the lot transport unit 5, the lot processing unit 6, and the etching processing device 1).

The control unit 7 is, for example, a computer, and includes a computer-readable M. The storage medium 38 stores programs that control various processes executed in the substrate liquid processing apparatus 1. The control unit 7 controls the operation of the substrate liquid processing apparatus 1 by reading and executing the programs stored in the storage medium 38. The programs 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 computer-readable storage media 38 include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnetic optical disk (MO), and a memory card.

As described above, in the treatment tank 34 of the etching treatment device 1, an aqueous solution (aqueous phosphoric acid solution) of a chemical (phosphoric acid) with a predetermined concentration is used as a treatment liquid (etching liquid) to perform liquid treatment (etching treatment) on the substrate 8.

Next, the schematic configuration and piping system of the etching processing apparatus (substrate liquid processing apparatus) 1 will be described with reference to FIG. 2.

The etching processing device 1 has the aforementioned processing tank 34 that stores a phosphoric acid aqueous solution of a predetermined concentration as the processing liquid. The processing tank 34 has an inner tank 34A and an outer tank 34B. The phosphoric acid aqueous 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.

The upstream end of the 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. In the circulation line 50, a pump 51, a heater 52, and a filter 53 are interposed, in that order from the upstream side. By driving the pump 51, a circulation flow of the phosphoric acid aqueous 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.

The liquid processing section 39 is formed by the processing tank 34, the circulation line 50, and the equipment (51, 52, 53, etc.) in the circulation line 50. The processing tank 34 and the circulation line 50 also form a circulation system.

A gas nozzle 60 for discharging bubbles of an inert gas, such as nitrogen gas, into the phosphoric acid aqueous 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 regulator 60C consisting of an on-off valve, a flow control valve, a flow meter, etc.

The processing tank 34 is provided with the aforementioned substrate lifting mechanism 36. The substrate lifting mechanism 36 can hold multiple substrates 8 in a vertically upright position and arranged horizontally at intervals, and can raise and lower them in this state.

The etching processing device 1 has a phosphoric acid aqueous solution supply unit 40 that supplies 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 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.

The phosphoric acid aqueous solution supply 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. The phosphoric acid aqueous solution supply unit 40 has a phosphoric acid aqueous solution source 40A consisting of a tank for storing phosphoric acid aqueous solution, a phosphoric acid aqueous solution supply line 40B connecting the phosphoric acid aqueous solution source 40A and the outer tank 34B, and a flow meter 40C, a flow control valve 40D, and an on-off valve 40E interposed in order from the upstream side on the phosphoric acid aqueous solution supply line 40B. The phosphoric acid aqueous solution supply 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.

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

The silicon supply unit 42 has a silicon supply source 42A consisting of a tank that stores a silicon-containing compound solution, such as 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.

The phosphoric acid aqueous solution discharge section 43 is provided to discharge the phosphoric acid aqueous solution in the circulation system consisting of the liquid treatment section 39 and the circulation line 50, i.e., in the liquid treatment section 39. The phosphoric acid aqueous solution discharge section 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 sequence from the upstream side on the discharge line 43A. The phosphoric acid aqueous solution discharge section 43 can discharge the phosphoric acid aqueous solution at a controlled flow rate via the flow meter 43B and the flow control valve 43C.

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 flows out of the cooling tank 43E may be disposed of in a factory waste liquid system (not shown), or may be reused by sending it to the aqueous phosphoric acid solution supply source 40A after silicon contained in the aqueous phosphoric acid solution has been removed by a regeneration device (not shown).

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.

The discharge line 43A is provided with a silicon concentration meter 43G that measures the silicon concentration in the phosphoric acid aqueous solution. In addition, a phosphoric acid concentration meter 55B that measures the phosphoric acid concentration in the phosphoric acid aqueous solution is interposed in a branch line 55A that branches off from the circulation line 50 and is connected to the outer tank 34B. The outer tank 34B is provided with a liquid level meter 44 that detects the liquid level in the outer tank 34B.

