Etching apparatus and etching method

Abstract

To provide a technology that can reduce detachment of a catalyst layer due to the supply of an etching solution.SOLUTION: An etching apparatus according to an embodiment of the present disclosure includes a holder that holds a substrate having a catalytic layer containing a precious metal on its surface, a first slit nozzle that ejects an etching solution onto the substrate, and a first drive source that moves the first slit nozzle relative to the holder, and the etching solution is a chemical solution that etches an area of the substrate that comes into contact with the catalytic layer through a catalytic reaction with the catalytic layer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an etching apparatus and an etching method. [Background technology]

[0002] A technique is known in which an etching solution is supplied to a semiconductor substrate having a region covered with a catalyst layer made of a noble metal, and etching of the semiconductor substrate occurs at the position of the catalyst layer (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-50378 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique that can reduce detachment of a catalyst layer due to the supply of an etching solution. [Means for solving the problem]

[0005] An etching apparatus according to one embodiment of the present disclosure includes a holder for holding a substrate having a catalytic layer containing a precious metal on its surface, a first slit nozzle for ejecting an etching solution onto the substrate, and a first drive source for moving the first slit nozzle relative to the holder, wherein the etching solution is a chemical solution that etches an area of ​​the substrate that comes into contact with the catalytic layer through a catalytic reaction with the catalytic layer. [Effects of the Invention]

[0006] According to the present disclosure, it is possible to reduce detachment of the catalyst layer due to the supply of an etching solution. [Brief explanation of the drawings]

[0007] [Figure 1]1 is a cross-sectional view showing an etching apparatus according to an embodiment. [Figure 2] 1 is a cross-sectional view showing an etching apparatus according to an embodiment. [Figure 3] FIG. 1 is a plan view showing an etching apparatus according to an embodiment. [Figure 4] FIG. 2 is a diagram showing an etching liquid supply unit. [Figure 5] FIG. 10 is a cross-sectional view showing a modified example of the etching liquid supply unit. [Figure 6] FIG. 10 is a diagram showing a modified example of the first supply system. [Figure 7] FIG. 1 is a diagram (1) showing an example of the operation of an etching apparatus. [Figure 8] FIG. 2 is a diagram showing an example of the operation of the etching apparatus. [Figure 9] FIG. 3 is a diagram showing an example of the operation of the etching apparatus. [Figure 10] FIG. 4 is a diagram showing an example of the operation of the etching apparatus. [Figure 11] FIG. 5 is a diagram (5) showing an example of the operation of the etching device. [Figure 12] FIG. 10 is a diagram showing an etching apparatus according to a modified example of the embodiment. [Figure 13] 1 is a flowchart illustrating an etching method according to an embodiment. [Figure 14] FIG. 1 is a cross-sectional view (1) showing an etching method according to an embodiment. [Figure 15] FIG. 2 is a cross-sectional view (2) showing the etching method according to the embodiment. [Figure 16] FIG. 3 is a cross-sectional view (3) showing the etching method according to the embodiment. [Figure 17] FIG. 4 is a cross-sectional view (4) showing the etching method according to the embodiment. [Figure 18] FIG. 5 is a cross-sectional view (5) showing the etching method according to the embodiment. [Figure 19] FIG. 6 is a cross-sectional view (6) showing the etching method according to the embodiment. [Figure 20] 10 is an SEM image showing a cross section of a substrate when an etching solution is supplied by slit supply. [Figure 21] 10 is an SEM image showing a cross section of a substrate when an etching solution is supplied by spin supply. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, non-limiting exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings. In all the accompanying drawings, the same or corresponding reference numerals are used to designate the same or corresponding members or components, and redundant descriptions will be omitted.

[0009] In the following explanation, an XYZ Cartesian coordinate system is used, but this coordinate system is defined for the purpose of explanation and does not limit the attitude of the etching apparatus. The XY plane view is called a plan view, and when viewed from an arbitrary point, the +Z direction may be called the upper side, top, or top, and the -Z direction may be called the lower side, bottom, or bottom.

