Littelfuse, Inc.
Super junction field effect transistor with internal floating ring

Abstract:

A Super Junction Field Effect Transistor (FET) device includes a charge compensation region disposed on a substrate of semiconductor material. The charge compensation region includes a set of strip-shaped P- type columns, a floating ring-shaped P- type column that surrounds the set of strip-shaped P- type columns, and a set of ring-shaped P- type columns that surrounds the floating ring-shaped P- type column. A source metal is disposed above portions of the charge compensation region. The source metal contacts each of the strip-shaped P- type columns and each of the ring-shaped P- type columns. An oxide is disposed between the floating P- type column and the source metal such that the floating P- type column is electrically isolated from the source metal. The device exhibits a breakdown voltage that is 0.2% greater than if the floating P- type column were to contact the source metal.