Substrate processing apparatus and substrate processing method

Abstract

The substrate processing apparatus includes a processing tank, a discharge port group, an overflow tank, a circulation flow path, a liquid delivery unit, a first gas supply unit, a second gas supply unit, a first adjustment unit, a second adjustment unit, and a control unit. The processing tank performs etching processing by immersing a substrate having a metal film in a processing liquid. The discharge port group discharges the processing liquid into the processing tank. The liquid delivery unit delivers the processing liquid stored in the overflow tank to the circulation flow path. The first gas supply unit discharges gas into the processing tank. The second gas supply part discharges gas into the overflow groove. The control unit adjusts the concentration of an intermediate contributing to the reaction of the metal film on the surface of the substrate by adjusting at least one of the flow rate of the processing liquid discharged from the discharge port group, the flow rate of the gas discharged from the first gas supply unit, and the flow rate of the gas discharged from the second gas supply unit.

Description

Technical Field

[0001] The invention relates to a substrate processing device and a substrate processing method. Background Art

[0002] Conventionally, there is known a technique for etching a metal film formed on a substrate such as a semiconductor wafer (hereinafter also referred to as a wafer) (see Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2021-180253 Summary of the invention

[0006] Technical problem to be solved by the invention

[0007] The present invention provides a technology capable of improving the controllability of the etching rate of a metal film.

[0008] Technical solutions for solving technical problems

[0009] A substrate processing device according to one embodiment of the present invention includes a processing tank, a discharge port group, an overflow tank, a circulation flow path, a liquid supply unit, a first gas supply unit, a second gas supply unit, a first regulating unit, a second regulating unit, and a control unit. The processing tank immerses a substrate having a metal film in a processing liquid for etching. The discharge port group is arranged at a position lower than the substrate inside the processing tank, and discharges the processing liquid into the processing tank. The overflow tank stores the processing liquid overflowing from the processing tank. The circulation flow path connects the overflow tank with the discharge port group. The liquid supply unit discharges the processing liquid stored in the overflow tank to the circulation flow path. The first gas supply unit is arranged at a position lower than the substrate inside the processing tank, and discharges gas into the processing tank. The second gas supply unit is arranged inside the overflow tank, and discharges gas into the overflow tank. The first regulating unit regulates the flow rate of the gas discharged from the first gas supply unit. The second regulating unit regulates the flow rate of the gas discharged from the second gas supply unit. The control unit performs concentration adjustment processing by controlling the liquid delivery unit, the first adjustment unit and the second adjustment unit. The concentration adjustment processing adjusts at least one of the flow rate of the processing liquid discharged from the discharge port group, the flow rate of the gas discharged from the first gas supply unit and the flow rate of the gas discharged from the second gas supply unit to adjust the concentration of the intermediate contributing to the reaction of the metal film on the surface of the substrate.

[0010] Effects of the Invention

[0011] According to the present invention, the controllability of the etching rate of the metal film can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1This is a diagram showing an example of substrate processing.

[0013] Figure 2 This is a diagram showing an example of substrate processing.

[0014] Figure 3 This is a diagram showing an example of the regeneration of nitric acid consumed by the oxidation reaction of the molybdenum film.

[0015] Figure 4 It is a diagram showing the structure of the substrate processing apparatus according to the first embodiment.

[0016] Figure 5 It is a diagram showing the structure of the processing liquid supply unit according to the first embodiment.

[0017] Figure 6 This is a diagram showing the first gas supply unit and the second gas supply unit according to the first embodiment as viewed from above.

[0018] Figure 7 This is a flowchart showing the flow of processing executed by the substrate processing apparatus according to the embodiment.

[0019] Figure 8 It is an explanatory diagram of the density adjustment process according to the embodiment.

[0020] Fig. 9 It is an explanatory diagram of the density adjustment process according to the first modification of the embodiment.

[0021] Fig.10 It is an explanatory diagram of the density adjustment process according to the second modification of the embodiment.

[0022] Fig.11 It is an explanatory diagram of the density adjustment process according to the third modification of the embodiment.

[0023] Fig.12 It is an explanatory diagram of the density adjustment process according to the fourth modification of the embodiment.

[0024] Fig.13 It is an explanatory diagram of the density adjustment process according to the fifth modification of the embodiment. DETAILED DESCRIPTION

[0025] Hereinafter, with reference to the accompanying drawings, a method for implementing the substrate processing device and the substrate processing method of the present invention (hereinafter, referred to as an "embodiment") is described in detail. In addition, the present invention is not limited to the embodiment. In addition, the various embodiments can be appropriately combined within the scope that does not cause the processing content to be contradictory. In addition, in the following embodiments, the same reference numerals are marked on the same parts, and repeated descriptions are omitted.

[0026] In the embodiments shown below, expressions such as “certain”, “orthogonal”, “perpendicular” or “parallel” are sometimes used, but these expressions do not need to be strictly “certain”, “orthogonal”, “perpendicular” or “parallel”. That is, the above expressions allow for deviations in manufacturing accuracy, setting accuracy, etc.

[0027] In addition, in the drawings referred to below, in order to make the description easy to understand, an orthogonal coordinate system is sometimes indicated in which the X-axis direction, the Y-axis direction, and the Z-axis direction are orthogonal to each other and the positive direction of the Z-axis is set as the vertical upward direction. In addition, the rotation direction with the vertical axis as the rotation center is sometimes referred to as the θ direction.

[0028] <About substrate processing>

[0029] First, refer to Figure 1 and Figure 2 An example of substrate processing according to the present invention will be described. Figure 1 and Figure 2 This is a diagram showing an example of substrate processing.

[0030] like Figure 1 As shown, the substrate processing of the present invention is, for example, etching of a semiconductor wafer (hereinafter referred to as wafer W) having a molybdenum film (an example of a metal film) 101 and a plurality of silicon oxide films 102 formed on a polycrystalline silicon film 100. The plurality of silicon oxide films 102 are formed in multiple layers at intervals on the polycrystalline silicon film 100. The molybdenum film 101 is formed so as to cover each of the silicon oxide films 102.

[0031] Thus, the wafer W of the embodiment has a laminated film in which the molybdenum film 101 and the silicon oxide film 102 are alternately laminated. Before the etching process, the silicon oxide film 102 is covered by the molybdenum film 101. In addition, the wafer W only needs to be a laminated film including at least the molybdenum film 101, and the structure of the laminated film is not particularly limited. Figure 1 For example, the stacked film may include a titanium nitride film, a molybdenum nitride film, or the like between the molybdenum film 101 and the silicon oxide film 102 .

[0032] In addition, a plurality of grooves 103 are formed on the wafer W for allowing a processing liquid (etching liquid) to enter and etch the stacked molybdenum film 101. Figure 1 In FIG. 1 , only one slot 103 is shown.

[0033] The substrate processing of the embodiment is performed by etching the molybdenum film 101 of the wafer W, such as Figure 2 As shown, a portion (end portion) of the silicon oxide film 102 is exposed from the molybdenum film 101. As a treatment liquid for etching the molybdenum film 101, a treatment liquid containing at least nitric acid (HNO3), phosphoric acid (H3PO4) and water (H2O) as components is used. In addition, the treatment liquid may also contain acetic acid (CH3COOH).

[0034] The etching mechanism of the molybdenum film 101 is as follows: First, as shown in the chemical reaction formula (1), nitric acid (HNO3) in the processing solution oxidizes molybdenum to generate molybdic acid (H2MoO4) (oxidation reaction of the molybdenum film 101).

[0035] Mo+2HNO3→H2MoO4+2NO……(1)

[0036] Then, as shown in the chemical reaction formula (2), molybdic acid (H2MoO4) and hydroxide ions (OH - ) reaction. As a result, molybdic acid (H2MoO4) is ionized. In other words, the molybdenum film 101 is dissolved (etched).

[0037] H2MoO4+OH - →HMoO4-+H2O……(2)

[0038] In addition, if Figure 3 As shown, nitric acid (HNO 3 ) consumed by the oxidation reaction of the molybdenum film 101 is regenerated on the surface of the wafer W. Figure 3 1 is a diagram showing an example of the case where nitric acid (HNO3) consumed by the oxidation reaction of the molybdenum film 101 is regenerated. That is, first, the nitric oxide (NO) generated together with molybdic acid (H2MoO4) by the oxidation reaction of the molybdenum film 101 reacts with oxygen (O2) dissolved in the processing liquid, thereby generating nitrogen dioxide (NO2) as an intermediate. Then, the nitrogen dioxide (NO2) as an intermediate reacts with water (H2O) in the processing liquid, thereby regenerating nitric acid (HNO3) on the surface of the wafer W. A series of reactions related to the regeneration of nitric acid (HNO3) are represented by chemical reaction formulas (3) and (4).