[0010] [Etching equipment] An etching apparatus 1 according to an embodiment will be described with reference to Fig. 1 to Fig. 4. Fig. 1 and Fig. 2 are cross-sectional views showing the etching apparatus 1 according to the embodiment. Fig. 3 is a plan view showing the etching apparatus 1 according to the embodiment. Fig. 4 is a view showing an etching liquid supply unit 30.

[0011] The etching apparatus 1 includes a processing chamber 10, a substrate holder 20, an etching liquid supply unit 30, an inert gas supply unit 40, a liquid receiver 50, a wind pressure detection sensor 60, and a control unit 90.

[0012] The processing vessel 10 accommodates a substrate holder 20. A sidewall of the processing vessel 10 is provided with a loading / unloading port (not shown) for loading and unloading the substrate W. The substrate W is, for example, a silicon substrate. The substrate W has a catalytic layer containing a noble metal on its surface. The substrate W may have a first region coated with the catalytic layer containing the noble metal and a second region not coated with the catalytic layer containing the noble metal. The noble metal is, for example, gold (Au), silver (Ag), platinum (Pt), or ruthenium (Ru).

[0013] The substrate holder 20 includes a holder 21, a rotation shaft 22, and a drive unit 23. The holder 21 has, for example, a circular shape in a plan view. The holder 21 holds the substrate W in a horizontal position. The holder 21 has, for example, a horizontal upper surface with a suction port formed therein, and holds the substrate W horizontally by adsorbing the substrate W through the suction port. The holder 21 may include an internal heater and be configured to heat the substrate W. The holder 21 may include an internal flow path for circulating a temperature-controlling fluid and be configured to heat or cool the substrate W. The upper end of the rotation shaft 22 is connected to the lower surface of the holder 21. The drive unit 23 is connected to the lower end of the rotation shaft 22. The drive unit 23 can rotate the holder 21 and the substrate W by rotating the rotation shaft 22. The drive unit 23 includes, for example, a motor.

[0014] The etching liquid supply unit 30 includes a first slit nozzle 31 , a first driving source 32 , and a first supply system 33 .

[0015] The first slit nozzle 31 is provided above the upper surface of the substrate W held by the holder 21. The first slit nozzle 31 is an elongated nozzle extending along the X-axis. The first slit nozzle 31 has a first inlet 31a and a first outlet 31b. The first inlet 31a is provided at the upper end of the first slit nozzle 31. A first supply system 33 is connected to the first inlet 31a. The first outlet 31b is provided at the lower end of the first slit nozzle 31. The first outlet 31b is, for example, a rectangular opening extending along the X-axis. The first slit nozzle 31 discharges the etching liquid E1 introduced from the first supply system 33 via the first inlet 31a from the first outlet 31b toward the substrate W held on the holder 21.

[0016] The first drive source 32 moves the first slit nozzle 31 relative to the holder 21. The first drive source 32 has, for example, two or more linear motion mechanisms, and moves the first slit nozzle 31 in the horizontal and vertical directions.

[0017] The first supply system 33 includes a storage container 33a, a pipe 33b, a pressurized gas source 33c, a pipe 33d, an on-off valve 33e, and a temperature control pipe 33f.

[0018] The storage container 33a stores the etching solution E1. The etching solution E1 is a chemical solution that etches the area of ​​the substrate W that comes into contact with the catalytic layer formed on the substrate W through a catalytic reaction with the catalytic layer. In other words, the etching solution E1 is a chemical solution that etches the area of ​​the substrate W that comes into contact with the catalytic layer through a MacEtch (Metal Assisted Chemical Etching) reaction. The etching solution E1 contains a corrosive and an oxidizing agent. The corrosive is, for example, hydrofluoric acid (HF). The corrosive may be nitric acid (HNO3). The oxidizing agent is, for example, hydrogen peroxide (H2O2).

[0019] One end of the pipe 33b is inserted into the storage container 33a from above the storage container 33a, and the other end is connected to a pressurized gas source 33c.

[0020] The pressurized gas source 33c supplies pressurized gas such as nitrogen (N2) gas into the storage container 33a via the pipe 33b, thereby pressurizing the inside of the storage container 33a, whereby the etching solution E1 in the storage container 33a is introduced into the first slit nozzle 31 via the pipe 33d.

