Substrate processing apparatus and substrate processing method

Abstract

To provide a substrate processing device and a substrate processing method which can suppress reduction in uniformity of processing by preventing contact between air bubbles and a substrate.SOLUTION: A substrate W is immersed in processing liquid stored in a processing tank 10 and surface processing is performed. Air bubbles are discharged into the processing liquid from a plurality of air bubble supply pipes 51 during the processing of the substrate W. When the substrate W is immersed in the processing liquid stored in the processing tank 10 and the air bubbles are supplied from the air bubble supply pipes 51 to the processing liquid, a lid part 80 is opened at a prescribed opening degree. Since immersion processing of the substrate W is performed while supplying the air bubbles in the state where the lid part 80 is slightly opened, the air bubbles reaching the liquid level of the processing liquid are smoothly discharged to the outside of the processing tank 10 from a gap formed between a first lid body 81 and a second lid body 82, and reduction in uniformity of processing can be suppressed by preventing contact between the air bubbles and the substrate W.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a substrate processing apparatus and a substrate processing method for performing surface processing such as etching on a substrate using a processing liquid. Substrates to be processed include, for example, semiconductor substrates, substrates for liquid crystal display devices, substrates for flat panel displays (FPDs), substrates for optical disks, substrates for magnetic disks, and substrates for solar cells. [Background technology]

[0002] Conventionally, in the manufacturing process of semiconductor devices, substrate processing apparatuses are used to perform various processes on substrates such as semiconductor substrates. One such substrate processing apparatus is a batch-type substrate processing apparatus that stores a processing liquid in a processing tank and immerses multiple substrates in the processing liquid at the same time to perform surface processing such as cleaning and etching.

[0003] Patent Document 1 discloses a batch-type substrate processing apparatus that includes a processing liquid discharge unit that discharges a processing liquid below a plurality of substrates held by a substrate holder in a processing tank, and an air bubble supply unit that supplies air bubbles. By supplying air bubbles into the processing liquid in addition to discharging the processing liquid, the flow rate of the processing liquid in the processing tank increases, improving the efficiency of surface processing of the substrates.

[0004] In particular, in the etching process of polysilicon using tetramethylammonium hydroxide (TMAH), studies have been conducted to control the etching rate by replacing the dissolved oxygen in the solution with nitrogen by supplying nitrogen gas bubbles into the processing solution.To increase the etching rate and improve throughput, it is necessary to constantly supply nitrogen gas bubbles to reduce the dissolved oxygen concentration in the processing solution to the minimum. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-106254 Summary of the Invention [Problem to be solved by the invention]

[0006] In etching processes using TMAH, one approach to prevent oxygen from dissolving into the processing solution from the atmosphere is to install a lid (cover) on the processing tank and immerse part of the lid in the surface of the processing solution. However, if nitrogen gas bubbles are continuously supplied while the lid is partially immersed in the surface of the processing solution, the nitrogen gas bubbles accumulate at the interface between the lid and the processing solution and come into contact with the upper edge of the substrate, preventing etching at that contact point and reducing the in-plane uniformity of the etching process.

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a substrate processing apparatus and a substrate processing method that can prevent bubbles from coming into contact with the substrate and suppress a decrease in processing uniformity. [Means for solving the problem]

[0008] In order to solve the above problem, the invention of claim 1 provides a substrate processing apparatus for performing surface treatment on a substrate with a processing liquid, the apparatus comprising: a processing tank for storing the processing liquid; a processing liquid supply unit for supplying the processing liquid into the processing tank; a substrate holding unit for holding a substrate and immersing the substrate in the processing liquid stored in the processing tank; a tubular air bubble supply pipe disposed inside the processing tank for supplying air bubbles to the processing liquid stored in the processing tank from below the substrate held in the substrate holding unit; a lid unit having first and second lid bodies that rotate around horizontal axes at their ends and covering an upper opening of the processing tank; an opening / closing drive unit that rotates the first and second lid bodies to open and close the lid unit; and a control unit that controls the opening / closing drive unit, wherein the control unit controls the opening / closing drive unit so that the lid unit opens to a predetermined opening when the substrate is immersed in the processing liquid and air bubbles are supplied to the processing liquid.

[0009] Furthermore, the invention of claim 2 is characterized in that, in the substrate processing apparatus according to the invention of claim 1, the control unit controls the opening / closing drive unit so that the lid unit opens when the supply of bubbles starts from the bubble supply pipe.

[0010] The invention of claim 3 is characterized in that, in the substrate processing apparatus of the invention of claim 1, the control unit controls the opening / closing drive unit so that the lid unit opens when the liquid level of the processing liquid drops to a predetermined height position after the supply of bubbles from the bubble supply pipe has started.

[0011] Furthermore, the invention of claim 4 is characterized in that, in the substrate processing apparatus according to any one of the inventions of claims 1 to 3, the control unit controls the opening / closing drive unit so that the lid unit opens at an opening degree corresponding to the dissolved oxygen concentration in the processing liquid.

[0012] Furthermore, the invention of claim 5 is characterized in that, in the substrate processing apparatus according to any one of the inventions of claims 1 to 3, the control unit controls the opening / closing drive unit so that the lid unit opens at an opening degree corresponding to the flow rate of bubbles supplied from the bubble supply pipe.

[0013] The invention of claim 6 is a substrate processing apparatus for performing surface treatment on a substrate with a processing liquid, comprising: a processing tank for storing the processing liquid; a processing liquid supply unit for supplying the processing liquid into the processing tank; a substrate holding unit for holding a substrate and immersing the substrate in the processing liquid stored in the processing tank; a tubular air bubble supply pipe disposed inside the processing tank for supplying air bubbles from below the substrate held by the substrate holding unit to the processing liquid stored in the processing tank; a lid for covering an upper opening of the processing tank; an elevation drive unit for raising and lowering the lid; and a control unit for controlling the elevation drive unit, wherein the control unit controls the elevation drive unit so that the lid is raised to a predetermined height position when the substrate is immersed in the processing liquid and air bubbles are supplied to the processing liquid.

[0014] Furthermore, the invention of claim 7 is characterized in that, in the substrate processing apparatus according to the invention of claim 6, the control unit controls the lifting drive unit so that the lid unit rises when the supply of bubbles starts from the bubble supply pipe.

[0015] Furthermore, the invention of claim 8 is characterized in that, in the substrate processing apparatus of the invention of claim 6, the control unit controls the lifting drive unit so that the lid unit rises when the liquid level of the processing liquid drops to a predetermined height position after the supply of bubbles from the bubble supply pipe has started.

[0016] Furthermore, the invention of claim 9 is characterized in that, in the substrate processing apparatus according to any one of the inventions of claims 6 to 8, the control unit controls the lifting drive unit so that the lid unit rises to a height position corresponding to the dissolved oxygen concentration in the processing liquid.

[0017] Furthermore, the invention of claim 10 is characterized in that, in the substrate processing apparatus according to any one of the inventions of claims 6 to 8, the control unit controls the lifting drive unit so that the lid unit rises to a height position according to the flow rate of bubbles supplied from the bubble supply pipe.

[0018] The invention of claim 11 is characterized in that, in the substrate processing apparatus according to any one of the inventions of claims 6 to 10, the lid portion comes into contact with a layer of bubbles formed on the surface of the processing liquid.

[0019] The invention of claim 12 is a substrate processing method for performing surface processing on a substrate using a processing liquid, characterized by comprising: an immersion step of holding and immersing the substrate in processing liquid stored in a processing tank; an air bubble supply step of supplying air bubbles to the processing liquid from below the substrate held in the processing liquid; and an opening step of opening a lid portion covering an upper opening of the processing tank to a predetermined opening degree, the lid portion having a first lid body and a second lid body that rotate around a horizontal axis at an end while the substrate is immersed in the processing liquid and air bubbles are being supplied to the processing liquid.

[0020] The invention of claim 13 is the substrate processing method according to claim 12, characterized in that the lid is opened when the bubble supplying step is started.

[0021] The invention of claim 14 is characterized in that, in the substrate processing method according to the invention of claim 12, the lid is opened when the liquid level of the processing liquid drops to a predetermined height after the bubble supply process is started.

[0022] Furthermore, the invention of claim 15 is characterized in that, in the substrate processing method according to any one of the inventions of claims 12 to 14, in the opening step, the lid portion is opened at an opening degree corresponding to the dissolved oxygen concentration in the processing liquid.

[0023] Furthermore, the invention of claim 16 is characterized in that, in the substrate processing method according to any one of the inventions of claims 12 to 14, in the opening step, the lid portion is opened at an opening degree corresponding to the flow rate of bubbles supplied into the processing liquid.

[0024] The invention of claim 17 is a substrate processing method for performing surface processing on a substrate using a processing liquid, characterized by comprising: an immersion step of holding and immersing the substrate in processing liquid stored in a processing tank; an air bubble supply step of supplying air bubbles to the processing liquid from below the substrate held in the processing liquid; and a lifting step of lifting a lid portion covering an upper opening of the processing tank to a predetermined height position while the substrate is immersed in the processing liquid and air bubbles are being supplied to the processing liquid.

[0025] The invention of claim 18 is the substrate processing method according to claim 17, wherein the lid is raised when the bubble supplying step is started.

