| 摘要 |
PURPOSE:To obtain an etchant which shows good controllability and results in the mirror surface by using a mixed aqueous solution of glacial acetic acid, hydrogen peroxide solution and water. CONSTITUTION:A deteriorated layer 2 by surface polishing of germanium substrate 1 is eliminated by etching using a mixed solution of glacial acetic acid of 90cc, hydrogen peroxide solution of 60cc and water of 30cc as the etchant and gurd ring 3 and P<+> part 4 are formed by the ion implantation method. Since the deteriorated layer 5 is generated by ion implantation, it is removed by etching using a mixed solution of glacial acetic acid of 60cc, hydrogen peroxide solution of 10cc and water of 50cc as the etchant, an SiO2 film 6 is formed and an Al electrode 7 is formed. The etching of germanium can be done with the control of several hundreds A and the mirror surface can be obtained. Accordingly, a planar type avalanche photodiode can be manufactured. |
