Patent ID: 7176546
Filing Date: 2007-02-13
Classification: H01L,Y02E

Abstract:
1. A diode circuit comprising: a semiconductor substrate having a main surface, wherein the semiconductor substrate comprises: a first semiconductor layer of a first doping type; a second semiconductor layer of a second doping type; and a third semiconductor layer disposed between the first and the second semiconductor layer, the concentration of free charge carriers in the third semiconductor layer smaller than a concentration of free charge carriers of the first and the second semiconductor layer, wherein the second semiconductor layer is a buried layer in the semiconductor substrate, wherein the first semiconductor layer is disposed on the main surface of the semiconductor substrate; wherein a trench is present in the third semiconductor layer, the trench extending from the main surface of the semiconductor substrate at least partially to the buried layer, a first contact for contacting the first semiconductor layer disposed on the main surface of the semiconductor substrate; a second contact for contacting the buried layer, wherein the second contact extends from the main surface of the semiconductor substrate to the buried layer, wherein the second contact includes a heavily doped area in the third semiconductor layer, the heavily doped area being spatially arranged around the trench in the third semiconductor layer, wherein the trench includes an isolator layer; and an insulation trench extending from the main surface of the semiconductor substrate to the buried layer and essentially surrounding the first semiconductor layer, wherein the second contact is arranged outside the insulation trench and extends through the third semiconductor layer.