Method of fabricating semiconductor power devices within high resistivity isolation rings

Abstract

Abstract Improved performance characteristics are possible for semiconductor power devices by encircling the active elements with a high-resistivity isolation ring. Power devices encircled by a high-resistivity isolation ring may be fabricated by a method that includes the step of growing a bar of single-crystal semiconductor material having a radial resistivity varying in a controlled manner from the center thereof. This single crystal bar is then sliced perpendicularly transverse to the longitudinal axis into plane surface wafers of a desired thickness. After various surface preparation techniques, the active regions of the semiconductor power device may be formed in one of the plane surfaces at a desired resistivity section of the slice by photomask and etch techniques. By forming a center section of uniform resistivity encircled by a ring of high-resistivity material, which in turn is encircled by another uniform resistivity area, an integrated circuit may be fabricated on one slice of a single-crystal bar. In these circuits, the power devices would be isolated within the center region by means of the high-resistivity ring.

Inventors

• 👤 William L Fowler

Bibliographic Details