Substrate processing equipment

Abstract

The present invention provides a substrate processing device capable of improving the uniformity of substrate processing by forming bubbles of inert gas in a processing liquid. A plurality of liquid supply pipes (31) and a plurality of bubble tube sections (37) are arranged at the bottom of a processing tank (18). Liquid spray holes (31a, 31b) for spraying processing liquid toward the lower inner side and the lower outer side are formed on the liquid supply pipe (31). A gas spray hole (37a) for spraying nitrogen toward the lower inner side is formed on the bubble tube section (37). The bubble tube section (37) is divided into a first spray section (41) and a second spray section (42) by a partition (40) at approximately the center of the arrangement range of the substrate (11). Nitrogen is supplied to the first spray section (41) and the second spray section (42) of each bubble tube section (37), and the flow rate of the nitrogen is independently adjusted by a flow adjustment section (52) respectively connected to the first spray section (41) and the second spray section (42).

Description

Technical Field

[0001] The present invention relates to a substrate processing device such as a semiconductor wafer. Background Art

[0002] There is a substrate processing device that immerses a substrate such as a semiconductor wafer in a phosphoric acid aqueous solution stored in a processing tank, and removes, for example, a silicon nitride film formed on the surface of the substrate by wet etching. As a substrate processing device that performs such wet etching, a batch-type substrate processing device is known that immerses a plurality of substrates in a processing liquid such as a phosphoric acid aqueous solution in a processing tank while standing and holding them at a predetermined interval to perform etching processing. In order to miniaturize the device, the batch-type substrate processing device often keeps the interval between the plurality of substrates small.

[0003] There is known a substrate processing apparatus that promotes the upward flow of the processing liquid by forming bubbles of an inert gas (e.g., nitrogen) in the processing liquid in the processing tank (e.g., see Patent Document 1). In the substrate processing apparatus of Patent Document 1, in order to form bubbles of the inert gas in the processing liquid composed of an aqueous phosphoric acid solution, a plurality of gas nozzles are arranged below a plurality of substrates in the processing tank, and an upward flow of the processing liquid in the processing tank is generated by ejecting an inert gas from each gas nozzle.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2019-50349 Summary of the invention

[0007] Problems to be solved by the invention

[0008] In a batch-type substrate processing device that holds multiple substrates in a processing liquid at a small interval, it is useful to promote the upward flow of the processing liquid by forming bubbles in the processing liquid. However, even if bubbles are formed in the processing liquid in the processing tank, it cannot be said to be sufficient for the uniformity of the surface treatment of each substrate and the uniformity of the treatment between substrates, and it is hoped that it will be improved. In particular, when a high-viscosity processing liquid such as an aqueous phosphoric acid solution is used for processing, it is difficult for the processing liquid to flow between the substrates, so it is difficult to obtain the uniformity of the treatment, and further improvement is expected.

[0009] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a substrate processing apparatus capable of improving the uniformity of substrate processing by bubbles of an inert gas formed in a processing liquid.

[0010] Means for solving problems

[0011] The substrate processing device of the present invention comprises: a processing tank, which stores processing liquid and allows a plurality of substrates to be arranged and accommodated in the processing tank in an upright state at a specified interval; a bubble forming part, which has a plurality of bubble tube parts, and the plurality of bubble tube parts are divided into a tubular first ejection part extending in the arrangement direction of the plurality of substrates and a tubular second ejection part coaxial with the first ejection part and extending in the arrangement direction within the arrangement range of the plurality of substrates, one end of the divided side of the first ejection part and the second ejection part is closed, and a plurality of gas injection holes are formed on the first ejection part and the second ejection part along the arrangement direction, and in the processing tank, the plurality of bubble tube parts are spaced apart in a horizontal direction orthogonal to the arrangement direction below the plurality of accommodated substrates; and a plurality of flow adjustment parts, which are arranged corresponding to each of the first ejection part and each of the second ejection parts, and independently adjust the flow rate of the inert gas relative to the corresponding first ejection part or the second ejection part.

[0012] In addition, the substrate processing device of the present invention includes: a processing tank, which stores a processing liquid and allows a plurality of substrates to be arranged and accommodated in the processing tank in an upright state at a specified interval; a liquid supply pipe, which is arranged in the processing tank below the plurality of accommodated substrates and has a plurality of liquid spray holes formed in the arrangement direction of the plurality of substrates for spraying the processing liquid toward the inner side and the outer side below; and a bubble tube portion, which is arranged in the processing tank below the plurality of accommodated substrates and has a plurality of gas injection holes formed in the arrangement direction, and the plurality of gas injection holes spray an inert gas obliquely downward to form bubbles of the inert gas in the processing liquid.

[0013] Effects of the Invention

[0014] According to the substrate processing device of the present invention, each of the multiple bubble tube sections is divided into a first ejection section and a second ejection section within the arrangement range of the multiple substrates, and the flow rates of the inert gas relative to the first ejection section or the second ejection section are independently adjusted by multiple flow adjustment sections, thereby making it possible to utilize the bubbles of inert gas formed in the processing liquid to further improve the uniformity of substrate processing.

