Patent ID: 8110888

Claim:
A semiconductor device comprising a lightly-doped substrate of a first semiconductor type, a central active area formed in the substrate, and a high-voltage termination structure surrounding the central active area, wherein the high-voltage termination structure further comprises: a plurality of first termination regions of a second semiconductor type extending to a first depth beneath an upper surface of the substrate; a plurality of first spans of the substrate laterally separating the first termination regions; a plurality of discrete field oxide regions substantially covering the first spans of the substrate; a plurality of second spans of the substrate above the first termination regions laterally separating the discrete field oxide regions; at least one second termination region of the first semiconductor type subjacent each first span of the substrate, the second termination region adjoining and forming a p-n junction with one of the first termination regions on a side of the respective first termination region nearest to the central active region, extending to a second depth from the surface of the substrate less than the first depth; and a plurality of field plates, each field plate covering a portion of each respective field oxide region closest to the central active area, the field plates being laterally separated by gap regions of the substrate; each field plate having a first end overlying and capacitively or resistively coupled to the respective first termination region and a second end overlying a portion of the respective discrete field oxide region nearest to the central active area, so that the field plate and field plate ends are spaced laterally away from the p-n junction; the dopant concentration in the second termination regions being light enough to avoid premature avalanche in the depletion region and heavy enough to counteract the field effect from positive charges above the oxide-semiconductor interface.