Method for the manufacture of a Schottky gate field effect transistor

摘要

In the manufacture of a Schottky gate field effect transistor, an insulating film is deposited on the main surface of a semiconductor substrate and is then selectively removed to form therein a window through which the substrate surface region for forming an active layer is exposed to a space in which the gate will ultimately be provided. A metal which forms a Schottky junction between it and the semiconductor of the active layer and can be removed by anisotropic etching and a metal which can be used as a mask for the etching of the above metal are deposited in layers on the insulating film and the substrate surface exposed through the window. The overlying metal layer thus deposited is planarized to leave in the window alone. The underlying metal layer is selectively removed by anisotropic etching through the overlying metal layer remaining in the window, thus forming a gate electrode made up of the overlying and underlying metal layers. The structure thus obtained is small in the overlapping of the gate electrode on the adjoining insulating films, ensuring the reduction of parasitic capacitances to thereby speed up the operation of the device.