[0015] According to the substrate processing device of the present invention, since the processing liquid is sprayed toward the lower inner side and the lower outer side from the liquid supply pipe, and the bubbles of inert gas are sprayed toward the lower inner side from the bubble tube part, it is possible to effectively form bubbles of inert gas in the processing liquid, which can further improve the uniformity of substrate processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a block diagram showing the structure of a substrate processing apparatus.

[0017] Figure 2 It is a perspective view showing the structure of the bracket.

[0018] Figure 3 It is an explanatory diagram schematically showing the layout of the liquid supply pipe and the bubble tube portion.

[0019] Figure 4 It is a cross-sectional view showing a liquid ejection hole formed in a liquid supply pipe.

[0020] Figure 5 It is a cross-sectional view showing an air injection hole formed in the bubble tube portion.

[0021] Figure 6 It is a perspective view showing an example of the structure of the bubble tube portion.

[0022] Figure 7 It is an explanatory diagram showing the ejection directions of the processing liquid and the nitrogen gas from the liquid supply pipe and the bubble pipe portion.

[0023] Figure 8 : is a time chart showing the change in the flow rate of the nitrogen gas flowing into the bubble tube portion.

[0024] Fig. 9 It is an explanatory diagram showing an example of a substrate processing apparatus provided with six bubble tube units.

[0025] Fig.10 It is an explanatory diagram showing measurement points on a substrate where the etching amount is measured. DETAILED DESCRIPTION

[0026] exist Figure 1 In the embodiment, the substrate processing apparatus 10 uses a processing liquid 12 to remove a thin film formed on a substrate 11. In this example, the substrate 11 is a silicon wafer (semiconductor substrate), and the processing liquid 12 is used to perform an etching process to selectively remove (etch) a silicon oxide film (SiO 2 Film) and silicon nitride film (Si 3 N 4 The treatment liquid 12 is phosphoric acid (H 3 PO 4 ) is an aqueous solution of phosphoric acid dissolved in pure water (deionized water).

[0027] The substrate processing device 10 includes a tank portion 14, a circulation mechanism 15, and a bubble generating mechanism 16. The tank portion 14 includes a box-shaped processing tank 18 and an outer tank 19 integrally provided on the upper outer side of the processing tank 18. The processing tank 18 stores a processing liquid 12. The processing liquid 12 is supplied to the processing tank 18 by the circulation mechanism 15. The outer tank 19 receives the processing liquid 12 overflowing from the processing tank 18. The processing liquid 12 overflowing to the outer tank 19 is returned to the processing tank 18 by the circulation mechanism 15. In addition, the substrate processing device 10 is provided with a cover member (not shown) for opening and closing the upper part of the tank portion 14.

[0028] The substrate processing device 10 is a batch processing device, and a plurality of substrates 11 held by a support 21 are accommodated in a processing tank 18, and these substrates 11 are immersed in a processing liquid 12. The substrates 11 are arranged in a vertical direction to the paper surface and held by the support 21 in an upright posture, that is, the substrate surfaces (front and back) are in a vertical direction. Figure 1 As shown, the support 21 moves between a lowered position for immersing each substrate 11 in the processing liquid 12 in the processing tank 18 and a raised position for rising from the lowered position and lifting the substrate 11 from the processing liquid 12 .

[0029] The circulation mechanism 15 includes a circulation pump 23, a damper 24, a filter 25, a heater 26, a bubble cutter 27, and a liquid supply pipe section 28. The circulation pump 23 is connected to the outer tank 19, and the damper 24, the filter 25, the heater 26, the bubble cutter 27, and the liquid supply pipe section 28 are sequentially connected from the circulation pump 23. The circulation pump 23, the damper 24, the filter 25, the heater 26, and the bubble cutter 27 are arranged outside the tank section 14. The liquid supply pipe section 28 is composed of two liquid supply pipes 31. The two liquid supply pipes 31 are arranged at the same height, that is, at the same horizontal plane, at the bottom of the processing tank 18, and are set at a position lower than the support 21 in the lowered position, that is, at a position lower than the substrate 11 accommodated in the processing tank 18.

[0030] The circulation pump 23 delivers the treatment liquid 12 in the outer tank 19 to the liquid supply pipe 31. The damper 24 temporarily stores an appropriate amount of the treatment liquid 12 to suppress the flow rate fluctuation of the treatment liquid 12 in the circulation mechanism 15, and the filter 25 removes particles and the like in the treatment liquid 12. The heater 26 heats the treatment liquid 12 supplied to the treatment tank 18 to a temperature above the boiling point, and the bubble cutter 27 removes bubbles in the supplied treatment liquid 12. The liquid supply pipe 31 is provided with a plurality of liquid injection holes 31a, 31b (see Figure 3 ), the treatment liquid 12 from the circulation mechanism 15 is sprayed into the treatment tank 18 through the respective spray holes 31a, 31b. The treatment liquid 12 in the treatment tank 18 has a temperature of, for example, about 150°C to 165°C.