Next, the configuration of the processing tank 34 of the etching processing device 1 will be described in detail with reference to Figures 3 to 7. For ease of explanation, an XYZ orthogonal coordinate system is set and referenced as necessary. Note that the negative X direction is sometimes called the "front" or "forward", the positive X direction is sometimes called the "rear" or "rear", the negative Y direction is sometimes called the "right side" or "rightward", and the positive Y direction is sometimes called the "left side" or "leftward".

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 housed inside the outer tank 34B. The aqueous phosphoric acid solution that overflows from the inner tank 34A flows into the outer tank 34B. While the liquid treatment is being performed, most of the inner tank 34A, including the bottom, is immersed in the aqueous phosphoric acid solution in the outer tank 34B.

The outer tank 34B is housed 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.

The processing liquid supply nozzle 49 is a cylindrical body extending in the X direction (horizontal direction) inside the inner tank 34A. The processing liquid supply nozzle 49 ejects processing liquid from a plurality of ejection ports 49D (see Figures 3 and 4) drilled on its circumferential 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 supply nozzle 49 is supplied with processing liquid (aqueous phosphoric acid solution) from a pipe 49A extending vertically.

The gas nozzle 60 is a cylindrical body extending in the X direction (horizontal direction) at a height position lower than the treatment liquid supply nozzle 49 in the inner tank 34A. The gas nozzle 60 ejects bubbles of inert gas (e.g., nitrogen gas) from a plurality of ejection ports 60D (see Figures 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 treatment liquid (phosphoric acid aqueous solution) from a pipe 60A extending vertically.

The substrate lifting mechanism 36 has a support plate 36A extending in the vertical direction (Z direction) that is raised 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 end is supported by the support plate 36A (see also FIG. 9). Each substrate support member 36B has a plurality of 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 substrates 8 (e.g., 50 to 52 substrates) in a vertical position with intervals in the horizontal direction (X direction). Such substrate lifting mechanisms 36 are well known in the art, and detailed illustrations and explanations of the structure are omitted.

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 connected 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 the liquid receiving container 80 and a rotation actuator 84 (see Figures 4 and 5). By operating the rotary actuator 84, the first lid 71 and the second lid 72 can rotate (pivot) about their respective rotation axes extending in the horizontal direction (X direction) between a closed position (position shown in FIGS. 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 FIG. 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 FIG. 3).

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.

During normal operation of the etching processing apparatus 1, the first lid 71 and the second lid 72 are 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, preventing a drop in the temperature of the aqueous phosphoric acid solution in the inner tank 34A and preventing water vapor generated from the boiling aqueous phosphoric acid solution from escaping to the outside of the processing tank 34.

The first lid 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 that extend in the X direction, and a third splash shielding portion 71E that extends in the Y direction. Similarly, the second lid 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 that extend in the X direction, and a third splash shielding portion 72E that extends in the Y direction.

A large rectangular recess 71R is formed on the top 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.

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 opposing side walls 712R and 713R so as not to prevent the overflow of the phosphoric acid aqueous solution from the inner tank 34A to the outer tank 34B (see arrow OF in FIG. 6). Although not shown, the upper ends of the four side walls of the inner tank 34A have multiple V-shaped notches at intervals to facilitate smooth overflow.

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

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 into the outer tank 34B. These 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.

When the first lid body 71 is in the open position, the second splash shielding portion 71C 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 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.

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

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 said 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.

There is no need 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 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 hardly reaches the outer tank 34B.

The second lid 72 is formed generally as a mirror image of the first lid 71, and the structures of the first lid 71 and the second lid 72 are generally the same. 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 numbers of corresponding parts of the first lid 71 and the second lid 72 (parts in symmetrical positions, parts with the same function), and the only difference is whether the first two digits of the reference numbers are "71" or "72".

