| 摘要 |
PURPOSE:To form channel cutting regions accurately in narrower areas, by performing selective etching by suing a mask member, forming window parts where the thickness of an oxide film becomes thin in the field oxide film, and doping impurities through said window parts into a semiconductor substrate. CONSTITUTION:A field oxide film 2 is formed on a substrate 1. Thereafter, a mask member 3 is formed. Window parts 4 for forming a channel cutting regions are formed in the field oxide film 2 by etching by using the mask member 3. Impurities 5 are doped into the semiconductor substrate 1 beneath the field oxide film 2 by using said window parts 4. Since the window parts 4 where the thickness of the oxide film is thin are formed and then the impurities 5 are doped, the narrow, deep impurity doping can be performed. Thus, the channel cutting regions 6 can be formed accurately in narrow areas. |
