Trench semiconductor device having shaped gate dielectric and gate electrode structures and method

Abstract

A semiconductor device includes a region of semiconductor material having first and second opposing major surfaces. A trench structure includes a trench extending into the region of semiconductor material from the first major surface, wherein the first major surface defines a first horizontal plane in a cross-sectional view. The trench structure further includes a conductive material disposed within the trench and separated from the region of semiconductor material by a dielectric region. A Schottky contact region is disposed adjacent the first major surface on opposing sides of the trench structure, the Schottky contact region having an upper surface residing on a second horizontal plane in the cross-sectional view. The dielectric region comprises an uppermost surface and configured such that a major portion of the uppermost surface is disposed above the first horizontal plane in the cross-sectional view. The structure and method provide a semiconductor device with improved performance (e.g., reduced leakage and more stable breakdown voltage) and improved reliability.