[0021] One end of the pipe 33d is inserted into the storage container 33a from above the storage container 33a, and the other end is connected to the first inlet 31a of the first slit nozzle 31.

[0022] The on-off valve 33e is provided midway along the pipe 33d. The on-off valve 33e is a valve that controls the on / off of the flow of the etching liquid E1. When the on-off valve 33e is open, the etching liquid E1 is allowed to flow through the first slit nozzle 31, and when it is closed, the etching liquid E1 is not allowed to flow through the first slit nozzle 31.

[0023] The temperature control pipe 33f is provided midway through the pipe 33d. The temperature control pipe 33f covers at least a portion of the pipe 33d. A temperature control fluid flows through the temperature control pipe 33f. The temperature control pipe 33f adjusts the temperature of the etching liquid E1 flowing through the pipe 33d.

[0024] The inert gas supply unit 40 includes a second slit nozzle 41, a second drive source 42, and a second supply system 43.

[0025] The second slit nozzle 41 is an elongated nozzle extending along the X-axis. The second slit nozzle 41 is provided parallel to the first slit nozzle 31. The second slit nozzle 41 has a second inlet 41a and a second outlet 41b. The second inlet 41a is provided at the upper end of the second slit nozzle 41. A second supply system 43 is connected to the second inlet 41a. Nitrogen gas is introduced as an inert gas from the second supply system 43 into the second inlet 41a. The second outlet 41b is provided at the lower end of the second slit nozzle 41. The second outlet 41b is, for example, a rectangular opening extending along the X-axis. The second slit nozzle 41 discharges nitrogen gas, introduced from the second supply system 43 via the second inlet 41a, from the second outlet 41b toward the substrate W held on the holder 21.

[0026] The second drive source 42 changes the distance L1 between the first slit nozzle 31 and the second slit nozzle 41 by moving the second slit nozzle 41 relative to the first slit nozzle 31. The second drive source 42 has, for example, two or more linear motion mechanisms, and moves the second slit nozzle 41 in the horizontal and vertical directions.

[0027] The second supply system 43 is connected to the second inlet 41a and introduces nitrogen gas into the second slit nozzle 41.

[0028] The liquid receiver 50 is provided around the substrate W held on the holder 21, and receives the etching liquid E1 that splashes from the outer periphery of the substrate W. This makes it possible to prevent the liquid from splashing when the substrate W rotates.

[0029] The wind pressure detection sensor 60 is attached to the first slit nozzle 31 on a side closer to the second slit nozzle 41. The wind pressure detection sensor 60 detects the wind pressure of the nitrogen gas discharged from the second slit nozzle 41 and transmits the detected wind pressure to the control unit 90. A plurality of wind pressure detection sensors 60 may be attached to the first slit nozzle 31 along the X-axis.

[0030] The control unit 90 is an electronic circuit such as a CPU (Central Processing Unit), FPGA (Field Programmable Gate Array), ASIC (Application Specific Integrated Circuit), etc. The control unit 90 executes various control operations described in this specification by executing instruction codes stored in a memory or by being a circuit designed for a specific application.

[0031] The control unit 90 may control the second driving source 42 based on the wind pressure detected by the wind pressure detection sensor 60, thereby changing the distance L1.

[0032] When the etching liquid E1 is supplied to the substrate W, the etching liquid E1 penetrates between the catalytic layer and the substrate W, and etching proceeds between the catalytic layer and the substrate W. Therefore, if a liquid flow of the etching liquid E1 occurs on the substrate W during supply, the catalytic layer may be detached from the position where it was formed on the substrate W.

[0033] The etching apparatus 1 according to this embodiment includes a holder 21, a first slit nozzle 31, and a first drive source 32. The holder 21 holds a substrate W having a catalytic layer containing a precious metal on its surface. The first slit nozzle 31 discharges an etching solution E1, which is a chemical liquid that etches the area of ​​the substrate W that comes into contact with the catalytic layer through a catalytic reaction with the catalytic layer. The first drive source 32 moves the first slit nozzle 31 relative to the holder 21. In this case, the etching solution E1 can be supplied without or with little liquid flow on the substrate W. This reduces detachment of the catalytic layer due to the supply of the etching solution E1.