[0026] The invention of claim 19 is characterized in that, in the substrate processing method according to the invention of claim 17, after the bubble supply process is started, the lid portion is raised when the liquid level of the processing liquid drops to a predetermined height position.

[0027] The invention of claim 20 provides a substrate processing method according to any one of claims 17 to 19, wherein rise In the step, the lid is raised to a height position according to the dissolved oxygen concentration in the treatment liquid.

[0028] The invention of claim 21 provides a substrate processing method according to any one of claims 17 to 19, wherein rise In the step, the lid portion is raised to a height position according to the flow rate of the bubbles supplied into the processing liquid.

[0029] Furthermore, the invention of claim 22 is characterized in that, in the substrate processing method according to any one of the inventions of claims 17 to 21, the lid portion comes into contact with a layer of bubbles formed on the surface of the processing liquid. [Effects of the Invention]

[0030] According to the inventions of claims 1 to 5, when a substrate is immersed in a processing liquid and air bubbles are supplied to the processing liquid, the lid opens to a predetermined opening degree, so that air bubbles that reach the surface of the processing liquid are smoothly discharged to the outside of the processing tank through the gap formed by the open lid, preventing contact between the air bubbles and the substrate and suppressing a decrease in processing uniformity.

[0031] In particular, according to the invention of claim 4, the lid opens at an opening angle corresponding to the dissolved oxygen concentration in the treatment liquid, thereby making it possible to both prevent the external atmosphere from coming into contact with the treatment liquid and smoothly expel bubbles that have reached the surface of the treatment liquid.

[0032] In particular, according to the invention of claim 5, the lid opens at an opening angle according to the flow rate of bubbles supplied from the bubble supply pipe, so that it is possible to prevent the external atmosphere from coming into contact with the treatment liquid and smoothly discharge bubbles that have reached the surface of the treatment liquid.

[0033] According to the inventions of claims 6 to 11, when a substrate is immersed in a processing liquid and bubbles are supplied to the processing liquid, the lid portion rises to a predetermined height position. Therefore, even if bubbles that reach the surface of the processing liquid form clusters, the bubbles can be prevented from coming into contact with the substrate, thereby suppressing a decrease in processing uniformity.

[0034] In particular, according to the invention of claim 11, the lid portion comes into contact with the layer of bubbles formed on the surface of the treatment liquid, so that it is possible to reliably prevent the treatment liquid from coming into contact with the external atmosphere.

[0035] According to the inventions of claims 12 to 16, when a substrate is immersed in a chemical solution and air bubbles are supplied to the treatment solution, the lid covering the upper opening of the treatment tank is opened to a predetermined opening degree, so that air bubbles that reach the surface of the treatment solution are smoothly discharged to the outside of the treatment tank through the gap formed by the open lid, preventing contact between the air bubbles and the substrate and suppressing a decrease in uniformity of the treatment.

[0036] In particular, according to the invention of claim 15, the lid portion is opened at an opening degree corresponding to the dissolved oxygen concentration in the treatment liquid, so that it is possible to both prevent the external atmosphere from coming into contact with the treatment liquid and smoothly discharge air bubbles that have reached the surface of the treatment liquid.

[0037] In particular, according to the invention of claim 16, the lid portion is opened at an opening degree corresponding to the flow rate of bubbles supplied into the processing liquid, so that it is possible to both prevent the external atmosphere from coming into contact with the processing liquid and smoothly discharge bubbles that have reached the surface of the processing liquid.

[0038] According to the inventions of claims 17 to 22, when a substrate is immersed in a processing liquid and air bubbles are supplied to the processing liquid, the lid covering the upper opening of the processing tank is raised to a predetermined height position. Therefore, even if air bubbles reach the surface of the processing liquid and form clusters, the air bubbles are prevented from coming into contact with the substrate, thereby suppressing a decrease in processing uniformity.

[0039] In particular, according to the invention of claim 22, the lid portion comes into contact with the layer of bubbles formed on the surface of the processing liquid, so that it is possible to reliably prevent the external atmosphere from coming into contact with the processing liquid. [Brief explanation of the drawings]

[0040] [Figure 1] 1 is a schematic plan view showing the overall configuration of a substrate processing apparatus according to the present invention; [Figure 2] 2 is a diagram showing the configuration of a processing section of the substrate processing apparatus of FIG. 1. FIG. [Figure 3] FIG. 10 is a diagram showing a state in which the lifter is raised. [Figure 4] FIG. 10 is a diagram showing a state in which the lifter is lowered. [Figure 5] FIG. 2 is a view of the nozzles, the dispersion plate, and the straightening plate as seen from the bottom of the treatment tank. [Figure 6] 2 is a plan view of a processing section of the substrate processing apparatus of FIG. 1, viewed from above. [Figure 7] FIG. 2 is a block diagram showing the configuration of a control unit. [Figure 8] FIG. 10 is a view showing the processing tank with the lid closed and no air bubbles being supplied. [Figure 9] FIG. 10 is a view showing a processing tank with the lid open and a substrate being processed; [Figure 10] FIG. 10 is a diagram illustrating an example of a conversion table. [Figure 11] FIG. 10 is a diagram illustrating the configuration of a processing unit according to a fourth embodiment. [Figure 12] FIG. 10 is a view showing the processing tank in a state where the lid is raised and a substrate is being processed. DETAILED DESCRIPTION OF THE INVENTION

[0041] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Hereinafter, expressions indicating relative or absolute positional relationships (e.g., "in one direction," "along one direction," "parallel," "orthogonal," "center," "concentric," "coaxial," etc.) not only strictly represent the positional relationship but also represent a state of relative angular or distance displacement within a tolerance or a range that provides equivalent functionality, unless otherwise specified. Furthermore, expressions indicating an equal state (e.g., "identical," "equal," "homogeneous," etc.) not only represent a state of strict quantitative equality but also represent a state of difference that provides a tolerance or equivalent functionality, unless otherwise specified. Furthermore, expressions indicating a shape (e.g., "circular," "square," "cylindrical," etc.) not only represent a geometrically strict shape but also represent a shape within a range that provides equivalent functionality, such as irregularities or chamfers, unless otherwise specified. Furthermore, expressions such as "comprise," "comprise," "include," "have," etc., regarding components, are not exclusive expressions that exclude the presence of other components. Furthermore, the expression "at least one of A, B, and C" includes "A only," "B only," "C only," "any two of A, B, and C," and "all of A, B, and C."

[0042] First Embodiment FIG. 1 is a schematic plan view showing the overall configuration of a substrate processing apparatus 100 according to the present invention. The substrate processing apparatus 100 is a batch-type substrate processing apparatus that performs surface processing on multiple substrates W collectively using a processing liquid. The substrates to be processed are circular silicon semiconductor substrates. Note that in FIG. 1 and the subsequent figures, the dimensions and number of parts are exaggerated or simplified as necessary for ease of understanding. Also, to clarify the directional relationships between the figures, FIG. 1 and the subsequent figures are appropriately illustrated with an XYZ Cartesian coordinate system in which the Z-axis direction is the vertical direction and the XY plane is the horizontal plane.

[0043] The substrate processing apparatus 100 mainly includes a load port 110, a transfer robot 140, a posture conversion mechanism 150, a pusher 160, a main transfer robot 180, a substrate processing group 120, a transfer cassette 170, and a control unit 70.

[0044] The load port 110 is provided at an end of the substrate processing apparatus 100, which is formed in a substantially rectangular shape in a plan view. Carriers C that accommodate multiple substrates W (hereinafter simply referred to as "substrates") to be processed in the substrate processing apparatus 100 are placed on the load port 110. Carriers C that accommodate unprocessed substrates W are transported by an automated guided vehicle (AGV, OHT) or the like and placed on the load port 110. Carriers C that accommodate processed substrates W are also removed from the load port 110 by the automated guided vehicle.

[0045] The carrier C is typically a FOUP (front opening unified pod) that stores substrates W in an enclosed space. The carrier C uses multiple holding shelves formed inside to hold multiple substrates W in a horizontal position (with the normal line aligned vertically) and stacked at regular intervals in the vertical direction (Z direction). The maximum number of substrates that can be stored in the carrier C is 25 or 50. In addition to the FOUP, the carrier C may also be in the form of a SMIF (Standard Mechanical Interface) pod or an OC (open cassette) that exposes the stored substrates W to the outside air.

[0046] A pod opener (not shown) and the like are provided at the boundary between the main body of the substrate processing apparatus 100 and the load port 110. The pod opener opens and closes the front cover of the carrier C placed on the load port 110.

[0047] The carry-in / out robot 140 carries unprocessed substrates W from a carrier C placed on the load port 110 into the main body of the substrate processing apparatus 100 while the lid of the carrier C is open, and carries processed substrates W from the main body of the substrate processing apparatus 100 out to the carrier C. More specifically, the carry-in / out robot 140 transports multiple substrates W between the carrier C and the posture conversion mechanism 150. The carry-in / out robot 140 is configured to be rotatable in a horizontal plane, and includes a batch hand (not shown) that is movable forward and backward and is made up of hand elements stacked in multiple stages, each capable of holding one substrate W.

