Patent ID: 8735949

Claim:
A junction type field effect transistor comprising: a first conductive type semiconductor substrate; a first conductive type drift layer provided on a first main surface of the first conductive type semiconductor substrate; a second conductive type gate region provided on a surface of the first conductive type drift layer; a first conductive type channel layer provided on the first conductive type drift layer and the second conductive type gate region; a first conductive type source region provided on a surface of the first conductive type channel layer to face the second conductive type gate region, the first conductive type source region having an impurity concentration higher than an impurity concentration of the first conductive type channel layer; a source electrode provided on the first conductive type channel layer and the first conductive type source region, the source electrode being in Schottky contact with the first conductive type channel layer and in ohmic contact with the first conductive type source region; a drain electrode provided on a second main surface on an opposite side of the first main surface of the first conductive type semiconductor substrate; a second conductive type gate contact layer provided on the surface of the first conductive type channel layer to reach the second conductive type gate region, the second conductive type gate contact layer having an impurity concentration higher than the second conductive type gate region; and a gate electrode provided on the gate contact layer, an impurity concentration of the first conductive type channel layer being higher than an impurity concentration of the first conductive type drift layer.