High band gap layer to isolate wells in high voltage power integrated circuits

Abstract

An integrated circuit is provided in which a relatively low band gap material is used as a semiconductor device layer and in which an underlying high (wide) band gap material is used as an insulating layer. The insulating material has a high thermal conductivity to allow heat dissipation in conjunction with dielectric isolation. The integrated circuit includes one or more semiconductor wells which are each surrounded on their sides by an insulating material. The bottom of the semiconductor wells are disposed atop the high band gap material which provides both electrical isolation and thermal conductivity. A semiconductor substrate may be provided to support the high band gap material. A layer of insulating material may also be provided between the high band gap material and the semiconductor substrate.

What is claimed is:  
     
         1 . An integrated circuit comprising: 
 a semiconductor substrate having a first semiconductor device formed therein;    a thermally conductive layer of low carrier lifetime material disposed atop said semiconductor substrate; and    a semiconductor device layer disposed on said layer with low carrier lifetime;    at least a second semiconductor device and a third semiconductive device being formed in said semiconductor device layer.