Mos-pilot structure for an insulated gate transistor.

摘要

A MOS-pilot structure for an IGT device consisting of a multiplicity of IGT cells interconnected in a lattice network includes a plurality of pilot emitter electrodes each in electrical contact with only at least one pilot emitter region of a first plurality of the multiplicity of IGT cells and electrically isolated from a common cathode electrode of the multiplicity of IGT cells. The plurality of pilot emitter electrodes are each electrically connected to a contact metal strip deposited on the substrate surface and spaced therefrom by a layer of insulation. The contact metal strip is connected to ground potential through a sense resistor for producing a sense voltage responsive only to the channel currents flowing through the at least one pilot emitter regions; therefore, a MOS pilot structure that utilizes only the MOS channel current to produce the sense voltage to cause turn-off of the IGT device at a large total current is disclosed. The MOS-pilot structure does not suffer from the avalanche breakdown problems during turn-off, that are associated with other prior art IGT pilot structures.