[0034] In contrast, when a predetermined liquid is discharged onto the substrate W from a discharge nozzle and the substrate W is rotated to supply the etching liquid E1 onto the substrate W by spin supply, which spreads the predetermined liquid over the surface of the substrate W, a liquid flow occurs on the substrate W when the substrate W is rotated, etc. If a liquid flow occurs on the substrate W, the catalyst layer is likely to detach from the substrate W.

[0035] The etching liquid supply unit 30 may have a temperature adjustment function. FIG. 5 is a cross-sectional view showing a modified example of the etching liquid supply unit 30. As shown in FIG. 5, the etching liquid supply unit 30 may have a temperature adjustment mechanism 34. The temperature adjustment mechanism 34 has a temperature adjustment fluid flow path 34a, a temperature adjustment fluid inlet 34b, and a temperature adjustment fluid supply system 34c. The temperature adjustment fluid flow path 34a is provided inside the first slit nozzle 31. The temperature adjustment fluid inlet 34b is connected to the temperature adjustment fluid flow path 34a. The temperature adjustment fluid supply system 34c supplies a temperature adjustment fluid to the temperature adjustment fluid flow path 34a via the temperature adjustment fluid inlet 34b. The temperature adjustment mechanism 34 controls the temperature of the etching liquid E1 in the first slit nozzle 31 to be constant, for example, by supplying the temperature adjustment fluid from the temperature adjustment fluid supply system 34c to the temperature adjustment fluid flow path 34a via the temperature adjustment fluid inlet 34b.

[0036] Alternatively, the first supply system 33 may be configured to separately store a corrosive agent (e.g., hydrofluoric acid) and an oxidizing agent (e.g., hydrogen peroxide), mix them in the first supply system 33, and introduce them into the first slit nozzle 31. In this case, deactivation of the stored hydrogen peroxide can be prevented. FIG. 6 is a diagram showing a modified example of the first supply system 33. As shown in FIG. 6, the first supply system 33 includes a pure water source 33g, a pipe 33d, a first storage container 33h, a pipe 33i, a pressurized gas source 33j, a pipe 33k, a second storage container 33l, a pipe 33m, a pressurized gas source 33n, a pipe 33o, an on-off valve 33e, and a temperature control pipe 33f.

[0037] The pure water source 33g supplies pure water via a pipe 33d to the first slit nozzle 31. The pure water source 33g is, for example, factory DIW (De-Ionized Water).

[0038] First storage container 33h stores hydrofluoric acid. One end of pipe 33i is inserted into first storage container 33h from above, and the other end is connected to pressurized gas source 33j. One end of pipe 33k is inserted into first storage container 33h from above, and the other end is connected to pipe 33d. Pressurized gas source 33j supplies nitrogen gas as pressurized gas into first storage container 33h via pipe 33i, thereby pressurizing the inside of first storage container 33h. As a result, hydrofluoric acid in first storage container 33h is introduced into pipe 33d via pipe 33k.

[0039] Second storage container 33l stores hydrogen peroxide. One end of pipe 33m is inserted into second storage container 33l from above, and the other end is connected to pressurized gas source 33n. One end of pipe 33o is inserted into second storage container 33l from above, and the other end is connected to pipe 33d. Pressurized gas source 33n supplies nitrogen gas as pressurized gas into second storage container 33l via pipe 33m, thereby pressurizing the inside of second storage container 33l. As a result, hydrogen peroxide in second storage container 33l is introduced into pipe 33d via pipe 33o.

[0040] Furthermore, the etching apparatus 1 may include a state detection sensor instead of or in addition to the wind pressure detection sensor 60. The state detection sensor is attached, for example, to the first slit nozzle 31 on a side closer to the second slit nozzle 41. The state detection sensor detects the state of the etching liquid E1 discharged from the first slit nozzle 31 and transmits the detected state to the control unit 90. The control unit 90 may change the distance L1 by controlling the second drive source 42 based on the state of the etching liquid E1 detected by the state detection sensor. The state of the etching liquid E1 includes, for example, the flow of the etching liquid E1. The state detection sensor is, for example, a camera. A plurality of state detection sensors may be attached along the X-axis.

