Field-effect transistor and method of producing same

Abstract

A field-effect transistor has its gate length made to be minute, and a short channel effect is prevented. The field-effect transistor which attains the above objects has first and second semiconductor regions having different impurity concentrations disposed so as to be adjacent to each other. A source electrode is disposed on the second semiconductor region with a high impurity concentration, a drain electrode on the first semiconductor region with a low impurity concentration, and a gate electrode on the first semiconductor region side of the second semiconductor region. To produce the above field-effect transistor, a production method comprises a step of forming a first semiconductor region on the major surface of a semiconductor substrate, a step of forming a gate electrode to divide the first semiconductor region, and a step of doping impurities in the first semiconductor region on one side of the gate electrode with the gate electrode as the mask, to form a second semiconductor region which is of the same conductive type with the first semiconductor region and has a different impurity concentration from the first semiconductor region.