JPS6422058A - Manufacture of charge coupled device - Google Patents

Abstract

PURPOSE:To prevent a center position from deviating from a predetermined position, and make the barrier height symmetric with respect to the right and the left, by a method wherein, after a first field oxidation treatment is performed by covering a prearranged portion for forming a overflow drain with an oxidation resistance mask, the mask is eliminated, and impurity determining the conductivity type inverse to a substrate is doped. CONSTITUTION:A prearranged portion 4 for forming a field oxide film on a silicon semiconductor substrate 1 is exposed from a resist film 6 acting as an anti-etching mask, excepting a portion 5 for forming an overflow drain. A silicon nitride film 3' of the exposed portion is etched and eliminated with hot phosphoric acid. After eliminating of the resist film 6 and washing, a first field oxidation treatment is performed by applying silicon nitride films 31, 32 to an oxidation resistance mask, and a preliminary film 7 for field oxidation is formed. The positions of the stripe-type silicon nitride film 32 are eliminated with hot phosphoric acid by applying a resist film 8 covering the other positions of the silicon nitride film 31 to an anti-etching film. The doping of impurity for determining a conductivity type inverse to the silicon substrate 1, e.g. N-type, is performed to form an overflow drain 9.