[0039] 2NO+O2→2NO2……(3)

[0040] 3NO2+H2O→2HNO3+NO……(4)

[0041] In this way, the etching of the molybdenum film 101 is performed by the oxidation reaction and dissolution of the molybdenum film 101. In addition, the nitric acid (HNO3) consumed by the oxidation reaction of the molybdenum film 101 is regenerated by the reaction of nitrogen dioxide (NO2) as an intermediate with water (H2O) in the processing liquid. Therefore, in the processing liquid, the more the concentration of nitrogen dioxide (NO2) as an intermediate increases, the more the oxidation reaction of the molybdenum film 101 is promoted, and the etching rate of the molybdenum film 101 increases. On the other hand, the more the concentration of nitrogen dioxide (NO2) as an intermediate decreases, the more the oxidation reaction of the molybdenum film 101 is suppressed, and the etching rate of the molybdenum film 101 decreases. Based on these mechanisms, the inventors of the present application found that the etching rate of the molybdenum film 101 changes according to the change in the concentration of nitrogen dioxide (NO2), an intermediate that contributes to the oxidation reaction of the molybdenum film 101, on the surface of the wafer W.

[0042] Therefore, in the substrate processing apparatus of the embodiment, the etching rate of the molybdenum film 101 is increased or decreased by adjusting the concentration of nitrogen dioxide (NO 2 ) as an intermediate in the processing liquid on the surface of the wafer W.

[0043] In addition, as parameters for adjusting the concentration of nitrogen dioxide (NO2) as an intermediate on the surface of the wafer W, there can be cited the concentration of oxygen (O2) dissolved in the processing liquid, the flow rate of the liquid flow in the processing tank, etc. These parameters can be adjusted by adjusting at least one of the flow rate of the processing liquid and the flow rate of the gas supplied to the processing tank.

[0044] Therefore, in the substrate processing apparatus of the embodiment, by adjusting at least one of the flow rate of the processing liquid and the flow rate of the gas supplied into the processing tank, the concentration of nitrogen dioxide (NO2) as an intermediate on the surface of the wafer W is adjusted. Thus, the controllability of the etching rate of the molybdenum film 101 can be improved.

[0045] (Implementation Method)

[0046] <Structure of substrate processing apparatus>

[0047] First, refer to Figure 4 , the structure of the substrate processing apparatus according to the first embodiment is described. Figure 4 It is a diagram showing the structure of the substrate processing apparatus according to the first embodiment.

[0048] Figure 4 The substrate processing apparatus 1 shown immerses a plurality of wafers W held in a vertical posture in a processing liquid, thereby performing etching processing on a plurality of wafers W at once. As described above, in the etching processing, a processing liquid containing at least nitric acid, phosphoric acid and water as components is used, and the molybdenum film 101 is etched by the etching processing.

[0049] like Figure 4As shown, the substrate processing device 1 of the embodiment includes an inner tank 11, an outer tank 12, a substrate holding part 20, a processing liquid supply part 30_1~30_3, a circulation flow path 50, a flow adjustment part 60, a first gas supply part 70, a second gas supply part 80 and a control device 90.

[0050] In addition, below, when the processing liquid supply parts 30_1 to 30_3 are not distinguished, they may be simply described as the processing liquid supply part 30.

[0051] (Inner groove 11 and outer groove 12)

[0052] The inner tank 11 is a box-shaped tank with an upper opening, and stores a processing liquid inside. A batch consisting of a plurality of wafers W is immersed in the inner tank 11. Thus, the inner tank 11 is an example of a processing tank for immersing a substrate having a metal film in the processing liquid to perform an etching process.

[0053] The outer tank 12 is arranged around the upper part of the inner tank 11. The upper part of the outer tank 12 is open, and stores the treatment liquid overflowing from the inner tank 11. Thus, the outer tank 12 corresponds to an example of an overflow tank that stores the treatment liquid overflowing from the treatment tank.

[0054] A new liquid supply unit for supplying a new liquid of the treatment liquid may be connected to the outer tank 12. Also, an independent supply unit for independently supplying nitric acid, phosphoric acid, and water as components of the treatment liquid may be connected to the outer tank 12.

[0055] (Substrate Holding Unit 20)

[0056] The substrate holding part 20 holds a plurality of wafers W in a vertical posture (in a longitudinal state). In addition, the substrate holding part 20 holds a plurality of wafers W in a state of being arranged at a certain interval in the horizontal direction (here, the Y-axis direction). The substrate holding part 20 is connected to a lifting mechanism (not shown) and can move the plurality of wafers W between a processing position inside the inner tank 11 and a standby position above the inner tank 11.

[0057] (Processing Liquid Supplying Unit 30)

[0058] The processing liquid supply unit 30 is disposed in the inner tank 11 at a position below the plurality of wafers W, and discharges the processing liquid into the inner tank 11 .

[0059] Here, refer to Figure 5 , the structure of the processing liquid supply part 30 is demonstrated. Figure 5 It is a diagram showing the structure of the processing liquid supply unit 30 according to the first embodiment.

[0060] like Figure 5As shown, the processing liquid supply part 30_1~30_3 includes nozzles 31_1~31_3. The nozzles 31_1~31_3 are, for example, cylindrical components, extending along the arrangement direction of the plurality of wafers W (Y-axis direction). In the upper part of the nozzles 31_1~31_3, a plurality of discharge ports 32_1~32_3 are provided along the extension direction of the nozzles 31_1~31_3. The discharge ports 32_1~32_3 are, for example, circular, and the opening diameter is, for example, about 0.5mm~1.0mm in diameter. The discharge ports 32_1~32_3 discharge the processing liquid, for example, toward the vertical upper side (Z-axis positive direction).

[0061] The nozzles 31_1 to 31_3 are connected to supply paths 52_1 to 52_3 described later, and discharge the processing liquid supplied from the supply paths 52_1 to 52_3 from the plurality of discharge ports 32_1 to 32_3.

[0062] (Circulation Flow Path 50)

[0063] return Figure 4 The circulation flow path 50 connects the outer tank 12 and the treatment liquid supply parts 30_1 to 30_3 . Specifically, the circulation flow path 50 includes a discharge path 51 , a plurality of supply paths 52_1 to 52_3 , and a bypass path 53 . The discharge path 51 is connected to the bottom of the outer tank 12 .

[0064] A pump (an example of a liquid delivery unit) 55, a heater 56, and a filter 57 are provided in the discharge path 51. The pump 55 delivers the processing liquid in the outer tank 12 to the circulation path 50 (discharge path 51). The heater 56 heats the processing liquid flowing in the discharge path 51 to a temperature suitable for etching treatment. The filter 57 removes impurities from the processing liquid flowing in the discharge path 51. In addition, a filter bypass path 58 that bypasses the filter 57 is provided in the discharge path 51, and an on-off valve 59 that switches the opening and closing state of the filter bypass path 58 is provided in the filter bypass path 58. The on-off valve 59 is electrically connected to the control device 90 and is controlled by the control device 90. The on-off valve 59 can adjust the flow rate of the processing liquid flowing in the circulation path 50 (discharge path 51) by switching the opening and closing state of the filter bypass path 58.

[0065] The pump 55 and the heater 56 are electrically connected to the control device 90 and controlled by the control device 90. The pump 55 can adjust the flow rate of the processing liquid supplied to the processing liquid supply unit 30 according to the control of the control device 90. That is, the pump 55 adjusts the flow rate of the processing liquid supplied from the supply paths 52_1 to 52_3 to the processing liquid supply units 30_1 to 30_3 by changing the liquid delivery pressure of the pump 55. Thus, the pump 55 adjusts the flow rate of the processing liquid discharged from the plurality of discharge ports 32_1 to 32_3 provided in the processing liquid supply units 30_1 to 30_3.

[0066] A plurality of supply paths 52_1 to 52_3 branch from the discharge path 51. The supply path 52_1 is connected to the processing liquid supply unit 30_1, the supply path 52_2 is connected to the processing liquid supply unit 30_2, and the supply path 52_3 is connected to the processing liquid supply unit 30_3.

