Method of manufacturing borderless contact hole including a silicide

Abstract

A method of manufacturing a borderless contact hole. A substrate having a pad oxide layer and a silicon nitride layer formed thereon is provided. A trench is formed to penetrate through the silicon nitride layer and the pad oxide layer and into the substrate. A first oxide layer is formed in the trench, wherein a surface level of the first oxide layer is lower than that of the substrate. An etching stop layer is formed on the silicon nitride layer, a sidewall of the trench and the first oxide layer, conformally. A second oxide layer is formed on the etching stop layer and fills the trench. A portion of the second oxide layer, a portion of the etching stop layer, the silicon nitride layer and the pad oxide layer are removed. A portion of the second oxide layer in the trench and a portion of the etching stop layer in the trench are removed to form a recess until the surface level constructed by the remaining second oxide layer and the remaining etching stop layer is lower than a surface level of the substrate. A source/drain region is formed in the substrate adjacent to the trench. A silicide layer is formed on a surface of the source/drain region and a sidewall of the recess. A dielectric layer is formed over the substrate. A contact hole is formed to penetrate through the dielectric layer and exposes a portion of the silicide layer.