Patent ID: 9064949
Filing Date: 2015-06-23
Classification: H01L

Abstract:
1. A transistor structure comprising: a semiconductor layer overlying a substrate and having a primary surface that generally corresponds to a first plane; a trench extending into the semiconductor layer and having a tapered shape including a relatively wider portion adjacent to the primary surface and a relatively narrower portion farther from the primary surface as compared to the relatively wider portion, wherein, from a cross-sectional view, the relatively narrower portion is defined by a substantially planar sidewall that lies along a second plane that intersects the first plane at an angle of greater than approximately 70°; a doped semiconductor region that lies adjacent to a sidewall of the trench having the tapered shape, wherein the doped semiconductor region extends to the narrower portion and has a dopant concentration greater than a dopant concentration of the semiconductor layer at a location adjacent to the primary surface, and wherein the doped semiconductor region is part of the drain region of the transistor structure; and a gate member disposed outside of the trench.