[0041] Furthermore, the etching apparatus 1 may include a discharge pressure sensor instead of or in addition to the wind pressure detection sensor 60. The discharge pressure sensor is attached to, for example, the first slit nozzle 31. The discharge pressure sensor detects, for example, the discharge pressure of the etching solution E1 discharged from the first slit nozzle 31, and transmits the detected discharge pressure to the control unit 90. The control unit 90 may change the distance L1 by controlling the second drive source 42 based on the discharge pressure of the etching solution E1 detected by the discharge pressure sensor.

[0042] [Operation of the Etching Apparatus] An example of the operation of the etching apparatus 1 will be described with reference to FIGS. 7 to 11. FIGS. 7 to 11 are diagrams showing an example of the operation of the etching apparatus 1. In FIGS. 7 to 11, (a) is a plan view, and (b) is a side view. In (b), the holding table 21 is not shown. The operation of the etching apparatus 1 is performed under the control of a control unit 90.

[0043] 7, before the supply of etching liquid E1 begins, the holder 21 holds the substrate W in a horizontal position. At this time, the first slit nozzle 31 and the second slit nozzle 41 are positioned so as not to overlap with the holder 21 in a plan view, for example, on the negative side of the Y axis direction relative to the holder 21. The second slit nozzle 41 is positioned on the positive side of the Y axis direction relative to the first slit nozzle 31. In other words, the second slit nozzle 41 is positioned ahead of the first slit nozzle 31 in the traveling direction.

[0044] Next, as shown in FIG. 8 , the first slit nozzle 31 moves toward the positive side in the Y-axis direction and ejects the etching solution E1 from the first outlet 31b onto the upper surface of the substrate. The second slit nozzle 41 moves toward the positive side in the Y-axis direction and ejects nitrogen gas from the second outlet 41b onto the upper surface of the substrate. In this case, the nitrogen gas ejected from the second outlet 41b reduces the liquid flow of the etching solution E1 ejected from the first outlet 31b, which spreads forward in the direction of travel of the first slit nozzle 31. This reduces the detachment of the catalyst layer due to the supply of the etching solution E1. The movement speed of the first slit nozzle 31 and the second slit nozzle 41 is, for example, 5 mm / sec or more and 20 mm / sec or less. At the initial stage of ejection of the etching solution E1, the control unit 90 controls the first drive source 32 and the second drive source 42 so that the distance L1 becomes the first distance. At the beginning of the discharge of the etching liquid E1, the flow rate and discharge pressure of the etching liquid E1 between the upper surface of the substrate W and the first slit nozzle 31 decrease due to the etching liquid E1 flowing out of the substrate W and into the gap between the substrate W and the liquid receiving part 50. In this case, the etching liquid E1 is unlikely to spread forward in the direction of travel of the first slit nozzle 31. Therefore, the control part 90 sets the distance L1 to a relatively long first distance.

[0045] Next, as shown in FIG. 9 , the first slit nozzle 31 moves further in the Y-axis direction positive while discharging the etching solution E1 from the first outlet 31b, and the second slit nozzle 41 moves in the Y-axis direction positive while discharging nitrogen gas from the second outlet 41b. In this case, the nitrogen gas discharged from the second outlet 41b reduces the liquid flow of the etching solution E1 discharged from the first outlet 31b that spreads forward in the direction of travel of the first slit nozzle 31. This makes it easier to reduce detachment of the catalyst layer due to the supply of the etching solution E1. During the middle stage of discharging the etching solution E1, the control unit 90 controls the first drive source 32 and the second drive source 42 so that the distance L1 becomes the second distance. The second distance is shorter than the first distance. In the middle of the discharge of the etching liquid E1, the flow of the etching liquid E1 out of the substrate W and the flow of the etching liquid E1 into the gap between the substrate W and the liquid receiving part 50 are small, so the flow rate and discharge pressure of the etching liquid E1 between the upper surface of the substrate W and the first slit nozzle 31 increase. In this case, the etching liquid E1 tends to spread forward in the direction of travel of the first slit nozzle 31. Therefore, the control part 90 sets the distance L1 to a relatively short second distance.

