Insulated gate field effect transistor.

摘要

An insulated gate field effect transistor formed in one surface of a semiconductor substrate (1) has a channel, the surface portion of which has an impurity (9) with a conductivity type opposite to that of the substrate (1), and the deeper portion of which has an impurity (8) of the same conductivity type to the substrate. Moreover, the source and/or the drain (6, 7) of the transistor has an impurity layer of a conductivity type opposite to that of the substrate, with an impurity distribution (13, 14) gently sloped. The use of such impurity distributions overcomes the problems of the short-channel effect and reduction of the source-drain breakdown voltage which are present in standard devices. This enables a shorter channel to be used for a given source-drain breakdown voltage which is of advantage in a LSI having a high density of integration.