As shown in FIG. 6, when the first lid body 71 and the second lid body 72 are in the closed position, the side wall 712R extending upward from the bottom wall 711R of the first lid body 71 and the side wall 722R extending upward from the bottom wall 721R of the second lid body 72 face each other, and a gap G of height H is formed between both side walls. By providing the recesses 71R and 72R, it is possible to suppress an increase in the weight of the first lid body 71 and the second lid body 72 caused by providing a gap of height H.

When the underside (underside of bottom wall 711R) of main body 71A of first lid 71 and the underside (underside of bottom wall 721R) of main body 72A of second lid 72 are in contact with the liquid level of the treatment liquid in inner tank 34A as shown in FIG. 6, the boiling or bubbling phosphoric acid aqueous solution may splash upward from the gap between first lid 71 and second lid 71 and splash around. However, by providing gap G of height H as described above, it becomes difficult for the treatment liquid to splash outward from gap G. To achieve this effect, height H can be set to, for example, about 5 cm or more.

When the treatment liquid in the inner tank 34A is an aqueous phosphoric acid solution, at least the main body parts 71A and 72A of the first lid 71 and the second lid 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 crack 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 lid 71 and the second lid 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 aqueous phosphoric acid solution in the treatment tank 34, especially in the inner tank 34A, will splash outward through the gap. However, by providing a gap G with the height H as described above, it is possible to at least significantly suppress the splashing of the aqueous phosphoric acid solution from the gap G.

In addition, in order to facilitate overflow, as described above, when the bottom wall 711R (721R) is inclined 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 a 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).

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 above or beyond 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 FIG. 3 to FIG. 5, the cover 73 (and the plate-like body 73P) are not shown to avoid complicating the drawings.

In addition, because the gap G has a height H, the momentum of the droplets of the treatment liquid that splash from the surface of the phosphoric acid aqueous solution in the inner tank 34A weakens before they collide with the cover 73. Therefore, the treatment liquid that collides with the cover 73 does not fly out to the side.

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

As shown in FIG. 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.

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

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

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

In the illustrated embodiment, the board holder 74 is an elongated plate-like body formed separately from the second lid body 72, and is fixed to the body portion 72A of the second lid body 72 by screwing. Alternatively, the board holder 74 may be formed integrally with the second lid body 72. In either case, the board holder 74 forms part of the side wall 722R of the body portion 72A of the second lid body 72.

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 to prevent or suppress 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.

As shown diagrammatically in FIG. 9, a camera 90 and lighting 92 are provided above the processing tank 34. If the images required for the image processing described below 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 part of the control unit 7, or may be a separate arithmetic processing unit.

The camera 90 can be positioned directly above the top opening of the inner tank 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 can be provided at a lower position (a height position close to the top opening of the inner tank 34A) and a moving mechanism can be provided to move the camera 90 between a position directly above the inner tank 34A and a position away from directly above the inner tank 34A. The camera 90 can be provided at a position other than the above as long as it can acquire the images required for substrate position determination, which will be described later.

A fan filter unit (FFU) 100 is disposed further above the camera 90. Clean air is blown downward from the fan filter unit 100. This downflow of clean air prevents gas or mist from reaching the camera 90, even if gas or mist from the treatment liquid (chemical liquid) that may fog the lens of the camera 90 or corrode the camera 90, rises from the treatment tank 34.

The camera 90 may be protected from gas or mist from the processing liquid by providing a cover (not shown) surrounding the camera 90 and flowing a suitable shielding gas (clean air or inert gas) through the cover.

When the processing liquid stored in the processing tank 34 is phosphoric acid, the gas rising above the processing tank 34 is essentially water vapor, and has little effect on the camera 90.

Next, the operation of the etching processing device 1 will be described. 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 that circulates within the above-mentioned circulation system is formed.