[0048] The posture conversion mechanism 150 rotates the plurality of substrates W received from the carry-in / out robot 140 by 90° around the X axis to convert the posture of the substrates W from a horizontal posture to an upright posture (a posture in which the normal is along the horizontal direction). In addition, before transferring the substrates W to the carry-in / out robot 140, the posture conversion mechanism 150 converts the posture of the substrates W from an upright posture to a horizontal posture.

[0049] The pusher 160 is disposed between the attitude changing mechanism 150 and the transfer cassette 170. The pusher 160 transfers the substrate W in an upright attitude between the attitude changing mechanism 150 and an elevation stage (not shown) provided in the transfer cassette 170.

[0050] The transfer cassette 170 and the substrate processing unit group 120 are arranged in a row along the X direction. The substrate processing unit group 120 includes five processing units 121, 122, 123, 124, and 125. The processing units 121 to 125 are main components of the substrate processing apparatus 100 that perform various surface treatments on substrates W. As shown in FIG. 1, the processing units 121, 122, 123, 124, and 125 are arranged in this order from the (+X) side within the substrate processing apparatus 100. Each of the processing units 121, 122, 123, and 124 includes a processing tank 10 that stores a processing liquid.

[0051] The processing units 121 and 123 each store the same or different chemical liquids and immerse a plurality of substrates W in the chemical liquids at once to perform chemical processing such as etching. The processing units 122 and 124 each store a rinse liquid (typically pure water) and immerse a plurality of substrates W in the rinse liquid at once to perform rinsing.

[0052] In the substrate processing unit group 120, processing unit 121 and processing unit 122 are paired, and processing unit 123 and processing unit 124 are paired. A single lifter 20, which is a dedicated transport mechanism, is provided for the pair of processing unit 121 and processing unit 122. Lifter 20 is movable in the X direction between processing unit 121 and processing unit 122. Lifter 20 is also capable of moving up and down in each of processing unit 121 and processing unit 122. Similarly, a single lifter 20, which is a dedicated transport mechanism, is provided for the pair of processing unit 123 and processing unit 124.

[0053] The lifter 20 holds the plurality of substrates W received from the main transport robot 180 and immerses the substrates W in the chemical liquid stored in the processing tank 10 of the processing unit 121. After the chemical liquid processing is completed, the lifter 20 lifts the substrates W from the processing unit 121 and transfers them to the processing unit 122, where they are immersed in the rinse liquid stored in the processing tank of the processing unit 122. After the rinse processing is completed, the lifter 20 lifts the substrates W from the processing unit 122 and hands them over to the main transport robot 180. Similar operations of the lifter 20 are performed in the processing units 123 and 124 as well.

[0054] The processing section 125 includes a mechanism for reducing the pressure inside the sealed drying chamber to less than atmospheric pressure, a mechanism for supplying an organic solvent (e.g., isopropyl alcohol (IPA)) into the drying chamber, and a lifter 20. The processing section 125 receives the substrate W from the main transport robot 180 via the lifter 20, places it in the drying chamber, and dries the substrate W by supplying the organic solvent to the substrate W while maintaining a reduced pressure atmosphere inside the drying chamber. After the drying process, the substrate W is transferred to the main transport robot 180 via the lifter 20.

[0055] The transfer cassette 170 is disposed below the main transport robot 180, which is at the standby position (the position of the main transport robot 180 in FIG. 1). The transfer cassette 170 includes a lifting stage (not shown). The lifting stage lifts the substrate W received from the pusher 160 while maintaining the substrate W in an upright position, and delivers it to the main transport robot 180. The lifting stage also lowers the substrate W received from the main transport robot 180, and delivers it to the pusher 160.

[0056] The main transport robot 180 is configured to slide along the X direction as indicated by the arrow AR1 in Fig. 1. The main transport robot 180 transports the substrate W between a standby position above the transfer cassette 170 and a processing position above any one of the processing units 121, 122, 123, 124, and 125.

[0057] The main transport robot 180 is equipped with a pair of substrate chucks 181 that collectively grip a plurality of substrates W. The main transport robot 180 can collectively grip a plurality of substrates W by narrowing the gap between the pair of substrate chucks 181, and can release the gripped state by widening the gap between the substrate chucks 181. With this configuration, the main transport robot 130 can transfer substrates W to and from the lifting stage of the transfer cassette 170, and can also transfer substrates W to and from each lifter 20 provided in the substrate processing unit group 120.

[0058] Next, the configuration of the processing unit 121 provided in the substrate processing apparatus 100 will be described. Here, the processing unit 121 will be described, but the processing unit 123 also has a similar configuration. Fig. 2 is a diagram showing the configuration of the processing unit 121. As shown in Fig. 2, the processing unit 121 mainly includes a processing tank 10 that stores a processing liquid, a lifter 20 that holds multiple substrates W and moves them up and down, a processing liquid supply unit 30 that supplies the processing liquid into the processing tank 10, a drainage unit 40 that discharges the processing liquid from the processing tank 10, an air bubble supply unit 50 that supplies air bubbles into the processing liquid stored in the processing tank 10, and a lid unit 80 that opens and closes the top opening of the processing tank 10.

[0059] The processing tank 10 is a storage container made of a chemical-resistant material such as quartz. The processing tank 10 has a double-tank structure including an inner tank 11 that stores the processing liquid and immerses the substrate W therein, and an outer tank 12 formed around the upper periphery of the inner tank 11. The inner tank 11 and the outer tank 12 each have an upper opening that opens upward. The height of the upper edge of the outer tank 12 is slightly higher than the height of the upper edge of the inner tank 11. If the processing liquid is further supplied from the processing liquid supply unit 30 when the processing liquid is stored up to the upper edge of the inner tank 11, the processing liquid will overflow from the top of the inner tank 11 and into the outer tank 12. The processing tank 10 of this embodiment is designed to save liquid by reducing the amount of processing liquid used, and the capacity of the inner tank 11 is relatively small.

[0060] In this specification, the term "processing liquid" is a conceptual term that includes various chemical liquids and pure water. Examples of chemical liquids include liquids for etching or liquids for removing particles. Specific examples of chemical liquids that can be used include TMAH (tetramethylammonium hydroxide), SC-1 liquid (a mixed solution of ammonium hydroxide, hydrogen peroxide, and pure water), SC-2 liquid (a mixed solution of hydrochloric acid, hydrogen peroxide, and pure water), and phosphoric acid. Chemical liquids also include those diluted with pure water. In this embodiment, a mixed solution of TMAH, IPA (isopropyl alcohol), and pure water is used as the processing liquid.

[0061] The lifter 20 is a transport mechanism for holding and transporting substrates W up and down. The lifter 20 has a back plate 22 extending vertically (Z direction) and three holding bars 21 extending horizontally (Y direction) from the lower end of the back plate 22. The lower end of the back plate 22 is formed in a V shape. Each of the three holding bars 21 extending from the lower end of the back plate 22 has a plurality of holding grooves (e.g., 50) engraved at a predetermined pitch. A plurality of substrates W are held in an upright position parallel to each other at a predetermined interval on the three holding bars 21 with their peripheral edges fitted into the holding grooves.

[0062] The lifter 20 is connected to a drive mechanism 24 conceptually shown in FIG. 2 and moves up and down. FIGS. 3 and 4 are diagrams showing the lifting and lowering operation of the lifter 20. When the drive mechanism 24 is operated with the lid 80 open, the lifter 20 moves up and down, and the substrate W held by the lifter 20 is moved up and down between an immersion position inside the processing bath 10 (position in FIG. 4) and a lifted position above the processing bath 10 (position in FIG. 3), as indicated by arrow AR21 in FIG. 2. When the processing bath 10 contains a processing liquid, the substrate W is lowered to the immersion position, whereby the substrate W is immersed in the processing liquid and subjected to surface processing. That is, during processing, the lifter 20 holds the substrate W and functions as a substrate holder that immerses the substrate W in the processing liquid stored in the processing bath 10.

[0063] Returning to Figure 2, the processing liquid supply unit 30 includes a nozzle 31 and a piping system for supplying the processing liquid to the nozzle 31. The nozzle 31 is disposed at the bottom of the inner tank 11 of the processing tank 10. A distribution plate 15 is provided directly above the nozzle 31 so as to face the nozzle 31. Furthermore, a straightening plate 17 is provided above the distribution plate 15.

[0064] FIG. 5 is a view of the nozzles 31, the distribution plate 15, and the rectifying plate 17 as seen from the bottom of the processing tank 10. The tip portion (the portion extending into the processing tank 10) of the pipe 32 of the processing liquid supply unit 30 constitutes the pipe 132. A plurality of nozzles 31 are formed above the pipe 132. Each nozzle 31 is connected to the pipe 132. A distribution plate 15 is provided above each of the plurality of nozzles 31. The distribution plate 15 is a disk-shaped member provided parallel to the horizontal plane. The nozzles 31 protrude vertically upward from the pipe 132 toward the distribution plate 15. A rectifying plate 17 is provided further above the distribution plate 15, spanning the entire horizontal cross section of the inner tank 11. A plurality of processing liquid holes 17a are formed on the entire surface of the rectifying plate 17.

