Substrate processing apparatus and substrate processing method

Abstract

The present disclosure relates to a substrate processing apparatus and a substrate processing method that improve uniformity of etching processing in a technique of etching a plurality of substrates in conjunction. The substrate processing apparatus of the present disclosure includes a processing tank, first and second nozzle groups, a first changing unit, a second changing unit, and a control unit. The processing tank is used to immerse a plurality of substrates in a processing liquid to perform etching processing. The first and second nozzle groups are disposed inside the processing tank at positions lower than the plurality of substrates and are used to spray the processing liquid into the inside of the processing tank. The first changing unit is used to change the flow rate of the processing liquid sprayed from the first nozzle group. The second changing unit is used to change the flow rate of the processing liquid sprayed from the second nozzle group. The control unit controls the first changing unit and the second changing unit during etching processing to perform flow rate changing processing that increases and decreases the flow rate of the processing liquid sprayed from the first nozzle group and the flow rate of the processing liquid sprayed from the second nozzle group in different manners.

Description

Technical Field

[0001] This disclosure relates to a substrate processing apparatus and a substrate processing method. Background Technology

[0002] In Patent Document 1, a technique is known to etch multiple substrates simultaneously by immersing multiple substrates in a processing tank containing a processing solution.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-14470 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] This disclosure provides a technique for improving the uniformity of etching processes in a technique of etching multiple substrates simultaneously.

[0008] Solution for solving the problem

[0009] A substrate processing apparatus according to one aspect of this disclosure includes a processing tank, a first group of ejector ports and a second group of ejector ports, a first adjustment unit, a second adjustment unit, and a control unit. The processing tank is used to immerse multiple substrates in a processing liquid for etching. The first group of ejector ports and the second group of ejector ports are disposed inside the processing tank and below the multiple substrates, for ejecting processing liquid into the processing tank. The first adjustment unit is used to adjust the flow rate of the processing liquid ejected from the first group of ejector ports. The second adjustment unit is used to adjust the flow rate of the processing liquid ejected from the second group of ejector ports. During the etching process, the control unit controls the first and second adjustment units to perform flow rate adjustment processing, increasing and decreasing the flow rates of the processing liquid ejected from the first and second groups of ejector ports in different ways.

[0010] The effects of the invention

[0011] According to this disclosure, in the technique of etching multiple substrates simultaneously, the uniformity of the etching process can be improved. Attached Figure Description

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

[0013] Figure 2 This is a diagram showing the structure of the substrate processing apparatus according to the first embodiment.

[0014] Figure 3 This is a diagram showing the structure of the processing fluid supply unit according to the first embodiment.

[0015] Figure 4 This is a flowchart illustrating the processing procedure performed by the substrate processing apparatus according to the first embodiment.

[0016] Figure 5 This is an explanatory diagram of the traffic change processing involved in the first embodiment.

[0017] Figure 6 This is a diagram showing how the location of fluid flow stagnation changes due to flow rate variations.

[0018] Figure 7 This is a diagram showing how the location of fluid flow stagnation changes due to flow rate variations.

[0019] Figure 8 This is a diagram showing the structure of a substrate processing apparatus according to a variation of the first embodiment.

[0020] Figure 9 This is an explanatory diagram of the flow change processing involved in a variation of the first embodiment.

[0021] Figure 10 This is a diagram showing the structure of the substrate processing apparatus according to the second embodiment.

[0022] Figure 11 This is a diagram showing the gas supply section according to the second embodiment from above.

[0023] Figure 12 This is an explanatory diagram of the traffic change processing involved in the second embodiment.

[0024] Figure 13 It is a graph showing the change of in-plane temperature difference over time during the etching process.

[0025] Explanation of reference numerals in the attached figures

[0026] 1: Substrate processing apparatus; 11: Inner tank; 12: Outer tank; 20: Substrate holding section; 30: Processing liquid supply section; 30_1~30_3: Processing liquid supply section; 31_1~31_3: Nozzle; 32_1~32_3: Spray outlet; 50: Circulation flow path; 51: Discharge path; 52_1~52_3: Supply path; 53_1: Bypass path; 55: Pump; 56: Heater; 57: Filter; 60_1~60_3: ​​Flow rate changing section; 70: Control device; 71: Control section; 72: Storage section; 80: Gas supply section; 81: Nozzle; 82: Spray outlet; 83: Supply path; 84: Gas supply source; 85: Flow rate changing section; 100: Polycrystalline silicon film; 101: Tungsten film; 102: Titanium nitride film; 103: Silicon oxide film; W: Wafer. Detailed Implementation

[0027] Hereinafter, embodiments (hereinafter referred to as "Embodiments") for implementing the substrate processing apparatus and substrate processing method based on the present disclosure will be described in detail with reference to the accompanying drawings. However, the present disclosure is not limited to these embodiments. Furthermore, the various embodiments can be appropriately combined without contradicting the processing content. In the following embodiments, the same reference numerals are used for the same parts, and repeated descriptions are omitted.

[0028] Furthermore, in the embodiments shown below, expressions such as "fixed," "orthogonal," "perpendicular," or "parallel" are sometimes used, but these expressions do not need to be strictly "fixed," "orthogonal," "perpendicular," or "parallel." That is, the above expressions allow for deviations in, for example, manufacturing precision, setting precision, etc.

[0029] Furthermore, in the accompanying figures mentioned below, an orthogonal coordinate system is sometimes shown, defining mutually orthogonal X-axis, Y-axis, and Z-axis directions, with the positive Z-axis direction set as the vertically upward direction, to facilitate understanding and explanation. Additionally, the direction of rotation about the vertical axis is sometimes referred to as the θ direction.

[0030] <About substrate processing>

[0031] First, refer to Figure 1 An example of substrate processing based on this disclosure will be described. Figure 1 This is a diagram illustrating an example of substrate processing.

