Patent ID: 8895399

Claim:
A method of making a semiconductor device, comprising: providing a substrate including semiconductor material of a first conductivity type; forming a buried semiconductor layer of a second conductivity type in the substrate; forming a first semiconductor layer of the second conductivity type over the buried semiconductor layer; forming a trench through the first semiconductor layer and through the buried semiconductor layer; forming a first insulating layer on a wall of the trench; depositing an insulating material in the trench; forming a discrete device by, (a) doping the first semiconductor layer to form a second semiconductor layer of the first conductivity type, and (b) forming a third semiconductor layer of the second conductivity type in the second semiconductor layer; forming a second insulating layer in contact with the first semiconductor layer, second semiconductor layer, third semiconductor layer, first insulating layer, and insulating material; forming a first metal layer directly above and abutting the second semiconductor layer; and forming a second metal layer directly above and abutting the third semiconductor layer, wherein the insulating material in the trench surrounds the discrete device.