JP7562072B2 - Method for forming conductive member - Google Patents

Description

An embodiment of the present invention relates to a method for forming a conductive member.

Patent Document 1 describes a method of forming a laminated film by overlapping coating of a chemically amplified negative resist and a chemically amplified positive resist. Specifically, a chemically amplified negative resist is applied onto a through-hole forming substrate to form a negative resist film, and this negative resist film is selectively exposed. A chemically amplified positive resist is overlappingly applied onto this exposed negative resist film to form a laminated film consisting of a negative resist film and a positive resist film, and this positive resist film is selectively exposed. After that, development is performed to form a pattern consisting of a laminated film consisting of the exposed parts of the negative resist film and the unexposed parts of the positive resist film.

JP 2009-188359 A

An embodiment of the present invention provides a method for forming a conductive member that can efficiently form a conductive member in a predetermined area on a substrate.

A method for forming a conductive member according to one embodiment of the present invention includes the steps of: forming a first resist having a first opening exposing a first region on a substrate having a first region and a second region located inside the first region in a top view; forming a second resist having a second opening exposing the second region and a third opening located on the first resist and exposing a part of the top surface of the first resist continuously on the first resist and on the substrate in the first opening; forming a conductive material on the second resist, on the substrate in the second opening, and on the first resist in the third opening; and removing the conductive material formed on the second resist and on the first resist in the third opening by removing the first resist and the second resist.

An embodiment of the present invention provides a method for forming a conductive member that can efficiently form a conductive member in a predetermined area on a substrate.

4 is a flowchart showing an example of a method for forming a conductive member according to the embodiment. FIG. 2 is a schematic top view illustrating an example of a conductive member formed on a base body. FIG. 3 is a schematic cross-sectional view showing a part of a cross section taken along line III-III in FIG. 2 . FIG. 2 is a schematic cross-sectional view illustrating a step of forming a resist on a substrate. FIG. 11 is a schematic cross-sectional view illustrating a step of exposing a resist using a first mask. FIG. 2 is a schematic cross-sectional view illustrating a step of performing a first heat treatment. FIG. 4 is a schematic cross-sectional view illustrating a developing step. FIG. 4 is a schematic cross-sectional view illustrating a step of forming a resist. FIG. 11 is a schematic cross-sectional view illustrating a step of exposing the resist using a second mask. FIG. 4 is a schematic cross-sectional view for explaining an exposure step. FIG. 11 is a schematic cross-sectional view illustrating a step of performing a second heat treatment. FIG. 11 is a schematic cross-sectional view for explaining a step of exposing the entire surface. FIG. 4 is a schematic cross-sectional view illustrating a developing step. Schematic cross-sectional view for explaining a step of forming a conductive material. FIG. 11 is a schematic cross-sectional view illustrating a step of removing a conductive material. FIG. 4 is a schematic top view showing an example of the arrangement of the wiring forming portion 110. FIG. 17 is a schematic top view showing an example of an enlarged wiring formation portion and its periphery in FIG. 16 before a conductive material is formed. FIG. 18 is a schematic top view showing an example in which a part of the grid pattern in FIG. 17 is enlarged. FIG. 17 is a schematic cross-sectional view showing an example of a portion of a cross section taken along line XIX-XIX in FIG. 16 .

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc. are not necessarily the same as those in reality. Even when the same part is shown, the dimensions and ratios of each part may be different depending on the drawing.
In this specification and each drawing, elements similar to those described above with reference to the previous drawings are given the same reference numerals and detailed descriptions thereof will be omitted as appropriate.

FIG. 1 is a flow chart showing an example of a method for forming a conductive member.
As shown in FIG. 1, the method for forming a conductive member includes a step of forming a first resist (ST210), a step of forming a second resist (ST220), a step of forming a conductive material (ST230), and a step of removing the conductive material (ST240).