[0065] The processing liquid supplied to the pipe 132 is discharged from the nozzle 31 toward the distribution plate 15 located directly above. When the processing liquid stored in the processing tank 10 is discharged upward from the nozzle 31, the flow of the processing liquid hits the distribution plate 15, dispersing the pressure of the liquid and causing the processing liquid to spread horizontally along the surface of the distribution plate 15. The processing liquid spread horizontally by the distribution plate 15 then rises through the multiple processing liquid holes 17a of the rectifying plate 17, forming a laminar flow that flows from bottom to top within the processing tank 10. In other words, the rectifying plate 17 forms a laminar flow of the processing liquid within the processing tank 10.

[0066] 2, the piping system that supplies the processing liquid to the nozzle 31 is configured by piping 32 equipped with a pump 33, a heater 34, a filter 35, a flow rate control valve 36, and a valve 37. The pump 33, heater 34, filter 35, flow rate control valve 36, and valve 37 are arranged in this order from upstream to downstream of the piping 32 (from the outer tank 12 to the inner tank 11).

[0067] The tip side of the pipe 32 extends into the treatment tank 10 to form pipe 132 (FIG. 5), and the base end side of the pipe 32 is connected to the outer tank 12. The pipe 32 guides the treatment liquid flowing out of the outer tank 12 back into the inner tank 11. In other words, the treatment liquid supply unit 30 circulates the treatment liquid in the treatment tank 10. The pump 33 discharges the treatment liquid from the outer tank 12 into the pipe 32 and sends the treatment liquid to the nozzle 31. The heater 34 heats the treatment liquid flowing through the pipe 32. When phosphoric acid or the like is used as the treatment liquid, the treatment liquid is heated by the heater 34, and the heated treatment liquid is stored in the treatment tank 10.

[0068] The filter 35 filters the processing liquid flowing through the pipe 32 to remove impurities and the like. The flow rate control valve 36 adjusts the flow rate of the processing liquid flowing through the pipe 32. The valve 37 opens and closes the flow path of the pipe 32. By operating the pump 33 and opening the valve 37, the processing liquid discharged from the outer bath 12 flows through the pipe 32 and is supplied to the nozzle 31, and the flow rate is regulated by the flow rate control valve 36.

[0069] The drainage unit 40 includes a pipe 41 and a valve 45. The tip of the pipe 41 is connected to the bottom wall of the inner tank 11 of the processing tank 10. A valve 45 is provided midway along the path of the pipe 41. The base of the pipe 41 is connected to a drainage facility in the factory where the substrate processing apparatus 1 is installed. When the valve 45 is opened, the processing liquid stored in the inner tank 11 is rapidly discharged from the bottom of the inner tank 11 into the pipe 41 and treated in the drainage facility.

[0070] The processing liquid supply unit 30 circulates the processing liquid in the processing tank 10, and when the processing liquid becomes insufficient due to drainage by the drainage unit 40, for example, a new liquid supply mechanism (not shown) supplies new processing liquid to the processing tank 10. Specifically, the new liquid supply mechanism includes a chemical liquid supply unit that supplies chemical liquid to the outer tank 12 or the inner tank 11, and a pure water supply unit that supplies pure water. The chemical liquid supply unit supplies the chemical liquid to the processing tank 10, and the pure water supply unit supplies pure water, thereby diluting the chemical liquid.

[0071] The bubble supply unit 50 includes a plurality of bubble supply pipes 51 (six in this embodiment) and a piping system for supplying gas to the pipes. The six bubble supply pipes 51 are arranged inside the inner bath 11 of the processing bath 10, above the rectifying plate 17 and below the substrate W held in an immersion position by the lifter 20.

[0072] Each of the six bubble supply pipes 51 is a long, circular tubular member extending along the Y direction. A row of bubble holes (not shown) is provided on the upper side of each bubble supply pipe 51. The bubble supply pipes 51 are made of a material that is chemically resistant to the processing liquid, such as PFA (perfluoroalkoxyalkane), PEEK (polyetheretherketone), or quartz (PFA is used in this embodiment).

[0073] The piping system that supplies gas to the six bubble supply pipes 51 includes pipes 52, a gas supply mechanism 53, a flow meter 55, and a gas supply source 54. The tip side of one pipe 52 is connected to each of the six bubble supply pipes 51. The base end of the pipe 52 is connected to the gas supply source 54. A flow meter 55 is provided at the base end where the six pipes 52 join. A gas supply mechanism 53 is provided for each of the six pipes 52. In other words, one gas supply mechanism 53 is provided for each of the six bubble supply pipes 51. The gas supply source 54 delivers gas to each pipe 52. The gas supply mechanism 53 includes a mass flow controller, an on-off valve, etc. (not shown), and supplies gas to the bubble supply pipes 51 via the pipes 52 and adjusts the flow rate of the supplied gas. The total flow rate of the gas supplied to the six bubble supply pipes 51 can be measured by the flow meter 55.

[0074] When gas is supplied to the six bubble supply pipes 51, each bubble supply pipe 51 discharges gas from below the substrate W held in an immersion position by the lifter 20 into the processing liquid stored in the processing tank 10. When gas is supplied from the six bubble supply pipes 51 into the processing liquid while the processing liquid is stored in the processing tank 10, the gas forms bubbles and rises in the processing liquid. The gas supplied by the bubble supply unit 50 is, for example, an inert gas. The inert gas is, for example, nitrogen or argon (nitrogen is used in this embodiment).

[0075] Furthermore, each of the plurality of bubble holes provided in each bubble supply pipe 51 is disposed so as to be located between the adjacent substrates W held by the lifter 20. Therefore, bubbles formed by discharging gas from the plurality of bubble holes formed in each bubble supply pipe 51 rise between the adjacent substrates W.

[0076] The lid 80 opens and closes the top opening of the processing tank 10. Figure 6 is a plan view of the processing unit 121 as seen from above. The lid 80 has a first lid body 81 and a second lid body 82. The first lid body 81 and the second lid body 82 are flat plate-shaped members. Both the first lid body 81 and the second lid body 82 are made of PTFE (polytetrafluoroethylene), a type of fluororesin with excellent chemical resistance.

[0077] The first cover 81 is connected to a first opening and closing mechanism 83 conceptually shown in FIG. 6. Similarly, the second cover 82 is connected to a second opening and closing mechanism 84. The first opening and closing mechanism 83 and the second opening and closing mechanism 84 are configured, for example, by pulse motors. The first opening and closing mechanism 83 and the second opening and closing mechanism 84 rotate the first cover 81 and the second cover 82, respectively, around a rotation axis C1 that runs in the horizontal direction (Y-axis direction), as indicated by arrow AR22 in FIG. 2 and arrow AR6 in FIG. 6.

[0078] The rotation axis C1 is provided so as to pass through the respective ends of the first cover 81 and the second cover 82. Therefore, when the first opening and closing mechanism 83 and the second opening and closing mechanism 84 rotate the first cover 81 and the second cover 82, respectively, around the rotation axis C1, the cover unit 80 opens and closes like a double door. In other words, the first opening and closing mechanism 83 and the second opening and closing mechanism 84 are opening and closing drive units that rotate the first cover 81 and the second cover 82 to open and close the cover unit 80.

[0079] When the lid portion 80 is closed, the lid portion 80 covers the upper opening of the treatment tank 10. When the lid portion 80 is closed, the entire upper part of the inner tank 11 is covered by both the first lid body 81 and the second lid body 82. In addition, the first lid body 81 and the second lid body 82 cover the upper part of a portion of the outer tank 12. The remaining part of the outer tank 12 (part of the (+Y) side) is covered by the outer tank cover 14.

[0080] When the lid 80 is closed, the processing solution stored in the processing tank 10 is isolated from the external atmosphere by the first lid 81 and the second lid 82, thereby preventing oxygen from dissolving into the processing solution. In particular, in this embodiment, when the lid 80 is closed while the processing solution is stored in the inner tank 11 of the processing tank 10 up to its upper end, the first lid 81 and the second lid 82 come into contact with the surface of the processing solution. Therefore, air does not exist between the first lid 81 and the second lid 82 and the processing solution, thereby more reliably preventing oxygen from dissolving into the processing solution. When the lid 80 is closed, a gap is formed between the upper end of the inner tank 11 and the first lid 81 and the second lid 82. When the lid 80 is closed, a small gap is formed between the tip ((+X) side end) of the first lid 81 and the tip ((-X) side end) of the second lid 82 (see FIG. 2 ).

[0081] On the other hand, when the lid 80 is open, the upper opening of the processing tank 10 is open, and the substrate W can be raised and lowered between the immersion position and the lifted position by the lifter 20. When the lid 80 is open, the processing liquid stored in the processing tank 10 comes into contact with the external atmosphere.

[0082] The opening and closing of lid portion 80 is not limited to either fully open or fully closed. Under the control of control unit 70, first opening and closing mechanism 83 and second opening and closing mechanism 84 can rotate first lid body 81 and second lid body 82 by an appropriate angle so that lid portion 80 can be opened to any desired degree.

[0083] Returning to FIG. 2, the treatment tank 10 is provided with a pressure gauge 61, a dissolved oxygen concentration meter 62, and a liquid level sensor 63. The pressure gauge 61 measures the liquid pressure of the treatment liquid stored in the inner tank 11 of the treatment tank 10. The dissolved oxygen concentration meter 62 measures the concentration of oxygen dissolved in the treatment liquid stored in the treatment tank 10 (dissolved oxygen concentration). The liquid level sensor 63 measures the height position of the liquid surface (liquid level) of the treatment liquid stored in the inner tank 11 of the treatment tank 10. The liquid level sensor 63 can be, for example, a fiber sensor or a capacitance sensor.

