SEMICONDUCTOR DEVICE AND METHOD OF PRODUCING THE SAME.

摘要

An insulated gate field-effect transistor used as a switching element in computers and a method of producing the same. In order to improve dynamic characteristics of the transistor by decreasing the junction capacitance between a substrate (1) and a source (7) or a drain (8), an an insulating layer (2) is provided under the source region and the drain region. In order to decrease the drop of carrier mobility and to suppress the short channel effect, furthermore, the impurity concentration is lowered on the surface of the semiconductor layer just under the gate and is heightened on the side of the substrate.