Patent ID: 7948033

Claim:
A superjunction semiconductor device comprising: a semiconductor substrate having a surface configured to form a first electrode; a region of semiconductor material formed in spaced relationship with the semiconductor substrate and having an active region and a termination region, the region of semiconductor material having a first conductivity type and a first charge density; an active device formed in the active region, wherein the active device comprises: first and second trenches formed in the region of semiconductor material, wherein the first and second trenches have sidewall surfaces; first doped regions of a second conductivity type opposite the first conductivity type formed along at least portions of the sidewall surfaces of the first and second trenches, wherein the first doped regions have a second charge density configured to balance the first charge density to form a superjunction structure; a base region of the second conductivity type formed in the region of semiconductor material between the first and second trenches; a source region of the first conductivity type formed in the base region; a first insulated control electrode adjacent the base region and the source region and configured to control current flow between the source region and the first electrode; and a first trench fill material formed within the first and second trenches; and a termination structure formed in the termination region, wherein the termination structure comprises: a plurality of termination trenches formed in the body of semiconductor material and extending to the semiconductor substrate, wherein each of the plurality of termination trenches has second doped regions of the second conductivity type formed along sidewall surfaces, wherein the second doped regions have the second charge density configured to balance the first charge density; a second trench fill material formed within the plurality of termination trenches, wherein the second trench fill material comprises a material that is configured to allow a depletion region to spread through at least a portion of the plurality of termination trenches; and an insulating layer formed overlying the termination structure and configured so that the second trench fill material within the plurality of termination trenches and the second doped regions are floating.