Substrate liquid treatment device

Abstract

The present invention provides a substrate liquid processing device. Prevent the droplets of the processing liquid scattered from the surface of the processing liquid in the inner tank from scattering to unexpected areas outside the inner tank. The substrate liquid processing device comprises: an inner tank, which can accumulate the processing liquid and has an upper opening; an outer tank, which is arranged on the outer side of the inner tank and allows the processing liquid to flow into from the inner tank; a first cover body, which can move between a closed position covering the first area of ​​the upper opening of the inner tank and an open position opening the first area of ​​the upper opening; and a second cover body, which can move between a closed position covering the second area of ​​the upper opening of the inner tank and an open position opening the second area of ​​the upper opening. The first cover body has a bottom wall and side walls extending upward from the bottom wall, and the second cover body has a bottom wall and side walls extending upward from the bottom wall. When the first cover body and the second cover body are in the closed position, the side wall of the first cover body is close to and faces the side wall of the second cover body, and a gap with a height is formed between these side walls.

Description

Technical Field

[0001] The present invention relates to a substrate liquid processing device for performing liquid processing on a substrate using a processing liquid. Background Art

[0002] The manufacturing process of semiconductor devices includes a silicon nitride film etching process. In this silicon nitride film etching process, a substrate such as a semiconductor wafer is immersed in a phosphoric acid aqueous solution stored in a processing tank to wet-etch a silicon nitride film formed on the surface of the substrate.

[0003] The liquid processing device used for such wet etching includes, for example: an inner tank that stores a processing liquid (aqueous phosphoric acid solution); an outer tank that receives the processing liquid overflowing from the inner tank; and a circulation line and a circulation pump that circulate the processing liquid discharged from the outer tank in a manner that returns to the inner tank.

[0004] The phosphoric acid aqueous solution in the inner tank is maintained in a boiling state. Therefore, each time the bubbles generated by boiling reach the liquid surface, the phosphoric acid aqueous solution generates droplets, which are scattered around the inner tank. If the droplets are scattered outside the outer tank, the environment around the treatment tank may be polluted. In addition, since the treatment liquid flows out of the circulation system, it may be difficult to manage the components of the treatment liquid.

[0005] Patent Documents 1 and 2 describe the following: In order to prevent the phosphoric acid aqueous solution from scattering around the processing tank, a pair of covers (referred to as "automatic covers" in Patent Documents 1 and 2) are provided that are opened only when the substrate is loaded and unloaded. Patent Documents 1 and 2 do not describe the specific structure of the cover, but only schematically show it as a rectangular parallelepiped object.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 09-181041

[0009] Patent Document 2: Japanese Patent Application Publication No. 2006-041253 Summary of the invention

[0010] Problem that the invention aims to solve

[0011] An object of the present invention is to provide a substrate liquid processing apparatus having a cover structure capable of preventing or significantly suppressing the splashes of a boiling processing liquid from flying out of a processing tank and adhering to a cover or scattering to the outside of the cover.

[0012] Solutions for solving problems

[0013] According to a technical solution of the present invention, a substrate liquid processing device is provided, which includes: an inner tank, which can accumulate processing liquid and has an upper opening; an outer tank, which is arranged on the outer side of the inner tank, and the processing liquid flows into the outer tank from the inner tank; a first cover body, which can move between a closed position covering a first part of the upper opening of the inner tank and an open position opening the first part of the upper opening; and a second cover body, which can move between a closed position covering a second part of the upper opening of the inner tank and an open position opening the second part of the upper opening, the first cover body having a bottom wall and side walls extending upward from the bottom wall, the second cover body having a bottom wall and side walls extending upward from the bottom wall, when the first cover body and the second cover body are in the closed position, the side walls of the first cover body are close to and face the side walls of the second cover body, and a gap with a height is formed between these side walls.

[0014] In recent years, the applicant has conducted research on the following: by making the cover body contact with the phosphoric acid aqueous solution in the treatment tank, the controllability of the temperature and boiling state of the treatment liquid in the treatment tank is improved. If the cover body is in contact with the liquid, even if the cover body is provided in the treatment tank, the possibility of the droplets of the phosphoric acid aqueous solution flying out from the small gap between the treatment tank and the cover body is high. According to the above-mentioned embodiment of the present invention, when the cover body is provided in the treatment tank, not only when the cover body is not in contact with the liquid, but also when the cover body is in contact with the liquid, the droplets of the phosphoric acid aqueous solution can be suppressed from scattering to the outside of the cover body.

[0015] Effects of the Invention

[0016] According to the technical aspects of the present invention described above, it is possible to prevent or significantly suppress the processing liquid from escaping from the gap between the first cover body and the second cover body. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic plan view showing the overall structure of the substrate liquid processing system.

[0018] Figure 2 This is a system diagram showing the structure of an etching device incorporated in a substrate liquid processing system.

[0019] Figure 3 This is a schematic longitudinal cross-sectional view of a processing tank of an etching device in the transverse direction.

[0020] Figure 4 This is a schematic longitudinal cross-sectional view of the processing tank.

[0021] Figure 5 This is a schematic top view of the processing tank.

[0022] Figure 6 This is a longitudinal sectional view in the transverse direction of the processing tank, showing only the cover body and its peripheral components in the closed position and showing them in detail.

