Superjunction trench device formation methods

Abstract

Methods for forming semiconductor structures are provided for a semiconductor device employing a superjunction structure and overlying trench with embedded control gate. An embodiment comprises forming interleaved first and second spaced-apart regions of first and second semiconductor materials of different conductivity type and different mobilities so that the second semiconductor material has a higher mobility for the same carrier type than the first semiconductor material, and providing an overlying third semiconductor material in which a trench is formed with sidewalls having thereon a fourth semiconductor material that has a higher mobility than the third material, adapted to carry current between source regions, through the fourth semiconductor material in the trench and the second semiconductor material in the device drift space to the drain. In a further embodiment, the first and third semiconductor materials are relaxed materials and the second and fourth semiconductor materials are strained semiconductor materials.