ELECTROSTATIC INDUCTION TYPE TRANSISTOR

摘要

PURPOSE:To obtain SIT having an extremely low resistance at induction and a good frequency characteristic with high withstand voltage, by burying p<+>-gate region in an n<->-type source region that reaches the desired depth from a wafer surface. CONSTITUTION:An p<+>-layer 25 is provided and n<->-epitaxial layer 23 is grown by making B diffusion having desired shape, depth and density on n<->n<+>Si-substrate that has n<->-layer of approximately 30-200mum thickness. n<+>-Source region 24 and p-gate region 26 are formed by ion injection. It is easy to form region 24 in a deep area if a proton is implanted at desired depth in advance and specified additive impurity is implanted there after. The buried gate structure SIT that has the source region of high impurity concentration protruded from the wafer surface to the vicinity of the gate, holds a high withstanding voltage between the gate and source and also between the gate and drain in addition to a small electrostatic capacitance and a large conversion conductance, and can perform a high speed and high frequency operation with high electric power.