[0084] The control unit 70 controls various operating mechanisms provided in the substrate processing apparatus 100. The control unit 70 also controls the operation of the processing unit 121. FIG. 7 is a block diagram showing the configuration of the control unit 70. The hardware configuration of the control unit 70 is similar to that of a general computer. That is, the control unit 70 includes a CPU, which is a circuit that performs various arithmetic processing, a ROM, which is a read-only memory that stores basic programs, a RAM, which is a readable and writable memory that stores various information, and a storage unit 74 (e.g., a magnetic disk or SSD) that stores control software, data, etc. The processing in the substrate processing apparatus 100 progresses as the CPU of the control unit 70 executes a predetermined processing program.

[0085] Control elements such as a first opening and closing mechanism 83 and a second opening and closing mechanism 84 are electrically connected to the control unit 70. Sensors such as a pressure gauge 61, a dissolved oxygen concentration meter 62, and a liquid level sensor 63 are also connected to the control unit 70. The control unit 70 controls the operation of the first opening and closing mechanism 83 and the like based on the measurement results of the dissolved oxygen concentration meter 62 and the like.

[0086] A display unit 77 and an input unit 76 are also connected to the control unit 70. The display unit 77 and the input unit 76 function as a user interface for the substrate processing apparatus 100. The control unit 70 displays various information on the display unit 77. An operator of the substrate processing apparatus 100 can input various commands and parameters from the input unit 76 while checking the information displayed on the display unit 77. The input unit 76 can be, for example, a keyboard or a mouse. The display unit 77 can be, for example, a liquid crystal display. In this embodiment, a liquid crystal touch panel provided on the outer wall of the substrate processing apparatus 100 is used as the display unit 77 and the input unit 76, thereby combining the functions of both.

[0087] A recipe 71 and a conversion table 72, which define procedures and conditions for processing a substrate W, are stored in the memory unit 74 of the control unit 70. The recipe 71 is acquired by the substrate processing apparatus 100, for example, when an operator of the apparatus inputs parameters via the display unit 77 and input unit 76 and stores the parameters in the memory unit 74. Alternatively, the processing recipe may be transferred to the substrate processing apparatus 100 via communication from a host computer that manages multiple substrate processing apparatuses 100 and stored in the memory unit 74. The control unit 70 controls the operation of the gas supply mechanism 53 and the like based on the description of the recipe 71 stored in the memory unit 74, thereby causing the surface processing of the substrate W to proceed as described in the recipe 71. The conversion table 72 will be described in more detail below.

[0088] Next, the processing operation of the processing unit 121 having the above configuration will be described. In the processing unit 121 of this embodiment, the processing liquid overflows from the inner tank 11 to the outer tank 12 of the processing tank 10, and the processing liquid flowing out from the outer tank 12 returns to the inner tank 11, thereby circulating the processing liquid. Specifically, the processing liquid flowing out from the outer tank 12 to the piping 32 is sent to the nozzle 31 by the pump 33. At this time, the processing liquid flowing through the piping 32 is heated by the heater 34 as needed. The flow rate of the processing liquid flowing through the piping 32 is controlled by the flow control valve 36. Furthermore, as needed, a drainage unit 40 discharges used processing liquid from the processing tank 10, and a new liquid supply mechanism supplies new processing liquid to the processing tank 10. In this embodiment, a strongly alkaline mixture of TMAH, IPA, and pure water is used as the processing liquid, and polysilicon is etched using TMAH. In polysilicon etching using TMAH, it is known that the etching rate decreases as the dissolved oxygen concentration in the processing liquid increases. Therefore, it is important to reduce the amount of oxygen dissolved in the processing liquid. That is, when etching is performed using TMAH as in this embodiment, the dissolved oxygen concentration in the processing solution is made as low as possible to increase the etching rate.

[0089] The processing liquid fed to the nozzle 31 is discharged from the nozzle 31 upward into the inner tank 11. The processing liquid discharged from the nozzle 31 hits the distribution plate 15 and spreads horizontally along the surface of the distribution plate 15. The processing liquid spread horizontally by the distribution plate 15 reaches the straightening plate 17, passes through the multiple processing liquid holes 17a, and forms an upward laminar flow in the inner tank 11 from the processing liquid holes 17a. The processing liquid that reaches the top of the inner tank 11 overflows and flows into the outer tank 12.

[0090] Before a substrate W is loaded into the processing tank 10, i.e., when no substrate W is present in the processing tank 10, the lid 10 is closed and the upper opening of the processing tank 10 is covered by the lid 80. This isolates the processing liquid stored in the processing tank 10 from the external atmosphere, thereby preventing oxygen from dissolving into the processing liquid. It also prevents foreign matter from dropping into the processing liquid from the space above the processing tank 10 and mixing into it.

[0091] Next, the lid 80 is opened to expose the upper opening of the processing tank 10, and the substrates W are immersed in the processing liquid while a laminar flow of the processing liquid rising in the processing tank 10 is formed. Specifically, the lifter 20 receives the plurality of substrates W transported by the main transport robot 180 at a lifting position above the processing tank 10. The substrates W are placed on three holding rods 21 and held by the lifter 20. Next, the control unit 70 operates the drive mechanism 24 to lower the lifter 20, and the substrates W are lowered to an immersion position in the processing tank 10, where they are immersed in the processing liquid.

[0092] After the lifter 20 stops descending and holds the substrate W in the immersion position, the control unit 70 operates the first opening / closing mechanism 83 and the second opening / closing mechanism 84 to close the first lid 81 and the second lid 82. As a result, the upper opening of the processing tank 10 is covered by the lid 80, and the processing liquid stored in the processing tank 10 is isolated from the external atmosphere by the first lid 81 and the second lid 82, thereby preventing oxygen from dissolving in the processing liquid.

[0093] 8 is a diagram showing the processing tank 10 with the lid 80 closed and no air bubbles being supplied. When the lid 80 is closed, at least the lower surfaces of the first lid 81 and the second lid 82 are immersed in the processing solution. This reduces the amount of air remaining between the surface of the processing solution and the lid 80, making it possible to more effectively prevent oxygen from dissolving in the processing solution. However, even when the lid 80 is closed, the height positions of the lower surfaces of the first lid 81 and the second lid 82 are higher than the height position of the upper end of the substrate W held in the immersion position.

[0094] After the substrate W is held in the immersion position and the lid unit 80 is closed, the supply of bubbles begins from the multiple bubble supply pipes 51. Specifically, the gas supply mechanism 53 of the bubble supply unit 50 supplies gas (nitrogen) to the corresponding bubble supply pipes 51. The gas supplied to the bubble supply pipes 51 is discharged into the processing liquid from multiple bubble holes provided on the upper side of the bubble supply pipes 51 to form bubbles. Since the multiple bubble holes are arranged so as to be located between adjacent substrates W held by the lifter 20, the bubbles discharged from the bubble supply pipes 51 rise between the adjacent substrates W. That is, a large number of bubbles rise near the surfaces of the substrates W.

[0095] With a laminar flow of the processing liquid formed in the processing tank 10, the substrates W are held at the immersion position by the lifter 20, and a laminar flow of the processing liquid flows between the substrates W. This exposes the surfaces of the substrates W to the processing liquid, and surface processing (etching processing in this embodiment) of the substrates W progresses. When nitrogen bubbles are supplied from the multiple bubble supply pipes 51 into the processing liquid, the dissolved oxygen in the processing liquid is replaced with nitrogen, thereby reducing the dissolved oxygen concentration, and as a result, the etching rate of the substrates W can be increased.

[0096] Nitrogen bubbles discharged from the six bubble supply pipes 51 rise in the processing liquid and reach the liquid surface. If the lid 80 remains closed, a large number of bubbles will adhere to the lid 80 and remain at the interface between the processing liquid and the first and second lids 81 and 82, causing the vicinity of the upper end of the substrate W to come into contact with the bubbles. In particular, in this embodiment, the lower surfaces of the first and second lids 81 and 82 are immersed in the processing liquid, and the distance between the lower surfaces and the upper end of the substrate W is quite narrow. Therefore, even if even a small number of bubble clusters form on the lower surfaces of the first and second lids 81 and 82, the vicinity of the upper end of the substrate W will easily come into contact with the bubbles. In this case, the vicinity of the upper end of the substrate W will no longer come into contact with the processing liquid and will not be etched. As a result, the in-plane uniformity of the etching process on the substrate W may be impaired. In particular, in this embodiment, because the processing liquid contains IPA, bubbles are difficult to eliminate and tend to remain.

[0097] Therefore, in the first embodiment, when the substrate W is immersed in the processing liquid stored in the processing tank 10 and bubbles are supplied to the processing liquid from the bubble supply pipe 51, the control unit 70 controls the first opening and closing mechanism 83 and the second opening and closing mechanism 84 so that the lid unit 80 opens at a predetermined opening degree. In the first embodiment, the control unit 70 controls the first opening and closing mechanism 83 and the second opening and closing mechanism 84 so that the lid unit 80 opens when the supply of bubbles from the multiple bubble supply pipes 51 starts.

