Trench MOS device having a termination structure with multiple field-relaxation trenches for high voltage applications

摘要

A termination structure for a semiconductor device includes a semiconductor substrate having an active region and a termination region. Two or more trench cells are located in the termination region and extend from a boundary of the active region toward an edge of the semiconductor substrate. A termination trench is formed in the termination region on a side of the trench cells remote from the active region. A conductive spacer is located adjacent to a sidewall of the termination trench nearest the trench cells. A first oxide layer is formed in the termination trench and contacts a sidewall of the conductive spacer. A first conductive layer is formed on a backside surface of the semiconductor substrate. A second conductive layer is formed atop the active region and the termination region.

主权项

1. A termination structure for a semiconductor device, said termination structure comprising:
a semiconductor substrate having an active region and a termination region; a plurality of trench cells located only in the termination region and extending from a boundary of the active region toward an edge of the semiconductor substrate; a termination trench formed in the termination region on a side of the plurality of trench cells remote from the active region; a conductive spacer located adjacent a sidewall of the termination trench nearest the plurality of trench cells; a first oxide layer formed in the termination trench and contacting a sidewall of the conductive spacer; a first conductive layer formed on a backside surface of the semiconductor substrate; a second conductive layer formed atop the active region and the termination region wherein the plurality of trench cells are filled with a conductive material up to a top surface of a plurality of mesas; wherein the second conductive layer extends from the active area as a continuous layer and completely covering the plurality of trench cells and at least a portion of the termination trench such that the second conductive layer, the conductive spacer and a field plate formed in the termination region are electrically coupled to one another.