Patent ID: 6011279
Filing Date: 2000-01-04
Classification: H01L

Abstract:
A high voltage, high current field control bipolar switch comprising:a bulk single crystal silicon carbide substrate of a first conductivity type having an upper surface and a lower surface;a first epitaxial layer of a second conductivity type silicon carbide upon said upper surface of said substrate;a second epitaxial layer of said second conductivity type silicon carbide formed on said first epitaxial layer of silicon carbide;a plurality of regions of a third conductivity type silicon carbide formed in said second epitaxial layer to form a gate grid in said second epitaxial layer;a third epitaxial layer of said second conductivity type silicon carbide formed on said second epitaxial layer;a fourth epitaxial layer of said second conductivity type silicon carbide upon said third epitaxial layer said fourth epitaxial layer having a higher carrier concentration than is present in said first epitaxial layer, said second epitaxial layer and said third epitaxial layer;a first ohmic contact upon said fourth epitaxial layer;a second ohmic contact formed on said lower surface of said substrate; andan ohmic gate contact connected to said gate grid for pinching off the flow of current between said first ohmic contact and said second ohmic contact when a bias is applied to said ohmic gate contact.