The heater 52 of the circulation line 50 is then operated to heat the phosphoric acid aqueous solution in the inner tank 34A to a predetermined temperature (e.g., 160°C). The first lid 71 and the second lid 72 are positioned in the closed position at the latest by the time heating by the heater 52 begins. 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.

Before one lot of substrates 8 is introduced into the phosphoric acid aqueous solution in the inner tank 34A, the silicon concentration (which affects the etching selectivity of silicon nitride film to 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 the silicon supply unit 42 to the outer tank 34B. 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 measured by the silicon concentration meter 43G.

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 tank 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 descends, and the substrates 8 supported by the substrate support member 36B are submerged in the phosphoric acid aqueous solution in the inner tank 34A. At this time, it is preferable to stop bubbling to prevent the substrate 8 from floating up from the substrate support member 36B.

After the substrates 8 are submerged in the phosphoric acid aqueous solution in the inner tank 34A and a predetermined time (e.g., about 5 seconds) has elapsed, the second lid 72 is moved to the closed position. The substrate holder 74 provided on the second lid 72 engages with the upper peripheral edge of the substrate 8 to restrain the substrate 8. The substrate 8 is then imaged by the camera 90. Based on the image result, it is determined whether all of the substrates 8 are in the appropriate position (in particular, whether the substrate holder 74 is properly 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 of the substrates 8 are in the appropriate position, the first lid 71 is moved to the closed position.

Next, bubbling begins 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 a wet etching process (liquid process) is performed on the substrate 8.

By keeping the first lid 71 and the second lid 72 in the closed position during the etching process of the substrate 8, the temperature drop near the liquid surface of the aqueous phosphoric acid solution in 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. In addition, since the inner tank 34A is immersed in the aqueous phosphoric acid solution in the outer tank 34B, the temperature drop in 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 amount of etching of the substrate 8 can be maintained at a high level.

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

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

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. In this way, 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).

Then, 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 aqueous phosphoric acid solution in the circulation system are adjusted, and another lot of substrates 8 is processed in the same manner as above.

Next, one embodiment of substrate position determination will be described. Prior to substrate position determination, a number 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 positioned below the liquid surface of the processing liquid. After a predetermined time (e.g., 5 seconds) has elapsed, the second lid 72 with the substrate holder 74 is moved to the closed position while the first lid 71 is kept in the open position (shown by the dashed line in FIG. 9). Next, substrate position determination is performed.

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 in 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 displayed.

The substrate position determination unit 94 cuts out a region AR from the image so as to include the portion of each substrate 8 close to the liquid surface (see the schematic diagram in FIG. 11). The region AR can 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.

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).

The distribution of gray values can be a distribution along a line having a width of multiple 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 gray value calculated based on signals from multiple pixels lined up in the Y-directional at the same X-directional position can be treated as the gray value at a certain X-directional position. This can improve the detection accuracy.

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 in 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 lid 71 or the second lid 72. If the first lid 71 or the second lid 72 is transparent, the line sensor may be provided, for example, inside the recess 71R, 72R. In this case, the line sensor receives the object light that has passed through the first lid 71 or the second lid 72.

An example of the distribution of gray values along the arrow XS in FIG. 11 is shown in FIG. 12. The image portion corresponding to the APEX of each substrate 8 has the highest brightness 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 ± deviation within the allowable range) of the substrates 8, and the bottom is between the adjacent peaks. At this time, as shown diagrammatically 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".

Figure 13 shows the cause of an improper substrate holding state. As shown on the left side of Figure 13, when the upper edge of one substrate 8 approaches the upper edge of an adjacent substrate 8, the second lid 72 is closed and the substrate presser 74 is brought closer to the substrate 8, causing the upper edges of the adjacent substrates 8 to come into contact with each other and get stuck in the same substrate holding groove 74G. This phenomenon is called a "bridge (wafer bridge)." Because the flow of processing liquid is poor between the two substrates 8 where the bridge occurs, it is possible that the intended substrate processing results will not be obtained (for example, deterioration of in-plane uniformity).