FIG. 2 is a schematic top view for explaining an example of a conductive member 20 formed on a base 10 by the method for forming a conductive member shown in FIG.
FIG. 3 is a schematic cross-sectional view taken along line III-III in FIG.
2 and 3, the resist and conductive material used in the process of forming the conductive member 20 described later are removed from the base 10, and only the conductive member 20 is formed. The base 10 is, for example, a sapphire substrate. The conductive member 20 is used, for example, as wiring or a connection terminal. The material of the conductive member 20 may be any conductive material, such as gold (Au), copper (Cu), or an alloy containing at least one of these materials. A method of forming the conductive member 20 according to the embodiment will be described in detail below.

The method for forming a conductive member includes a step of forming a first resist (ST210). More specifically, the step of forming the first resist includes a step of forming a first resist having a first opening exposing the first region on a base having a first region and a second region located inside the first region in a top view. The step of forming the first resist will be described with reference to FIGS. 4 to 7.
FIG. 4 is a schematic cross-sectional view for explaining a step of forming a resist on a substrate.
FIG. 5 is a schematic cross-sectional view for explaining the step of exposing the resist using a first mask.
6 and 7 are schematic cross-sectional views for explaining the developing step.

The step of forming the first resist includes a step of forming a resist 30 on the substrate 10 as shown in FIG. 4. The resist 30 is, for example, a positive photoresist. The positive photoresist has a function in which the exposed portion is more soluble in a developer, and the portion not exposed by development remains. As the positive photoresist, for example, TCIR-ZR8800PB manufactured by Tokyo Ohka Kogyo Co., Ltd. can be used. In the embodiment, for example, the resist 30 can be applied to the substrate 10 using a spin coater device with a drop amount of 1.6 cc to 2.4 cc and a rotation speed of 1600 rpm to 2400 rpm. In the embodiment, for example, the drop amount is 2 cc and the rotation speed is 2000 rpm. As a result, the resist 30 is applied to the substrate 10. The thickness of the resist 30 is, for example, 1.0 μm to 4.0 μm, for example, 2.0 μm.

The step of forming the first resist includes a step of exposing the resist 30 using a first mask. In the step of exposing the resist 30, as shown in FIG. 5, a first mask M1 having an opening is placed on the substrate 10 on which the resist 30 is formed. Next, the resist 30 formed on the substrate 10 is exposed through the first mask M1. The illustrated arrow indicates the exposure direction, and in the embodiment, the exposure direction is a direction perpendicular to the upper surface of the substrate 10. In the embodiment, the exposure amount is 1800 j/m ² or more and 2600 j/m ² or less, for example, 2200 j/m ^2. The resist 30 formed on the substrate 10 includes a portion located on the first region AR1 of the substrate 10 that is exposed, and a portion located on the fourth region AR4 of the substrate 10 that is not exposed by the first mask M1. Hereinafter, the portion of the resist 30 that corresponds to the first region AR1 is referred to as the resist 31, and the portion that corresponds to the fourth region AR4 is referred to as the resist 32.

The step of forming the first resist includes a developing step. The developing step includes a step of performing a first heat treatment on the substrate 10 coated with the resist 30 as shown in Fig. 6, and a step of developing the resist as shown in Fig. 7. In the embodiment, the first heat treatment can be performed by heating at a temperature of 105°C or more and 125°C or less for 70 seconds or more and 110 seconds or less. In the embodiment, the first heat treatment is performed by heating at a temperature of 115°C or more for 90 seconds. The portion of the resist 32 that is not exposed to light is less likely to be exposed to light and developed after the first heat treatment.
Next, the resist 31 is developed with a developer. In an embodiment, the development time can be 85 seconds or more and 125 seconds or less, for example, 105 seconds. This develops the resist 31 in the first region AR1 exposed in the step of exposing the resist 30. As shown in FIG. 7, the resist 31 on the exposed first region AR1 is removed, and a first opening OP1 surrounded by the resist 32 is formed. The first region AR1 of the substrate 10 is exposed in the first opening OP1. In the embodiment, the resist 32 is referred to as a first resist 32.