[0067] The bypass path 53 branches off from the discharge path 51 and is connected to the outer tank 12 .

[0068] (Flow rate adjustment unit 60)

[0069] The flow rate regulator 60 is, for example, a liquid flow controller (LFC) and regulates the flow rate of the processing liquid supplied to the processing liquid supply units 30_1 to 30_3. That is, the flow rate regulator 60 regulates the flow rate of the processing liquid discharged from the plurality of discharge ports 32_1 to 32_3 provided in the processing liquid supply units 30_1 to 30_3.

[0070] Specifically, the flow rate adjustment unit 60 is provided in the bypass path 53 , and adjusts the flow rate of the processing liquid supplied from the supply paths 52_1 to 52_3 to the processing liquid supply units 30_1 to 30_3 by adjusting the flow rate of the processing liquid flowing in the bypass path 53 .

[0071] The flow rate adjustment unit 60 is electrically connected to the control device 90 and is controlled by the control device 90 .

[0072] (First Gas Supply Unit 70 and Second Gas Supply Unit 80)

[0073] The first gas supply unit 70 is arranged in the inner tank 11 at a position lower than the plurality of wafers W and the plurality of processing liquid supply units 30_1 to 30_3. The first gas supply unit 70 includes a plurality of nozzles 71, and gas is ejected from the nozzles 71 into the inner tank 11. Thus, the first gas supply unit 70 can adjust the flow rate of the processing liquid in the inner tank 11 and the concentration of oxygen dissolved in the processing liquid.

[0074] The second gas supply unit 80 is disposed inside the outer tank 12. The second gas supply unit 80 includes a plurality of nozzles 81, and discharges gas from the nozzles 81 into the outer tank 12. Thus, the second gas supply unit 80 can adjust the concentration of oxygen dissolved in the processing liquid.

[0075] Here, refer to Figure 6 , the structures of the first gas supply unit 70 and the second gas supply unit 80 are described. Figure 6 This is a diagram showing the first gas supply unit 70 and the second gas supply unit 80 of the first embodiment as viewed from above.

[0076] like Figure 6As shown, the plurality of nozzles 71 included in the first gas supply unit 70 are, for example, cylindrical components extending along the arrangement direction (Y-axis direction) of the plurality of wafers W. A plurality of discharge ports 72 are provided at the upper portion of the nozzle 71 along the extending direction of the nozzle 71. In addition, the plurality of discharge ports 72 do not necessarily need to be provided at the upper portion of the nozzle 71. For example, the plurality of discharge ports 72 may also be provided at the lower portion of the nozzle 71 and discharge gas diagonally downward.

[0077] The plurality of nozzles 71 are connected to a gas supply source 74a via a flow rate adjustment unit 73a. The gas supply source 74a supplies gas to the plurality of nozzles 71. Here, nitrogen (N2) gas is supplied from the gas supply source 74a to the plurality of nozzles 71, but the gas supplied from the gas supply source 74a to the plurality of nozzles 71 may be, for example, an inert gas other than nitrogen gas such as a rare gas. As the rare gas, for example, argon (Ar) gas or neon (Ne) gas may be used.

[0078] The flow rate adjustment unit 73 a is constituted by, for example, an LFC, an on-off valve, etc., and adjusts the flow rate of the nitrogen gas supplied from the gas supply source 74 a to the plurality of nozzles 71 .

[0079] In addition, the plurality of nozzles 71 are connected to a gas supply source 74b via a flow rate adjustment unit 73b. The gas supply source 74b supplies gas to the plurality of nozzles 71. Here, oxygen (O2) gas is supplied from the gas supply source 74b to the plurality of nozzles 71, but the gas supplied from the gas supply source 74b to the plurality of nozzles 71 may be an oxygen-containing gas other than oxygen, such as air or ozone (O3) gas.

[0080] The flow rate adjustment unit 73 b is composed of, for example, an LFC, an on-off valve, etc., and adjusts the flow rate of oxygen supplied from the gas supply source 74 b to the plurality of nozzles 71 .

[0081] In this way, the first gas supply unit 70 can selectively discharge nitrogen gas as an inert gas or oxygen gas as an oxygen-containing gas as a gas. The flow rate adjustment units 73a and 73b can adjust the flow rate of nitrogen gas or oxygen gas discharged from the first gas supply unit 70. The flow rate adjustment units 73a and 73b are equivalent to an example of a first adjustment unit that adjusts the flow rate of the gas discharged from the first gas supply unit 70.

[0082] In addition, the plurality of nozzles 81 included in the second gas supply unit 80 is, for example, a cylindrical member extending along the arrangement direction (Y-axis direction) of the plurality of wafers W. In the upper portion of the nozzle 81, a plurality of discharge ports 82 are provided along the extending direction of the nozzle 81. In addition, the plurality of discharge ports 82 do not necessarily need to be provided in the upper portion of the nozzle 81. For example, the plurality of discharge ports 82 may also be provided in the lower portion of the nozzle 81 and may discharge gas obliquely downward.

[0083] The plurality of nozzles 81 are connected to a gas supply source 84a via a flow rate adjustment unit 83a. The gas supply source 84a supplies gas to the plurality of nozzles 81. Here, nitrogen gas is supplied from the gas supply source 84a to the plurality of nozzles 81, but the gas supplied from the gas supply source 84a to the plurality of nozzles 81 may be, for example, an inert gas other than nitrogen gas such as a rare gas. As the rare gas, for example, argon gas or neon gas may be used.

[0084] The flow rate adjustment unit 83 a is composed of, for example, an LFC, an on-off valve, etc., and adjusts the flow rate of the nitrogen gas supplied from the gas supply source 84 a to the plurality of nozzles 81 .

[0085] In addition, the plurality of nozzles 81 are connected to a gas supply source 84b via a flow rate adjustment unit 83b. The gas supply source 84b supplies gas to the plurality of nozzles 81. Here, oxygen is supplied from the gas supply source 84b to the plurality of nozzles 81, but the gas supplied from the gas supply source 84b to the plurality of nozzles 81 may be an oxygen-containing gas other than oxygen, such as air or ozone gas.

[0086] The flow rate adjustment unit 83 b is composed of, for example, an LFC, an on-off valve, etc., and adjusts the flow rate of oxygen gas supplied to the plurality of nozzles 81 of the gas supply source 84 b.

[0087] In this way, the second gas supply unit 80 can selectively discharge nitrogen gas as an inert gas or oxygen gas as an oxygen-containing gas as a gas. The flow rate adjustment units 83a and 83b can adjust the flow rate of nitrogen gas or oxygen gas discharged from the second gas supply unit 80. The flow rate adjustment units 83a and 83b are equivalent to an example of a second adjustment unit that adjusts the flow rate of the gas discharged from the second gas supply unit 80.

[0088] (Control device 90)

[0089] return Figure 4 The control device 90 is, for example, a computer, and includes a control unit 91 and a storage unit 92. The storage unit 92 is implemented by, for example, a semiconductor storage element such as a RAM, a flash memory, or a storage device such as a hard disk or an optical disk, and stores a program for controlling various processes executed in the substrate processing device 1. The control unit 91 includes a microcomputer having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an input / output port, and various circuits, and controls the operation of the substrate processing device 1 by reading and executing the program stored in the storage unit 92.

[0090] In addition, the program may be a program recorded on a computer-readable storage medium, and installed from the storage medium to the storage unit 92 of the control device 90. Examples of computer-readable storage media include a hard disk (HD), a floppy disk (FD), a compact disk (CD), a magneto-optical disk (MO), and a memory card.

[0091] (Specific Operation of the Substrate Processing Device 1)

[0092] Next, refer to Figure 7 , the specific operation of the substrate processing device 1 according to the embodiment is described. Figure 7 1 is a flowchart showing the flow of processing performed by the substrate processing apparatus 1 according to the embodiment. Figure 7 Each of the processes shown is executed under the control of the control unit 91 .

[0093] like Figure 7 As shown, in the substrate processing apparatus 1, first, a concentration adjustment process (step S101) is started to adjust the concentration of nitrogen dioxide (NO2), an intermediate product contributing to the oxidation reaction of the molybdenum film 101, on the surface of the wafer W in the processing liquid stored in the inner tank 11. The content of this concentration adjustment process will be described later.

