Patent ID: 6924176

Claim:
A method of manufacturing a semiconductor device having a conductive path which is formed on an insulative layer which covers over a semiconductor element on a semiconductor substrate, the method comprising: forming a conductive layer on said insulative layer, said conductive layer having a through portion which extends to said semiconductor substrate through said insulative layer at a portion corresponding to said conductive path, said conductive layer being electrically connected to said semiconductor substrate via said through portion; forming said conductive path by performing a patterning process on said conductive layer using a plasma etching in a state where said conductive layer is electrically connected to said semiconductor substrate via said through portion; and after said conductive path is formed, performing a heating process on said semiconductor substrate or said conductive path in order to disconnect an electrical connection between said through portion and said semiconductor substrate by a reaction between said through portion and said semiconductor substrate, wherein said semiconductor substrate is made of silicon crystal, said insulative layer is made of silicon dioxide, and a conductive material of said conductive layer is made of a metal material which permits a diffusion of silicon by heating, and wherein said reaction between said through portion and said semiconductor substrate is diffusion of silicon from said silicon crystal into said metal material, and said electrical connection of said through portion and said semiconductor substrate is completely disconnected by a cavity which is formed in said semiconductor substrate by said diffusion.