The method for forming a conductive member includes a step of forming a second resist (ST220). More specifically, the step of forming the second resist includes a step of continuously forming a second resist on the first resist and on the substrate within the first opening, the second resist having a second opening exposing the second region and a third opening located on the first resist and exposing a part of the top surface of the first resist. The step of forming the second resist will be described with reference to FIGS. 8 to 13.
FIG. 8 is a schematic cross-sectional view for explaining the step of forming the resist 40. As shown in FIG.
FIG. 9 is a schematic cross-sectional view for illustrating the step of exposing the resist using the second mask.
FIG. 10 is a schematic cross-sectional view for explaining the exposure step.
FIG. 11 is a schematic cross-sectional view for explaining the step of performing the second heat treatment.
FIG. 12 is a schematic cross-sectional view for explaining the step of exposing the entire surface.
FIG. 13 is a schematic cross-sectional view for explaining the developing step.

The step of forming the resist 40 includes a step of forming the resist 40 on the substrate 10 on which the first resist 32 is formed. In the step of forming the resist 40, as shown in FIG. 8, the resist 40 is formed on the substrate 10 on which the first resist 32 is formed. The resist 40 is, for example, a negative photoresist. The negative photoresist has a function of reducing the solubility of the exposed portion in the developer, and leaving the exposed portion by development. As the negative photoresist, for example, AZ-5218E manufactured by Merck Electronics Co., Ltd. can be used. As shown in FIG. 8, the resist 40 is continuously formed on the first resist 32 and on the substrate 10 in the first opening OP1. The thickness of the first resist 32 is thinner than the thickness of the resist 40. In this way, it is possible to reduce the occurrence of so-called sagging, in which the resist 40 on the first resist 32 around the first opening OP1 hangs down toward the substrate 10. The thickness of the resist 40 is, for example, 1.0 μm or more and 4.0 μm or less, for example, 3.0 μm.

The step of forming the second resist includes a step of exposing the resist 40 using a second mask. In the step of exposing the resist 40, as shown in FIG. 9, a second mask M2 having an opening is placed on the substrate 10 on which the resist 40 is applied. The second mask M2 is placed facing a part of the second region AR2 in the first region AR1 and a part of the third region AR3 of each region AR4 adjacent to the first region AR1. Here, the exposure amount is set to a value such that only the surface portion of the resist 40 is exposed to light. In the embodiment, the exposure amount can be 220 j/m ² or more and 540 j/m ² or less, for example, 380 j/m ^2. By exposing the resist 40 in this way, a surface portion 41 exposed to light is formed in the resist 40, as shown in FIG. 10.

The process of forming the second resist includes a process of performing a second heat treatment. The second heat treatment is, for example, heating at a temperature of 90° C. to 110° C. for 100 seconds to 140 seconds. In the embodiment, the second heat treatment is performed by heating at a temperature of 100° C. for 120 seconds. The exposed surface portion 41 of the resist 40 is hardened after the second heat treatment. As a result, the surface portion 41 is not exposed to light. In FIG. 11, the surface portion 41 after the second heat treatment is shown as the surface portion 42. On the other hand, the unexposed portion of the resist 40 other than the surface portion 42 has the same function as a positive photoresist after the second heat treatment. In other words, the resist 40 other than the surface portion 42 after the second heat treatment has a function of increasing the solubility in the developer at the portion exposed in the exposure process described later.

The step of forming the second resist includes a step of exposing the entire surface. In the step of exposing the entire surface, as shown in FIG. 12, the entire upper surface of the substrate 10 on which the resist 40 including the surface portion 42 is formed is exposed. In an embodiment, the exposure amount can be 0.20 mj/cm ² or more and 0.30 mj/cm ² or less, for example, 0.25 mj/cm ^2. By exposing the entire upper surface of the substrate 10, the resist 40 other than the surface portion 42 is exposed to light. The portion of the resist 40 exposed in the step of exposing the entire surface is referred to as the resist 43. On the other hand, the surface portion 42 that was exposed in the step of exposing the resist 40 is not exposed to light.