[0023] Figure 7 It is a three-dimensional diagram of the cover.

[0024] Figure 8 It means from Figure 6 A longitudinal cross-sectional view of the cover body shown moving from a closed position to an open position.

[0025] Description of Reference Numerals

[0026] 34A, inner groove; 34B, outer groove; 71, first cover body; 72, second cover body; 711R, 721R, bottom wall; 712R, 722R, side wall; 71R, 72R, recess; 73, cover, seal; 73P, plate-like body; H, height; G, gap. DETAILED DESCRIPTION

[0027] Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, a substrate liquid processing system 1A in which a substrate liquid processing apparatus 1 according to an embodiment of the present invention is incorporated will be described as a whole.

[0028] like Figure 1 As shown, the substrate liquid processing system 1A includes a carrier loading and unloading unit 2 , a batch forming unit 3 , a batch placing unit 4 , a batch conveying unit 5 , a batch processing unit 6 , and a control unit 7 .

[0029] The carrier loading and unloading unit 2 loads and unloads a carrier 9 that accommodates a plurality of (eg, 25) substrates (silicon wafers) 8 arranged vertically in a horizontal posture.

[0030] The carrier input / output unit 2 is provided with a carrier placement unit 10 for placing a plurality of carriers 9, a carrier conveying mechanism 11 for conveying the carriers 9, carrier storage units 12 and 13 for temporarily storing the carriers 9, and a carrier placement table 14 for placing the carriers 9. The carrier storage unit 12 temporarily stores the substrates 8 to be products before the substrates 8 are processed by the batch processing unit 6. The carrier storage unit 13 temporarily stores the substrates 8 to be products after the substrates 8 are processed by the batch processing unit 6.

[0031] The carrier input / output unit 2 uses the carrier conveying mechanism 11 to convey the carrier 9 input from the outside to the carrier placement unit 10 to the carrier storage unit 12 and the carrier placement table 14. The carrier input / output unit 2 uses the carrier conveying mechanism 11 to convey the carrier 9 placed on the carrier placement table 14 to the carrier storage unit 13 and the carrier placement unit 10. The carrier 9 conveyed to the carrier placement unit 10 is output to the outside.

[0032] The batch forming unit 3 forms a batch consisting of a plurality of (e.g., 50) substrates 8 that are simultaneously processed by combining the substrates 8 accommodated in one or more carriers 9. In addition, when forming a batch, the batch may be formed in a manner that the surfaces on which patterns are formed of two adjacent substrates 8 face each other, or the batch may be formed in a manner that the surfaces on which patterns are formed of all substrates 8 face the same direction.

[0033] The batch forming unit 3 is provided with a substrate conveying mechanism 15 for conveying a plurality of substrates 8. The substrate conveying mechanism 15 can change the posture of the substrate 8 from a horizontal posture to a vertical posture and from a vertical posture to a horizontal posture during the conveyance of the substrate 8.

[0034] The batch forming unit 3 uses the substrate conveying mechanism 15 to convey the substrate 8 from the carrier 9 mounted on the carrier mounting table 14 to the batch mounting unit 4, and places the substrate 8 forming the batch on the batch mounting unit 4. In addition, the batch forming unit 3 conveys the batch mounted on the batch mounting unit 4 to the carrier 9 mounted on the carrier mounting table 14 using the substrate conveying mechanism 15. In addition, the substrate conveying mechanism 15 has the following two types of substrate supporting units as substrate supporting units for supporting the plurality of substrates 8: a pre-processing substrate supporting unit that supports the substrate 8 before processing (before being conveyed by the batch conveying unit 5); and a post-processing substrate supporting unit that supports the substrate 8 after processing (after being conveyed by the batch conveying unit 5). Thus, particles and the like attached to the substrate 8 and the like before processing are prevented from being transferred to the substrate 8 and the like after processing.

[0035] The batch placing section 4 temporarily places (stands by) the batch conveyed between the batch forming section 3 and the batch processing section 6 by the batch conveying section 5 using the batch placing table 16 .

[0036] The batch placement section 4 is provided with an input-side batch placement table 17 on which a batch before processing (before being transported by the batch transport section 5) is placed, and an output-side batch placement table 18 on which a batch after processing (after being transported by the batch transport section 5) is placed. A plurality of substrates 8 for one batch are placed on the input-side batch placement table 17 and the output-side batch placement table 18 in a vertical orientation in a front-to-back arrangement.

[0037] In the batch placement section 4, a batch formed by the batch forming section 3 is placed on an input-side batch placement table 17, and the batch is input to the batch processing section 6 via the batch conveying section 5. In the batch placement section 4, a batch output from the batch processing section 6 via the batch conveying section 5 is placed on an output-side batch placement table 18, and the batch is conveyed to the batch forming section 3.

[0038] The batch transport unit 5 transports the batch between the batch placement unit 4 and the batch processing unit 6 and within the batch processing unit 6 .

[0039] The batch conveying unit 5 is provided with a batch conveying mechanism 19 for conveying a batch. The batch conveying mechanism 19 includes a rail 20 arranged along the batch placing unit 4 and the batch processing unit 6, and a moving body 21 that moves along the rail 20 while holding a plurality of substrates 8. A substrate holding body 22 that holds a plurality of substrates 8 arranged in a vertical posture and is provided on the moving body 21 so as to be able to move forward and backward.

