INTEGRATED TERMINATION FOR MULTIPLE TRENCH FIELD PLATE

摘要

A semiconductor device includes a vertical MOS transistor with a plurality of parallel RESURF drain trenches separated by a constant spacing in a vertical drain drift region. The vertical MOS transistor has chamfered corners; each chamfered corner extends across at least five of the drain trenches. A RESURF termination trench surrounds the drain trenches, separated from sides and ends of the drain trenches by distances which are functions of the drain trench spacing. At the chamfered corners, the termination trench includes external corners which extend around an end of a drain trench which extends past an adjacent drain trench, and includes internal corners which extend past an end of a drain trench which is recessed from an adjacent drain trench. The termination trench is separated from the drain trenches at the chamfered corners by distances which are also functions of the drain trench spacing.

主权项

1. A transistor, comprising:
a semiconductor substrate having a transistor region including a chamfered corner; a first trench and a second trench each positioned within the transistor region and parallel to each other, the first trench having a first end enclosed by the chamfered corner, the second trench having a second end enclosed by the chamfered corner and longer than the first end; and a terminal trench laterally surrounding the first and second trenches, the terminal trench having:
an longitudinal segment parallel to the first and second trenches;a first corner connected to the longitudinal segment and pointing at the chamfered corner, the first corner adjacent to the first end of the first trench;a second corner extending from the first corner and pointing away from the chamfered corner, the second corner positioned between the first and second ends; anda third corner extending from the second corner and pointing at the chamfered corner, the third corner adjacent to the second end of the second trench.