The process of forming the second resist includes a developing process. The resist 43 in the second region AR2 and the third region AR3 is developed with a developer. In the embodiment, the developing time can be 55 seconds or more and 95 seconds or less, for example, 75 seconds. Here, the surface portion 42 is less likely to be dissolved by the developer. Therefore, the portions of the resist 43 located in the second region AR2 and the third region AR3 are preferentially dissolved by the developer, rather than the portions located below the surface portion 42. As a result, the portions of the resist 43 located in the second region AR2 and the third region AR3 are removed, and the second opening OP2 and the third opening OP3 are formed as shown in FIG. 13. In addition, when the second opening OP2 and the third opening OP3 are formed, the developer flows in from the second opening OP2 and the third opening OP3, and the developer comes into contact with and dissolves a portion of the surface of the resist 43 located below the surface portion 42. Therefore, in a cross-sectional view, the widths of the second opening OP2 and the third opening OP3 each become smaller from the bottom to the top of the resist 43. Thus, the portion including the resist 40 in which the second opening OP2 and the third opening OP3 are formed, and the surface portion 42 is referred to as the second resist 44.

The method for forming a conductive member includes a step of forming a conductive material (ST230). More specifically, the step of forming the conductive material is a step of forming a conductive material on the second resist, on the base in the second opening, and on the first resist in the third opening. The step of forming the conductive material will be described with reference to FIG. 14.
FIG. 14 is a schematic cross-sectional view for explaining the step of forming a conductive material.

In the process of forming the conductive material, for example, as shown in FIG. 14, a conductive member 20 is formed on the second resist 44, on the base 10 in the second opening OP2, and on the first resist 32 in the third opening OP3. The conductive member 20 can be formed by, for example, a sputtering method.

The method for forming the conductive member 20 includes a step of removing the conductive material (ST240). More specifically, the step of removing the conductive material is a step of removing the first resist 32 and the second resist 44, thereby removing the conductive member 20 formed on the second resist 44 and on the first resist 32 in the third opening.
FIG. 15 is a schematic cross-sectional view for explaining the step of removing the conductive material.

In the process of removing the conductive material, as shown in FIG. 15, first, a stripping liquid having a function of stripping the first resist 32 and the second resist 44 from the base 10 is poured onto the base 10. The arrows shown in FIG. 15 show an example of the flow direction of the stripping liquid. As a result, the stripping liquid is allowed to penetrate into the second resist 44 and the first resist 32 from the second opening OP2 and the third opening OP3. The contact time (immersion time) between the stripping liquid and the second resist 44 and the first resist 32 can be 600 seconds or more and 1800 seconds or less, for example, 1200 seconds. Then, the second resist 44 and the first resist 32 are stripped from the base 10. As a result, the conductive member 20 other than the portion located in the second region AR2 of the base 10 is removed together with the second resist 44 and the first resist 32. In this way, as shown in FIG. 1, the conductive material is not formed in any part of the base 10 other than the second region AR2, and the conductive member 20 can be efficiently formed in a predetermined region of the base 10.

Next, the step of removing the conductive material will be described in more detail.
The conductive member 20 is used, for example, to test the conductive performance of a semiconductor portion formed on a wafer.

FIG. 16 is a schematic top view showing an example of the arrangement of the wiring forming portion 110. As shown in FIG.
FIG. 17 is an enlarged view of the wiring formation portion 110 and its surroundings in FIG. 16 before the conductive material is formed, and is a schematic top view showing an example of the second region AR2 and the third region AR3.
FIG. 18 is a schematic top view showing an example in which a part 120 of the grid pattern P in FIG. 17 is enlarged.
The region 100 is, for example, a part of a wafer including a plurality of element regions 150. The element region 150 is a light-emitting portion in which an electrode is formed. In FIG. 16, the region 100 has two wiring formation portions 110 spaced apart from each other in the horizontal direction (hereinafter, first direction) and vertical direction (hereinafter, second direction) shown in the figure. The interval W1 between adjacent wiring formation portions 110 in the first direction can be 1000 μm or more and 100 mm or less, for example, 11500 μm. The interval W2 between adjacent wiring formation portions 110 in the second direction can be 1000 μm or more and 100 mm or less, for example, 13500 μm. The wiring formation portion 110 is located in a first region AR1 of the base 10. In a top view, a fourth region AR4 of the base 10 located outside the first region AR1 includes a plurality of element regions 150.