[0046] Next, as shown in FIG. 10 , the first slit nozzle 31 moves further in the Y-axis direction while discharging the etching solution E1 from the first outlet 31b, and the second slit nozzle 41 moves in the Y-axis direction while discharging nitrogen gas from the second outlet 41b. In this case, the nitrogen gas discharged from the second outlet 41b reduces the liquid flow of the etching solution E1 discharged from the first outlet 31b that spreads forward in the direction of travel of the first slit nozzle 31. This makes it easier to reduce detachment of the catalyst layer due to the supply of the etching solution E1. During the latter stage of discharging the etching solution E1, the control unit 90 controls the first drive source 32 and the second drive source 42 so that the distance L1 becomes a third distance. The third distance is longer than the second distance. The third distance may be the same as the first distance. In the latter stage of discharging the etching liquid E1, the flow rate and discharge pressure of the etching liquid E1 between the upper surface of the substrate W and the first slit nozzle 31 decrease due to the etching liquid E1 flowing out of the substrate W and the etching liquid E1 flowing into the gap between the substrate W and the liquid receiving part 50. In this case, the etching liquid E1 is less likely to spread forward in the direction of travel of the first slit nozzle 31. Therefore, the control part 90 sets the distance L1 to a relatively long third distance.

[0047] 11, when the first slit nozzle 31 is positioned on the Y-axis direction positive side of the substrate W, the first slit nozzle 31 stops discharging the etching liquid E1, and the second slit nozzle 41 stops discharging the nitrogen gas. In this way, the etching liquid E1 is supplied to the entire top surface of the substrate W.

[0048] In the above example, the distance L1 between the first slit nozzle 31 and the second slit nozzle 41 is changed in three stages: the initial stage, the middle stage, and the final stage of ejection. However, this is not limiting. The distance L1 may be changed in multiple stages, such as four or more stages. The distance L1 may also be changed linearly.

[0049] [Modification of Etching Apparatus] An etching apparatus 1A according to a modified example will be described with reference to Fig. 12. Fig. 12 is a diagram showing an etching apparatus 1A according to a modified example of the embodiment.

[0050] 12, the etching apparatus 1A differs from the etching apparatus 1 in that it does not include an inert gas supply unit 40. The other configurations may be the same as those of the etching apparatus 1.

[0051] The etching apparatus 1A, like the etching apparatus 1, includes a holder 21, a first slit nozzle 31, and a first drive source 32. The holder 21 holds a substrate W having a catalytic layer containing a precious metal on its surface. The first slit nozzle 31 ejects an etching solution E1, which is a chemical liquid that etches the area of ​​the substrate W that comes into contact with the catalytic layer through a catalytic reaction with the catalytic layer. The first drive source 32 moves the first slit nozzle 31 relative to the holder 21. In this case, the etching solution E1 can be supplied on the substrate W with little or no liquid flow. This reduces detachment of the catalytic layer due to the supply of the etching solution E1.

[0052] [Etching Method] An etching method according to an embodiment will be described with reference to Fig. 13 to Fig. 19. Fig. 13 is a flowchart showing the etching method according to an embodiment. Figs. 14 to 19 are cross-sectional views showing the etching method according to an embodiment. As shown in Fig. 13, the etching method according to an embodiment includes a preparation step S1, a pretreatment step S2, an etching step S3, and a post-treatment step S4.

[0053] In the preparation step S1, as shown in Fig. 14, a substrate 101 having a catalyst layer 102 containing a noble metal on its surface is prepared. The substrate 101 is, for example, a silicon substrate. The catalyst layer 102 is formed by, for example, film formation using chemical vapor deposition (CVD) or physical vapor deposition (PVD) and patterning using lithography. Residues 103 containing a noble metal may adhere to the surface of the substrate 101.

