| 摘要 |
PURPOSE:To remove a stress concentration in an interface between an island region and an isolation by a method wherein an insulating film that unified with the insulator is provided on a surface of an island region of the semiconductor device with an island region which isolated a bottom and a side phases by a porous oxidation. CONSTITUTION:A boron is injected to the surface of an N type Si substrate 21 to form a P type layer 31, an N type epitaxial layer 32 is formed thereupon. An SiO2 layer mask 33 is arranged on the surface of the epitaxial layer, and the boron is selectively diffused, and after the P type isolation region 34 to be reached to the P type layer 31 is formed, the mask 33 is removed to form the P type layer 35 throughout the surface of the epitaxial layer. The said substrate is doped in a hydrofluoric aqueous solution to perform an anodizing while performing the light illumination and the P type portion is converted to the porosity layer 37-39 and oxidized thereof, the unified SiO2 layer 22-24 are formed. In this way, the completely isolated island region 25 without the stress concentration can be readily formed. |
