HETERO-JUNCTION TYPE FIELD-EFFECT TRANSISTOR

摘要

PURPOSE:To facilitate manufacture extremely by forming a fourth semiconductor layer having electron affinity larger than a first semiconductor layer. CONSTITUTION:A fourth semiconductor layer 24 having electron affinity larger than a first semiconductor layer 21 is shaped. When control voltage is applied between a first electrode 41 as an electrode and a third electrode 43 as a source electrode at a value less than threshold voltage, the bottom of a well at the potential of the interface between a second semiconductor layer 22 and the first semiconductor layer 21 as shown in A is brought to a level lower than the Fermi level of the first semiconductor layer 21 as shown in B in the bottom of a well at the potential of the interface between the second semiconductor layer 22 and a region between a first semiconductor region 31 as a source region as a layer for forming an N channel and a second semiconductor region 32 as a drain region.