Two conductive members 20 are arranged within the wiring formation section 110. A second opening OP2 is present around the conductive members 20. A second resist 44 is arranged around the second region AR2. In the embodiment, the second resist 44 is formed, for example, in a grid pattern P having a plurality of third openings OP3.

As shown in FIG. 18, a part 120 of the grid pattern P includes two third openings OP3.
The shape of the third opening OP3 in the top view includes polygons such as triangles and squares, circles, ellipses, and the like. In the example shown in FIG. 18, the shape of the third opening OP3 is rectangular. The distance W3 between the third openings OP3 can be 5 μm or more and 20 μm or less, for example, 10 μm. The opening shape of the third opening OP3 formed in the second resist 44 may be stripe-shaped, island-shaped, or the like. In addition, when the method for forming the conductive member of the embodiment is included in the process of forming the element region 150, for example, the same shape as the shape of the electrode of the element may be used as the opening shape of the second opening OP2 formed in the second resist 44. Thereby, in order to form the second opening OP2, a mask used in another process can be used, and the cost of forming the conductive member can be reduced.

FIG. 19 is a schematic cross-sectional view showing an example of a portion of a cross section taken along line XIX-XIX in FIG.
As shown in FIG. 19, the grid pattern P, the wiring forming portion 110, the grid pattern P, and the wiring forming portion 110 are arranged along the horizontal direction shown in the figure. The wiring forming portion 110 has a second region AR2. The base 10 has a first region AR1 surrounded by the first resist 32 in a top view. A second opening OP2 is formed in the second resist 44 located in the second region AR2. The width W11 between the end of the second region AR2 and the end of the first region AR1 is 50 μm or more and 760 μm or less, for example, 100 μm. By setting the width W11 in such a range, the second resist 44 can be stably arranged on the first resist 32 having a step. The interval W12 between the two second regions AR2 is 10,000 μm or more, for example, 11,000 μm. The grid pattern P of the second resist 44 has a plurality of third openings OP3 in a cross-sectional view. The width W13 of the third opening OP3 is 10 μm or more and 760 μm or less, for example, 700 μm, in a cross-sectional view. The conductive member 20 is disposed on the second resist 44. The thickness of the conductive member 20 can be 0.05 μm or more and 1.0 μm or less, for example, 0.2 μm. The width W14 of the conductive member 20 disposed on the second resist 44 between the adjacent third openings OP3 is 5 μm or more and 1000 μm or less, for example, 700 μm, in a cross-sectional view. The width W15 of the second resist 44 between the second opening OP2 and the third opening OP3 is 5 μm or more and 1000 μm or less, in a cross-sectional view.

