| 摘要 |
PURPOSE:To prevent impurity diffusion to the side surface of a groove by forming an insulating film, through which a specific impurity is difficult to pass, to the inner surface of the groove dug to one main surface of a semiconductor base body, removing the insulating film on the bottom of the groove and filling the inside of the groove with a substance to which an impurity is added. CONSTITUTION:A U-shaped groove 4 reaching a p type substrate 1 from the surface of an n type silicon layer 2 is bored. A nitride film9 is deposited uniformly on the whole surface. The nitride film 9 on the bottom of the groove and an oxide film 5b are removed through dry etching to expose one part of the p type substrate 1. Silicon chemically formed in the vapor phase is deposited on the whole surface, and a polysilicon layer 10 to which an impurity such as boron is added is formed to the inside of the groove and the upper surface of a section, where there is no groove, sufficiently thickly. Boron as the impurity in the polysilicon layer is diffused into the p type substrate 1 through the bottom of the groove to shape a p type channel stopper layer 7. An insulator isolation section is obtained by forming an oxide film to the upper surface section of the polysilicon layer in the groove. |