[0032] like Figure 1 As shown, in the substrate processing based on this disclosure, for example, an etching is performed on a wafer W on which a tungsten film 101, a titanium nitride film 102, and a silicon oxide film 103 are formed on a polysilicon film 100. Specifically, multiple layers of silicon oxide films 103 are formed on the polysilicon film 100 in a spaced-apart manner, and titanium nitride films 102 are formed around each silicon oxide film 103 to cover them. Additionally, the tungsten film 101 is formed to cover both the titanium nitride film 102 and the silicon oxide film 103. Therefore, before the etching process, the titanium nitride film 102 and the silicon oxide film 103 are covered by the tungsten film 101.

[0033] In the substrate processing based on this disclosure, a recess is formed on the wafer W by etching back the tungsten film 101 and the titanium nitride film 102. For example, a processing solution containing phosphoric acid (H3PO4), acetic acid (CH3COOH), nitric acid (HNO3), and water (H2O) is used as the etching solution for etching the tungsten film 101 and the titanium nitride film 102.

[0034] Specifically, firstly, only the tungsten film 101 exposed on the surface is etched, thereby exposing the titanium nitride film 102 covered by the tungsten film 101 (first etching process). Then, both the tungsten film 101 and the titanium nitride film 102 are etched simultaneously (second etching process).

[0035] Patent document 1 discloses the following technology: supplying a gas such as nitrogen from a gas nozzle located at the bottom of the processing tank to form a liquid flow of processing liquid in the processing tank, thereby improving the uniformity of the etching process.

[0036] However, in the above-mentioned techniques, it is possible to form regions with very little etching within the surface of the wafer (hereinafter referred to as "special regions").

[0037] One possible reason is the stagnation of the fluid flow. That is, it is believed that when there are areas where the processing fluid does not flow and stagnates, the displacement of the processing fluid in those areas decreases, thereby reducing the etching amount in those areas.

[0038] Therefore, in the first embodiment, by forcibly disrupting the liquid flow within the processing tank, stagnation of the liquid flow in fixed locations is avoided. This makes it difficult to form specific areas, thus improving the uniformity of the etching process.

[0039] In addition, galvanic corrosion occurring during the second etching process is also considered to be a contributing factor. Galvanic corrosion refers to the phenomenon where the metal with the lower potential (standard electrode potential) corrodes rapidly when different metals are brought into contact in an aqueous solution. The greater the flow rate of the gas supplied to the processing tank, the more pronounced the galvanic corrosion becomes.

[0040] Therefore, in the second embodiment, the gas supply to the processing tank is restricted after a fixed period has elapsed since the start of the etching process. This allows for the suppression of Giovanni corrosion during the second etching process, in which both the tungsten film 101 and the titanium nitride film 102 are simultaneously etched.

[0041] (First Implementation)

[0042] <Structure of the substrate processing device>

[0043] First, refer to Figure 2 The structure of the substrate processing apparatus according to the first embodiment will be explained. Figure 2 This is a diagram showing the structure of the substrate processing apparatus according to the first embodiment.

[0044] Figure 2The substrate processing apparatus 1 shown etches multiple wafers W held in a vertical position simultaneously by immersing them in a processing solution. As described above, the etching process uses a processing solution containing phosphoric acid, acetic acid, nitric acid, and water to etch the tungsten film 101 and the titanium nitride film 102.

[0045] like Figure 2 As shown, the substrate processing apparatus 1 according to the first embodiment includes an inner tank 11, an outer tank 12, a substrate holding section 20, a processing liquid supply section 30_1 to 30_3, a circulation flow path 50, a flow rate changing section 60_1 to 60_3, and a control device 70.

[0046] Furthermore, in the following text, without distinguishing between the processing fluid supply units 30_1 to 30_3, it may sometimes be referred to simply as the processing fluid supply unit 30. Also, without distinguishing between the flow rate change units 60_1 to 60_3, it may sometimes be referred to simply as the flow rate change unit 60.

[0047] (Inner groove 11 and outer groove 12)

[0048] The inner tank 11 is a box-shaped tank open at the top, and the processing liquid is stored inside the inner tank 11. A batch of wafers formed by multiple wafers W is immersed in the inner tank 11. In this way, the inner tank 11 is equivalent to an example of a processing tank in which multiple substrates are immersed in the processing liquid for etching.

[0049] An outer tank 12 is disposed around the upper part of the inner tank 11. The upper part of the outer tank 12 is open for storing the processing liquid that overflows from the inner tank 11. In this way, the outer tank 12 is equivalent to an overflow tank for storing the processing liquid that overflows from the processing tank.

[0050] Furthermore, the outer tank 12 can also be connected to a new liquid supply unit for supplying new liquid to the treatment liquid. Additionally, the outer tank 12 can also be connected to separate supply units for separately supplying phosphoric acid, acetic acid, nitric acid, and water, which are components of the treatment liquid.

[0051] (Substrate holding section 20)

[0052] The substrate holding section 20 holds multiple wafers W in a vertical orientation (longitudinal position). Additionally, the substrate holding section 20 holds the multiple wafers W in a state where they are arranged at fixed intervals in the horizontal direction (Y-axis direction in this case). The substrate holding section 20 is connected to a lifting mechanism (not shown), thereby enabling the multiple wafers W to move between a processing position inside the inner tank 11 and a waiting position above the inner tank 11.

[0053] (Processing fluid supply unit 30)

[0054] The processing fluid supply unit 30 is disposed inside the inner tank 11 and below the plurality of wafers W, for spraying processing fluid into the inner tank 11.

[0055] Here, refer to Figure 3 The structure of the processing fluid supply unit 30 will be explained. Figure 3 This is a diagram showing the structure of the processing liquid supply unit 30 according to the first embodiment.

[0056] like Figure 3 As shown, the processing fluid supply units 30_1 to 30_3 include nozzles 31_1 to 31_3. The nozzles 31_1 to 31_3 are, for example, cylindrical components extending along the arrangement direction (Y-axis direction) of the plurality of wafers W. At the upper part of the nozzles 31_1 to 31_3, along the extending direction of the nozzles 31_1 to 31_3, a plurality of nozzle outlets 32_1 to 32_3 are provided. The nozzle outlets 32_1 to 32_3 are, for example, circular, with an opening diameter of, for example, approximately 0.5 mm to 1.0 mm. The nozzle outlets 32_1 to 32_3 spray the processing fluid, for example, vertically upward (positive Z-axis direction).