In this manner, in the region 100 in which the second opening OP2 and the third opening OP3 are arranged, first, the stripping liquid is poured onto the upper surface of the base 10. In the second opening OP2, the stripping liquid permeates into the second resist 44 from the wall surface of the second resist 44, and also permeates into the first resist 32 from the second resist 44 into which the stripping liquid has permeated. In the third opening OP3, the stripping liquid permeates into the second resist 44 from the wall surface of the second resist 44, and also permeates into the upper surface of the first resist 32 exposed from the conductive member 20, and into the first resist 32 from the second resist 44 into which the stripping liquid has permeated. The width W15 between the second opening OP2 and the third opening OP3 is 5 μm or more and 1000 μm or less. Therefore, the stripping liquid sufficiently permeates into the first resist 32 and the second resist 44 located between the second opening OP2 and the third opening OP3. The width W14 of the adjacent third openings OP3 is 5 μm or more and 1000 μm or less. Therefore, the stripping solution sufficiently penetrates the first resist 32 and the second resist 44 located between the adjacent third openings OP3. In this way, the stripping solution sufficiently penetrates the first resist 32 and the second resist 44 on the substrate 10. The widths W15 and W14 may be made large when the stripping solution has a high function of penetrating the first resist 32 and the second resist 44, and may be made small when the function of penetrating is low. After a specified contact time (immersion time) has elapsed, the first resist 32 and the second resist 44 are removed from the substrate 10 by, for example, a lift-off method. As a result, the first resist 32 and the conductive member 20 on the first resist 32, the second resist 44 and the conductive member 20 on the second resist 44 are removed from the substrate 10.

When forming a conductive member using a resist, the resist is peeled off by infiltrating a stripping solution through the openings of the resist. However, if the distance between the openings of the resist is large, it may be difficult for the stripping solution to penetrate the resist and to peel off the resist. In addition, in order to completely remove the resist, a process of repeatedly performing the lift-off method or a process of immersing the resist in acetone or the like for a long time is required, which increases the processing time. Therefore, it is difficult to efficiently form the conductive member in a predetermined region. In addition, if a resist having a plurality of openings for easily infiltrating the stripping solution is used in a portion other than the region where the conductive member is to be placed, a conductive material is formed on the substrate other than the region where the conductive member is to be placed.
According to the method for forming a conductive member of the embodiment, a first resist 32 and a second resist having a second opening OP2 and a third opening OP3 located on the first resist 32 are formed on the substrate 10 other than the second region AR2 in which the conductive member 20 is arranged, and a conductive material is formed. As a result, a conductive material is formed on the second resist 44, on the second region AR2 of the substrate 10 in the second opening OP2, and on the first resist 32 in the third opening OP3. Thereafter, by infiltrating a stripping solution from the second opening OP2 and the third opening OP3, the stripping solution can be easily infiltrated into the entire interface between the substrate 10 and the resist, so that the resist can be easily removed from the substrate 10. The conductive material formed in the portion other than the second region AR2 is removed together with the first resist 32 and the second resist 44, so that the conductive member 20 can be efficiently formed in a predetermined region on the substrate 10.

In addition, in a cross-sectional view, the widths of the second opening OP2 and the third opening OP3 each become smaller from the bottom to the top of the second resist 44. This reduces the area of the portion of the base 10 where the second resist 44 is disposed, and increases the area of the first resist 32 exposed at the third opening OP. This makes it easier for the stripping solution to penetrate into the interface between the first resist 32 and the second resist 44, and into the interface between the second resist 44 and the base 10.

In the above embodiment, the resist 30 is a positive photoresist, and the resist 40 formed on the resist 30 is a negative photoresist, but this is not limited to the above. For example, a resist whose function is inverted from negative to positive upon exposure may be used for the resist 30, and a negative resist may be used for the resist 40. By using a resist whose function is inverted from negative to positive for the resist 30, the resist 30 is less susceptible to the effects of exposure when the resist 40 is exposed to light. This makes it possible to pattern the resist 40 without affecting the resist 30.

Embodiments include the following:

(Appendix 1)
forming a first resist on a substrate having a first region and a second region located inside the first region when viewed from above, the first resist having a first opening exposing the first region;
forming a second resist having a second opening exposing the second region and a third opening located on the first resist and exposing a part of an upper surface of the first resist, continuously on the first resist and on the substrate within the first opening;
forming a conductive material on the second resist, on the substrate in the second opening, and on the first resist in the third opening;
removing the first resist and the second resist to remove the conductive material formed on the second resist and on the first resist in the third opening;
A method for forming a conductive member comprising:

(Appendix 2)
2. The method for forming a conductive member according to claim 1, wherein the second resist has a plurality of the third openings when viewed from above.