[0094] Next, in the substrate processing apparatus 1, a feeding process (step S102) is performed to immerse the plurality of wafers W in the inner tank 11. In the feeding process, the control unit 91 controls a lifting mechanism (not shown) included in the substrate holding unit 20 to lower the substrate holding unit 20, thereby immersing the plurality of wafers W in the processing liquid stored in the inner tank 11.

[0095] Furthermore, before the start of the feeding process, the control unit 91 controls the pump 55 to start supplying the treatment liquid from the outer tank 12 to the treatment liquid supply units 30_1 to 30_3. Furthermore, before the start of the feeding process, the control unit 91 controls the flow rate adjustment unit 60 to close the bypass path 53. Furthermore, before the start of the feeding process, the control unit 91 controls the on-off valve 59 to close the filter bypass path 58. That is, before the start of the feeding process, all the treatment liquid flowing in the circulation flow path 50 is supplied to the treatment liquid supply units 30_1 to 30_3.

[0096] Next, an etching process is performed in the substrate processing apparatus 1 (step S103). In the etching process, the plurality of wafers W are immersed in the processing liquid in the inner tank 11 for a predetermined time. Thus, the molybdenum film 101 is etched.

[0097] Then, in the substrate processing apparatus 1 , a carry-out process is performed (step S104 ). In the carry-out process, the control unit 91 controls a lifting mechanism (not shown) included in the substrate holding unit 20 to raise the substrate holding unit 20 , thereby lifting the plurality of wafers W from the inner tank 11 .

[0098] Thereafter, the substrate processing apparatus 1 ends the concentration adjustment process (step S105 ), and ends a series of substrate processes in the substrate processing apparatus 1 .

[0099] Next, refer to Figure 8 , the contents of the concentration adjustment processing are explained. Figure 8 It is an explanatory diagram of the density adjustment process according to the embodiment.

[0100] exist Figure 8 In the figure, the time changes of "circulation flow", "discharge flow (processing liquid)", "inner tank discharge flow (gas)", "outer tank discharge flow (gas)", "liquid delivery pressure", "inner tank valve opening" and "outer tank valve opening" in the substrate processing performed by the substrate processing device 1 are shown. The "circulation flow" is the flow rate of the processing liquid flowing in the circulation flow path 50, and the "discharge flow (processing liquid)" is the flow rate of the processing liquid discharged from the processing liquid supply parts 30_1 to 30_3. In addition, the "inner tank discharge flow (gas)" is the flow rate of the gas discharged from the first gas supply part 70 to the inside of the inner tank 11, and the "outer tank discharge flow (gas)" is the flow rate of the gas discharged from the second gas supply part 80 to the inside of the outer tank 12. In addition, the "liquid delivery pressure" is the liquid delivery pressure of the pump 55, that is, the pressure when the pump 55 delivers the processing liquid to the circulation flow path 50. The “inner tank valve opening” is the opening of the on-off valve (solenoid valve) of the flow regulating section 73a or 73b, and the “outer tank valve opening” is the opening of the on-off valve (solenoid valve) of the flow regulating section 83a or 83b.

[0101] In addition, Figure 8 In the embodiment, the first gas supply unit 70 and the second gas supply unit 80 discharge nitrogen (N 2 ) gas as an inert gas as the gas.

[0102] The control unit 91 adjusts the liquid delivery pressure of the pump 55, the inner tank valve opening of the flow rate adjustment unit 73a, and the outer tank valve opening of the flow rate adjustment unit 83a, and adjusts the discharge flow rate of the processing liquid supply unit 30, the inner tank discharge flow rate of the first gas supply unit 70, and the outer tank discharge flow rate of the second gas supply unit 80. Thus, the control unit 91 adjusts the concentration of nitrogen dioxide (NO2) contributing to the reaction of the molybdenum film 101 on the surface of the wafer W.

[0103] For example, in Figure 8In the example shown, the control unit 91 reduces the concentration of nitrogen dioxide on the surface of the wafer W. That is, the control unit 91 increases the discharge flow rate of the processing liquid supply parts 30_1 to 30_3 from the flow rate F4 to the flow rate F5 (> F4) by increasing the liquid delivery pressure of the pump 55 from the pressure P0 to the pressure P1 (> P0) at the time t1 before the time t2 when the processing is started. The pressure P0 and the flow rate F4 can be, for example, the liquid delivery pressure of the pump 55 and the discharge flow rate of the processing liquid supply parts 30_1 to 30_3 used in the previous substrate processing. In addition, the control unit 91 can also control the on-off valve 59 to switch the filter bypass path 58 from the closed state to the open state, thereby further increasing the discharge flow rate of the processing liquid supply parts 30_1 to 30_3. The control unit 91 can increase the flow rate of the processing liquid in the inner tank 11 by increasing the discharge flow rate of the processing liquid supply parts 30_1 to 30_3.

[0104] In addition, the control unit 91 increases the inner tank valve opening of the flow regulator 73a from 0 to the opening V1 at time t1, thereby increasing the inner tank discharge flow rate of the first gas supply unit 70 from 0 to the flow rate F7. The control unit 91 generates bubbling of nitrogen gas in the inner tank 11 by increasing the inner tank discharge flow rate of the first gas supply unit 70, thereby reducing the concentration of oxygen (O2) dissolved in the processing liquid in the inner tank 11.

[0105] In addition, at time t1, the control unit 91 increases the outer tank valve opening of the flow rate regulator 83a from 0 to the opening V2, thereby increasing the outer tank discharge flow rate of the second gas supply unit 80 from 0 to the flow rate F8. The control unit 91 generates nitrogen bubbles in the outer tank 12 by increasing the outer tank discharge flow rate of the second gas supply unit 80, thereby reducing the concentration of oxygen (O2) dissolved in the processing liquid in the inner tank 11.

[0106] In this way, in the substrate processing device 1, the nitrogen dioxide present on the surface of the wafer W is diffused by increasing the flow rate of the processing liquid in the inner tank 11. In addition, in the substrate processing device 1, the generation of nitrogen dioxide is suppressed by reducing the concentration of oxygen (O2) dissolved in the processing liquid in the inner tank 11 (refer to the above-mentioned chemical reaction formula (3)). Thus, the control unit 91 can reduce the concentration of nitrogen dioxide, an intermediate that contributes to the oxidation reaction of the molybdenum film 101, on the surface of the wafer W before the etching process starts. Thus, the oxidation reaction of the molybdenum film 101 can be suppressed, and thus the etching rate of the molybdenum film 101 can be reduced. That is, according to the substrate processing device 1 of the embodiment, the controllability of the etching rate of the molybdenum film 101 can be improved.

[0107] Next, the control unit 91 performs the feeding process during the period from time t2 to time t3. During the feeding process, the control unit 91 controls the lifting mechanism (not shown) included in the substrate holding unit 20 to lower the substrate holding unit 20, thereby immersing the plurality of wafers W in the processing liquid stored in the inner tank 11. During the period from time t2 to time t3, the control unit 91 reduces the inner tank valve opening of the flow rate adjustment unit 73a from the opening V1 to 0, thereby reducing the inner tank discharge flow rate of the first gas supply unit 70 from the flow rate F7 to 0. In addition, during the period from time t2 to time t3, the control unit 91 reduces the outer tank valve opening of the flow rate adjustment unit 83a from the opening V2 to 0, thereby reducing the outer tank discharge flow rate of the second gas supply unit 80 from the flow rate F8 to 0.

[0108] Thus, in the substrate processing apparatus 1, during the period (from time t2 to time t3) when the plurality of wafers W are immersed in the processing liquid, the discharge of nitrogen gas from the first gas supply unit 70 and the second gas supply unit 80 is stopped. Thus, the flow rate of the processing liquid in the inner tank 11 can be temporarily reduced, and as a result, the wafers W can be prevented from falling off the substrate holding unit 20.

[0109] Next, at time t3 when the etching process is started, the control unit 91 increases the inner tank discharge flow rate of the first gas supply unit 70 from 0 to flow rate F7 again by increasing the inner tank valve opening of the flow regulator 73a from 0 to opening V1 again. In addition, at time t3, the control unit 91 increases the outer tank discharge flow rate of the second gas supply unit 80 from 0 to flow rate F8 again by increasing the outer tank valve opening of the flow regulator 83a from 0 to opening V2 again. Thus, the control unit 91 can reduce the concentration of nitrogen dioxide, an intermediate that contributes to the oxidation reaction of the molybdenum film 101, on the surface of the wafer W during the etching process. Thus, the oxidation reaction of the molybdenum film 101 can be suppressed, and thus the etching rate of the molybdenum film 101 can be reduced. That is, according to the substrate processing device 1 of the embodiment, the controllability of the etching rate of the molybdenum film 101 can be improved.