[0057] Nozzles 31_1 to 31_3 are connected to supply paths 52_1 to 52_3 (described later) and are used to spray the treatment fluid supplied from supply paths 52_1 to 52_3 from multiple nozzles 32_1 to 32_3.

[0058] (Circular Flow 50)

[0059] Return to Figure 2 The circulation path 50 connects the outer tank 12 to the treatment fluid supply units 30_1 to 30_3. Specifically, the circulation path 50 includes a discharge path 51, multiple supply paths 52_1 to 52_3, and multiple bypass paths 53_1 to 53_3. The discharge path 51 is connected to the bottom of the outer tank 12.

[0060] A pump 55, a heater 56, and a filter 57 are provided in the discharge path 51. The pump 55 pumps the processing liquid from the outer tank 12 to the discharge path 51. The heater 56 heats the processing liquid flowing through the discharge path 51 to a temperature suitable for etching. The filter 57 removes impurities from the processing liquid flowing through the discharge path 51. The pump 55 and heater 56 are electrically connected to a control device 70 for control.

[0061] Multiple supply paths 52_1 to 52_3 branch off from the discharge path 51. Among them, supply path 52_1 is connected to the processing liquid supply unit 30_1, supply path 52_2 is connected to the processing liquid supply unit 30_2, and supply path 52_3 is connected to the processing liquid supply unit 30_3.

[0062] Multiple bypass paths 53_1 to 53_3 connect multiple supply paths 52_1 to 52_3 to the outer tank 12. Specifically, bypass path 53_1 branches off from supply path 52_1 to connect to the outer tank 12, bypass path 53_2 branches off from supply path 52_2 to connect to the outer tank 12, and bypass path 53_3 branches off from supply path 52_3 to connect to the outer tank 12.

[0063] (Traffic Change Department 60)

[0064] The flow rate control units 60_1 to 60_3 are, for example, LFCs (liquid flow controllers) used to change the flow rate of the processed liquid supplied to the processed liquid supply units 30_1 to 30_3. Specifically, the flow rate control units 60_1 to 60_3 are used to change the flow rate of the processed liquid ejected from the multiple nozzles 32_1 to 32_3 provided in the processed liquid supply units 30_1 to 30_3.

[0065] Specifically, a flow rate changing unit 60_1 is provided in the bypass path 53_1, and changes the flow rate of the processed liquid supplied from the supply path 52_1 to the processed liquid supply unit 30_1 by changing the flow rate of the processed liquid flowing through the bypass path 53_1. A flow rate changing unit 60_2 is provided in the bypass path 53_2, and changes the flow rate of the processed liquid supplied from the supply path 52_2 to the processed liquid supply unit 30_2 by changing the flow rate of the processed liquid flowing through the bypass path 53_2. A flow rate changing unit 60_3 is provided in the bypass path 53_3, and changes the flow rate of the processed liquid supplied from the supply path 52_3 to the processed liquid supply unit 30_3 by changing the flow rate of the processed liquid flowing through the bypass path 53_3.

[0066] The flow rate change units 60_1 to 60_3 are electrically connected to the control device 70 and are controlled by the control device 70.

[0067] (Control device 70)

[0068] The control device 70 is, for example, a computer, and includes a control unit 71 and a storage unit 72. The storage unit 72 is implemented, for example, using semiconductor memory elements such as RAM and flash memory, or storage devices such as hard disks and optical disks, and stores programs for controlling various processes executed in the board processing apparatus 1. The control unit 71 includes a microcomputer with a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), input / output ports, and various circuits. The control unit 71 controls the operation of the board processing apparatus 1 by reading and executing the programs stored in the storage unit 72.

[0069] Alternatively, the program may be recorded on a computer-readable storage medium and installed from that storage medium into the storage unit 72 of the control device 70. Examples of computer-readable storage media include hard disks (HD), floppy disks (FD), optical disks (CD), magneto-optical disks (MO), and memory cards.

[0070] (Specific operations of substrate processing apparatus 1)

[0071] Next, refer to Figure 3 and Figure 4 The specific operation of the substrate processing apparatus 1 according to the first embodiment will be explained. Figure 4 This is a flowchart illustrating the processing procedure performed by the substrate processing apparatus 1 according to the first embodiment. Furthermore, it is executed under the control of the control unit 71. Figure 4 The processes shown are as follows.

[0072] like Figure 4 As shown, in the substrate processing apparatus 1, firstly, a transfer process is performed to immerse multiple wafers W in the inner tank 11 (step S101). During the transfer process, the control unit 71 controls a lifting mechanism (not shown) provided on the substrate holding unit 20 to lower the substrate holding unit 20, thereby immersing multiple wafers W in the processing liquid stored in the inner tank 11.

[0073] Furthermore, before the transfer process begins, the control unit 71 controls the pump 55 to pre-start supplying processing fluid from the outer tank 12 to the processing fluid supply units 30_1 to 30_3. Additionally, before the transfer process begins, the control unit 71 controls the flow rate control units 60_1 to 60_3 to close the bypass paths 53_1 to 53_3. That is, before the transfer process begins, all the processing fluid flowing through the circulation path 50 is supplied to the processing fluid supply units 30_1 to 30_3.

[0074] Next, an etching process is performed in the substrate processing apparatus 1 (step S102). In the etching process, the state in which the multiple wafers W are immersed in the processing liquid in the inner tank 11 is maintained for a predetermined time. As a result, firstly, the tungsten film 101 exposed on the surface is etched to expose the titanium nitride film 102, and then the tungsten film 101 and the titanium nitride film 102 are etched simultaneously.

[0075] Next, a removal process (step S103) is performed in the substrate processing apparatus 1. During the removal process, the control unit 71 controls a lifting mechanism (not shown) provided 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. When the removal process is completed, the control unit 71 ends a series of substrate processing in the substrate processing apparatus 1.

