Method of fabricating a metal-oxide-semiconductor device having a

Abstract

A metal-oxide-semiconductor device having a semiconductor-on-insulator structure comprises an insulator substrate; a single crystal semiconductor substrate provided on the insulator substrate, the single crystal semiconductor substrate and the insulator substrate forming a part of the semiconductor-on-insulator structure; source and drain regions doped to a first conduction type and defined in the single crystal semiconductor substrate; a channel region defined in the single crystal semiconductor substrate so as to be interposed between the source and drain regions, the channel region being doped to a second conduction type opposite to the first conduction type with a first impurity concentration level; a gate insulator film provided on the single crystal semiconductor substrate in correspondence to the channel region; and a gate electrode provided on the gate insulator film in correspondence to the channel region with a predetermined gate length; wherein the channel region is defined by a back channel elimination region having an increased impurity concentration level exceeding the first impurity concentration level such that the back channel elimination region is located adjacent to the insulator substrate for eliminating the back channel effect, the back channel elimination region being provided under the gate electrode in a manner such that the back channel elimination region is separated from the source and the drain regions by a region having a smaller impurity concentration level.