[0098] 9 is a diagram showing the processing tank 10 in a state where the lid 80 is open and a substrate W is being processed. Bubbles that are discharged from the bubble supply pipe 51 and reach the surface of the processing liquid are discharged from the gap formed between the first lid 81 and the second lid 82 when the lid 80 is opened, as indicated by arrow AR9. This allows the bubbles that reach the surface of the processing liquid to be smoothly discharged outside the processing tank 10, preventing bubble clusters from coming into contact with a portion of the substrate W and preventing etching of that portion from being hindered.

[0099] When the lid 80 is opened too far (for example, fully open), a sufficiently wide path for the bubbles to be discharged is ensured, but the external atmosphere easily comes into contact with the processing liquid, resulting in increased oxygen dissolution. This may result in a higher concentration of dissolved oxygen in the processing liquid, despite the supply of bubbles from the bubble supply pipe 51. Conversely, when the lid 80 is opened too little (for example, almost fully closed), contact between the external atmosphere and the processing liquid is prevented, preventing oxygen dissolution. However, bubbles may not be sufficiently discharged, which may result in contact between the bubbles and a portion of the substrate W, impairing the in-surface uniformity of the etching process on the substrate W. In other words, the lid 80 needs to be opened to an extent that allows for both preventing contact between the external atmosphere and the processing liquid and allowing for sufficient bubble discharge.

[0100] In the first embodiment, the control unit 70 controls the first opening / closing mechanism 83 and the second opening / closing mechanism 84 so that the lid unit 80 opens at an opening degree corresponding to the dissolved oxygen concentration in the treatment liquid stored in the treatment tank 10. Specifically, for example, a table defining the correlation between the dissolved oxygen concentration and an appropriate opening degree is created in advance, the dissolved oxygen concentration in the treatment liquid stored in the treatment tank 10 is measured by the dissolved oxygen concentration meter 62, and the control unit 70 controls the first opening / closing mechanism 83 and the second opening / closing mechanism 84 to an appropriate opening degree based on the measurement result of the dissolved oxygen concentration meter 62. The control unit 70 controls the first opening / closing mechanism 83 and the second opening / closing mechanism 84 so that the opening degree of the lid unit 80 decreases as the dissolved oxygen concentration measured by the dissolved oxygen concentration meter 62 increases.

[0101] By opening the lid 80 to an appropriate degree, it is possible to prevent the external atmosphere from contacting the processing liquid, while also discharging bubbles that have reached the surface of the processing liquid, thereby preventing the bubbles from contacting the substrate W. As a result, it is possible to smoothly discharge bubbles while suppressing the incorporation of oxygen from the atmosphere, thereby preventing a decrease in the in-plane uniformity of the etching process.

[0102] After the etching process has been performed for a predetermined period of time, the control unit 70 operates the first opening / closing mechanism 83 and the second opening / closing mechanism 84 to fully open the first lid 81 and the second lid 82. Next, the control unit 70 operates the drive mechanism 24 to raise the lifter 20 and lift the substrate W from the processing bath 10. Next, the main transport robot 180 receives the processed substrate W from the lifter 20. In this manner, a series of processes in the processing unit 121 is completed.

[0103] In the first embodiment, when the substrate W is immersed in the processing liquid stored in the processing tank 10 and air bubbles are supplied to the processing liquid from the air bubble supply pipe 51, the control unit 70 controls the first opening / closing mechanism 83 and the second opening / closing mechanism 84 so that the lid unit 80 opens to a predetermined opening angle. That is, the immersion processing of the substrate W is performed while air bubbles are supplied with the lid unit 80 slightly open. As a result, air bubbles supplied from the air bubble supply pipe 51 and reaching the surface of the processing liquid are smoothly discharged to the outside of the processing tank 10 through the gap formed between the first lid body 81 and the second lid body 82 by the opening of the lid unit 80, preventing contact between the air bubbles and the substrate W and suppressing a decrease in processing uniformity.

[0104] Furthermore, in the first embodiment, the control unit 70 controls the first opening / closing mechanism 83 and the second opening / closing mechanism 84 so that the lid unit 80 opens when the supply of bubbles starts from the plurality of bubble supply pipes 51. Therefore, when the first bubble supplied from the bubble supply pipe 51 reaches the liquid surface of the processing liquid, the lid unit 80 is already open, and contact between the bubbles and the substrate W can be reliably prevented.

[0105] Furthermore, in the first embodiment, the control unit 70 controls the first opening / closing mechanism 83 and the second opening / closing mechanism 84 so that the lid unit 80 opens at an opening degree corresponding to the dissolved oxygen concentration in the processing liquid stored in the processing tank 10. This makes it possible to prevent the external atmosphere from contacting the processing liquid and to smoothly discharge bubbles that have reached the surface of the processing liquid, thereby suppressing the intrusion of oxygen from the atmosphere and preventing an increase in the dissolved oxygen concentration, while reliably preventing contact between the bubbles and the substrate W and suppressing a decrease in processing uniformity.

[0106] Second Embodiment Next, a second embodiment of the present invention will be described. The configuration of the substrate processing apparatus of the second embodiment is the same as that of the first embodiment (FIGS. 1 and 2). The processing procedure for the substrate W in the second embodiment is also generally similar to that of the first embodiment. In the first embodiment, the opening degree of the lid portion 80 is adjusted based on the dissolved oxygen concentration in the processing liquid stored in the processing tank 10, but in the second embodiment, the opening degree of the lid portion 80 is adjusted based on the supply flow rate of bubbles.

[0107] In the second embodiment, when the lid unit 80 is opened to a predetermined opening degree, the control unit 70 controls the first opening / closing mechanism 83 and the second opening / closing mechanism 84 so that the lid unit 80 opens to an opening degree corresponding to the flow rate of bubbles supplied from the plurality of bubble supply pipes 51. Specifically, the total flow rate of bubbles supplied from the six bubble supply pipes 51 into the processing liquid is specified in a recipe 71 (see FIG. 7 ). A table that specifies the correlation between the bubble supply flow rate and an appropriate opening degree is also created in advance. The control unit 70 controls the first opening / closing mechanism 83 and the second opening / closing mechanism 84 so that the lid unit 80 opens to an appropriate opening degree based on the bubble supply flow rate specified in the recipe 71. The control unit 70 controls the first opening / closing mechanism 83 and the second opening / closing mechanism 84 so that the opening degree of the lid unit 80 increases as the flow rate of bubbles supplied from the six bubble supply pipes 51 increases. Therefore, even if a large amount of bubbles is supplied from the bubble supply pipe 51, the lid 80 is opened sufficiently widely, so that the large amount of bubbles that reach the surface of the processing liquid are smoothly discharged to the outside of the processing tank 10 through the gap formed between the first lid 81 and the second lid 82. Furthermore, even if the opening of the lid 80 is large, a large amount of nitrogen flows out through the gap between the first lid 81 and the second lid 82, preventing the external atmosphere from flowing toward the surface of the processing liquid.

[0108] Even in the second embodiment, it is possible to prevent the external atmosphere from coming into contact with the processing liquid and smoothly discharge bubbles that have reached the surface of the processing liquid, thereby suppressing the incorporation of oxygen from the atmosphere and preventing an increase in the dissolved oxygen concentration, while reliably preventing contact between the bubbles and the substrate W and suppressing a decrease in processing uniformity.

[0109] Third Embodiment Next, a third embodiment of the present invention will be described. The configuration of the substrate processing apparatus of the third embodiment is the same as that of the first embodiment (FIGS. 1 and 2). Furthermore, the processing procedure for the substrate W in the third embodiment is also generally similar to that of the first embodiment. In the first embodiment, the lid portion 80 is opened at the same time as the supply of bubbles from the bubble supply pipe 51 is started, but in the third embodiment, the lid portion 80 is opened a short time after the supply of bubbles from the bubble supply pipe 51 is started.

[0110] In the third embodiment, after the supply of bubbles from the plurality of bubble supply pipes 51 begins, the control unit 70 controls the first opening / closing mechanism 83 and the second opening / closing mechanism 84 so that the lid unit 80 opens when the liquid level of the processing liquid in the processing tank 10 drops to a predetermined height. If bubbles continue to be supplied from the plurality of bubble supply pipes 51 while the lid unit 80 is closed, a large number of bubbles will remain on the underside of the lid unit 80, and as the number of remaining bubbles increases, the liquid level of the processing liquid will gradually drop. If the liquid level of the processing liquid drops below the upper end of the substrate W held in the immersion position, the bubbles will come into contact with the vicinity of the upper end of the substrate W. For this reason, in the third embodiment, the lid unit 80 is opened just before the liquid level of the processing liquid drops to the upper end of the substrate W held in the immersion position.

[0111] Specifically, the control unit 70 determines the timing to open the lid unit 80 based on a conversion table 72 (see FIG. 7) stored in the memory unit 74. FIG. 10 is a diagram showing an example of the conversion table 72. The horizontal axis of the figure indicates the total flow rate of bubbles supplied into the processing liquid from the plurality of bubble supply pipes 51. The vertical axis of the figure indicates the time required for the liquid level of the processing liquid to reach a predetermined height position after the supply of bubbles from the bubble supply pipes 51 begins. Hereinafter, the "predetermined height position" refers to a height position directly above the upper end of the substrate W held in an immersion position by the lifter 20. Hereinafter, this "predetermined height position" will be referred to as the critical height position. Note that the conversion table 72 in FIG. 10 is based on the assumption that the lid unit 80 is closed.