[0076] The control unit 71 performs flow rate change processing during the etching process, which modifies the flow rate of the processing liquid supplied from the processing liquid supply units 30_1 to 30_3. (Refer to...) Figures 5-7 This will explain the content of the traffic change processing.

[0077] Figure 5 This is an explanatory diagram of the traffic change processing involved in the first embodiment. Additionally, Figure 6 and Figure 7 This is a diagram showing how the location of fluid flow stagnation changes due to flow rate variations.

[0078] Figure 5 The diagram shows the changes over time in "circulation flow rate," "ejection flow rate," "bypass flow rate," and "valve opening" during the etching process. "Circulation flow rate" refers to the flow rate of the processing fluid flowing through the circulation path 50, and "ejection flow rate" refers to the flow rate of the processing fluid ejected from the processing fluid supply units 30_1 to 30_3. Additionally, "bypass flow rate" refers to the flow rate of the processing fluid supplied to the outer tank 12 from the bypass paths 53_1 to 53_3, and "valve opening" refers to the opening degree of the on / off valves (solenoid valves) provided in the flow rate changing units 60_1 to 60_3.

[0079] In addition, Figure 5 In the diagram, solid lines represent the flow rate or opening degree corresponding to the processing fluid supply unit 30_1, dashed lines represent the flow rate or opening degree corresponding to the processing fluid supply unit 30_2, and single-dot dashed lines represent the flow rate or opening degree corresponding to the processing fluid supply unit 30_3. Additionally, in... Figure 5 In the diagram, a double-dotted line represents the circulating flow rate.

[0080] In addition, Figure 6 and Figure 7 In the diagram, solid arrows represent the treatment fluid ejected from the treatment fluid supply units 30_1 to 30_3, and the length of the solid arrows represents the ejection flow rate of the treatment fluid. Additionally, in... Figure 6 and Figure 7 In the diagram, the flow of the processing liquid formed in the inner tank 11 is indicated by a shaded arrow.

[0081] like Figure 5 As shown, the control unit 71 changes the valve opening of the flow rate changing units 60_1 to 60_3 to change the bypass flow rate, thereby changing the ejection flow rate of the treatment fluid supply units 30_1 to 30_3.

[0082] The control unit 71 increases and decreases the flow rates of the processing liquid ejected from the processing liquid supply unit 30_1, the processing liquid ejected from the processing liquid supply unit 30_2, and the processing liquid ejected from the processing liquid supply unit 30_3 in different ways.

[0083] For example, in Figure 5In the example shown, the control unit 71 alternately changes the valve openings of the flow rate changing units 60_1 to 60_3 between the first opening V1 and the second opening V2 (<V1), so that the bypass flow rate alternately changes between the third flow rate F3 and the fourth flow rate F4 (<F3). Thereby, the control unit 71 can alternately change the ejection flow rate of the processing liquid supply units 30_1 to 30_3 between the first flow rate F1 and the second flow rate F2 (<F1).

[0084] Alternatively, in the above process, the control unit 71 may change the directions of change of the ejection flow rate between the processing liquid supply units 30_1 to 30_3. For example, when the control unit 71 reduces the ejection flow rate of the processing liquid supply unit 30_1 from the first flow rate F1 to the second flow rate F2, the control unit 71 increases the ejection flow rate of the processing liquid supply unit 30_2 from the second flow rate F2 to the first flow rate F1. In addition, when the control unit 71 increases the ejection flow rate of the processing liquid supply unit 30_1 from the second flow rate F2 to the first flow rate F1, the control unit 71 reduces the ejection flow rate of the processing liquid supply unit 30_2 from the first flow rate F1 to the second flow rate F2. By changing the directions of change of the ejection flow rate between the processing liquid supply units 30_1 to 30_3 in this way, the liquid flow of the processing liquid in the inner tank 11 can be disturbed.

[0085] In addition, the control unit 71 may also make the timing of changing the ejection flow rate different between the processing liquid supply units 30_1 to 30_3. For example, after the control unit 71 reduces the ejection flow rate of the processing liquid supply unit 30_1 from the first flow rate F1 to the second flow rate F2, during the period until the ejection flow rate of the processing liquid supply unit 30_1 is increased from the second flow rate F2 to the first flow rate F1, the control unit 71 reduces the ejection flow rate of the processing liquid supply unit 30_3 from the first flow rate F1 to the second flow rate F2. By making the timing of changing the ejection flow rate different between the processing liquid supply units 30_1 to 30_3 in this way, the liquid flow of the processing liquid in the inner tank 11 can also be disturbed.

[0086] According to the substrate processing apparatus 1 according to the first embodiment, as Figure 6 shown, even if the liquid flow in the inner tank 11 is stagnant SA, by disturbing the liquid flow of the processing liquid, it is possible to make the place where the stagnation SA occurs change, as Figure 7 shown. Thereby, it is possible to suppress the formation of a specific region with an extremely small etching amount on the wafer W. That is, the uniformity of the etching process can be improved.

[0087] In addition, in the substrate processing apparatus 1 according to the first embodiment, it is assumed that the processing liquid that does not flow into the processing liquid supply units 30_1 to 30_3 among the processing liquid flowing through the circulation flow path 50 is discharged to the outer tank 12 connected to the circulation flow path 50. Thus, as Figure 5As shown, the ejection flow rate of the processing fluid supply units 30_1 to 30_3 can be varied while maintaining the circulation flow rate at a fixed flow rate F0. By keeping the circulation flow rate constant in this way, the load on the pump 55 can be kept constant. If the load on the pump 55 changes, the pressure acting on the filter 57 may change, causing foreign matter to be discharged from the filter 57. The substrate processing apparatus 1 according to the first embodiment controls the flow rate variation units 60_1 to 60_3 to keep the circulation flow rate constant, thereby keeping the load on the pump 55 constant. Therefore, according to the substrate processing apparatus 1, the discharge of foreign matter from the filter 57 can be suppressed.

