Method of forming a contact on a semiconductor device

Abstract

A method of forming a contact on a semiconductor device is provided. First, a substrate is provided. A plurality of gate structures defined by a plurality of word lines in a first direction, and a plurality of diffusion regions covered by a first dielectric layer in a second direction are provided over the substrate. The gate structures located underneath the word lines and isolated by the diffusion regions. Then, an etching stop layer is formed. The etching stop layer and the first dielectric layer have different etching selectivity. A second dielectric layer is formed over the substrate. Furthermore, a plurality of contact holes to the diffusion regions between the word lines are formed by using the etching stop layer as a self-aligned mask.

Dependencies are inferred from the claim text.