[0110] Next, the control unit 91 performs the etching process during a period from time t3 to time t4.

[0111] Next, the control unit 91 performs the delivery process during the period from time t4 to time t5. In the delivery process, the control unit 91 controls the lifting mechanism (not shown) included in the substrate holding unit 20 to raise the substrate holding unit 20, thereby lifting the plurality of wafers W from the processing liquid in the inner tank 11. During the period from time t4 to time t5, the control unit 91 reduces the inner tank valve opening of the flow rate adjustment unit 73a from the opening V1 to 0, thereby reducing the inner tank discharge flow rate of the first gas supply unit 70 from the flow rate F7 to 0. During the period from time t2 to time t3, the control unit 91 reduces the outer tank valve opening of the flow rate adjustment unit 83a from the opening V2 to 0, thereby reducing the outer tank discharge flow rate of the second gas supply unit 80 from the flow rate F8 to 0.

[0112] Thus, in the substrate processing apparatus 1, during the period of lifting the plurality of wafers W from the processing liquid (the period from time t4 to time t5), the discharge of nitrogen gas from the first gas supply unit 70 and the second gas supply unit 80 is stopped. Thus, the flow rate of the processing liquid in the inner tank 11 can be temporarily reduced, and as a result, the wafers W can be prevented from falling off from the substrate holding unit 20.

[0113] Next, when the delivery process is finished at time t5, the control unit 91 reduces the delivery pressure of the pump 55 from pressure P1 to pressure P0 (<P1), thereby reducing the discharge flow rate of the treatment liquid supply parts 30_1 to 30_3 from flow rate F5 to flow rate F4 (<F5). In addition, the control unit 91 may control the on-off valve 59 to switch the filter bypass path 58 from an open state to a closed state, thereby further reducing the discharge flow rate of the treatment liquid supply parts 30_1 to 30_3. By reducing the discharge flow rate of the treatment liquid supply parts 30_1 to 30_3, the control unit 91 can restore the flow rate of the treatment liquid in the inner tank 11 to the initial flow rate.

[0114] exist Figure 8 In the example shown, the control unit 91 adjusts the concentration of nitrogen dioxide on the surface of the wafer W that contributes to the reaction of the molybdenum film 101 by adjusting the discharge flow rate of the processing liquid supply unit 30, the discharge flow rate of the inner tank of the first gas supply unit 70, and the discharge flow rate of the outer tank of the second gas supply unit 80. Without being limited to this, the control unit 91 may also adjust the concentration of nitrogen dioxide on the surface of the wafer W by adjusting at least one of the discharge flow rate of the processing liquid supply unit 30, the discharge flow rate of the inner tank of the first gas supply unit 70, and the discharge flow rate of the outer tank of the second gas supply unit 80. In this case, the control unit 91 may also reduce the concentration of nitrogen dioxide on the surface of the wafer W by performing at least one of a process of increasing the discharge flow rate of the processing liquid supply unit 30, a process of increasing the discharge flow rate of the inner tank of the first gas supply unit 70, and a process of increasing the discharge flow rate of the outer tank of the second gas supply unit 80.

[0115] Next, refer to Figures 9 to 13 ,right Figure 8 A modified example of the density adjustment process shown will be described. Fig. 9 It is an explanatory diagram of the density adjustment process according to the first modification of the embodiment.

[0116] Concentration adjustment process of modification example 1 Figure 8 The difference of the concentration adjustment process shown in FIG. 1 is that the outer tank valve opening of the flow rate adjustment unit 83a is maintained at 0, and the outer tank discharge flow rate of the second gas supply unit 80 is maintained at 0, so that the bubbling of nitrogen gas in the outer tank 12 is not generated. That is, the control unit 91 only increases the inner tank discharge flow rate of the first gas supply unit 70, and only generates nitrogen bubbling in the inner tank 11. Figure 8 Compared with the concentration adjustment treatment shown in FIG. 1 , the decrease in the concentration of oxygen (O2) dissolved in the processing liquid in the inner tank 11 can be reduced, and thus the decrease in the concentration of nitrogen dioxide on the surface of the wafer W can be reduced. Therefore, according to Modification 1, the decrease in the etching rate of the molybdenum film 101 can be reduced compared with the embodiment.

[0117] Fig.10 It is an explanatory diagram of the density adjustment process according to the second modification of the embodiment.

[0118] Concentration adjustment process of modification example 2 Figure 8 The difference of the concentration adjustment process shown in FIG. 1 is that the inner tank valve opening of the flow rate adjustment unit 73a is maintained at 0, and the inner tank discharge flow rate of the first gas supply unit 70 is maintained at 0, so that the bubbling of nitrogen gas in the inner tank 11 is not generated. That is, the control unit 91 only increases the outer tank discharge flow rate of the second gas supply unit 80, and only generates nitrogen bubbling in the outer tank 12. Figure 8 Compared with the concentration adjustment process shown in the figure, the decrease range of the concentration of oxygen (O2) dissolved in the processing liquid in the inner tank 11 can be reduced and the flow rate of the processing liquid can be reduced, so the decrease range of the concentration of nitrogen dioxide on the surface of the wafer W can be reduced. Therefore, according to Modification 2, the decrease range of the etching rate of the molybdenum film 101 can be reduced compared with the embodiment.

[0119] Fig.11 FIG. 2 is an explanatory diagram of the concentration adjustment process according to the third modification of the embodiment. Fig.11 In the embodiment, the first gas supply unit 70 and the second gas supply unit 80 discharge oxygen (O 2 ) gas as an oxygen-containing gas as gas.

[0120] The control unit 91 adjusts the liquid delivery pressure of the pump 55, the inner tank valve opening of the flow rate adjustment unit 73b, and the outer tank valve opening of the flow rate adjustment unit 83b to adjust the discharge flow rate of the processing liquid supply unit 30, the inner tank discharge flow rate of the first gas supply unit 70, and the outer tank discharge flow rate of the second gas supply unit 80. Thus, the control unit 91 adjusts the concentration of nitrogen dioxide on the surface of the wafer W that contributes to the reaction of the molybdenum film 101.

[0121] For example, in Fig.11 In the example shown, the control unit 91 increases the concentration of nitrogen dioxide on the surface of the wafer W. That is, the control unit 91 reduces the liquid delivery pressure of the pump 55 from the pressure P0 to the pressure P2 (<P0) at time t1 before the time t2 when the processing is started, thereby reducing the discharge flow rate of the processing liquid supply parts 30_1 to 30_3 from the flow rate F4 to the flow rate F6 (<F4). The pressure P0 and the flow rate F4 may be, for example, the liquid delivery pressure of the pump 55 and the discharge flow rate of the processing liquid supply parts 30_1 to 30_3 used in the previous substrate processing. In addition, the control unit 91 may also increase the flow rate of the processing liquid flowing in the bypass path 53 by controlling the flow regulator 60 to further reduce the discharge flow rate of the processing liquid supply parts 30_1 to 30_3. By reducing the discharge flow rate of the processing liquid supply parts 30_1 to 30_3, the control unit 91 can reduce the flow rate of the processing liquid in the inner tank 11.

[0122] In addition, at time t1, the control unit 91 increases the inner tank valve opening of the flow rate regulator 73b from 0 to opening V1, thereby increasing the inner tank discharge flow rate of the first gas supply unit 70 from 0 to flow rate F7. The control unit 91 generates bubbling of oxygen in the inner tank 11 by increasing the inner tank discharge flow rate of the first gas supply unit 70, thereby increasing the concentration of oxygen (O2) dissolved in the processing liquid in the inner tank 11.

[0123] In addition, at time t1, the control unit 91 increases the outer tank valve opening of the flow rate regulator 83b from 0 to the opening V2, thereby increasing the outer tank discharge flow rate of the second gas supply unit 80 from 0 to the flow rate F8. The control unit 91 generates bubbling of oxygen in the outer tank 12 by increasing the outer tank discharge flow rate of the second gas supply unit 80, and can increase the concentration of oxygen (O2) dissolved in the processing liquid in the inner tank 11.