[0088] like Figure 5 As shown, the control unit 71 may also perform the aforementioned flow rate change process multiple times during the etching process, that is, repeatedly increase and decrease the ejection flow rate of the processing liquid supply units 30_1 to 30_3. The flow rate change process can be performed continuously or intermittently. By performing the flow rate change process multiple times in this way, the effect of disturbing the flow of the processing liquid can be improved.

[0089] Furthermore, the control unit 71 can repeatedly perform flow rate change processing from the start of the etching process to the end of the etching process. By continuously performing flow rate change processing throughout the entire etching process, the effect of disrupting the flow of the processing liquid can be further improved.

[0090] exist Figure 5 In the example shown, the pre-change ejection flow rate (e.g., first flow rate F1) and post-change ejection flow rate (e.g., second flow rate F2) between the processing fluid supply units 30_1 to 30_3 are assumed to be the same. However, this is not a limitation; the control unit 71 may also make at least one of the pre-change and post-change ejection flow rates between the processing fluid supply units 30_1 to 30_3 different. This improves the effect of disrupting the flow of the processing fluid.

[0091] exist Figure 5 In the example shown, the change cycle (the time from changing the spray flow rate to restoring the original spray flow rate) of the spray flow rate between the processing fluid supply units 30_1 and 30_3 is set to be the same. However, the control unit 71 may also make the change cycle of the spray flow rate between the processing fluid supply units 30_1 and 30_3 different. This can improve the effect of disturbing the flow of the processing fluid.

[0092] In addition, Figure 5In the example shown, the ejection flow rate of the treatment fluid supply units 30_1 to 30_3 is varied between the first flow rate F1 and the second flow rate F2. However, the control unit 71 may also increase or decrease the ejection flow rate of the treatment fluid supply units 30_1 to 30_3 in multiple stages. For example, the control unit 71 may decrease (increase) the ejection flow rate of the treatment fluid supply units 30_1 to 30_3, maintain the decreased (increased) ejection flow rate for a fixed time, and then further decrease (increase) the ejection flow rate. This improves the effect of disrupting the flow of the treatment fluid.

[0093] <Modifications of the substrate processing apparatus 1 according to the first embodiment>

[0094] Next, refer to Figure 8 To illustrate a variation of the substrate processing apparatus 1 according to the first embodiment described above. Figure 8 This is a diagram showing the structure of a substrate processing apparatus according to a variation of the first embodiment.

[0095] like Figure 8 As shown, the substrate processing apparatus 1A according to the modified example includes a circulation path 50A. The circulation path 50A includes a discharge path 51, multiple supply paths 52_1 to 52_3, and a bypass path 53A. The bypass path 53A branches off from the discharge path 51 and connects to the outer tank 12.

[0096] Furthermore, in the substrate processing apparatus 1A according to the modified example, flow rate changing units 60_1 to 60_3 are respectively provided in supply paths 52_1 to 52_3. Specifically, flow rate changing unit 60_1 is provided in supply path 52_1, flow rate changing unit 60_2 is provided in supply path 52_2, and flow rate changing unit 60_3 is provided in supply path 52_3.

[0097] Next, refer to Figure 9 This will illustrate the content of the traffic change processing involved in the variant example. Figure 9 This is an explanatory diagram of the flow change processing involved in a variation of the first embodiment. Figure 9 In the diagram, a single dot double dash represents the bypass flow.

[0098] like Figure 9 As shown, the control unit 71 changes the valve opening of the flow rate changing units 60_1 to 60_3 between a first opening V1 and a second opening V2, thereby changing the ejection flow rate of the treatment fluid supply units 30_1 to 30_3 between a first flow rate F1 and a second flow rate F2. As a result, the flow of the treatment fluid in the inner tank 11 is disturbed, thereby suppressing the formation of special areas.

[0099] In the modified example, the bypass flow rate varies correspondingly to the total ejection flow rate of the processing fluid supply units 30_1 to 30_3. That is, when the total ejection flow rate of the processing fluid supply units 30_1 to 30_3 increases, the bypass flow rate decreases, and when the total ejection flow rate of the processing fluid supply units 30_1 to 30_3 decreases, the bypass flow rate increases. This allows the circulating flow rate to be maintained at flow rate F0.

[0100] (Second Implementation)

[0101] Figure 10 This is a diagram illustrating the structure of the substrate processing apparatus according to the second embodiment. (As shown) Figure 10 As shown, the substrate processing apparatus 1B according to the second embodiment includes a circulation path 50B.

[0102] The circulation path 50B has the same structure as the circulation paths 50 and 50A described above, except that it does not have a bypass path. Specifically, the circulation path 50B includes a discharge path 51 connected to the outer tank 12 and supply paths 52_1 to 52_3 branching off from the discharge path 51 and connected to the processing fluid supply units 30_1 to 30_3. Furthermore, a pump 55, a heater 56, and a filter 57 are provided in the discharge path 51.

[0103] Additionally, the substrate processing apparatus 1B includes a gas supply unit 80. The gas supply unit 80 is disposed inside the inner tank 11 and is located below the plurality of wafer Ws and the plurality of processing liquid supply units 30_1 to 30_3. The gas supply unit 80 includes a plurality of nozzles 81, and by ejecting gas from the nozzles 81 into the interior of the inner tank 11, a flow of processing liquid is generated inside the inner tank 11.

[0104] Reference Figure 11 To explain the structure of the gas supply unit 80. Figure 11 This is a view of the gas supply unit 80 according to the second embodiment from above.

[0105] like Figure 11 As shown, the gas supply unit 80 includes a plurality of nozzles 81, which are, for example, cylindrical components extending along the arrangement direction (Y-axis direction) of the plurality of wafers W. At the upper part of the nozzles 81, a plurality of outlets 82 are provided along the extending direction of the nozzles 81. Furthermore, the plurality of outlets 82 are not necessarily located at the upper part of the nozzles 81. For example, the plurality of outlets 82 may also be located at the lower part of the nozzles 81 to eject gas obliquely downwards.