Figure 12 shows an example of a gray value distribution obtained for 50 substrates 8. In Figure 12, the distance between adjacent gray value peaks is wider at the ends 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 Figure 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 Figure 14. The distance between adjacent peaks also becomes larger. This can be used to detect the occurrence of a bridge. Note that in Figure 14, the solid line is the curve obtained when the substrates are held in an appropriate state.

The determination of whether a bridge has occurred is included in the determination of whether the deviation between the actual position of at least one substrate 8 and the reference position is within an acceptable range.

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) to proceed.

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); 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. Once 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.

If the bridge is not eliminated despite the above operations, the second lid 72 may be opened and closed and the substrate position determination may be repeated until the bridge is eliminated. Alternatively, once the second lid 72 has been opened and closed and the substrate position determination has been performed a predetermined number of times, bubbling may be started and the first lid 71 may be closed to continue liquid processing, regardless of whether the bridge has been eliminated. Alternatively, even if a bridge was generated when the second lid 72 was first closed, bubbling may be started and the first lid 71 may be closed to continue liquid processing.

The bubbling of nitrogen gas 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 perspective, it is preferable to set a limit on the number of attempts to open and close the second lid 72 and determine the substrate position. However, depending on the type of processing, the above-mentioned problems may not occur, so it is not necessary to set a limit on the number of retries.

If the substrate 8 is not held down by the substrate holder 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, regardless of the procedure used for processing, it is preferable to perform bubbling with the second lid 72 in the closed position.

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 substrate 8 of lot M (M is the ID of the lot) in the processing bath 34, bridges 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 on the 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 has occurred may be subject to software marking.

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

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

The timing for closing the second lid 72 with the substrate holder 74 can also be determined using the substrate position determination described above. During 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 the 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 has decreased to a level that does not cause problems, the second lid 72 with the substrate holder 74 may be closed.

It has been confirmed through 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, once 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 performing substrate position determination. Even in this case, bridging problems rarely occur. Even if bridging does occur, the occurrence of bridging can be identified by substrate position determination after the second lid 72 is closed, and measures can be taken as necessary.

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 once it has been confirmed that the deviation (position deviation) of the actual position of the substrate 8 relative to the reference position of the substrate 8 is stable and within a predetermined range. In this case, the occurrence of bridges can be more reliably prevented.

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 results (e.g., etching amount) of the substrate 8 will decrease, but this does not happen according to this embodiment.

In the above embodiment, only the presence or absence of a bridge is taken into consideration in determining the substrate position, but this is not limited to the above. In determining the substrate position, 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 engage (or the X coordinate of the substrate holding groove 74G of the substrate holder 74). The deviation between the reference X coordinate and the actual X coordinate may be determined for each substrate 8, 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.

In the above embodiment, images of all boards 8 were taken and position determination was performed for all boards 8, but images of only some of the boards may be taken and position determination performed for only some of the boards 8. Due to the arrangement of the inner tank 34A and the nozzles, position deviation may occur only in boards 8 located in specific locations. In such cases, images may be taken and board position determination may be performed for only some of the boards. For this reason, a function may be provided that automatically adjusts the imaging range of the camera 90 based on past board position determinations. In this way, the burden of calculation processing can be reduced and the accuracy of board position determination can be improved.

In the above embodiment, the camera is placed 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 part 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.

Note that, as shown in FIG. 3, if the first lid 71 is in close contact with the surface of the processing liquid when the first lid 71 is in the closed position, and if the first lid 71 is made of a transparent material such as quartz, the camera 90 may be able to capture an image with sufficient clarity to allow substrate position determination to be performed without hindrance even when the first lid 71 is in the closed position. In such a case, the substrate position determination may be performed based on an image obtained when the first lid 71 is in the closed position.

