摘要 |
An underlayer is formed on a side wall 101a of a through hole 101 out of the side wall 101a of the through hole 101 and a substrate main surface, with a main surface having a low adhesion to a conductive layer disposed as an upper surface, and the conductive layer is formed on the substrate main surface and the side wall 101a of the through hole 101 on which the underlayer is formed, and the underlayer formed on the side wall 101a of the through hole 101 is selectively etched. |