[0031] By the circulation mechanism 15 configured as described above, the treatment liquid 12 overflowing from the treatment tank 18 to the outer tank 19 is filtered, heated, and returned to the treatment tank 18. In addition, the circulation mechanism 15 is provided with a pure water supply mechanism (not shown) for adding water to the circulating treatment liquid 12. The pure water supply mechanism adjusts the amount of water added to the treatment liquid 12 to maintain the phosphoric acid concentration of the treatment liquid 12 in the treatment tank 18 at a constant value.

[0032] The bubble generating mechanism 16 includes a bubble forming section 33 and an air supply section 35. The bubble forming section 33 is composed of a plurality of (four in this example) bubble tube sections 37 disposed at the bottom of the processing tank 18. The bubble tube section 37 is provided with a plurality of gas injection holes 37a (see Figure 3 ), by ejecting nitrogen (N 2 ), forming bubbles in the processing liquid 12. The bubble generating mechanism 16 improves the fluidity of the processing liquid 12 by forming nitrogen bubbles in the processing liquid 12. In addition, the rise of the bubbles promotes the movement of the substrates 11 and the substrates 11 and the support plate 44 (see Figure 2 ) between the processing liquid 12 to flow upward. Each bubble tube portion 37 is arranged at the same height at the bottom of the processing tank 18, and is arranged below the support 21 in the descending position, similar to the liquid supply pipe 31, and is set at a position lower than the substrate 11 accommodated in the processing tank 18.

[0033] The gas supply unit 35 supplies nitrogen gas to the bubble forming unit 33. As described in detail later, each bubble tube unit 37 of the bubble forming unit 33 is divided into a first ejection unit 41 and a second ejection unit 42 (see FIG. Figure 3 ), the gas supply section 35 can independently adjust the nitrogen flow rate of the first ejection section 41 and the second ejection section 42 for each bubble tube section 37.

[0034] like Figure 2 As shown, the bracket 21 has a pair of support plates 44, a bottom bar 45 and a pair of side bars 46. The pair of support plates 44 are spaced apart in the arrangement direction of the substrates 11 (hereinafter referred to as the substrate arrangement direction, arrow X direction). The bottom bar 45 and the pair of side bars 46 are spaced apart from each other in the horizontal direction orthogonal to the substrate arrangement direction, i.e., the width direction (arrow Y direction), and their respective ends are fixed to the pair of support plates 44. A plurality of grooves are formed on the bottom bar 45 and the pair of side bars 46 at a certain interval along the substrate arrangement direction. In addition, Figure 2 In the figure, for the sake of convenience, the number of grooves depicted is less than the actual number. In this example, the grooves are actually provided in such a manner that fifty substrates 11 are held on the holder 21.

[0035] The substrate 11 is held by the support 21 in a state where the peripheral edge of the bottom end thereof enters the groove of the bottom strip 45 and the peripheral edges of both sides of the lower half enter the grooves of the pair of side strips 46. Thus, the support 21 holds each substrate 11 in a three-point standing posture, and arranges and holds a plurality of substrates 11 at a predetermined interval in a state where the front surfaces, the back surfaces, or the front surfaces and the back surfaces are opposite to each other.

[0036] The holder 21 constructed as described above has an open bottom, and is configured not to hinder the processing liquid 12 and bubbles from entering between the held substrates 11 and between the substrate 11 and the support plate 44 from below.

[0037] Figure 3 The layout of the processing tank 18 as viewed from above is schematically shown. Figure 3 In order to simplify the drawings, the number of substrates 11 is reduced, and some parts are omitted. The layout of the liquid supply tube 31 and the bubble tube portion 37 is line symmetrical with the center line parallel to the substrate arrangement direction passing through the center of the substrate 11 as the symmetry axis. In this way, the layout of the liquid supply tube 31 and the bubble tube portion 37 is preferably line symmetrical with the straight line parallel to the center line along the substrate arrangement direction passing through the center of the substrate 11 as the symmetry axis. In addition, the liquid supply tube 31 and the bubble tube portion 37 are tubular in shape extending in the substrate arrangement direction, and in this example, they are circular in shape with a constant diameter.

[0038] In the width direction, the two liquid supply pipes 31 are arranged at a predetermined distance in the width direction. In this example, the liquid supply pipe 31 is arranged just below the end of the substrate 11 in the width direction, and the distance from the position in the width direction of the vertical line passing through the center of the substrate 11 accommodated in the processing tank 18 (hereinafter referred to as the width direction center) to the liquid supply pipe 31 is smaller than the radius of the substrate 11.

[0039] Two of the four bubble tubes 37 are disposed near the center in the width direction and are close to each other. The other two bubble tubes 37 are disposed near the liquid supply tube 31 and outside the liquid supply tube 31. Therefore, the other two bubble tubes 37 are disposed directly below the end of the substrate 11 in the width direction.

[0040] In addition, the side closer to the center in the width direction is the inner side, and the side farther from the center in the width direction is the outer side. In addition, in the following, when specially distinguishing between the two bubble tube portions 37 close to the center in the width direction and the other two bubble tube portions 37, the former will be referred to as the inner bubble tube portion 37 and the latter will be referred to as the outer bubble tube portion 37 for explanation.