[0054] The pretreatment step S2 is performed after the preparation step S1. In the pretreatment step S2, as shown in FIG. 15 , a pretreatment liquid 104 is supplied to the substrate 101 to remove residues 103 adhering to the surface of the substrate 101. The pretreatment step S2 is performed using, for example, an etching apparatus 1. Specifically, the first slit nozzle 31 discharges the pretreatment liquid 104 from the first outlet 31b, and the second slit nozzle 41 discharges nitrogen gas from the second outlet 41b, thereby supplying the pretreatment liquid 104 to the substrate 101. In this case, detachment of the catalyst layer 102 due to the supply of the pretreatment liquid 104 is easily reduced. Furthermore, the pretreatment step S2 and the etching step S3 can be performed consecutively in the same etching apparatus 1. In the pretreatment step S2, the pretreatment liquid 104 may be supplied to the substrate 101 by spin supply. In the pretreatment step S2, the pretreatment liquid 104 may be supplied to the substrate 101 by immersing the substrate 101 in the pretreatment liquid 104. The pretreatment liquid 104 is, for example, a nitric acid-based chemical liquid with a nitric acid concentration of 15% or less, or may be a diluted aqueous solution of hydrofluoric acid of 5 mol / L or less.

[0055] The etching step S3 is performed after the pretreatment step S2. In the etching step S3, as shown in FIG. 16, an etching solution E1 is supplied to the substrate 101. The etching step S3 is performed using an etching apparatus 1. Specifically, the first slit nozzle 31 discharges the etching solution E1 from the first outlet 31b, and the second slit nozzle 41 discharges nitrogen gas from the second outlet 41b, thereby supplying the etching solution E1 to the substrate 101. The etching solution is, for example, an aqueous solution of 10 mol / L or less of hydrofluoric acid and 0.1 mol / L or less of hydrogen peroxide. When the etching solution E1 is held on the surface of the substrate 101 after being supplied, as shown in FIG. 17, a MacEtch reaction proceeds, and only the region where the catalyst layer 102 is formed is selectively and vertically etched, forming a recess 105 in the substrate 101. The time for which the etching solution E1 is held on the surface of the substrate 101 is, for example, 10 minutes or more and 20 minutes or less.

[0056] The post-treatment process S4 is performed after the etching process S3. In the post-treatment process S4, as shown in FIG. 18 , the catalyst layer 102 is removed by supplying a post-treatment liquid 106 to the substrate 101. The post-treatment process S4 is performed using, for example, an etching apparatus 1. Specifically, the first slit nozzle 31 discharges the post-treatment liquid 106 from the first outlet 31b, and the second slit nozzle 41 discharges nitrogen gas from the second outlet 41b, thereby supplying the post-treatment liquid 106 to the substrate 101. In this case, the etching process S3 and the post-treatment process S4 can be performed consecutively in the same etching apparatus 1. In the post-treatment process S4, the post-treatment liquid 106 may be supplied to the substrate 101 by spin supply. In the post-treatment process S4, the post-treatment liquid 106 may be supplied to the substrate 101 by immersing the substrate 101 in the post-treatment liquid 106. When the substrate 101 is immersed in the post-treatment liquid 106, the post-treatment liquid 106 may be stirred. In this case, removal of the catalyst layer 102 can be accelerated. The post-treatment liquid 106 may be a chemical liquid having a higher concentration than the pre-treatment liquid 104. In this case, removal of the catalyst layer 102 can be accelerated. The post-treatment liquid 106 may be, for example, a nitric acid-based chemical liquid of 15% or less, which may be a chemical liquid having a higher concentration than the pre-treatment liquid 104. After a predetermined time has elapsed since the supply of the post-treatment liquid 106, the post-treatment liquid 106 is removed by washing with pure water or the like. As a result, recesses 105 are formed on the surface of the substrate 101, as shown in FIG. 19 .

