Field effect transistor and method for producing same

摘要

A field effect transistor includes: a semiconductor substrate; an active layer formed on a part of a principal surface of the semiconductor substrate and having a predetermined impurity concentration; and first and second heavily doped layers having an impurity concentration higher than the impurity concentration of the active layer formed in two respective areas of the principal surface of the semiconductor substrate, located on both sides of the active layer and in contact with the active layer. A gate electrode is formed on a surface of the active layer and a drain electrode and a source electrode are formed on respective surfaces of the first and second heavily doped layers. At least one of the drain electrode and the source electrode is formed so as to extend onto a surface of the active layer.