Semiconductor device manufacturing method and semiconductor device

1. A semiconductor device manufacturing method comprising:

forming a base conductive member on a surface of a substrate, and in a hole section formed in the substrate;

forming a resist on a part of the base conductive member;

removing the resist halfway through its thickness, after forming a conductive layer on a part except for a part at which the resist is formed and before forming the mask metal on the conductive layer;

forming a mask metal on the conductive layer with a surface of the conductive layer protected by the resist removed halfway;

removing the resist removed halfway after forming the mask metal; and

etching the base conductive member using the mask metal as a mask to form the conductive layer into a predetermined shape.

2. The semiconductor device manufacturing method according to claim 1 , comprising:

forming the conductive layer on a side wall and a bottom surface in the hole section formed in the substrate when forming the conductive layer on the part except for the part at which the resist is formed; and

forming the mask metal on the conductive layer formed on the side wall and the bottom surface in the hole section when forming the mask metal on the conductive layer.

3. The semiconductor device manufacturing method according to claim 1 , comprising:

forming a cap metal on an electrode pad section composed of the conductive layer when forming the mask metal.

4. The semiconductor device manufacturing method according to claim 1 , wherein

the mask metal is composed of a Ni base layer and an Au layer formed on the base layer.