[0041] The liquid supply pipe 31 has a plurality of liquid ejection holes 31a and a plurality of liquid ejection holes 31b on its lower wall. The liquid ejection holes 31a and 31b are arranged linearly at a predetermined pitch in the substrate arrangement direction. The liquid ejection holes 31a and 31b penetrate the wall of the liquid supply pipe 31.

[0042] In this example, the liquid ejection holes 31a and the liquid ejection holes 31b are arranged at a pitch twice the arrangement pitch of the substrates 11, and are arranged directly below the gap between two adjacent substrates 11 and between the substrate 11 and the support plate 44. In addition, in the substrate arrangement direction, the positions of the liquid ejection holes 31a and the liquid ejection holes 31b of the liquid supply pipe 31 and the positions of the liquid ejection holes 31a and 31b between the two liquid supply pipes 31 are the same. Therefore, the liquid ejection holes 31a and 31b are not arranged directly below a portion of the gap between two adjacent substrates 11.

[0043] The front end (the lower end in the figure) of the liquid supply tube 31 is closed, and the base end (the upper end in the figure) is connected to the bubble cutter 27 of the circulation mechanism 15. Thus, the processing liquid 12 is supplied from the base end side into the liquid supply tube 31 through the circulation mechanism 15, and the supplied processing liquid 12 is sprayed into the processing tank 18 from the respective spray holes 31a, 31b.

[0044] The bubble tube section 37 is divided into a first ejection section 41 on one end side and a second ejection section 42 on the other end side by a partition plate 40 provided between one end and the other end. That is, the first ejection section 41 and the second ejection section 42 are not connected inside and form independent spaces. Such a bubble tube section 37 is a structure in which the tubular first ejection section 41 and the second ejection section 42 are coaxially extended along the substrate arrangement direction.

[0045] In each bubble tube section 37, a plurality of gas injection holes 37a are formed in a linear arrangement at a predetermined pitch along the substrate arrangement direction in the tube wall portion of the lower half thereof. The gas injection holes 37a penetrate the tube wall of the bubble tube section 37. The arrangement pitch of the gas injection holes 37a can be set arbitrarily, but is preferably the same as the arrangement pitch of the substrate 11. As shown in the figure, the gas injection holes 37a of each bubble tube section 37 are preferably arranged directly below the gap between two adjacent substrates 11 and between the substrate 11 and the support plate 44. Therefore, the gas injection holes 37a are preferably arranged at the same pitch as the entire bubble tube section 37 without separating the first ejection section 41 and the second ejection section 42.

[0046] In addition, the position of the partition 40 in the bubble tube portion 37 in the substrate arrangement direction can be set appropriately, but it is preferably set to a position substantially in the center of the arrangement range of the arranged substrates 11, avoiding the position of the gas injection hole 37a. By providing the partition 40 at a position substantially in the center of the arrangement range of the substrates 11, the number of gas injection holes 37a of one of the first ejection portion 41 and the second ejection portion 42 does not increase, and the difference in the nitrogen gas injection amount between the gas injection hole 37a on the front end (end on the partition 40 side) side and the gas injection hole 37a on the base end (end on the opposite side to the partition 40) side of the first ejection portion 41 or the second ejection portion 42 can be reduced. As a result, the nitrogen gas flow rate of the first ejection portion 41 and the second ejection portion 42 can be easily adjusted. In this example, since the gas injection hole 37a is provided at the center position of the arrangement range of the substrates 11, the position of the partition 40 is offset from the center position toward one end side of the bubble tube portion 37 by the arrangement pitch of the substrates 11. Therefore, the number of the gas injection holes 37a on the first gas injection portion 41 side is one less than the number on the second gas injection portion 42 side. In addition, the “substantially the center” of the arrangement range of the substrates 11 refers to a range where the distance from the center position of the arrangement range is less than or equal to three times the arrangement pitch of the substrates 11.

[0047] The first ejection part 41 and the second ejection part 42 of each bubble tube part 37 are connected to the gas supply part 35 through independent supply pipes 51, and are independently supplied with nitrogen gas from the gas supply part 35. The first ejection part 41 and the second ejection part 42 are connected to the supply pipes 51 at their base ends.

[0048] The gas supply unit 35 has eight flow rate adjustment units 52 corresponding to the first ejection units 41 and the second ejection units 42 respectively provided on the four bubble tube units 37. That is, one flow rate adjustment unit 52 is provided for one first ejection unit 41 or one second ejection unit 42, and the corresponding components are connected to each other through the supply pipe 51. Each flow rate adjustment unit 52 is composed of a flow rate adjustment valve or the like that can independently adjust the flow rate. A filter 53 for removing foreign matter in the nitrogen gas is connected between the first ejection unit 41, the second ejection unit 42 and the flow rate adjustment unit 52.

[0049] The flow rate adjustment unit 52 receives the supply of nitrogen gas from the gas supply source (not shown) through the pressure reducing regulator 54, and adjusts the flow rate so that the nitrogen gas flows to the corresponding first ejection unit 41 or second ejection unit 42. The flow rates of nitrogen gas flowing to each first ejection unit 41 and each second ejection unit 42 are independently adjusted by these flow rate adjustment units 52.