[0106] Multiple nozzles 81 are connected to a gas supply source 84 via a supply path 83. The gas supply source 84 is used to supply gas to the multiple nozzles 81. Here, it is assumed that nitrogen is supplied from the gas supply source 84 to the multiple nozzles 81, but the gas supplied from the gas supply source 84 to the multiple nozzles 81 may also be an inactive gas other than nitrogen, such as argon.

[0107] A flow rate changing unit 85 is provided in the supply path 83. The flow rate changing unit 85 is composed of, for example, an LFC, an on / off valve for fully closing or fully opening the supply path 83, and is used to change the flow rate of nitrogen supplied from the gas supply source 84 to the multiple nozzles 81.

[0108] Next, refer to Figure 12 This will explain the content of the traffic change processing involved in the second embodiment. Figure 12 This is an explanatory diagram of the traffic change processing involved in the second embodiment.

[0109] The control unit 71 controls the flow rate change unit 85 to eject nitrogen gas from the gas supply unit 80 at a first flow rate F11 during period T1. Furthermore, the control unit 71 controls the flow rate change unit 85 to change the nitrogen gas ejection flow rate during period T2, which follows period T1, to a second flow rate less than the first flow rate F1, specifically to 0. Period T2 continues at least until the etching process is completed.

[0110] The expected start timing of period T2 is, for example, a timing in the etching process earlier than the timing at which the titanium nitride film 102 covered by the tungsten film 101 is exposed.

[0111] By reducing the nitrogen ejection flow rate during the later etching process, in which the tungsten film 101 and the titanium nitride film 102 are simultaneously etched, the occurrence of Giavian corrosion can be suppressed.

[0112] In addition, nitrogen gas is sprayed into the inner tank 11 in the early stage of the etching process where multiple wafers W are immersed in the inner tank 11, thereby effectively improving the uniformity of the etching process.

[0113] Reference Figure 13 This point needs clarification. Figure 13 This is a graph showing the change in in-plane temperature difference over time during the etching process. The in-plane temperature difference refers to the difference between the highest and lowest temperatures within the plane of wafer W. Figure 13 In the diagram, solid lines represent the change of in-plane temperature difference over time when etching is performed while nitrogen is being ejected from the gas supply section, and dashed lines represent the change of in-plane temperature difference over time when etching is performed without nitrogen being ejected from the gas supply section.

[0114] like Figure 13As shown, when etching is performed while nitrogen is being ejected, the in-plane temperature difference of wafer W can be reduced earlier compared to etching without nitrogen ejection. This effect is known to be particularly noticeable in the early stages of the etching process.

[0115] The lower the in-plane temperature of wafer W, the smaller the in-plane deviation of the etching amount. Therefore, by performing the etching process while emitting nitrogen gas from the gas supply unit 80 during the initial stage T1 of the etching process, the uniformity of the etching process can be improved.

[0116] In the substrate processing apparatus 1B according to the second embodiment, nitrogen gas is ejected from the gas supply unit 80 at the beginning of the etching process, while the amount of nitrogen ejected is limited at the end of the etching process, or more preferably, the nitrogen ejection is stopped. This reduces the in-plane temperature difference of the wafer W earlier in the etching process, thereby improving the in-plane uniformity of the etching process. Furthermore, by suppressing the occurrence of Giovanni etching at the end of the etching process, the reduction in in-plane uniformity of the etching process can be suppressed.

[0117] Therefore, according to the substrate processing apparatus 1B of the second embodiment, in the technique of etching multiple wafers W on which multiple metal layers are formed simultaneously, the uniformity of the etching process can be improved.

[0118] In addition, Figure 12 In the example shown, period T1 is assumed to include the loading process before the etching process begins, but period T1 only needs to include at least the period after the etching process begins. The start timing of period T1 can be, for example, a timing immediately preceding the start of immersion of the multiple wafers W in the processing solution in the inner tank 11, or a timing immediately following the end of immersion of the multiple wafers W in the processing solution in the inner tank 11. Alternatively, the start timing of period T1 can also be a timing within the period from the start of immersion of the multiple wafers W in the processing solution in the inner tank 11 to the end of immersion.

[0119] (Other variations)

[0120] In the first embodiment, an example of a substrate processing apparatus 1 and 1A having three nozzles 31_1 to 31_3 was described, but the substrate processing apparatus 1 and 1A only need to have at least two nozzles.

[0121] In the first embodiment, an example is shown where the substrate processing apparatus 1, 1A has a plurality of nozzles 31_1 to 31_3 and a plurality of nozzle outlets 32_1 to 32_3 are provided in each nozzle 31_1 to 31_3. However, it is not limited to this; for example, the substrate processing apparatus 1, 1A may also have a processing liquid supply unit with a plurality of nozzle outlet groups (including a first nozzle outlet group and a second nozzle outlet group) having different supply paths provided on a flat plate-shaped member.

[0122] As described above, the substrate processing apparatus according to the embodiments (for example, substrate processing apparatus 1, 1A) includes a processing tank (for example, an inner tank 11), a first group of nozzles (for example, any one of the plurality of nozzles 32_1 to 32_3 provided in the processing liquid supply units 30_1 to 30_3), a second group of nozzles (for example, any other one of the plurality of nozzles 32_1 to 32_3 provided in the processing liquid supply units 30_1 to 30_3), a first change unit (for example, any one of the plurality of flow rate change units 60_1 to 60_3), a second change unit (for example, any other one of the plurality of flow rate change units 60_1 to 60_3), and a control unit (for example, a control unit 71). The processing tank is used to immerse a plurality of substrates (for example, wafer W) in the processing liquid for etching. The first group of nozzles and the second group of nozzles are disposed inside the processing tank and at a position below the plurality of substrates, for spraying the processing liquid into the processing tank. The first changing unit is used to change the flow rate of the processing liquid ejected from the first nozzle group. The second changing unit is used to change the flow rate of the processing liquid ejected from the second nozzle group. During the etching process, the control unit controls the first and second changing units to perform flow rate changing processing, which increases and decreases the flow rates of the processing liquid ejected from the first nozzle group and the processing liquid ejected from the second nozzle group in different ways. Therefore, according to the substrate processing apparatus of the embodiment, in the technique of etching multiple substrates simultaneously, the uniformity of the etching process can be improved.