[0124] Thus, in the substrate processing apparatus 1 of variation 3, nitrogen dioxide is retained on the surface of the wafer W by reducing the flow rate of the processing liquid in the inner tank 11. In addition, in the substrate processing apparatus 1, the generation of nitrogen dioxide is promoted by increasing the concentration of oxygen (O2) dissolved in the processing liquid in the inner tank 11 (refer to the above chemical reaction formula (3)). Thus, the control unit 91 can increase the concentration of nitrogen dioxide, an intermediate that contributes to the oxidation reaction of the molybdenum film 101, on the surface of the wafer W before the etching process begins. Thus, the oxidation reaction of the molybdenum film 101 is promoted, and thus the etching rate of the molybdenum film 101 can be increased. That is, according to the substrate processing apparatus 1 of variation 3, the controllability of the etching rate of the molybdenum film 101 can be improved.

[0125] Next, the control unit 91 performs the feeding process during the period from time t2 to time t3. During the feeding process, the control unit 91 controls the lifting mechanism (not shown) included in the substrate holding unit 20 to lower the substrate holding unit 20, thereby immersing the plurality of wafers W in the processing liquid stored in the inner tank 11. During the period after time t2, the control unit 91 reduces the inner tank valve opening of the flow regulator 73b from the opening V1 to 0, thereby reducing the inner tank discharge flow rate of the first gas supply unit 70 from the flow rate F7 to 0. In addition, during the period from time t2 to time t3, the control unit 91 reduces the outer tank valve opening of the flow regulator 83b from the opening V2 to 0, thereby reducing the outer tank discharge flow rate of the second gas supply unit 80 from the flow rate F8 to 0.

[0126] Thus, in the substrate processing apparatus 1, during the period (from time t2 to time t3) when the plurality of wafers W are immersed in the processing liquid, the discharge of oxygen from the first gas supply unit 70 and the second gas supply unit 80 is stopped. Thus, the flow rate of the processing liquid in the inner tank 11 can be reduced, and as a result, the wafers W can be prevented from falling off from the substrate holding unit 20.

[0127] Next, at the time t3 when the etching process is started, the control unit 91 increases the outer tank valve opening of the flow rate adjustment unit 83b from 0 to the opening V2 again, thereby increasing the outer tank discharge flow rate of the second gas supply unit 80 from 0 to the flow rate F8 again. Thus, the control unit 91 can increase the concentration of nitrogen dioxide, an intermediate that contributes to the oxidation reaction of the molybdenum film 101, on the surface of the wafer W during the etching process. Thus, the oxidation reaction of the molybdenum film 101 is promoted, and thus the etching rate of the molybdenum film 101 can be increased. That is, according to the substrate processing device 1 of the modification example 3, the controllability of the etching rate of the molybdenum film 101 can be improved.

[0128] In addition, the control unit 91 also maintains the inner tank discharge flow rate of the first gas supply unit 70 at 0 after the time t3 when the etching process starts. As a result, during the etching process, the flow rate of the processing liquid in the inner tank 11 can be reduced, and nitrogen dioxide can be retained on the surface of the wafer W. As a result, the oxidation reaction of the molybdenum film 101 can be further promoted, so that the etching rate of the molybdenum film 101 can be further increased.

[0129] Next, the control unit 91 performs the etching process during a period from time t3 to time t4.

[0130] Next, the control unit 91 performs the delivery process during the period from time t4 to time t5. During the delivery process, the control unit 91 controls the lifting mechanism (not shown) included in the substrate holding unit 20 to raise the substrate holding unit 20, thereby lifting the plurality of wafers W from the processing liquid in the inner tank 11. During the period from time t4 to time t5, the control unit 91 reduces the outer tank valve opening of the flow rate regulator 83b from the opening V2 to 0, thereby reducing the outer tank discharge flow rate of the second gas supply unit 80 from the flow rate F8 to 0.

[0131] Thus, in the substrate processing apparatus 1, during the period (from time t4 to time t5) when the plurality of wafers W are lifted from the processing liquid, the discharge of oxygen from the first gas supply unit 70 and the second gas supply unit 80 is stopped. Thus, the flow rate of the processing liquid in the inner tank 11 can be reduced, and as a result, the wafers W can be prevented from falling off from the substrate holding unit 20.

[0132] Next, after the delivery process is completed at time t5, the control unit 91 increases the delivery pressure of the pump 55 from the pressure P2 to the pressure P0 (> P2), thereby increasing the discharge flow rate of the treatment liquid supply parts 30_1 to 30_3 from the flow rate F6 to the flow rate F4 (> F6). In addition, the control unit 91 can also control the flow adjustment unit 60 to close the bypass path 53. The control unit 91 can restore the flow rate of the treatment liquid in the inner tank 11 to the initial flow rate by increasing the discharge flow rate of the treatment liquid supply parts 30_1 to 30_3.

[0133] exist Fig.11In the example shown, the control unit 91 adjusts the concentration of nitrogen dioxide on the surface of the wafer W that contributes to the reaction of the molybdenum film 101 by adjusting the discharge flow rate of the processing liquid supply unit 30, the discharge flow rate of the inner tank of the first gas supply unit 70, and the discharge flow rate of the outer tank of the second gas supply unit 80. Without being limited to this, the control unit 91 may also adjust the concentration of nitrogen dioxide on the surface of the wafer W by adjusting at least one of the discharge flow rate of the processing liquid supply unit 30, the discharge flow rate of the inner tank of the first gas supply unit 70, and the discharge flow rate of the outer tank of the second gas supply unit 80. In this case, the control unit 91 may also increase the concentration of nitrogen dioxide on the surface of the wafer W by performing at least one of a process of reducing the discharge flow rate of the processing liquid supply unit 30, a process of increasing the discharge flow rate of the inner tank of the first gas supply unit 70, and a process of increasing the discharge flow rate of the outer tank of the second gas supply unit 80.

[0134] Fig.12 It is an explanatory diagram of the density adjustment process according to the fourth modification of the embodiment.

[0135] like Fig.12 As shown, at time t3 when the etching process is started, the control unit 91 increases the inner tank valve opening of the flow rate adjustment unit 73b from 0 to the opening V1 again, thereby increasing the inner tank discharge flow rate of the first gas supply unit 70 from 0 to the flow rate F7 again. As a result, the control unit 91 can increase the concentration of nitrogen dioxide, an intermediate that contributes to the oxidation reaction of the molybdenum film 101, on the surface of the wafer W during the etching process. As a result, the oxidation reaction of the molybdenum film 101 is promoted, and thus the etching rate of the molybdenum film 101 can be increased. That is, according to the substrate processing device 1 of Modification 4, the controllability of the etching rate of the molybdenum film 101 can be improved.

[0136] Fig.13 It is an explanatory diagram of the density adjustment process according to the fifth modification of the embodiment.

[0137] exist Fig.13 In the example shown, the control unit 91 reduces the concentration of nitrogen dioxide on the surface of the wafer W before starting the process of carrying the wafer W in and out, and increases the concentration of nitrogen dioxide on the surface of the wafer W during the etching process.

[0138] Specifically, the control unit 91 increases the discharge flow rate of the processing liquid supply parts 30_1 to 30_3 from flow rate F4 to flow rate F5 (> F4) by increasing the liquid delivery pressure of the pump 55 from pressure P0 to pressure P1 (> P0) at time t1 before the time t2 at which the processing is started. The pressure P0 and the flow rate F4 can be, for example, the liquid delivery pressure of the pump 55 and the discharge flow rate of the processing liquid supply parts 30_1 to 30_3 used in the previous substrate processing, respectively. In addition, the control unit 91 can also further increase the discharge flow rate of the processing liquid supply parts 30_1 to 30_3 by controlling the on-off valve 59 to switch the filter bypass path 58 from a closed state to an open state. The control unit 91 can increase the flow rate of the processing liquid flow in the inner tank 11 by increasing the discharge flow rate of the processing liquid supply parts 30_1 to 30_3.

[0139] In addition, at time t1, the control unit 91 increases the inner tank valve opening of the flow rate regulator 73a from 0 to opening V1, thereby increasing the inner tank discharge flow rate of the first gas supply unit 70 from 0 to flow rate F7. The control unit 91 generates bubbling of nitrogen gas in the inner tank 11 by increasing the inner tank discharge flow rate of the first gas supply unit 70, thereby reducing the concentration of oxygen (O2) dissolved in the processing liquid in the inner tank 11.

