Abstract: An integrated circuit having a substrate with a first conductivity type of semiconductor material. A buried layer is formed in the substrate. The buried layer has a second conductivity type of semiconductor material. A first semiconductor layer is formed over the buried layer. The first semiconductor layer has the second conductivity type of semiconductor material. A trench is formed through the first semiconductor layer and buried layer and extends into the substrate. The trench is lined with an insulating layer and filled with an insulating material. A second semiconductor layer is formed in the first semiconductor layer. The second semiconductor layer has the first conductivity type of semiconductor material. A third semiconductor layer is formed in the second semiconductor layer. The third semiconductor layer has the second conductivity type of semiconductor material. The first, second, and third semiconductor layers form the collector, base, and emitter of a bipolar transistor.

Abstract: A discrete semiconductor device has a substrate with a first conductivity type of semiconductor material. A first semiconductor layer is formed over the substrate. The first semiconductor layer having the first conductivity type of semiconductor material. A second semiconductor layer over the first semiconductor layer. The second semiconductor layer has a second conductivity type of semiconductor material. A trench is formed through the second semiconductor layer and extends into the second semiconductor layer. The trench has a rounded or polygonal shape and vertical sidewalls. The trench is lined with an insulating layer and filled with an insulating material. A boundary between the first and second semiconductor layers forms a p-n junction. The trench surrounds the p-n junction to terminate the electric field of a voltage imposed on the second semiconductor layer. The discrete semiconductor device can also be a transistor, thyristor, triac, or transient voltage suppressor.