[0123] Alternatively, the control unit can perform multiple flow rate changes. This can improve the effectiveness of disrupting the flow of the treatment fluid.

[0124] Alternatively, the control unit may repeatedly perform flow rate changes from the start of the etching process until its completion. This further enhances the effect of disrupting the flow of the processing fluid.

[0125] Alternatively, the control unit may perform the processing of changes in the flow rate of the treated liquid ejected from the first spray nozzle group and the processing of changes in the flow rate of the treated liquid ejected from the second spray nozzle group at different timings. By making the timing of the changes in the ejection flow rates of the first and second spray nozzle groups different, the flow of the treated liquid in the treatment tank can be disrupted.

[0126] Alternatively, during flow rate change processing, the control unit may increase the flow rate of the treatment fluid ejected from the first spray nozzle group while simultaneously decreasing the flow rate of the treatment fluid ejected from the second spray nozzle group. By changing the direction of flow rate changes between the first and second spray nozzle groups in this way, the flow of the treatment fluid within the treatment tank can be disrupted.

[0127] Alternatively, the substrate processing apparatus according to the embodiment (for example, substrate processing apparatus 1) includes an overflow tank (for example, an outer tank 12) and a circulation path (for example, a circulation path 50). The overflow tank is used to store the processing liquid overflowing from the processing tank. The circulation path connects the overflow tank to a first group of nozzles and a second group of nozzles. Alternatively, the circulation path may include a discharge path (for example, discharge path 51), a first supply path (for example, any one of multiple supply paths 52_1 to 52_3), a second supply path (for example, any other one of multiple supply paths 52_1 to 52_3), a first bypass path (for example, any one of multiple bypass paths 53_1 to 53_3), and a second bypass path (for example, any other one of multiple bypass paths 53_1 to 53_3). The discharge path is connected to the overflow tank. The first supply path branches off from the discharge path to connect to the first group of nozzles. The second supply path branches off from the discharge path and connects to the second group of nozzles. The first bypass path branches off from the first supply path and connects to the overflow tank. The second bypass path branches off from the second supply path and connects to the overflow tank. In this case, the first changeover section can be provided in the first bypass path. Additionally, the second changeover section can be provided in the second bypass path. With the aforementioned structure, the discharge flow rates of the first and second groups of nozzles can be varied while keeping the circulation flow rate constant. Therefore, for example, the pump load is kept constant, thereby suppressing the discharge of foreign matter from the filter.

[0128] Alternatively, the substrate processing apparatus according to the embodiment (for example, substrate processing apparatus 1A) may include an overflow tank (for example, an outer tank 12) and a circulation path (for example, a circulation path 50A). The overflow tank is used to store the processing liquid overflowing from the processing tank. The circulation path connects the overflow tank to a first group of nozzles and a second group of nozzles. Alternatively, the circulation path may include a discharge path (for example, discharge path 51), a first supply path (for example, any one of a plurality of supply paths 52_1 to 52_3), a second supply path (for example, any other one of a plurality of supply paths 52_1 to 52_3), and a bypass path (for example, bypass path 53A). The discharge path is connected to the overflow tank. The first supply path branches off from the discharge path to connect to the first group of nozzles. The second supply path branches off from the discharge path to connect to the second group of nozzles. The bypass path branches off from the discharge path to connect to the overflow tank. In this case, a first changeover section may also be provided in the first supply path. Alternatively, the second changing section can be located in the second supply path. With this structure, the discharge flow rates of the first and second nozzle groups can be varied while keeping the circulation flow rate constant. Therefore, for example, the pump load is kept constant, thereby suppressing the discharge of foreign matter from the filter.

[0129] Alternatively, the control unit controls the first and second change units to perform flow rate change processing, thereby fixing the flow rate of the processed fluid flowing through the circulation path. This, for example, keeps the pump load constant, thereby suppressing the discharge of foreign matter from the filter.

[0130] Furthermore, the substrate processing apparatus according to the embodiment (as an example, substrate processing apparatus 1B) includes a processing tank (as an example, inner tank 11), a gas supply unit (as an example, gas supply unit 80), a changing unit (as an example, flow rate changing unit 85), and a control unit (as an example, control unit 71). The processing tank is used to immerse multiple substrates (as an example, wafer W) having multiple metal layers in a processing liquid for etching. The gas supply unit is disposed inside the processing tank and below the multiple substrates, and is used to spray gas (as an example, nitrogen) into the interior of the processing tank. The changing unit is used to change the flow rate of the gas sprayed from the gas supply unit. The control unit controls the changing unit to change the flow rate of the gas supplied from the gas supply unit to a second flow rate (as an example, 0) that is less than the first flow rate after gas is sprayed from the gas supply unit at a first flow rate (as an example, first flow rate F11) during a first period (as an example, period T1) from the start of the etching process. Therefore, according to the substrate processing apparatus of the embodiment, in the technique of etching multiple substrates having multiple metal layers formed together, the uniformity of the etching process can be improved.

[0131] It should be considered that all points in the embodiments disclosed herein are illustrative rather than restrictive. In fact, the above embodiments can be implemented in various ways. Furthermore, the above embodiments can be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

Claims

1. A substrate processing apparatus comprising: A processing tank is used to immerse multiple substrates in a processing solution for etching. The first and second spray outlet groups are disposed inside the processing tank and below the plurality of substrates, for spraying the processing liquid into the processing tank. A first modification unit is used to modify the flow rate of the treatment liquid ejected from the first group of nozzles; The second modification unit is used to modify the flow rate of the treatment liquid ejected from the second spray nozzle group; An overflow tank for storing the treatment liquid that overflows from the treatment tank; A circulation path connects the overflow trough to the first group of nozzles and the second group of nozzles, wherein the circulation path comprises: a discharge path connected to the overflow trough; a first supply path branching from the discharge path to connect to the first group of nozzles; a second supply path branching from the discharge path to connect to the second group of nozzles; a first bypass path branching from the first supply path to connect to the overflow trough; and a second bypass path branching from the second supply path to connect to the overflow trough; and The control unit controls the first modification unit and the second modification unit during the etching process to perform flow rate modification processing, which increases and decreases the flow rate of the processing liquid ejected from the first bypass path and the second bypass path, respectively, while maintaining the flow rate of the processing liquid flowing through the circulation path at a fixed flow rate.