[0040] The batch transport unit 5 receives the batch placed on the input-side batch stage 17 using the substrate holder 22 of the batch transport mechanism 19, and delivers the batch to the batch processing unit 6. The batch transport unit 5 receives the batch processed by the batch processing unit 6 using the substrate holder 22 of the batch transport mechanism 19, and delivers the batch to the output-side batch stage 18. The batch transport unit 5 transports the batch inside the batch processing unit 6 using the batch transport mechanism 19.

[0041] The batch processing unit 6 performs processing such as etching, cleaning, and drying on a plurality of substrates 8 arranged in a vertical posture as one batch.

[0042] Arranged in the batch processing section 6 are: a drying processing device 23, which performs drying processing on the substrate 8; a substrate holder cleaning processing device 24, which performs cleaning processing on the substrate holder 22; a cleaning processing device 25, which performs cleaning processing on the substrate 8; and two etching processing devices (substrate liquid processing devices) 1 of the present invention, which perform etching processing on the substrate 8.

[0043] The drying processing device 23 includes a processing tank 27 and a substrate lifting mechanism 28 which is freely provided in the processing tank 27. A drying processing gas (IPA (isopropyl alcohol) or the like) is supplied to the processing tank 27. A plurality of substrates 8 for one batch are arranged in a vertical posture front and back and are held by the substrate lifting mechanism 28. The drying processing device 23 receives a batch from the substrate holding body 22 of the batch conveying mechanism 19 by the substrate lifting mechanism 28, and lifts the batch by the substrate lifting mechanism 28, thereby performing a drying process on the substrates 8 by using the drying processing gas supplied to the processing tank 27. In addition, the drying processing device 23 delivers a batch from the substrate lifting mechanism 28 to the substrate holding body 22 of the batch conveying mechanism 19.

[0044] The substrate holder cleaning processing device 24 has a processing tank 29, which can supply a processing liquid and a dry gas for cleaning. After the processing liquid for cleaning is supplied to the substrate holder 22 of the batch conveying mechanism 19, the substrate holder 22 is cleaned by supplying a dry gas.

[0045] The cleaning processing device 25 includes a cleaning processing tank 30 and a rinsing processing tank 31, and substrate lifting mechanisms 32 and 33 are freely provided in the processing tanks 30 and 31. 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.

[0046] The etching processing apparatus 1 includes a processing tank 34 for etching and a processing tank 35 for rinsing, and substrate lifting mechanisms 36 and 37 are freely provided in the processing tanks 34 and 35. A processing liquid for etching (phosphoric acid aqueous 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 becomes a substrate liquid processing apparatus of the present invention.

[0047] These cleaning processing devices 25 have the same structure as the etching processing device 1. The etching processing device (substrate liquid processing device) 1 is described. A plurality of substrates 8 for one batch are arranged in a vertical posture and held by a substrate lifting mechanism 36. In the etching processing device 1, the batch is received from the substrate holding body 22 of the batch conveying mechanism 19 by the substrate lifting mechanism 36, and the batch is lifted and lowered by the substrate lifting mechanism 36, so that the batch is immersed in the etching processing liquid in the processing tank 34 to perform etching processing on the substrates 8. Thereafter, the etching processing device 1 delivers the batch from the substrate lifting mechanism 36 to the substrate holding body 22 of the batch conveying mechanism 19. In addition, the batch is received from the substrate holding body 22 of the batch conveying mechanism 19 by the substrate lifting mechanism 37, and the batch is lifted and lowered by the substrate lifting mechanism 37, so that the batch is immersed in the rinsing processing liquid in the processing tank 35 to perform rinsing processing on the substrates 8. Thereafter, the batch is delivered from the substrate lifting mechanism 37 to the substrate holding body 22 of the batch conveying mechanism 19.

[0048] The control unit 7 controls the operation of each unit of the substrate liquid processing system 1A (the carrier loading and unloading unit 2 , the batch forming unit 3 , the batch placing unit 4 , the batch transport unit 5 , the batch processing unit 6 , and the etching processing apparatus 1 ).

[0049] The control unit 7 is composed of, for example, a computer and has a storage medium 38 that can be read by the computer. The storage medium 38 stores a program for controlling various processes to be performed in the substrate liquid processing device 1. The control unit 7 controls the operation of the substrate liquid processing device 1 by reading the program stored in the storage medium 38 and executing the program. In addition, the program is a program stored in the storage medium 38 that can be read by the computer, and can also be a program installed from other storage media to the storage medium 38 of the control unit 7. As the storage medium 38 that can be read by the computer, there are, for example, a hard disk (HD), a floppy disk (FD), a compact disk (CD), a magneto-optical disk (MO), a memory card, etc.

[0050] As described above, in the treatment tank 34 of the etching treatment apparatus 1 , the substrate 8 is subjected to liquid treatment (etching treatment) using an aqueous solution (phosphoric acid aqueous solution) of a chemical (phosphoric acid) of a predetermined concentration as a treatment liquid (etching liquid).

[0051] Next, refer to Figure 2 The schematic structure and piping system of the etching processing apparatus (substrate liquid processing apparatus) 1 will be described.

