| 摘要 |
PURPOSE:To produce overflow drains with precision by a method wherein the mask used in the formation of a first doped region is coated with a metal film to be subjected to etching for the formation of a metal film pattern. CONSTITUTION:The formation of an oxide film 11 on a semiconductor substrate 10 of one conductive type is followed by the formation of photoresist patterns 12a-12e serving as masks in the next process of doping the substrate 10 for the creation of doped regions 13a-13d having the conductive type same as that of the substrate 10. Next, the entire surface is vapor plated with an Al film 14. The photoresist patterns 12a-12e are etched away for the formation of Al patterns 14f-14i. Photoresist patterns 15a-15c are formed, except between doped regions 13a and 13b and between doped regions 13c and 13d. The Al patterns 14f-14i and photoresist patterns 15a-15c serve as masks in a process of impurities implantation resulting in the formation of doped regions 16a and 16b with their conductivity reverse to that of the substrate 10. |
