Semiconductor device having a tapered gate structure and method

摘要

A semiconductor device includes a semiconductor body having a first surface vertically spaced apart from a second surface. A first trench vertically extends into the semiconductor body from the first surface and includes first and second sidewalls extending across the semiconductor body in a lateral direction that is parallel to the first surface. A field electrode is arranged in first trench and electrically insulated from the semiconductor body by a field dielectric. A first gate electrode is arranged in the first trench. The first gate electrode is electrically insulated from the field electrode by the field dielectric and is electrically insulated from the semiconductor body by a first gate oxide. The first gate electrode includes widened and tapered portions that are continuously connected and adjacent to one another in the lateral direction. The first gate oxide forms a non-perpendicular angle with the first sidewall in the lateral direction.

主权项

1. A semiconductor device, comprising:
a semiconductor body having a first surface; a first trench formed in the semiconductor body, the first trench comprising first and second sidewalls extending from the first surface in a vertical direction and a first trench bottom extending between the first and second sidewalls in a first lateral direction; a field dielectric filling the first trench; and a second trench formed within the first trench in the field dielectric comprising inner and outer sidewalls, wherein first and second sidewalls of the first trench and the inner and outer sidewalls of the second trench extend along the semiconductor body in a second lateral direction that is perpendicular to the first lateral direction and perpendicular to the vertical direction, and wherein the second trench comprises a widened portion adjacent to a narrow portion in the second lateral direction, wherein, in the widened portion, the inner and outer sidewalls extend the parallel to the first sidewall in the second lateral direction, and wherein, in the narrow portion, one of the inner and outer sidewalls is non-perpendicular and non-parallel to the first sidewall in the second lateral direction.