[0052] The etching treatment apparatus 1 has the aforementioned treatment tank 34 storing a phosphoric acid aqueous solution of a predetermined concentration as a treatment liquid. The treatment tank 34 has an inner tank 34A and an outer tank 34B. The phosphoric acid aqueous solution overflowing 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.

[0053] The bottom of the outer tank 34B is connected to the upstream end of the circulation line 50. The downstream end of the circulation line 50 is connected to the treatment liquid supply nozzle 49 provided in the inner tank 34A. The circulation line 50 is provided with a pump 51, a heater 52, and a filter 53 in order from the upstream side. By driving the pump 51, a circulation flow of the phosphoric acid aqueous solution is formed as follows: it is transported from the outer tank 34B to the inner tank 34A via the circulation line 50 and the treatment liquid supply nozzle 49, and then flows out from the inner tank 34A to the outer tank 34B again.

[0054] The liquid processing unit 39 is formed by the processing tank 34, the circulation line 50, and the equipment (51, 52, 53, etc.) in the circulation line 50. In addition, the processing tank 34 and the circulation line 50 constitute a circulation system.

[0055] A gas nozzle 60 is provided below the treatment liquid supply nozzle 49 in the inner tank 34A for ejecting bubbles of an inert gas such as nitrogen gas into the phosphoric acid aqueous solution in the inner tank 34A (for foaming). The inert gas such as nitrogen gas is supplied to the gas nozzle 60 from a gas supply source 60B via a flow regulator 60C composed of an on-off valve, a flow control valve, a flow meter, and the like.

[0056] The processing tank 34 is provided with the aforementioned substrate lifting mechanism 36. The substrate lifting mechanism 36 can hold the plurality of substrates 8 in a state where the plurality of substrates 8 are arranged at intervals in the horizontal direction in a vertically standing posture, and can also lift and lower the substrates in this state.

[0057] The etching processing device 1 has: a phosphoric acid aqueous solution supply unit 40, which supplies a phosphoric acid aqueous solution to the liquid processing unit 39; a pure water supply unit 41, which supplies pure water to the liquid processing unit 39; a silicon supply unit 42, which supplies a silicon solution to the liquid processing unit 39; and a phosphoric acid aqueous solution discharge unit 43, which discharges the phosphoric acid aqueous solution from the liquid processing unit 39.

[0058] 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 composed of the treatment tank 34 and the circulation line 50, that is, to the liquid treatment unit 39, preferably to the outer tank 34B as shown in the figure. The phosphoric acid aqueous solution supply unit 40 includes: a phosphoric acid aqueous solution supply source 40A, which is composed of a tank storing the phosphoric acid aqueous solution; a phosphoric acid aqueous solution supply line 40B, which connects 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 on-off valve 40E, which are interposed in the phosphoric acid aqueous solution supply line 40B in order from the upstream side. The phosphoric acid aqueous solution supply unit 40 can supply the phosphoric acid aqueous solution to the outer tank 34B at a flow rate controlled by the flow meter 40C and the flow control valve 40D.

[0059] 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 for supplying pure water at a predetermined temperature, and the 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.

[0060] The silicon supply unit 42 includes a silicon supply source 42A including a tank storing a silicon-containing compound solution, such as a liquid obtained by dispersing colloidal silicon, and a flow regulator 42B. The flow regulator 42B may include an on-off valve, a flow control valve, a flow meter, or the like.

[0061] The phosphoric acid aqueous solution discharge unit 43 is provided to discharge the phosphoric acid aqueous solution in the circulation system composed of the liquid treatment unit 39 and the circulation line 50, that is, in the liquid treatment unit 39. The phosphoric acid aqueous solution discharge unit 43 includes a discharge line 43A branched from the circulation line 50, a flow meter 43B, a flow control valve 43C, an on-off valve 43D, and a cooling tank 43E, which are sequentially provided from the upstream side to the discharge line 43A. The phosphoric acid aqueous solution discharge unit 43 can discharge the phosphoric acid aqueous solution at a flow rate controlled by the flow meter 43B and the flow control valve 43C.

[0062] The cooling tank 43E temporarily stores the phosphoric acid aqueous solution flowing from the discharge line 43A and cools it. The phosphoric acid aqueous solution (see reference numeral 43F) flowing out of the cooling tank 43E may be discarded to a factory waste liquid system (not shown) or may be transported to the phosphoric acid aqueous solution supply source 40A for reuse after silicon contained in the phosphoric acid aqueous solution is removed by a regeneration device (not shown).

[0063] In the example shown in the figure, the discharge line 43A is connected to the circulation line 50 (the position of the drain filter in the figure), but the present invention is not limited thereto and may be connected to other locations in the circulation system, such as the bottom of the inner tank 34A.

[0064] 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 the branch line 55A branched from the circulation line 50 and 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.

[0065] Next, refer to Figure 3 to Figure 7The structure of the processing tank 34 of the etching processing device 1 is described in detail. For the convenience of description, an XYZ orthogonal coordinate system is set and referenced as needed. In addition, the negative X direction is sometimes referred to as the "front side" or "front", the positive X direction is sometimes referred to as the "rear side" or "rear", the negative Y direction is sometimes referred to as the "right side" or "right", and the positive Y direction is sometimes referred to as the "left side" or "left".

