Field effect transistor with insulated gate inspection - by ion implantation of gate area and leakage current check between drain and source

摘要

Field effect transistors with an insulated gate are inspected by bombarding the gate area with ions which produce an inversion layer in the semiconductor. The ions penetrate only where the insulating layer is not coated by gate material. Any defects in the gate can be detected by the measurement of the leakage current between drain and source. This is a simple way of detecting defective gates during the final check. Time and temperature effects are excluded. The ion implantation effects a self-curing of the FET's in certain cases.