(Appendix 3)
When viewed from above, the width of the third opening is 700 μm or less.
3. A method for forming a conductive member according to claim 1 or 2.

(Appendix 4)
4. The method for forming a conductive member according to claim 2, wherein the distance between adjacent third openings is 5 μm or more and 1000 μm or less when viewed from above.

(Appendix 5)
The second resist is formed in a lattice shape when viewed from above.
5. A method for forming a conductive member according to any one of claims 1 to 4.

(Appendix 6)
6. The method for forming a conductive member according to claim 1, wherein the width of the second resist is 5 μm or more and 1000 μm or less when viewed from above.

(Appendix 7)
the first resist is a positive photoresist,
The second resist is a negative photoresist.
7. A method for forming a conductive member according to any one of claims 1 to 6.

(Appendix 8)
In a cross-sectional view, the widths of the second opening and the third opening of the second resist each become smaller from the bottom to the top of the second resist.
8. A method for forming a conductive member according to any one of claims 1 to 7.

(Appendix 9)
9. The method for forming a conductive member according to claim 1, wherein the first resist is thinner than the second resist.

(Appendix 10)
the base body has a plurality of element regions in a region located outside the first region when viewed from above,
10. The method for forming a conductive member according to claim 1, wherein the first resist is formed in the region having the plurality of element regions.

Reference Signs List 10: Base body, 20: Conductive member, 30: Resist (positive photoresist), 32: First resist, 40: Resist (negative photoresist), 44: Second resist, 100: Region, 110: Wiring formation portion, M1: First mask, M2: Second mask, P: Grid pattern

Claims (9)

A step of forming a first resist on a substrate having a first region and a second region located inside the first region when viewed from above, comprising:
forming a positive resist;
exposing the positive resist using a first mask;
subjecting the positive resist to a first heat treatment;
forming a first resist having a step of developing the positive resist to form a first opening exposing the first region;
forming a continuous second resist on the first resist and on the substrate within the first opening,
forming a negative resist on the substrate on which the first resist having the first opening is formed;
exposing the negative resist using a second mask to form a surface portion in the negative resist;
performing a second heat treatment on the negative resist having the surface portion formed thereon;
exposing the negative resist to light after the second heat treatment to increase the solubility of the exposed portion of the negative resist other than the surface portion in a developer;
developing the negative resist to form a second resist having a second opening exposing the second region and a third opening located on the first resist and exposing a portion of an upper surface of the first resist;
forming a conductive material on the second resist, on the substrate in the second opening, and on the first resist in the third opening;
removing the first resist and the second resist to remove the conductive material formed on the second resist and on the first resist in the third opening;
Equipped with
a width of each of the second opening and the third opening of the second resist decreases from a lower portion to an upper portion of the second resist;
The method for forming a conductive member , wherein the second resist has a thickness greater than a thickness of the first resist . The method for forming a conductive member according to claim 1, wherein the second resist has a plurality of the third openings when viewed from above. In a cross-sectional view, the width of the third opening is 760 μm or less.
The method for forming the conductive member according to claim 1 . The method for forming a conductive member according to claim 2, wherein the distance between adjacent third openings is 5 μm or more and 1000 μm or less when viewed from above. The second resist is formed in a lattice shape when viewed from above.
The method for forming the conductive member according to claim 1 . The method for forming a conductive member according to claim 5, wherein the width of the second resist is 5 μm or more and 1000 μm or less when viewed from above. the base body has a plurality of element regions in a region located outside the first region when viewed from above,
7. The method for forming a conductive member according to claim 1, wherein the first resist is formed in the region having the plurality of element regions. 7. The method for forming a conductive member according to claim 1, wherein a width between an end of the second region and an end of the first region is not less than 50 μm and not more than 760 μm. The substrate has a plurality of the second regions,
7. The method for forming a conductive member according to claim 1, wherein the distance between the second regions is 10,000 μm or more.

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