[0066] As described above, the treatment tank 34 includes 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 phosphoric acid aqueous solution overflowing 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 phosphoric acid aqueous solution in the outer tank 34B.

[0067] The outer tank 34B is housed in a liquid receiving container (water tank) 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.

[0068] The processing liquid supply nozzle 49 is composed of a cylindrical body extending in the X direction (horizontal direction) in the inner tank 34A. The processing liquid supply nozzle 49 has a plurality of spray ports 49D (see Figure 3 and Figure 4 ) sprays the processing liquid toward the substrate 8 held by the substrate lifting mechanism 36. In the figure, two processing liquid supply nozzles 49 are provided, but three or more processing liquid supply nozzles 49 may be provided. The processing liquid (phosphoric acid aqueous solution) is supplied to the processing liquid supply nozzles 49 from a pipe 49A extending in the vertical direction.

[0069] The gas nozzle 60 is composed of 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 has a plurality of ejection ports 60D (see FIG. Figure 3 and Figure 4 ) to eject bubbles of an inert gas (e.g., nitrogen). The bubbling of the inert gas stabilizes the boiling state of the phosphoric acid aqueous solution in the inner tank 34A. The inert gas is supplied to the gas nozzle 60 from a pipe 60A extending in a vertical direction.

[0070] The substrate lifting mechanism 36 includes: a support plate 36A, which is lifted and lowered by a lifting mechanism (not shown) and extends in the vertical direction (Z direction); and a pair of substrate supporting members 36B, one end of which is supported by the support plate 36A and extends in the horizontal direction (X direction). Each substrate supporting member 36B has a plurality of (e.g., 50 to 52) substrate supporting grooves (not shown) arranged at intervals in the horizontal direction (X direction). The peripheral edge of the substrate 8 is inserted into the substrate supporting groove. The substrate lifting mechanism 36 is capable of holding a plurality of (e.g., 50 to 52) substrates 8 in a vertical posture in a state where they are spaced apart in the horizontal direction (X direction). Such a substrate lifting mechanism 36 is well known in the technical field, and the illustration and description of the detailed structure are omitted.

[0071] The processing tank 34 is provided with a first cover 71 and a second cover 72 for opening and closing the upper opening of the inner tank 34A. The first cover 71 and the second cover 72 are respectively connected to the rotating shafts 71S and 72S extending in the horizontal direction (X direction). The rotating shafts 71S and 72S are connected to the bearings 83 and the rotating actuator 84 (see FIG. 8 ) fixed to the liquid receiving container 80. Figure 4 , Figure 5 By operating the rotary actuator 84, the first cover body 71 and the second cover body 72 can be centered on their respective rotation axes extending in the horizontal direction (X direction) in the closed position ( Figure 3 and Figure 6 The position shown in the figure) and the open position ( Figure 8 shown) between rotation (rotation) (refer to Figure 3 Arrows SW1, SW2 in the figure).

[0072] The first cover 71 and the second cover 72 do not cover the region of the upper opening of the inner tank 34A where the support plate 36A and the pipes 49A and 60A are provided.

[0073] During normal operation of the etching processing apparatus 1, the first cover body 71 and the second cover body 72 are in a closed position except when the substrate 8 held by the substrate lifting mechanism 36 is being input / output relative to the inner tank 34A, thereby preventing the temperature of the phosphoric acid aqueous solution in the inner tank 34A from decreasing and suppressing the release of water vapor generated from the boiling phosphoric acid aqueous solution to the outside of the processing tank 34.

[0074] The first cover 71 has a main body 71A that is substantially rectangular when viewed from above, a first splash shielding portion 71B, a second splash shielding portion 71C, and a sealing portion 71D extending along the X direction, and a third splash shielding portion 71E extending along the Y direction. Similarly, the second cover 72 has a main body 72A that is substantially rectangular, a first splash shielding portion 72B, a second splash shielding portion 72C, and a sealing portion 72D extending along the X direction, and a third splash shielding portion 72E extending along the Y direction.

[0075] A large rectangular recess 71R is formed on 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.

[0076] When the first cover 71 is in the closed position, the phosphoric acid solution is not prevented from overflowing from the inner tank 34A to the outer tank 34B (see Figure 6 A gap is provided between the side wall of the inner groove 34A and the side walls 712R and 713R in the manner of arrows OF, and the side wall 713R is close to and faces the side wall of the inner groove 34A. In addition, although not shown in the figure, a plurality of V-shaped notches are formed at intervals at the upper ends of the four side walls of the inner groove 34A to facilitate overflow.

[0077] The bottom wall 711R of the first cover body 71 is inclined so as to become higher as it moves away from the second cover body 72 in the Y direction (as it moves closer to the side wall of the inner groove 34A in the Y direction). Due to the inclination, the above-mentioned overflow is smoothly performed.

[0078] The phosphoric acid aqueous solution in the inner tank 34A is in a boiling state, so the droplets of the phosphoric acid aqueous solution also fly out of the inner tank 34A together with the phosphoric acid aqueous solution overflowing from the inner tank 34A to the outer tank 34B. The flying droplets collide with the first droplet shielding portion 71B of the first cover body 71 located 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 scatter to the outside of the outer tank 34B. It is preferred that the lower end of the first droplet shielding portion 71B of the first cover body 71 located in the closed position is located at least lower than the upper end of the side wall of the inner tank 34A that is adjacent.

