| 摘要 |
PURPOSE:To increase integration by a method wherein a semiconductor device is provided with a portion difference in level and an element separating region is provided in that portion with difference in level. CONSTITUTION:A silicon substrate 14 is vertically etched through reactive ion etching with an oxide film as a mask. Next, proton is used for the ion injection to form a donor layer 19 in the portions other than a wall surface. Then anodic forming is added so as to form porous silicon 21 on the wall surface, and the porous silicon is oxidized through wet oxidation to make it into an oxide film. At this time, the donor region 19 receives the donor killer effect and returns to the P type substrate with its surface oxidized. After this, a gate oxide film and a polycrystalline electrode are formed, which is followed by patterning through photoetching. Next a source 25 and a drain 26 are formed, while an insulated film 27 between the layers and Al wiring 28 are provided. By so doing, the dimension of an element separating region can be reduced to ''0''. |
