Patent ID: 8598623

Claim:
A termination structure for a semiconductor device including an active area housing active devices and a termination area surrounding the active area, the termination structure being formed in the termination area and comprising: a first semiconductor layer of a first conductivity type comprising a plurality of trenches formed in a top surface of the first semiconductor layer, the trenches forming mesas in the first semiconductor layer; a second semiconductor layer of a second conductivity type located at a bottom surface of the first semiconductor layer; a first epitaxial layer of the second conductivity type formed on sidewalls of the trenches and covering at least sidewalls of the mesas of the first semiconductor layer, the first epitaxial layer being electrically connected to the second semiconductor layer, wherein the thicknesses and the doping concentrations of the first epitaxial layer and a mesa of the first semiconductor layer are selected to achieve charge balance in operation; a first dielectric layer formed in the trenches adjacent the first epitaxial layer; and an array of termination cells formed in the termination area, the array of termination cells includes a first termination cell at an interface to the active area to a last termination cell, each termination cell comprising: a mesa of the first semiconductor layer having the first epitaxial layer formed on the sidewalls thereof; a first region of the first conductivity type formed in the top surface of the mesa and electrically connected to the first semiconductor layer; and a second region of the second conductivity type formed in the top surface of the mesa and electrically connected to the first epitaxial layer, the second region being spaced apart from the first region in the mesa, the second region being formed in each of the termination cells except the last termination cell, wherein the first region of the first termination cell is electrically connected to a source or emitter potential of the semiconductor device and the first epitaxial layer of the last termination cell is electrically connected to a drain or collector potential of the semiconductor device or near the drain or collector potential of the semiconductor device, the second regions of the remaining termination cells being electrically connected to the first regions of the next termination cells in the array.