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, typically, 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 position these lines and devices so as not to interfere with imaging.

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) can be used, as shown in FIG. 16. In this case, the camera 90 may be installed so that the camera lens is in close contact with the side of the inner tank 34A. Note that, if an image with sufficient clarity that the substrate position determination can be performed 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).

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) to hold the substrate 8. In this case, if the processing liquid is boiled vigorously or if gas is ejected 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.

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 out of the liquid. This makes it possible to detect any misalignment of the substrate that occurs during substrate processing or when the substrate is pulled out of the processing liquid.

In the above embodiment, the processing liquid is an aqueous phosphoric acid solution, but this is not limited thereto. For example, a processing liquid obtained by mixing additives such as acetic acid with SC1 or an aqueous phosphoric acid solution may be used. In the above embodiment, the film to be etched is a silicon nitride film, but this is not limited thereto and other films may be etched. The processing performed on the substrate in the processing tank may not include an etching process, and may include only a cleaning process. In other words, the present invention is applicable when processing is performed in the processing tank under conditions that cause splashes from the surface of the processing liquid. The substrate is not limited to a semiconductor wafer, but may be a substrate made of other materials such as glass or ceramic.

Please note that the ordinal numbers such as "first" and "second" placed before the components in the specification do not necessarily match the ordinal numbers placed before the components described in the claims (for example, "lid body").

34, 34A Processing tank 36B Substrate support member 36 Lifting mechanism 90 Imaging unit 94 Substrate position determination unit 7 Control unit

Claims (19)

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 that lifts and lowers 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: 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: The control unit is
a first timing after a 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 determination section determines the substrate position based on image data of the substrate captured at at least one of the timings. The substrate liquid processing apparatus according to claim 3, wherein the substrate position determination unit determines the substrate position based on image data of the substrate captured 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 using the first lid opening/closing mechanism. The substrate liquid processing apparatus according to claim 3 or 4, wherein the substrate position determination unit performs substrate position determination based on image data of the substrate captured 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/closing mechanism to perform an opening/closing operation to open the first lid and then move the first lid to a closed position again. The substrate liquid processing apparatus according to 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 the result of the substrate position determination until the deviation after the first lid is last moved to the closed position falls within the allowable range. The substrate liquid processing apparatus according to claim 5 or 6, wherein the control unit causes the lifting mechanism to lift and lower the substrate support member and rock the substrate supported by the substrate support member during the period from when the first lid body is opened until the first lid body is moved to the closed position again. 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. 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. 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. The substrate liquid processing apparatus according to claim 2, wherein the substrate position determination unit determines 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 in the substrate position determination. The substrate liquid processing apparatus according to claim 2, wherein the substrate position determination unit, in the substrate position determination, determines the deviation between the reference position and the actual position of each substrate supported by the substrate support member individually, and determines whether the deviation is within an allowable range for each substrate individually. The substrate liquid processing apparatus according to any one of claims 1 to 12, wherein the imaging unit is provided at a position that captures an image of the plurality of substrates from a direction in which substantially only the APEX of the plurality of substrates held by the substrate support member at the processing position appears on the image. The substrate liquid processing apparatus according to claim 13, further comprising an illumination unit that irradiates illumination light necessary for the imaging unit to image the substrate, and the illumination unit is disposed at a position where the illumination light can be irradiated so that the APEX is most brightly imaged. The substrate liquid processing apparatus according to 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 exhibiting a luminance peak in the image acquired by the imaging unit, and regarding the position of each peak as the actual position of each substrate. The substrate liquid processing apparatus according to 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 above the processing tank, to the side of the processing tank, and below the processing tank. The substrate liquid processing apparatus according to any one of claims 1 to 15, wherein the imaging unit includes a linear image sensor having imaging elements arranged along the arrangement direction of the plurality of substrates supported by the substrate support member. The substrate liquid processing apparatus according to 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 come into contact with another substrate. 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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