| 摘要 |
PURPOSE:To form a field domain with a large width in a way of self-matching by forming a separated structure utilizing advantages of a digging method and a selective oxidizing method which does not need a mask. CONSTITUTION:Narrow and deep grooves 18 for separation are formed. With those grooves 18, a distance between transistors can be reduced and a mask for burial diffusion can be eliminated. Moreover, a P<+> type layer for channel stopper and an N<+> type buried diffusion layer 2 are perfectly separated from each other and the N<+> type buried diffusion layer 2 does not extend horizontally against an element forming domain 23. Therefore, a parasitic capacity between the element domain and the substrate can be much reduced. As a wide and uniform field oxide film domain can be obtained by selective oxidization, a capacity between a wiring and the substrate also can be reduced significantly. Thus, as the grooves 18 for element separation are formed after the field oxide film 15 is formed, a domain in the side wall of the element forming domain where defects are easily created and which is usually a problem in a selective oxidization method, is removed by a digging process and the influence of the defects on the element forming domain is avoided. |