[0140] In addition, at time t1, the control unit 91 increases the outer tank valve opening of the flow rate regulator 83a from 0 to the opening V2, thereby increasing the outer tank discharge flow rate of the second gas supply unit 80 from 0 to the flow rate F8. The control unit 91 generates nitrogen bubbles in the outer tank 12 by increasing the outer tank discharge flow rate of the second gas supply unit 80, thereby reducing the concentration of oxygen (O2) dissolved in the processing liquid in the inner tank 11.

[0141] By performing this process, the control unit 91 can reduce the concentration of nitrogen dioxide on the surface of the wafer W before starting the feeding process. As a result, the etching rate of the molybdenum film 101 is reduced before starting the feeding process. During the feeding process, since the lower end of the wafer W is first immersed in the processing liquid stored in the inner tank 11, there is a tendency that the etching amount at the lower end of the wafer W is greater than the etching amount at the upper end of the wafer W. In response to this, the control unit 91 reduces the etching rate of the molybdenum film 101 before starting the feeding process to suppress the increase in the etching amount at the lower end of the wafer W, thereby reducing the difference in the etching amount at the upper and lower ends of the wafer W.

[0142] Next, the control unit 91 performs the feeding process during the period from time t2 to time t3. During the period from time t2 to time t3, the control unit 91 reduces the inner tank valve opening of the flow rate regulator 73a from the opening V1 to 0, thereby reducing the inner tank discharge flow rate of the first gas supply unit 70 from the flow rate F7 to 0. In addition, during the period from time t2 to time t3, the control unit 91 reduces the outer tank valve opening of the flow rate regulator 83a from the opening V2 to 0, thereby reducing the outer tank discharge flow rate of the second gas supply unit 80 from the flow rate F8 to 0. Thus, the flow rate of the processing liquid in the inner tank 11 can be temporarily reduced, and as a result, the wafer W can be suppressed from falling off the substrate holding unit 20.

[0143] Next, the control unit 91 performs the etching process during a period from time t3 to time t4.

[0144] At time t3 when the etching process starts, the control unit 91 reduces the liquid delivery pressure of the pump 55 from pressure P1 to pressure P2 (<P1), thereby reducing the discharge flow rate of the processing liquid supply units 30_1 to 30_3 from flow rate F5 to flow rate F6 (<F5). The control unit 91 can reduce the flow rate of the processing liquid in the inner tank 11 by reducing the discharge flow rate of the processing liquid supply units 30_1 to 30_3.

[0145] At time t3 when the etching process starts, the control unit 91 increases the inner tank valve opening of the flow rate adjustment unit 73b from 0 to the opening V1, thereby increasing the inner tank discharge flow rate of the first gas supply unit 70 from 0 to the flow rate F7. The control unit 91 generates bubbling of oxygen in the inner tank 11 by increasing the inner tank discharge flow rate of the first gas supply unit 70, thereby increasing the concentration of oxygen (O2) dissolved in the processing liquid in the inner tank 11.

[0146] The control unit 91 continues bubbling oxygen gas in the inner tank 11 from time t3 to time t31, and at time t31, reduces the inner tank valve opening of the flow rate adjustment unit 73b from the opening V1 to 0, thereby reducing the inner tank discharge flow rate of the first gas supply unit 70 from the flow rate F7 to 0. Thus, during the etching process, the flow rate of the processing liquid in the inner tank 11 can be reduced, and nitrogen dioxide can be retained on the surface of the wafer W. Thus, the oxidation reaction of the molybdenum film 101 can be further promoted, and the etching rate of the molybdenum film 101 can be further increased.

[0147] The control unit 91 maintains the inner tank discharge flow rate of the first gas supply unit 70 at 0 from time t31 to time t32, and at time t32, increases the inner tank valve opening of the flow regulator 73a from 0 to opening V1, thereby increasing the inner tank discharge flow rate of the first gas supply unit 70 from 0 to flow rate F7. The control unit 91 generates bubbling of nitrogen in the inner tank 11 by increasing the inner tank discharge flow rate of the first gas supply unit 70, and can reduce the concentration of oxygen (O2) dissolved in the processing liquid in the inner tank 11.

[0148] By performing this process, the control unit 91 can reduce the concentration of nitrogen dioxide on the surface of the wafer W before starting the delivery process. As a result, the etching rate of the molybdenum film 101 is reduced before starting the delivery process. In the delivery process, since the lower end of the wafer W is lifted up last from the processing liquid stored in the inner tank 11, there is a tendency that the etching amount at the lower end of the wafer W is greater than the etching amount at the upper end of the wafer W. In response to this, the control unit 91 reduces the etching rate of the molybdenum film 101 before starting the delivery process to suppress the increase in the etching amount at the lower end of the wafer W, thereby reducing the difference in the etching amount at the upper and lower ends of the wafer W.

[0149] In addition, at time t3, the control unit 91 increases the outer tank valve opening of the flow rate regulator 83b from 0 to the opening V2, thereby increasing the outer tank discharge flow rate of the second gas supply unit 80 from 0 to the flow rate F8. The control unit 91 generates bubbling of oxygen in the outer tank 12 by increasing the outer tank discharge flow rate of the second gas supply unit 80, and can increase the concentration of oxygen (O2) dissolved in the processing liquid in the inner tank 11.

[0150] The control unit 91 continues to bubble oxygen gas in the outer tank 12 from time t3 to time t32, and at time t32, controls the flow rate regulators 83a and 83b to switch the gas discharged from the second gas supply unit 80 from oxygen gas to nitrogen gas. Thus, the control unit 91 can reduce the concentration of oxygen (O2) dissolved in the processing liquid in the inner tank 11 by generating bubbling of nitrogen gas in the outer tank 12.

[0151] Next, the control unit 91 performs the delivery process during the period from time t4 to time t5. During the period from time t4 to time t5, the control unit 91 reduces the inner tank valve opening of the flow rate regulator 73a from the opening V1 to 0, thereby reducing the inner tank discharge flow rate of the first gas supply unit 70 from the flow rate F7 to 0. During the period from time t4 to time t5, the control unit 91 reduces the outer tank valve opening of the flow rate regulator 83a from the opening V2 to 0, thereby reducing the outer tank discharge flow rate of the second gas supply unit 80 from the flow rate F8 to 0. Thus, the flow rate of the processing liquid in the inner tank 11 can be reduced, and as a result, the wafer W can be suppressed from falling off the substrate holding unit 20.

[0152] Next, when the delivery process is finished at time t5, the control unit 91 reduces the delivery pressure of the pump 55 from pressure P1 to pressure P0 (<P1), thereby reducing the discharge flow rate of the processing liquid supply units 30_1 to 30_3 from flow rate F5 to flow rate F4 (<F5). The control unit 91 can restore the flow rate of the processing liquid in the inner tank 11 to the initial flow rate by reducing the discharge flow rate of the processing liquid supply units 30_1 to 30_3.

[0153] (Other Modifications)

[0154] In the above embodiment, an example in which the molybdenum film 101 of the wafer W is etched is described. However, the film to be etched may be a metal film other than the molybdenum film, such as a tungsten film.

[0155] In the above embodiment, an example is described in which the concentration adjustment process is started before the wafer W is carried in and is ended after the wafer W is carried out. However, the concentration adjustment process may be started and ended at any timing.

[0156] As described above, the substrate processing device of the embodiment (e.g., substrate processing device 1) includes a processing tank (e.g., inner tank 11), a discharge port group (e.g., multiple discharge ports 32_1 to 32_2 provided in the processing liquid supply parts 30_1 to 30_3), an overflow tank (e.g., outer tank 12), a circulation path (e.g., a circulation path 50), a liquid delivery part (e.g., a pump 55), a first gas supply part (e.g., a first gas supply part 70), a second gas supply part (e.g., a second gas supply part 80), a first adjustment part (e.g., a flow adjustment part 73a, 73b), a second adjustment part (e.g., a flow adjustment part 83a, 83b) and a control part (e.g., a control part 91). The processing tank immerses a substrate (e.g., a wafer W) having a metal film (e.g., a molybdenum film 101) in a processing liquid for etching. The discharge port group is arranged in a position lower than the substrate in the processing tank, and discharges the processing liquid into the processing tank. The overflow tank stores the processing liquid overflowing from the processing tank. The circulation flow path connects the overflow tank with the discharge port group. The liquid delivery unit delivers the treatment liquid stored in the overflow tank to the circulation flow path. The first gas supply unit is arranged inside the treatment tank at a position lower than the substrate, and discharges gas into the treatment tank. The second gas supply unit is arranged inside the overflow tank, and discharges gas into the overflow tank. The first regulating unit regulates the flow rate of the gas discharged from the first gas supply unit. The second regulating unit regulates the flow rate of the gas discharged from the second gas supply unit. The control unit performs a concentration adjustment process by controlling the liquid delivery unit, the first regulating unit, and the second regulating unit. The concentration adjustment process regulates at least one of the flow rate of the treatment liquid discharged from the discharge port group, the flow rate of the gas discharged from the first gas supply unit, and the flow rate of the gas discharged from the second gas supply unit to adjust the concentration of the intermediate (e.g., nitrogen dioxide) contributing to the reaction of the metal film on the surface of the substrate. Therefore, according to the substrate processing device of the embodiment, the controllability of the etching rate of the metal film can be improved.

