METHOD OF FABRICATING A MASK ROM

摘要

Fabrication method of mask ROM is composed of the following steps: growing a gate insulating layer and a channel region on the semiconductor substrate with a field oxide layer for isolation of device; growing a gate electrode between field oxides, source and drain regions and a stabilized insulating layer over the entire surface; making contact holes on the surface; patterning a conduction layer on the surface and making openings on the selected region; etching an anisotropically insulating layer below the opening to the degree that the gate electrode is exposed; doping impurity to activate in different modes with transistors on the unexposed wafer in the substrate.