[0079] The second splash shielding portion 71C plays the same role as the first splash shielding portion 71B when the first cover 71 is in the closed position when the first cover 71 is in the open position. Preferably, the lower end of the first splash shielding portion 71C of the first cover 71 in the open position is at least lower than the upper end of the side wall of the inner tank 34A adjacent thereto.

[0080] The sealing portion 71D is in the open position when the first cover 71 is in the open position (see Figure 8) covers the area from the rotation axis 71S to the side wall of the outer tank 34B in 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. The sealing portion 71D guides the liquid attached to the upper surface of the main body 71A when the first cover 71 is in the closed position (for example, the liquid dropped from the wet substrate when the substrate passes over the processing tank 34) to the drain space 81 between the outer tank 34B and the liquid receiving container 80 when the first cover 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.

[0081] 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 from the rotation axis 71S along the Y direction over the entire length of the end edge of the first cover body 71. The third splash shielding portion 71E plays the same role as the first splash shielding portion 71B when the first cover body 71 is in the closed position. It is preferred that the lower end of the third splash shielding portion 71E of the first cover body 71 in the closed position is located at least lower than the upper end of the side wall of the inner tank 34A to which it is adjacent.

[0082] The splash shielding portion extending along the edge of the first cover 71 extending in the Y direction may not be provided on the side close to the substrate lifting mechanism 36. The reason for this is that the phosphoric acid aqueous solution splashing in the positive X direction collides with the support plate 36A, the pipes 49A and 60A, etc. of the substrate lifting mechanism 36, and therefore hardly reaches the outer tank 34B.

[0083] The second cover 72 is formed to be substantially mirror-symmetrical with respect to the first cover 71, and the structures of the first cover 71 and the second cover 72 are substantially the same. Therefore, the description of the structure and function of the first cover 71 can be used for the description of the structure and function of the second cover 72. The reference numerals of the corresponding components of the first cover 71 and the second cover 72 (components located at symmetrical positions, components having the same function) have the same letters at the end, and only the first two digits of the reference numerals are different, that is, "71" or "72".

[0084] like Figure 6 As shown, when the first cover body 71 and the second cover body 72 are in the closed position, the side wall 712R extending upward from the bottom wall 711R of the first cover body 71 and the side wall 722R extending upward from the bottom wall 721R of the second cover body 72 face each other, and a gap G of height H is formed between the two side walls. By providing the recesses 71R and 72R, the increase in the weight of the first cover body 71 and the second cover body 72 caused by providing the gap of height H can be suppressed.

[0085] In such Figure 6 When the lower surface of the main body 71A of the first cover 71 (the lower surface of the bottom wall 711R) and the lower surface of the main body 72A of the second cover 72 (the lower surface of the bottom wall 721R) in the closed position as shown in the figure are in contact with the liquid surface of the treatment liquid in the inner tank 34A, the boiling phosphoric acid aqueous solution sometimes flies upward from the gap between the first cover 71 and the second cover and scatters around. However, by providing the gap G with a height H as described above, it is difficult for the boiling treatment liquid to fly outward from the gap G. In order to achieve this effect, the height H can be set to, for example, about 5 cm or more.

[0086] In the case where the treatment liquid in the inner tank 34A is a boiling phosphoric acid aqueous solution, at least the main body 71A, 72A of the first cover 71 and the second cover 72 is formed of a material such as quartz that is not damaged by the treatment liquid. In the case where the main body 71A, 72A is formed of quartz, the quartz may collide with each other and generate cracks and fragments. In order to prevent this, it is desirable to provide a gap between the first cover 71 and the second cover 72 in such a way that the main body 71A, 72A do not contact each other when the first cover 71 and the second cover 72 are in the closed position. In the case where a gap is provided between the main body 71A, 72A, the phosphoric acid aqueous solution in the treatment tank 34, especially in the inner tank 34A, may be scattered outward through the gap. However, by providing the gap G of the height H as described above, it is possible to at least significantly suppress the scattering of the phosphoric acid aqueous solution from the gap G.

[0087] In order to facilitate overflow, when the bottom wall 711R (721R) is inclined as described above and the bottom wall 711R (721R) is in contact with the phosphoric acid aqueous solution in the inner tank 34A, the top end of the bottom wall 711R (721R) is immersed in the phosphoric acid aqueous solution without the side wall 712R (722R) extending upward from the bottom wall 711R (721R). However, by providing the side wall 712R (722R) extending upward from the bottom wall 711R (721R) as described above, the height position of the liquid level of the phosphoric acid aqueous solution can be lower than the top end of the side wall 712R (722R).

[0088] like Figure 6 As shown, it is preferred that a cover 73 is provided on either the main body 71A of the first cover body 71 or the main body 72A of the second cover body 72 (here, the main body 71A) to cover the top of the other (here, the main body 72A) or to extend over and cover the gap G from above. By providing the cover 73, it is possible to prevent the processing liquid from flying upward from the gap G. In addition, Figure 3 to Figure 5 In order to avoid complication of the drawings, it should be noted that the cover 73 (and the plate-like body 73P) are not shown.

