FIELD-EFFECT TYPE TRANSISTOR

摘要

PURPOSE:To acquire normal ion characteristics between source-drain electrodes by properly selecting the thickness of a semiconductor layer in low impurity concentration on a semiconductor substrate and the quality of material of a semiconductor layer as a gate region. CONSTITUTION:A substrate 23 in which a comparatively thin semiconductor layer 22 having impurity concentration lower than a semiconductor substrate proper 21 is constituted on the semiconductor substrate proper 21 as an N type drain region having comparatively high impurity concentration is manufactured. A semiconductor layer 25 as a source region is formed on the main surface 24 of the substrate 23, and a P type semiconductor layer 26 as a gate region surrounding the layer 25 is formed. The layer 26 is extended onto a field insulating film 28, and formed by amorphous silicon. The substrate 25 is extended onto an insulating film 29 as an oxide film, and formed by polysilicon. Source electrodes 30 and 31 in Al are each connected to the layers 25, 26 in an ohmic manner. A drain electrode 32 in Au is attached onto the main surface 32 of the substrate proper 21 in an ohmic manner.