In the manufacture of a field-effect transistor, a silicon nitride film (underlaid with a thin silicon oxide film) is selectively formed on those parts of a semiconductor substrate of a first conductivity type at which a gate region and source and drain electrodes are to be formed, the formation of the...http://www.google.fr/patents/US4217153?utm_source=gb-gplus-shareBrevet US4217153 - Method of manufacturing semiconductor device