[0089] Furthermore, since the gap G has a height H, the momentum of the process liquid droplets flying from the surface of the phosphoric acid aqueous solution in the inner tank 34A is weakened before colliding with the cover 73. Therefore, the process liquid colliding with the cover 73 does not fly out to the side.

[0090] For example, Figure 6 As shown, the cover 73 can be provided by attaching and fixing a plate-like body 73P having a substantially rectangular cutout portion 73Q corresponding to 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. In this case, the cover 73 is formed by the edge portion of the plate-like body 73P.

[0091] like Figure 6 As shown in FIG. 1 , when the first cover body 71 and the second cover body 72 are in the closed position, a gap may be provided between the cover member 73 and the second cover body 72. Alternatively, when the first cover body 71 and the second cover body 72 are in the closed position, the cover member 73 may be in contact with the second cover body 72. In this case, the cover member 73 functions as a seal member that blocks the upper end of the gap G.

[0092] When the cover 73 is brought into contact with the second cover body 72, the cover 73 is preferably formed of a resin material such as a fluororesin material such as PTFE, PFA, etc., which is soft enough not to cause damage even if it collides with quartz and will not damage the quartz, and has relatively high corrosion resistance.

[0093] The cover 73 may be formed integrally with the first cover body 71. In addition, the cover 73 may not be provided. When the cover 73 is not provided, it is preferable to make the height H higher than when the cover 73 is provided.

[0094] In addition, a substrate retainer 74 may be provided on either the main body 71A of the first cover body 71 or the main body 72A of the second cover body 72 (here, the top end of the main body 72A of the second cover body 72). On the lower surface of the substrate retainer 74, a plurality of substrate holding grooves 74G are formed along the arrangement direction (X direction) of the substrates 8 and are arranged at the same X-direction position at the same pitch as the substrate support grooves (not shown) of the substrate support member 36B. The peripheral edge of a substrate 8 is accommodated in each substrate holding groove 74G. In addition, Figure 7 It should be noted that, although a portion where the substrate holding groove 74G is formed can be seen at the lower end portion of the substrate pressing member 74, this portion is actually hidden by the bottom wall 721R of the recess 72R and cannot be seen.

[0095] In the illustrated embodiment, the substrate pressing member 74 is composed of an elongated plate-shaped body formed independently of the second cover body 72, and is fixed to the main body 72A of the second cover body 72 by screwing. Alternatively, the substrate pressing member 74 may be formed integrally with the second cover body 72. In either case, the substrate pressing member 74 constitutes a part of the side wall 722R of the main body 72A of the second cover body 72.

[0096] When the substrate 8 is being processed, the substrate pressing member 74 of the second cover 72 located 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 sprayed from the processing liquid supply nozzle 49 at a large flow rate, or even if the boiling level of the processing liquid in the inner tank 34A becomes high, or even if nitrogen bubbling is performed vigorously, there is no need to worry that the substrate 8 will fall off the substrate support member 36B.

[0097] Next, the operation of the etching treatment apparatus 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 treatment unit 39. When a predetermined time has passed after the start of the supply of the phosphoric acid aqueous solution, the pump 51 of the circulation line 50 is operated to form a circulation flow that circulates in the above-mentioned circulation system.

[0098] The heater 52 of the circulation line 50 is operated to heat the phosphoric acid aqueous solution so that the phosphoric acid aqueous solution in the inner tank 34A reaches a predetermined temperature (e.g., 160° C.). The first cover 71 and the second cover 72 are located in the closed position at the latest at the start time of heating by the heater 52. The phosphoric acid aqueous solution at 160° C. is in a boiling state. When the phosphoric acid concentration exceeds a predetermined upper limit value due to evaporation of water caused by boiling and is detected by the phosphoric acid concentration meter 55B, pure water is supplied from the pure water supply unit 41.

[0099] Before a batch of substrates 8 are placed in the phosphoric acid aqueous solution in the inner tank 34A, the silicon concentration (which affects the etching selectivity of the silicon nitride film to the silicon oxide film) in the phosphoric acid aqueous solution 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 the 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. In order to confirm that the silicon concentration in the phosphoric acid aqueous solution in the circulation system is within a predetermined range, the phosphoric acid aqueous solution can be made to flow to the discharge line 43A and the silicon concentration can be measured using a silicon concentration meter 43G.

[0100] After the silicon concentration adjustment is completed, the first cover 71 and the second cover 72 are moved to the open position, and the plurality of substrates 8, for example, 50 substrates 8 forming one batch (also referred to as a processing batch or batch) held by the substrate lifting mechanism 36 are immersed in the phosphoric acid aqueous solution in the inner tank 34A. Thereafter, the first cover 71 and the second cover 72 are immediately returned to the closed position. By immersing the substrate 8 in the phosphoric acid aqueous solution for a predetermined time, the substrate 8 is subjected to a wet etching process (liquid treatment).