[0057] [Experimental results] In the experiment, first, a substrate 101 having a catalyst layer 102 containing ruthenium on its surface was prepared. Next, the prepared substrate 101 was placed on the holder 21 of the etching apparatus 1, and the etching solution E1 was supplied to the substrate 101 from the first outlet 31b of the first slit nozzle 31 (hereinafter also referred to as "slit supply"), and the substrate 101 was held for a predetermined time. Next, the cross section of the substrate 101 was observed using a scanning electron microscope (SEM).

[0058] For comparison, a substrate 101 having a catalyst layer 102 containing ruthenium on its surface was prepared, and the etching solution E1 was supplied by spin supply to the prepared substrate 101. Next, the cross section of the substrate 101 was observed with a scanning electron microscope.

[0059] Fig. 20 is an SEM image showing a cross section of the substrate 101 when the etching liquid E1 is supplied by slit supply. Fig. 21 is an SEM image showing a cross section of the substrate 101 when the etching liquid E1 is supplied by spin supply.

[0060] As shown in Figure 20, when etching solution E1 is supplied by slit supply, only the region where catalyst layer 102 is formed is selectively and vertically etched, and recesses 105 are formed on the surface of substrate 101. In contrast, as shown in Figure 21, when etching solution E1 is supplied by spin supply, catalyst layer 102 is detached. These results demonstrate that supplying etching solution E1 by slit supply can reduce detachment of catalyst layer 102 due to supply of etching solution E1.

[0061] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0062] 1. Etching equipment 21 Holding stand 31 First slit nozzle 32 First driving source 101 Substrate 102 Catalyst layer E1 Etching Solution

Claims

1. a holder that holds a substrate having a catalyst layer containing a noble metal on its surface; a first slit nozzle that ejects an etching solution onto the substrate; a first drive source that moves the first slit nozzle relatively to the holder; Equipped with the etching solution is a chemical solution that etches the region of the substrate that is in contact with the catalyst layer through a catalytic reaction with the catalyst layer; Etching equipment.

2. The first slit nozzle is a first inlet through which the etching solution is introduced; a first discharge port that discharges the etching liquid introduced from the first inlet; having The etching apparatus according to claim 1 .

3. a second slit nozzle disposed in parallel with the first slit nozzle and configured to eject an inert gas toward the substrate; The etching apparatus according to claim 1 .

4. a second drive source that changes the distance between the first slit nozzle and the second slit nozzle by moving the second slit nozzle relatively to the first slit nozzle; The etching apparatus according to claim 3 .

5. a state detection sensor for detecting a state of the etching liquid discharged from the first slit nozzle; the second driving source changes the distance based on the state detected by the state detection sensor; The etching apparatus according to claim 4 .

6. a wind pressure detection sensor attached to the first slit nozzle for detecting the wind pressure of the inert gas discharged from the second slit nozzle; the second driving source changes the distance based on the wind pressure detected by the wind pressure detection sensor. The etching apparatus according to claim 4 .

7. a discharge pressure sensor for detecting a discharge pressure of the etching liquid discharged from the first slit nozzle; the second driving source changes the distance based on the discharge pressure of the etching liquid detected by the discharge pressure sensor. The etching apparatus according to claim 4 .

8. The etching solution contains hydrofluoric acid and hydrogen peroxide. The etching apparatus according to claim 1 .

9. The noble metal is gold, silver, platinum, or ruthenium; The etching apparatus according to claim 1 .

10. The substrate has a first region coated with a catalytic layer containing a noble metal and a second region not coated with the catalytic layer. The etching apparatus according to claim 1 .

11. Further comprising a control unit, the control unit performs a process of etching a region of the substrate in contact with the catalyst layer by a catalytic reaction with the catalyst layer by discharging an etching solution from the first slit nozzle onto the substrate held on the holding stage while moving the first slit nozzle relative to the holding stage. The etching apparatus according to any one of claims 1 to 10.

12. a step of holding a substrate having a catalyst layer containing a noble metal on a holding table; a step of discharging an etching solution from a first slit nozzle onto the substrate held on the holding stage while moving the first slit nozzle relative to the holding stage, thereby etching a region of the substrate in contact with the catalyst layer through a reaction between the etching solution and the catalyst layer; The etching method comprises:

Images