[0157] The embodiments disclosed in the specification are illustrative in all aspects and are not considered to be restrictive. In fact, the above-mentioned embodiments can be implemented in many ways. In addition, the above-mentioned embodiments can be omitted, replaced, and changed in various ways without departing from the scope of the invention and its gist.

[0158] Description of Reference Numerals

[0159] 1. Substrate processing device

[0160] 11 Inner groove

[0161] 12 Outer groove

[0162] 20 substrate holding portion

[0163] 30_1~30_3 Treatment liquid supply unit

[0164] 31_1~31_3 Nozzle

[0165] 32_1~32_3 Exit

[0166] 50 Circulation Path

[0167] 51 Exhaust path

[0168] 52_1~52_3 Supply path

[0169] 53 Bypass path

[0170] 55 Pump

[0171] 56 Heater

[0172] 57 Filters

[0173] 58 Filter bypass path

[0174] 59 On / Off Valve

[0175] 60 Flow regulating unit

[0176] 70 first gas supply unit

[0177] 71 Nozzle

[0178] 72 Spit out

[0179] 73a Flow regulating unit

[0180] 73b Flow regulating unit

[0181] 74a Gas supply source

[0182] 74b Gas supply source

[0183] 80 Second gas supply unit

[0184] 81 Nozzle

[0185] 82 Spit out

[0186] 83a Flow regulating unit

[0187] 83b Flow regulation unit

[0188] 84a Gas supply source

[0189] 84b Gas supply source

[0190] 90 Control Device

[0191] 91 Control Department

[0192] 92 Storage

[0193] 100 Polysilicon film

[0194] 101 Molybdenum film

[0195] 102 Silicon oxide film

[0196] W chip.

Claims

1. A substrate processing device, characterized in that: include: A processing tank that immerses the substrate having the metal film in a processing liquid to perform an etching process; a discharge port group, which is arranged in the processing tank at a position lower than the substrate and discharges the processing liquid into the processing tank; an overflow tank for storing the treatment liquid overflowing from the treatment tank; A circulation flow path connecting the overflow trough and the discharge port group; a liquid delivery unit that delivers the treatment liquid stored in the overflow tank to the circulation flow path; A first gas supply unit is disposed in the processing tank at a position lower than the substrate and discharges gas into the processing tank; a second gas supply unit, which is disposed inside the overflow tank and discharges gas into the overflow tank; a first regulating unit for regulating a flow rate of the gas discharged from the first gas supply unit; a second regulating unit for regulating a flow rate of the gas discharged from the second gas supply unit; and A control unit controls the liquid supply unit, the first regulating unit, and the second regulating unit to perform a concentration adjustment process, wherein the concentration of an intermediate contributing to a reaction of the metal film on the surface of the substrate is adjusted by adjusting at least one of a flow rate of the processing liquid discharged from the discharge port group, a flow rate of the gas discharged from the first gas supply unit, and a flow rate of the gas discharged from the second gas supply unit.

2. The substrate processing device according to claim 1, characterized in that: The intermediate is nitrogen dioxide (NO2).

3. The substrate processing device according to claim 1, characterized in that: The first gas supply unit and the second gas supply unit selectively discharge an inert gas or an oxygen-containing gas as the gas.

4. The substrate processing device according to claim 3, characterized in that: The inert gas is nitrogen (N2) gas or a rare gas, The oxygen-containing gas is air, oxygen (O2) gas or ozone (O3) gas.

5. The substrate processing device according to claim 3, characterized in that: The first gas supply unit and the second gas supply unit discharge oxygen-containing gas as the gas, In the concentration adjustment process, the control unit increases the concentration of the intermediate on the surface of the metal film by performing at least one of a process of reducing the flow rate of the processing liquid discharged from the discharge port group, a process of increasing the flow rate of the gas discharged from the first gas supply unit, and a process of increasing the flow rate of the gas discharged from the second gas supply unit.

6. The substrate processing device according to claim 5, characterized in that: The control unit reduces a flow rate of the processing liquid discharged from the discharge port group by reducing a liquid supply pressure of the liquid supply unit.

7. The substrate processing device according to claim 5, characterized in that: The circulation flow path comprises: a discharge path connected to the overflow trough; a supply path branched from the discharge path and connected to the discharge port group; a bypass path branched from the discharge path and connected to the overflow tank; and a third regulating unit, which is provided in the bypass path and regulates the flow rate of the treatment liquid flowing in the bypass path; The control unit controls the third adjustment unit to increase a flow rate of the processing liquid flowing through the bypass path, thereby reducing a flow rate of the processing liquid discharged from the discharge port group.

8. The substrate processing device according to claim 5, characterized in that: The control unit stops the discharge of the gas from the first gas supply unit and the second gas supply unit during a period in which the substrate is immersed in the processing liquid and a period in which the substrate is lifted out of the processing liquid.

9. The substrate processing device according to claim 3, characterized in that: The first gas supply unit and the second gas supply unit discharge an inert gas as the gas, During the concentration adjustment process, the control unit reduces the concentration of the intermediate on the surface of the substrate by performing at least one of a process of increasing the flow rate of the processing liquid ejected from the ejection port group, a process of increasing the flow rate of the gas ejected from the first gas supply unit, and a process of increasing the flow rate of the gas ejected from the second gas supply unit.

10. The substrate processing device according to claim 9, characterized in that: The control unit increases the flow rate of the processing liquid discharged from the discharge port group by increasing the liquid supply pressure of the liquid supply unit.

11. The substrate processing device according to claim 9, characterized in that: The circulation flow path comprises: a discharge path connected to the overflow trough; a supply path branched from the discharge path and connected to the discharge port group; a filter disposed in the discharge path; a filter bypass path that bypasses the filter; and an on-off valve for switching the open and closed state of the filter bypass path, The control unit controls the on-off valve to switch the filter bypass path from a closed state to an open state, thereby increasing a flow rate of the processing liquid discharged from the discharge port group.

12. The substrate processing device according to claim 9, characterized in that: The control unit stops the discharge of the gas from the first gas supply unit and the second gas supply unit during a period in which the substrate is immersed in the processing liquid and a period in which the substrate is lifted out of the processing liquid.

13. The substrate processing device according to claim 1, wherein: The metal film is a molybdenum film or a tungsten film.

14. The substrate processing device according to claim 1, wherein: The treatment liquid is a treatment liquid containing at least nitric acid (HNO 3 ), phosphoric acid (H 3 PO 4 ) and water (H 2 O) as components.

15. A substrate processing method, characterized in that: The substrate processing method is a substrate processing method in a substrate processing device, The substrate processing device comprises: A processing tank that immerses the substrate having the metal film in a processing liquid to perform an etching process; a discharge port group, which is arranged in the processing tank at a position lower than the substrate and discharges the processing liquid into the processing tank; an overflow tank for storing the treatment liquid overflowing from the treatment tank; A circulation flow path connecting the overflow trough and the discharge port group; a liquid delivery unit that delivers the treatment liquid stored in the overflow tank to the circulation flow path; A first gas supply unit is disposed in the processing tank at a position lower than the substrate and discharges gas into the processing tank; a second gas supply unit, which is disposed inside the overflow tank and discharges gas into the overflow tank; a first regulating unit for regulating a flow rate of the gas discharged from the first gas supply unit; a second regulating unit for regulating a flow rate of the gas discharged from the second gas supply unit, The substrate processing method adjusts the concentration of the intermediate contributing to the reaction of the metal film on the surface of the substrate by adjusting at least one of the flow rate of the processing liquid discharged from the discharge port group, the flow rate of the gas discharged from the first gas supply unit, and the flow rate of the gas discharged from the second gas supply unit.

Images