[0101] By placing the first cover 71 and the second cover 72 in the closed position during the etching process of the substrate 8, the temperature drop near the liquid surface of the phosphoric acid aqueous solution in the inner tank 34A is suppressed, thereby suppressing the temperature distribution of the phosphoric acid aqueous solution in the inner tank 34A. In addition, since the inner tank 34A is immersed in the phosphoric acid aqueous solution in the outer tank 34B, the temperature drop of the phosphoric acid aqueous solution in the inner tank 34A caused by the heat dissipation from the wall of the inner tank 34A is suppressed, and the temperature distribution of the phosphoric acid aqueous solution in the inner tank 34A can be suppressed. Therefore, the in-plane uniformity and inter-plane uniformity of the etching amount of the substrate 8 can be maintained at a high level.

[0102] During the processing of one batch of substrates 8, silicon is dissolved from the substrates 8, and therefore the silicon concentration in the phosphoric acid aqueous solution in the circulation system increases. During the processing of one batch of substrates 8, in order to maintain the silicon concentration in the phosphoric acid aqueous solution in the circulation system or to intentionally change the silicon concentration, the phosphoric acid aqueous solution in the circulation system can be discharged by the phosphoric acid aqueous solution discharge unit 43 while the phosphoric acid aqueous solution supply unit 40 supplies the phosphoric acid aqueous solution.

[0103] As described above, when the processing of one batch of substrates 8 is completed, the first cover 71 and the second cover 72 are moved to the open position, and the substrates 8 are taken out from the inner tank 34A.

[0104] Thereafter, the first cover 71 and the second cover 72 are moved to the closed position again, and after the temperature, phosphoric acid concentration, and silicon concentration of the phosphoric acid aqueous solution in the circulation system are adjusted, another batch of substrates 8 are processed in the same manner as above.

[0105] In the above-mentioned embodiment, the processing liquid is a phosphoric acid aqueous solution, but it is not limited to this. For example, a processing liquid obtained by mixing SC1 or phosphoric acid aqueous solution with additives such as acetic acid may also be used. In addition, in the above-mentioned embodiment, the film to be etched is a silicon nitride film, but it is not limited to this, and it may be other films that become etching objects. In addition, the processing to be performed on the substrate in the processing tank may not include an etching process, but may only include a cleaning process. That is, in the processing tank, the present invention is applicable when the processing is performed under such conditions that foam is generated from the liquid surface of the processing liquid. The substrate is not limited to a semiconductor wafer, but may also be a substrate formed of other materials such as glass and ceramics.

Claims

1. A substrate liquid processing device, comprising: an inner tank capable of storing the treatment liquid and having an upper opening; an outer tank, which is arranged outside the inner tank, and the treatment liquid flows from the inner tank into the outer tank; a first cover body movable between a closing position covering a first area of ​​the upper opening of the inner tank and an opening position opening the first area of ​​the upper opening; and a second cover body that is movable between a closed position covering a second area of ​​the upper opening of the inner tank and an open position opening the second area of ​​the upper opening, The first cover body has a bottom wall and a side wall extending upward from the bottom wall. The second cover body has a bottom wall and a side wall extending upward from the bottom wall. When the first cover and the second cover are located at the closed position, the side wall of the first cover is close to and faces the side wall of the second cover, and a gap having a height is formed between the side walls. in, The bottom wall of the first cover is inclined so as to become higher as it is farther away from the side wall of the first cover, and the bottom wall of the second cover is inclined so as to become higher as it is farther away from the side wall of the second cover. When the first cover body and the second cover body are located at the closed position, the bottom surface of the bottom wall of the first cover body and the bottom surface of the bottom wall of the second cover body are in contact with the liquid surface in the inner tank when the processing liquid overflows from the inner tank to the outer tank. An upper end of the side wall of the first cover and an upper end of the side wall of the second cover are located above a liquid level in the inner tank of the processing liquid.

2. The substrate liquid processing device according to claim 1, wherein: Recesses are respectively formed on the upper surfaces of the first cover body and the second cover body, and the bottom wall and the side wall of the first cover body divide and form at least a portion of the recess of the first cover body, and the bottom wall and the side wall of the second cover body divide and form at least a portion of the recess of the second cover body.

3. The substrate liquid processing device according to claim 1, wherein: A cover member that covers a gap between an upper portion of a side wall of the first cover and an upper portion of a side wall of the second cover from above is provided on at least one of the first cover and the second cover.

4. The substrate liquid processing device according to claim 3, wherein: A plate-like body is attached to the upper surface of the cover body provided with the cover member among the first cover body and the second cover body, and the plate-like body extends above the gap beyond the side wall to constitute the cover member.

5. The substrate liquid processing device according to claim 1, wherein: A sealant is provided on at least one of the first cover and the second cover to seal a gap between an upper portion of a side wall of the first cover and an upper portion of a side wall of the second cover.

6. The substrate liquid processing device according to claim 5, wherein: The material constituting the first cover and the second cover has higher chemical solution resistance than the material constituting the sealing member, and the material constituting the sealing member has higher flexibility than the material constituting the first cover and the second cover.

7. The substrate liquid processing device according to claim 6, wherein: The first cover and the second cover are made of quartz, and the sealing member is made of fluorine-based resin.

8. The substrate liquid processing device according to claim 5, wherein: A plate-like body is attached to the upper surface of the cover provided with the sealing member among the first cover and the second cover. The plate-like body extends from the side wall toward the upper side of the gap to constitute the sealing member.

Images