Patent ID: 10090381

Abstract:
A semiconductor device comprises a lower structure on a substrate and including a recess region, first and second barrier layers covering an inner surface of the recess region and a top surface of the lower structure, the inner surface of the recess region including a bottom surface and an inner sidewall connecting the bottom surface to the top surface of the lower structure, and an interlayer dielectric layer provided on the second barrier layer and defining an air gap in the recess region. A first step coverage is obtained by dividing a thickness of the first barrier layer on an inner sidewall of the recess region by a thickness of the first barrier layer on the top surface of the lower structure. A second step coverage is obtained by dividing a thickness of the second barrier layer on the inner sidewall of the recess region by a thickness of the second barrier layer on the top surface of the lower structure. The first step coverage is different from the second step coverage.