[0050] However, even if the flow of the processing liquid 12 in the space where the substrates 11 are arranged is made uniform, or nitrogen bubbles are uniformly formed in the processing liquid 12, uniform etching may not be obtained. This is caused by various reasons such as a decrease in the etching rate caused by the flow of the processing liquid 12 in the processing tank 18 or an increase in the silicon dioxide concentration of the processing liquid 12 during the flow between the substrates 11 or between the substrate 11 and the support plate 44.

[0051] By dividing the four bubble tube sections 37 configured as above into the first ejection section 41 and the second ejection section 42, respectively, the amount of nitrogen bubbles in the processing liquid 12 provided to the range space of the substrate 11 held by the bracket 21 can be divided into two parts approximately at the position of the partition 40 in the substrate arrangement direction, and then divided into six areas of three parts in the central part and both sides in the width direction, and can be independently adjusted.

[0052] For example, by adjusting the flow rate of nitrogen gas to the inner bubble tube portion 37, the amount of bubbles in the central region in the width direction of the range of the substrate 11 can be increased or decreased. The amount of bubbles in the region on the first ejection portion 41 side and the region on the second ejection portion 42 side of the inner bubble tube portion 37 can be increased or decreased respectively. In addition, by adjusting the flow rate of nitrogen gas to the outer bubble tube portion 37, the amount of bubbles in one or both regions further outward than the center in the width direction of the range of the substrate 11 can be increased or decreased. In this case, the amount of bubbles in the region on the first ejection portion 41 side and the region on the second ejection portion 42 side can also be increased or decreased respectively.

[0053] The flow rate of nitrogen gas flowing to the first ejection part 41 and each second ejection part 42 (the set value of each flow adjustment part 52) ​​is determined in advance, for example, based on experiments, in such a manner that the difference in the etching amount of each part of the multiple substrates 11 held by each support 21 is reduced, taking into account the flow distribution of the processing liquid 12 in the processing tank 18, or the reduction in the etching rate caused by the increase in the silicon dioxide concentration of the local processing liquid 12.

[0054] like Figure 4 As shown, the liquid injection hole 31a is formed to penetrate the tube wall portion of the liquid supply tube 31 toward the lower inner side, and the liquid injection hole 31b is formed to penetrate the tube wall portion of the liquid supply tube 31 toward the lower outer side. Thus, the liquid injection hole 31a sprays the processing liquid 12 toward the lower inner side, and the liquid injection hole 31b sprays the processing liquid 12 toward the lower outer side. Here, in the width direction, the direction toward the center of the width direction is the inner direction, and the opposite direction is the outer direction. In addition, the so-called spraying direction toward the lower inner side means that it has a component toward the lower side and a component toward the inner side, and the so-called spraying direction toward the lower outer side means that it has a component toward the lower side and a component toward the outer side.

[0055] The inclination angle θ1 of the liquid ejection holes 31a and 31b (the angle of the axis of the liquid ejection holes 31a and 31b relative to the vertical downward direction) can be appropriately determined. In this example, the liquid ejection holes 31a and 31b are formed so that their axis coincides with the radial direction of the liquid supply pipe 31, and the inclination angle θ1 is 50°. In addition, the diameters of the liquid ejection holes 31a and 31b are the same, but the present invention is not limited thereto.

[0056] like Figure 5 As shown, the jet hole 37a is formed to penetrate the tube wall portion of the bubble tube portion 37 toward the lower inner side. Thus, the jet hole 37a ejects nitrogen toward the lower inner side, which has an inward component. The inclination angle θ2 of the jet hole 37a can be appropriately determined. In this example, the jet hole 37a is formed so that its axis is consistent with the radial direction of the bubble tube portion 37, and the inclination angle θ2 of the jet hole 37a is 45°. In the structure in which the jet hole 37a is directed downward, there is an advantage that it is difficult for the processing liquid 12 to penetrate into the bubble tube portion 37 through the jet hole 37a, and even if the processing liquid 12 penetrates into the bubble tube portion 37, it is easy to discharge. In addition, the diameters of the jet holes 37a are all the same, but are not limited to this.

[0057] Figure 6 The bubble tube section 37 used in this example is shown as viewed from the bottom. The bubble tube section 37 of this example is sandwiched by a partition 40, and is connected to each end of a straight tube-shaped first ejection section 41 and a second ejection section 42. The first ejection section 41 is connected to an end of a supply tube 51 with a smaller diameter than the bubble tube section 37 at the end surface of its base end. The supply tube 51 connected to the first ejection section 41 is bent in an L shape and the other end side extends upward. The second ejection section 42 on one side is connected to an end of a supply tube 51 with a smaller diameter than the bubble tube section 37 on the tube wall on its base end side. The supply tube 51 connected to the second ejection section 42 is bent in an L shape at one end side, and the central part is arranged along the bubble tube section 37, and the other end side extends upward. In addition, as the bubble tube section 37, it can also be configured as a structure in which a partition 40 is provided in a straight tube, or a structure in which the first ejection section 41 and the second ejection section 42 are not integrated but coaxially arranged.