2. The substrate processing apparatus according to claim 1, characterized in that, The control unit performs the aforementioned flow change processing multiple times.

3. The substrate processing apparatus according to claim 2, characterized in that, The control unit repeatedly performs the flow rate change process from the start of the etching process until the end of the etching process.

4. The substrate processing apparatus according to any one of claims 1 to 3, characterized in that, The control unit performs the processing of changing the flow rate of the treatment liquid ejected from the first nozzle group and the processing of changing the flow rate of the treatment liquid ejected from the second nozzle group at different time intervals during the flow rate change processing.

5. The substrate processing apparatus according to any one of claims 1 to 3, characterized in that, In the flow rate change processing, the control unit increases the flow rate of the treatment liquid ejected from the first nozzle group and decreases the flow rate of the treatment liquid ejected from the second nozzle group at a given time.

6. The substrate processing apparatus according to any one of claims 1 to 3, characterized in that, The first modification unit is located in the first bypass path. The second modification unit is located in the second bypass path.

7. A substrate processing apparatus comprising: A processing tank is used to immerse multiple substrates in a processing solution for etching. The first and second spray outlet groups are disposed inside the processing tank and below the plurality of substrates, for spraying the processing liquid into the processing tank. A first modification unit is used to modify the flow rate of the treatment liquid ejected from the first group of nozzles; The second modification unit is used to modify the flow rate of the treatment liquid ejected from the second spray nozzle group; An overflow tank for storing the treatment liquid that overflows from the treatment tank; A circulation path connects the overflow trough to the first group of nozzles and the second group of nozzles, wherein the circulation path includes: a discharge path connected to the overflow trough; a first supply path branching off from the discharge path to connect to the first group of nozzles; a second supply path branching off from the discharge path to connect to the second group of nozzles; and a bypass path branching off from the discharge path to connect to the overflow trough; and The control unit controls the first modification unit and the second modification unit during the etching process to perform flow rate modification processing, which increases and decreases the flow rate of the processing liquid ejected from the bypass path, while maintaining the flow rate of the processing liquid flowing through the circulation path at a fixed flow rate. This process increases and decreases the flow rate of the processing liquid ejected from the first nozzle group and the flow rate of the processing liquid ejected from the second nozzle group in different ways.

8. The substrate processing apparatus according to claim 7, characterized in that, The control unit performs the aforementioned flow change processing multiple times.

9. The substrate processing apparatus according to claim 8, characterized in that, The control unit repeatedly performs the flow rate change process from the start of the etching process until the end of the etching process.

10. The substrate processing apparatus according to any one of claims 7 to 9, characterized in that, The control unit performs the processing of changing the flow rate of the treatment liquid ejected from the first nozzle group and the processing of changing the flow rate of the treatment liquid ejected from the second nozzle group at different time intervals during the flow rate change processing.

11. The substrate processing apparatus according to any one of claims 7 to 9, characterized in that, In the flow rate change processing, the control unit increases the flow rate of the treatment liquid ejected from the first nozzle group and decreases the flow rate of the treatment liquid ejected from the second nozzle group at a given time.

12. The substrate processing apparatus according to any one of claims 7 to 9, characterized in that, The first modification unit is located in the first supply path. The second modification unit is located in the second supply path.

13. A substrate processing method, comprising the following steps: The multiple substrates are etched using a processing tank in which multiple substrates are immersed in a processing solution. In the etching process, the processing liquid is ejected into the processing tank from a first group of nozzles and a second group of nozzles located inside the processing tank and below the plurality of substrates. During the etching process, an overflow tank is used to store the processing liquid overflowing from the processing tank. The overflow trough is connected to the first nozzle group and the second nozzle group via a circulation flow path, wherein the circulation flow path includes: a discharge path connected to the overflow trough; a first supply path branching off from the discharge path to connect to the first nozzle group; a second supply path branching off from the discharge path to connect to the second nozzle group; a first bypass path branching off from the first supply path to connect to the overflow trough; and a second bypass path branching off from the second supply path to connect to the overflow trough. In the process of spraying the treatment liquid, by increasing and decreasing the flow rate of the treatment liquid sprayed from the first bypass path and the second bypass path respectively, the flow rate of the treatment liquid flowing through the circulation path is maintained at a fixed flow rate, while the flow rate of the treatment liquid sprayed from the first spray outlet group and the flow rate of the treatment liquid sprayed from the second spray outlet group are increased and decreased in different ways.

14. A substrate processing method, comprising the following steps: The multiple substrates are etched using a processing tank in which multiple substrates are immersed in a processing solution. In the etching process, the processing liquid is ejected into the processing tank from a first group of nozzles and a second group of nozzles located inside the processing tank and below the plurality of substrates. In the etching process, an overflow tank is used to store the processing liquid overflowing from the processing tank; wherein the overflow tank is connected to the first group of nozzles and the second group of nozzles via a circulation path, wherein the circulation path includes: a discharge path connected to the overflow tank; a first supply path branching off from the discharge path to connect to the first group of nozzles; a second supply path branching off from the discharge path to connect to the second group of nozzles; and a bypass path branching off from the discharge path to connect to the overflow tank; In the process of spraying the treatment liquid, by increasing and decreasing the flow rate of the treatment liquid sprayed from the bypass path, the flow rate of the treatment liquid flowing through the circulation path is maintained at a fixed flow rate, while the flow rates of the treatment liquid sprayed from the first group of spray outlets and the flow rates of the treatment liquid sprayed from the second group of spray outlets are increased and decreased in different ways.

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