| 摘要 |
PURPOSE:To enable to effectively operate the cutting off function of the entire semiconductor device by converting an electrode on the uppermost layer having a defect into an insulator such as oxide, nitride or carbide so that no main current flows to the region of this part. CONSTITUTION:A protective film 7 is enclosed on a semiconductor piece 1 and a substrate 2 except an aluminum 5a on an emitter having a defect and lead wire lead 4a of gate electrodes, this semiconductor device is dipped in a beaker 11, in which electrolyte 10 such as sulfuric acid solution is filled, a power source 13 is connected between an electrode 12 and the aluminum electrode 5a to perform an anodic oxidation, thereby converting part or full of the electrode 5a into alumina. |