[0058] Figure 7 1 shows the arrangement of each liquid supply pipe 31 and each bubble tube section 37 as viewed from the substrate arrangement direction, and the ejection direction of the processing liquid 12 and the nitrogen gas. As described above, the liquid supply pipe 31 is arranged just below the end portion in the width direction of the substrate 11, and ejects the processing liquid 12 from the ejection hole 31a to the inner side below, and ejects the processing liquid 12 from the ejection hole 31b to the outer side below. On the other hand, the bubble tube sections 37 are arranged in the center and both sides in the width direction, and eject nitrogen gas from the ejection hole 37a to the inner side below.

[0059] The processing liquid 12 from each liquid injection hole 31a is ejected downwardly and inwardly, thereby converting into a flow that expands and rises in the width direction from the bottom surface of the processing tank 18. Near the center of the width direction of the processing tank 18, the flows of the processing liquid 12 from a pair of liquid injection holes 31a that expand in the width direction merge, thereby forming a relatively strong upward flow, and generating a flow that passes through the central part of the width direction of the substrate 11 and moves upward. On the other hand, the processing liquid 12 from each liquid injection hole 31b is ejected downwardly and outwardly, thereby converting into a flow that rises from the bottom surface of the processing tank 18, and the outward expansion is limited by the side wall surface of the processing tank 18, and at the same time, an upward flow is formed that passes through the end of the width direction of the substrate 11.

[0060] As described above, the gas injection hole 37a of each bubble tube portion 37 injects nitrogen gas downwardly and inwardly. In addition, each bubble tube portion 37 is arranged at a position lower than the liquid supply tube 31, and more specifically, the gas injection hole 37a of the bubble tube portion 37 is located lower than the liquid injection holes 31a and 31b of the liquid supply tube 31.

[0061] By making the ejection directions of the treatment liquid 12 and nitrogen gas through the liquid ejection holes 31a, 31b and the gas ejection hole 37a have downward components, the treatment liquid 12 ejected from the liquid ejection holes 31a, 31b can effectively contain nitrogen bubbles near the bottom surface of the treatment tank 18. Thus, the nitrogen bubbles are used to promote the upward flow of the treatment liquid 12 as described above, so that it can effectively enter between the adjacent substrates 11 and between the support plate 44 and the substrate 11. In addition, the flow of the slag flow treatment liquid 12 is formed between the adjacent substrates 11 and between the support plate 44 and the substrate 11 by the treatment liquid 12 containing nitrogen bubbles, and the upward flow of the treatment liquid 12 is promoted. The treatment liquid 12 improves its fluidity by mixing nitrogen bubbles in the treatment liquid 12. In addition, if bubbles are formed in the treatment liquid 12, when the bubbles rise due to buoyancy, the bubbles push up the treatment liquid 12 on the upper side and suck the treatment liquid 12 on the lower side. Therefore, the upward flow of the processing liquid 12 and the stirring of the processing liquid 12 are promoted by the bubbles.

[0062] By making the ejection direction of the inner bubble tube portion 37 have an inward component, it is possible to make the processing liquid 12 near the center in the width direction where the flow tends to deteriorate contain more nitrogen bubbles, and the flow of the processing liquid 12 passing through the central portion in the width direction of the substrate 11 to the upper side can be effectively promoted. In addition, by making the ejection direction of the nitrogen gas from the outer bubble tube portion 37 arranged near the outer side of the liquid supply tube 31 to the lower inner side, the processing liquid 12 ejected from the liquid supply tube 31 to the lower outer side flows in a manner that introduces the nitrogen gas ejected from the outer bubble tube portion 37, so that the nitrogen gas can be easily introduced into the processing liquid 12 with high viscosity to form bubbles. Since the ejection hole 37a of the outer bubble tube portion 37 is located below the ejection hole 37b, the nitrogen gas can be more effectively introduced into the processing liquid 12. As a result, the flow mainly passing through the end portion in the width direction of the substrate 11 to the upper side is effectively promoted.

[0063] In addition, by making the spray holes 31a and 31b have a downward component, the processing liquid 12 can be effectively prevented from hitting specific parts of the substrate 11, and the local increase in etching rate and the mixing of foreign matter from the inclined surface into the surface of the substrate 11 can be effectively suppressed.

[0064] Next, the function of the above structure is explained. Figure 8 As shown, even in the idle period before the time t1 when the substrate 11 is not immersed in the processing liquid 12 in the processing tank 18, the nitrogen gas from the gas supply part 35 is supplied to the first ejection part 41 and the second ejection part 42 of each bubble tube part 37. The flow rate M1 of the nitrogen gas in the idle period is less than that in the etching period. As a result, the processing liquid 12 does not enter the inside of the first ejection part 41 and the second ejection part 42 through the gas injection hole 37a. In addition, the flow rate M1 of the nitrogen gas flowing to the first ejection part 41 and the second ejection part 42 of each bubble tube part 37 during the idle period does not need to be adjusted individually.