[0112] When the flow rate of bubbles supplied from the plurality of bubble supply pipes 51 is smaller than a certain value, bubbles do not accumulate on the underside of the lid 80, and the liquid level of the treatment liquid does not drop. When the flow rate of bubbles supplied from the plurality of bubble supply pipes 51 exceeds the certain value, bubbles accumulate on the underside of the lid 80, causing the liquid level to drop. The greater the flow rate of bubbles supplied from the bubble supply pipes 51, the more rapidly bubbles accumulate on the underside of the lid 80, and the faster the liquid level of the treatment liquid drops. In other words, the greater the flow rate of bubbles supplied from the bubble supply pipes 51, the shorter the time it takes for the liquid level of the treatment liquid to reach the critical height. The conversion table 72 shown in FIG. 10 may be created in advance based on experiments or simulations and stored in the storage unit 74.

[0113] The control unit 70 obtains, from the conversion table 72, the time required for the liquid level corresponding to the bubble supply flow rate defined in the recipe 71 to reach the critical height position. The control unit 70 then controls the first opening / closing mechanism 83 and the second opening / closing mechanism 84 so that the lid unit 80 opens when the required time has elapsed since the supply of bubbles began from the plurality of bubble supply pipes 51. In this way, the lid unit 80 opens when the liquid level of the processing liquid in the processing tank 10 drops to the critical height position (the height position directly above the upper end of the substrate W) after the supply of bubbles began from the plurality of bubble supply pipes 51. The remaining configuration of the third embodiment, except for the timing at which the lid unit 80 opens, is the same as that of the first embodiment.

[0114] As in the first embodiment, the third embodiment can also prevent bubbles from coming into contact with the substrate W, thereby suppressing deterioration in processing uniformity. Furthermore, the third embodiment keeps the lid 80 closed until the liquid level of the processing liquid drops and just before bubbles come into contact with the substrate W, thereby minimizing contact of the external atmosphere with the processing liquid.

[0115] <Fourth embodiment> Next, a fourth embodiment of the present invention will be described. Fig. 11 is a diagram showing the configuration of a processing unit of the fourth embodiment. In Fig. 11, the same elements as those in the first embodiment (Fig. 2) are given the same reference numerals. The fourth embodiment differs from the first embodiment in that it is provided with an elevation drive unit that raises and lowers the lid unit 80.

[0116] In the fourth embodiment, a first lifting mechanism 87 and a second lifting mechanism 88 are provided instead of the first opening / closing mechanism 83 and the second opening / closing mechanism 84 of the first embodiment. The first cover 81 is connected to the first lifting mechanism 87, which is conceptually shown in FIG. 11 . Similarly, the second cover 82 is connected to the second lifting mechanism 88. The first lifting mechanism 87 and the second lifting mechanism 88 are configured, for example, by a combination of a pulse motor and a ball screw. The first lifting mechanism 87 and the second lifting mechanism 88 respectively move the first cover 81 and the second cover 82 up and down in the vertical direction (Z-axis direction) as indicated by arrow AR11 in FIG. 11 . The first lifting mechanism 87 and the second lifting mechanism 88 cooperate to move the first cover 81 and the second cover 82 up and down the same distance, thereby lifting and lowering the cover unit 80 as a whole. That is, the first lifting mechanism 87 and the second lifting mechanism 88 are lifting drive units that raise and lower the lid unit 80.

[0117] When the lid 80 is in the lowered position, the lid 80 covers the upper opening of the treatment tank 10. Furthermore, when the lid 80 is in the lowered position, the treatment liquid stored in the treatment tank 10 is isolated from the external atmosphere by the first lid 81 and the second lid 82, thereby preventing oxygen from dissolving into the treatment liquid. Furthermore, when the lid 80 is lowered to the lower end position while the treatment liquid is stored up to the upper end in the inner tank 11 of the treatment tank 10, the first lid 81 and the second lid 82 come into contact with the liquid surface of the treatment liquid. That is, the state in which the lid 80 is lowered to the lower end position in the fourth embodiment is the same as the state in which the lid is closed in the first embodiment.

[0118] On the other hand, when the lid part 80 is raised from the lower end position, the gap between the upper end of the substrate W held in the immersion position by the lifter 20 and the lower surface of the lid part 80 increases. Furthermore, when the lid part 80 is raised while no bubbles are being supplied from the bubble supply pipe 51, the lower surface of the lid part 80 moves away from the liquid surface of the processing liquid.

[0119] The first lifting mechanism 87 and the second lifting mechanism 88 can raise and lower the lid part 80 to any height position between the upper end position and the lower end position under the control of the control part 70. The remaining configuration of the fourth embodiment is the same as that of the first embodiment, except for the provision of the first lifting mechanism 87 and the second lifting mechanism 88.

[0120] In the fourth embodiment, before a substrate W is loaded into the processing tank 10, i.e., when no substrate W is present in the processing tank 10, the lid 10 is lowered to the lower end position and the upper opening of the processing tank 10 is covered by the lid 80. This isolates the processing liquid stored in the processing tank 10 from the external atmosphere, thereby preventing oxygen from dissolving into the processing liquid. It also prevents foreign matter from dropping into the processing liquid from the space above the processing tank 10 and mixing into it.

[0121] Furthermore, when the substrate W is held at the immersion position by the lifter 20, i.e., when the substrate W is immersed in the processing liquid stored in the processing bath 10 and bubbles are being supplied to the processing liquid from the plurality of bubble supply pipes 51, the control unit 70 controls the first lifting mechanism 87 and the second lifting mechanism 88 so that the lid unit 80 rises from the lower end position to a predetermined height. As in the first embodiment, the control unit 70 may control the first lifting mechanism 87 and the second lifting mechanism 88 so that the lid unit 80 rises when the supply of bubbles starts from the plurality of bubble supply pipes 51. Alternatively, as in the third embodiment, the control unit 70 may control the first lifting mechanism 87 and the second lifting mechanism 88 so that the lid unit 80 rises when the liquid level of the processing liquid in the processing bath 10 drops to a predetermined height after the supply of bubbles starts from the plurality of bubble supply pipes 51.

[0122] 12 is a diagram showing the processing tank 10 in a state where the lid 80 is raised and a substrate W is being processed. When the lid 80 is raised from the lower end position, the gap between the upper end of the substrate W held in the immersion position and the lower surface of the lid 80 becomes relatively wide. Therefore, even if a large amount of bubbles supplied from the multiple bubble supply pipes 51 form bubble clusters on the surface of the processing liquid, the bubble clusters are prevented from coming into contact with a portion of the substrate W, and etching of that portion is prevented from being hindered.

[0123] As in the first embodiment, the control unit 70 controls the first lifting mechanism 87 and the second lifting mechanism 88 so that the lid unit 80 is raised to a height position corresponding to the dissolved oxygen concentration in the treatment liquid stored in the treatment tank 10. The control unit 70 controls the first lifting mechanism 87 and the second lifting mechanism 88 so that the height position of the lid unit 80 decreases as the dissolved oxygen concentration measured by the dissolved oxygen concentration meter 62 increases. Alternatively, as in the second embodiment, the control unit 70 may control the first lifting mechanism 87 and the second lifting mechanism 88 so that the lid unit 80 is raised to a height position corresponding to the flow rate of bubbles supplied from the multiple bubble supply pipes 51. The control unit 70 controls the first lifting mechanism 87 and the second lifting mechanism 88 so that the height position of the lid unit 80 increases as the flow rate of bubbles supplied from the six bubble supply pipes 51 increases.

[0124] In either case, the lid 80 is raised to a height position where the underside of the lid 80 comes into contact with the layer of bubbles formed on the surface of the processing liquid. By bringing the layer of bubbles formed on the surface of the processing liquid into contact with the underside of the lid 80, the external atmosphere does not get between the layer of bubbles and the underside of the lid 80, and it is possible to reliably prevent oxygen from the external atmosphere from dissolving into the processing liquid.

[0125] In the fourth embodiment, when the substrate W is immersed in the processing liquid stored in the processing bath 10 and bubbles are supplied to the processing liquid from the bubble supply pipe 51, the control unit 70 controls the first lifting mechanism 87 and the second lifting mechanism 88 so that the lid unit 80 rises from the lower end position to a predetermined height. That is, the immersion processing of the substrate W is performed while supplying bubbles with the gap between the lower surface of the lid unit 80 and the upper end of the substrate W slightly increased. As a result, even if bubbles supplied from the bubble supply pipe 51 and reaching the surface of the processing liquid form clusters, the bubbles can be prevented from coming into contact with the substrate W, thereby suppressing a decrease in processing uniformity.

