Patent ID: 8729659
Filing Date: 2014-05-20
Classification: H01L

Abstract:
1. A semiconductor device, comprising: a substrate; a first trench disposed in the substrate, the first trench comprising first sidewalls, a first bottom surface, and a first lower portion; a second trench disposed in the substrate, the second trench comprising second sidewalls, a second bottom surface, and a second lower portion, wherein the first trench and the second trench are disposed in a first region, and wherein no trench is disposed in a second region adjacent to the first region; and a first liner disposed only over the first sidewalls of the first lower portion and the first bottom surface of the first trench and a second liner disposed only over the second sidewalls of the second lower portion and the second bottom surface of the second trench, wherein a first distance from the first bottom surface to a first top of the first lower portion is substantially the same as a second distance from the second bottom surface to a second top of the second lower portion, wherein the first liner and the second liner are inwardly tapered, and wherein the first liner is the same as the second liner.