[0065] On the other hand, the processing liquid 12 is continuously supplied to the processing tank 18 through the respective liquid injection holes 31a of the liquid supply pipe 31 by the circulation mechanism 15. The processing liquid 12 ejected from the liquid injection holes 31a to the lower inner side and the lower outer side respectively turns upward at the bottom surface of the processing tank 18, and flows toward the upper part of the processing tank 18 while expanding in the width direction. Even during this idle period, nitrogen bubbles are formed in the processing liquid 12, although only a small amount.

[0066] The substrate 11 from which the silicon nitride film has been removed is immersed in the processing liquid 12 in the processing tank 18 by moving the support 21 to the lowered position while being held by the support 21 (time t1). When the substrate 11 is immersed in the processing liquid 12, after waiting for the temperature of the processing liquid 12 to recover, nitrogen gas is supplied to the first ejection part 41 and the second ejection part 42 of each bubble tube part 37 at a normal flow rate M2 (time t2). At this time, nitrogen gas is supplied to the first ejection part 41 and the second ejection part 42 of each bubble tube part 37 at a flow rate pre-adjusted by the corresponding flow rate adjustment part 52, and therefore the flow rate M2 is a value corresponding to each first ejection part 41 and each second ejection part 42, respectively.

[0067] The first ejection part 41 and the second ejection part 42 eject nitrogen from the ejection hole 37a at a flow rate corresponding to the flow rate supplied thereto, thereby forming nitrogen bubbles in the processing liquid 12. The processing liquid 12 flows upward in a manner of entering between the substrates 11 and between the substrate 11 and the support plate 44 by the flow of the processing liquid 12 as described above and the buoyancy of the nitrogen bubbles, and then rises along the surface of the substrate 11. In addition, at this time, the fluidity of the processing liquid 12 is improved due to the nitrogen bubbles contained therein. In this way, the flow of the processing liquid 12 between the substrates 11 and between the substrate 11 and the support plate 44 is promoted by the bubbles, and the degree thereof varies depending on the amount of nitrogen bubbles in the processing liquid 12.

[0068] After the substrate 11 is immersed in the processing liquid 12, at time t3 when the predetermined processing time has passed, the support 21 moves from the lowered position to the raised position. As a result, the substrate 11 is lifted from the processing liquid 12, the etching process is completed, and the idle period begins again. In addition, at this time t3, the flow rate of nitrogen gas flowing to the first ejection part 41 and the second ejection part 42 of each bubble tube part 37 is reduced to the flow rate M1 during the idle period.

[0069] However, as described above, during the etching process, even if nitrogen bubbles are uniformly formed in the processing liquid 12, uniform etching may not be obtained due to various reasons. However, in the substrate processing device 10 of this example, during the etching process, as described above, nitrogen gas at the flow rate set by each flow adjustment unit 52 is supplied to the first ejection unit 41 and the second ejection unit 42 of each bubble tube unit 37, respectively, and the bubble amount in six areas obtained by roughly dividing the range space of the substrate 11 held by the holder 21 is independently adjusted. That is, the flow of the processing liquid 12 along the surface of each substrate 11 is roughly adjusted for each area so that the etching rate does not differ between the parts of the substrate 11 and between the substrates 11. Therefore, the uniformity of etching is improved between the parts of each substrate 11 and between the substrates 11 held by the holder 21.

[0070] In the above embodiment, four bubble tubes are provided, but as long as multiple bubble tubes are provided, there is no particular limitation on the number. Fig. 9 The example in which six bubble tubes 37 and 67 are provided is a structure in which a bubble tube 67 close to the liquid supply tube 31 is further provided inside each liquid supply tube 31. The bubble tube 67 is provided with a gas injection hole 67a for ejecting nitrogen toward the lower outer side. The other structures are the same as those of the substrate processing device 10 described above. That is, the structure is that the bubble tube 37 disposed near the outer side of the liquid supply tube 31 ejects nitrogen toward the lower inner side, and the bubble tube 67 disposed near the inner side ejects nitrogen toward the lower outer side. Thus, the nitrogen ejected from the bubble tube 37 toward the lower inner side is effectively mixed with the processing liquid 12 ejected from the liquid supply tube 31 toward the lower outer side, and the nitrogen ejected from the bubble tube 67 toward the lower outer side is effectively mixed with the processing liquid 12 ejected from the liquid supply tube 31 toward the lower inner side. In this way, by increasing the number of bubble tubes, the space within the range of the substrate 11 held by the support 21 can be divided into finer parts, and the bubble amount can be adjusted independently.

[0071] In the above description, an example of a phosphoric acid aqueous solution is described as a treatment liquid, but the treatment liquid is not limited thereto, and is particularly useful for a treatment liquid with high viscosity. As a treatment liquid with high viscosity, for example, SPM (Sulfuric Acid Hydrogen Peroxide Mixture) which is a mixture of sulfuric acid and hydrogen peroxide can be cited.