[0126] <Modification> Although the embodiments of the present invention have been described above, various modifications can be made to the present invention without departing from the spirit and scope of the present invention. For example, in the third embodiment, the control unit 70 determines the timing to open the lid unit 80 based on the conversion table 72. Alternatively, the control unit 70 may determine the timing to open the lid unit 80 based on the measurement results of the pressure gauge 61. As the liquid level of the processing liquid stored in the processing tank 10 decreases, the liquid pressure of the processing liquid also decreases. That is, there is a correlation between the liquid level and the liquid pressure of the processing liquid stored in the processing tank 10. Therefore, the control unit 70 controls the first opening / closing mechanism 83 and the second opening / closing mechanism 84 so that the lid unit 80 opens when the measurement results of the pressure gauge 61 reach the liquid pressure corresponding to the liquid level of the processing liquid at the critical height position. In this way, the same effects as those of the third embodiment can be obtained.

[0127] Alternatively, the control unit 70 may determine the timing to open the lid unit 80 based on the measurement result of the liquid level sensor 63. The liquid level sensor 63 directly measures the liquid level of the processing liquid stored in the processing tank 10. Therefore, the control unit 70 may control the first opening / closing mechanism 83 and the second opening / closing mechanism 84 based on the measurement result of the liquid level sensor 63 so that the lid unit 80 opens when the liquid level of the processing liquid reaches a critical height position. Even in this case, the same effects as those of the third embodiment can be obtained.

[0128] Furthermore, in the second embodiment, the opening degree of the lid unit 80 is adjusted based on the supply flow rate of bubbles defined in the recipe 71. However, instead, the opening degree of the lid unit 80 may be adjusted based on the measurement results of the flow meter 55. The flow meter 55 measures the total flow rate of bubbles supplied from the six bubble supply pipes 51 into the processing liquid. Therefore, the control unit 70 controls the first opening / closing mechanism 83 and the second opening / closing mechanism 84 based on the actual measurement results of the flow meter 55 so that the opening degree of the lid unit 80 is appropriate.

[0129] Furthermore, when the flow rate of bubbles supplied from the plurality of bubble supply pipes 51 changes during the immersion process, the control unit 70 may control the opening / closing drive unit or the lifting drive unit to change the opening degree or height position of the lid unit 80 in response to the change. Specifically, when the flow rate of bubbles supplied to the processing liquid increases, the control unit 70 controls the opening / closing drive unit or the lifting drive unit to increase the opening degree or the height position of the lid unit 80. Conversely, when the flow rate of bubbles supplied to the processing liquid decreases, the control unit controls the opening degree or the height position of the lid unit 80 to decrease.

[0130] Furthermore, in each of the above embodiments, an exhaust mechanism may be added to forcibly exhaust bubbles that have reached the liquid surface of the processing liquid stored in the processing tank 10. This allows the bubbles to be more smoothly exhausted to the outside of the processing tank 10. [Explanation of symbols]

[0131] 10 Treatment tank 11 Inner tank 12 Outer tank 15 Dispersion plate 17 Rectifier plate 20 Lifter 22 Back plate 30 Processing liquid supply unit 31 nozzles 50 Bubble supply section 51 Bubble supply pipe 53 Gas supply mechanism 61 Pressure gauge 62 Dissolved oxygen concentration meter 63 Liquid level sensor 70 Control Unit 80 Lid 81 First lid 82 Second lid 83 1st opening / closing mechanism 84 2nd opening / closing mechanism 87 First lifting mechanism 88 Second lifting mechanism 100 Substrate processing apparatus W substrate

Claims

1. A substrate processing apparatus for performing surface treatment on a substrate using a processing liquid, a processing tank for storing a processing liquid; a processing liquid supply unit that supplies a processing liquid into the processing tank; a substrate holder that holds a substrate and immerses the substrate in the processing solution stored in the processing tank; a tubular bubble supply pipe disposed inside the processing tank and configured to supply bubbles from below the substrate held by the substrate holder to the processing liquid stored in the processing tank; a lid portion having a first lid body and a second lid body that rotate around a horizontal axis at an end, the lid portion covering an upper opening of the treatment tank; an opening / closing drive unit that rotates the first lid body and the second lid body to open and close the lid unit; a control unit that controls the opening / closing drive unit; Equipped with The control unit controls the opening / closing drive unit so that the lid unit opens to a predetermined opening degree when the substrate is immersed in the processing liquid and air bubbles are supplied to the processing liquid.

2. 2. The substrate processing apparatus according to claim 1, The substrate processing apparatus according to claim 1, wherein the control unit controls the opening / closing drive unit so that the lid unit opens when the supply of bubbles from the bubble supply pipe starts.

3. 2. The substrate processing apparatus according to claim 1, the control unit controls the opening / closing drive unit so that the lid unit opens when the liquid level of the processing liquid drops to a predetermined height position after the supply of bubbles from the bubble supply pipe has started.

4. 2. The substrate processing apparatus according to claim 1, The control unit controls the opening / closing drive unit so that the lid unit opens at an opening degree corresponding to the concentration of dissolved oxygen in the processing liquid.

5. 2. The substrate processing apparatus according to claim 1, The substrate processing apparatus, wherein the control unit controls the opening / closing drive unit so that the lid unit opens at an opening degree corresponding to a flow rate of bubbles supplied from the bubble supply pipe.

6. A substrate processing apparatus for performing surface treatment on a substrate using a processing liquid, a processing tank for storing a processing liquid; a processing liquid supply unit that supplies a processing liquid into the processing tank; a substrate holder that holds a substrate and immerses the substrate in the processing solution stored in the processing tank; a tubular bubble supply pipe disposed inside the processing tank and configured to supply bubbles from below the substrate held by the substrate holder to the processing liquid stored in the processing tank; a lid for covering an upper opening of the treatment tank; a lifting drive unit that lifts and lowers the lid unit; a control unit that controls the lifting drive unit; Equipped with The control unit controls the lifting drive unit so that the lid unit rises to a predetermined height position when the substrate is immersed in the processing liquid and air bubbles are supplied to the processing liquid.

7. 7. The substrate processing apparatus according to claim 6, The substrate processing apparatus according to claim 1, wherein the control unit controls the lifting drive unit so that the lid unit rises when the supply of bubbles from the bubble supply pipe starts.

8. 7. The substrate processing apparatus according to claim 6, the control unit controls the lifting drive unit so that the lid unit rises when the liquid level of the processing liquid drops to a predetermined height after the supply of bubbles from the bubble supply pipe has started.

9. 7. The substrate processing apparatus according to claim 6, The substrate processing apparatus according to claim 1, wherein the control unit controls the lifting drive unit so that the lid unit is raised to a height position corresponding to the concentration of dissolved oxygen in the processing liquid.

10. 7. The substrate processing apparatus according to claim 6, The substrate processing apparatus is characterized in that the control unit controls the lifting drive unit so that the lid unit rises to a height position corresponding to a flow rate of bubbles supplied from the bubble supply pipe.

11. 11. The substrate processing apparatus according to claim 6, The substrate processing apparatus is characterized in that the lid portion comes into contact with a layer of bubbles formed on the surface of the processing liquid.

12. A substrate processing method for performing a surface treatment on a substrate with a processing liquid, comprising: an immersion step of holding and immersing the substrate in a processing solution stored in a processing tank; a bubble supplying step of supplying bubbles into the processing liquid from below the substrate held in the processing liquid; an opening step of opening a lid unit covering an upper opening of the processing tank by a predetermined opening degree, the lid unit having a first lid body and a second lid body that rotate around a horizontal axis at an end thereof, when the substrate is immersed in the processing solution and air bubbles are supplied to the processing solution; A substrate processing method comprising:

13. 13. The substrate processing method according to claim 12, a step of opening the cover when the bubble supplying step is started;

14. 13. The substrate processing method according to claim 12, a step of supplying bubbles to the processing liquid; a step of opening the cover when the liquid level of the processing liquid drops to a predetermined height after the step of supplying bubbles is started;

15. 13. The substrate processing method according to claim 12, The substrate processing method, wherein the opening step opens the lid portion at an opening degree corresponding to the concentration of dissolved oxygen in the processing liquid.

16. 13. The substrate processing method according to claim 12, The substrate processing method, wherein the opening step opens the lid portion with an opening degree corresponding to a flow rate of bubbles to be supplied into the processing liquid.

17. A substrate processing method for performing a surface treatment on a substrate with a processing liquid, comprising: an immersion step of holding and immersing the substrate in a processing solution stored in a processing tank; a bubble supplying step of supplying bubbles into the processing liquid from below the substrate held in the processing liquid; a raising step of raising a lid covering an upper opening of the treatment tank to a predetermined height while the substrate is immersed in the treatment liquid and air bubbles are being supplied to the treatment liquid; A substrate processing method comprising:

18. 18. The substrate processing method according to claim 17, a step of raising the lid when the bubble supplying step is started;

19. 18. The substrate processing method according to claim 17, a step of raising the lid when the liquid level of the processing liquid has dropped to a predetermined height after the bubble supply step has started;

20. 18. The substrate processing method according to claim 17, In the raising step, the lid is raised to a height corresponding to a concentration of dissolved oxygen in the processing liquid.

21. 18. The substrate processing method according to claim 17, In the raising step, the lid portion is raised to a height corresponding to a flow rate of bubbles supplied into the processing liquid.

22. 22. The substrate processing method according to claim 17, a lid portion contacting a layer of bubbles formed on the surface of the processing liquid;

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