A semiconductor device having a hollow around a gate electrode and a method for producing the same

摘要

A semiconductor device operating at a high frequency, includes: a semiconductor layer; a first electrode for being applied with a voltage to control a current flowing in the semiconductor layer; a second electrode and a third electrode electrically connected to the semiconductor layer, at least one of the second and third electrodes being elongated above the first electrode to form a hollow around the first electrode by surrounding the first electrode with the second and third electrodes and the semiconductor layer; a passivation film formed over the second and third electrodes; and wherein the first electrode is directly in contact with an atmosphere in the hollow.