[0072] In addition, when bubbles are formed in the processing liquid, as described above, the bubbles promote the upward flow of the processing liquid and the stirring of the processing liquid, so that the uniformity of the temperature of the processing liquid on the surface of each substrate and between each substrate is improved. Therefore, it is particularly useful for the processing liquid whose temperature has a great influence on the substrate processing. As such a processing liquid, for example, SC1 (NH 4 OH and H 2 O 2 A mixed aqueous solution of) or other alkaline treatment liquid.

[0073] In Table 1, it is shown that Figure 1 The substrate processing apparatus 10 shown in the figure adjusts the flow rate of nitrogen gas supplied to the first and second ejection parts 41 and 42 of each bubble tube part 37 to form nitrogen bubbles in the processing liquid 12 and measures the degree of variation in etching when etching the substrate 11 .

[0074] In this measurement, the substrates 11 are sequentially placed as the first, second, third, ... fiftieth substrates from the front end side of the liquid supply tube 31, and the etching amounts at 25 measurement points of each of the first, twenty-fifth, and fiftieth substrates 11 are measured to find the deviation within the surface and the deviation within the batch. Fig.10As shown, the measurement point Mp is the center of the substrate 11 and each point on each radial line set at 45° intervals in the circumferential direction, and approximately 1 / 3, 2 / 3, and 3 / 3 of the radius from the center to the substrate 11. The in-plane deviation of the substrate 11 is calculated using the etching amount measured at 25 locations, and is determined by "etching deviation (%) = (maximum etching amount - minimum etching amount) / (2×average etching amount) × 100%)". The in-batch deviation is calculated using the etching amount of 25 locations of each of the three substrates 11, a total of 75 locations, using the same formula as the in-plane deviation. In addition, the diameter of the substrate 11 is 300 mm, the arrangement pitch of the substrate 11 is 5 mm, the processing liquid temperature is 163°C, and the etching time is 600 sec.

[0075] Table 1

[0076]

[0077] As can be seen from Table 1, the in-plane variation and the in-batch variation are reduced by forming nitrogen bubbles in the processing liquid 12. This shows that the in-plane variation and the in-batch variation are improved.

[0078] Description of Reference Numerals

[0079] 10: substrate processing device;

[0080] 11: Substrate;

[0081] 12: Treatment fluid;

[0082] 31: Liquid supply pipe;

[0083] 31a, 31b: liquid spray holes;

[0084] 35: Air supply department;

[0085] 37: bubble tube;

[0086] 37a: fumarole;

[0087] 41: first ejection part;

[0088] 42: second ejection portion;

[0089] 52: Flow adjustment unit.

Claims

1. A substrate processing device, characterized in that: include: A processing tank storing a processing liquid and arranging a plurality of substrates in a standing state at a predetermined interval to be accommodated in the processing tank; The bubble forming section comprises a plurality of bubble tube sections, wherein the plurality of bubble tube sections are divided into a first tubular ejection section extending in the arrangement direction of the plurality of substrates and a second tubular ejection section coaxial with the first ejection section and extending in the arrangement direction within an arrangement range of the plurality of substrates, wherein one end of the divided side of the first ejection section and the second ejection section is closed, and a plurality of ejection holes are formed on the first ejection section and the second ejection section along the arrangement direction, and the plurality of bubble tube sections are spaced apart and arranged in a horizontal direction orthogonal to the arrangement direction below the plurality of substrates accommodated in the processing tank; a liquid supply pipe section having a plurality of liquid supply pipes, wherein a plurality of liquid spray holes for spraying the processing liquid are formed in the plurality of liquid supply pipes in the arrangement direction of the plurality of substrates, wherein the plurality of liquid supply pipes are arranged below the plurality of substrates accommodated in the processing tank and are arranged inside the plurality of bubble pipe sections at intervals in the horizontal direction; as well as A plurality of flow rate adjustment parts are provided corresponding to each of the first ejection parts and each of the second ejection parts, and independently adjust the flow rate of the inert gas with respect to the corresponding first ejection part or the second ejection part.

2. The substrate processing apparatus according to claim 1, wherein: The plurality of gas injection holes of the first gas injection portion and the second gas injection portion inject the inert gas downward and inward.

3. A substrate processing device, characterized in that: include: A processing tank storing a processing liquid and arranging a plurality of substrates in a standing state at a predetermined interval to be accommodated in the processing tank; A liquid supply pipe, which is arranged below the plurality of substrates contained in the processing tank and has a plurality of liquid spray holes formed in the arrangement direction of the plurality of substrates for spraying the processing liquid toward the inner side and the outer side below; as well as a bubble tube portion, wherein the bubble tube portion is arranged below the plurality of substrates contained in the processing tank and has a plurality of gas injection holes formed in the arrangement direction, wherein the plurality of gas injection holes inject an inert gas obliquely downward to form bubbles of the inert gas in the processing liquid, The bubble tube portion is arranged closer to the outside of the liquid supply tube and is used to eject the inert gas downward and inward.

4. The substrate processing apparatus according to claim 3, wherein: The plurality of gas injection holes are arranged at a position lower than the plurality of liquid injection holes.

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