Method of forming an interconnect using thin films of ti and tin

Abstract

A semiconductor device has a semiconductor layer such as of Si, an insulator film formed on the semiconductor layer and having a contact hole formed therein, a first contacting layer such as of Ti formed in the contact hole so as to be in contact with the semiconductor layer, a second contacting layer such as of TiN formed on the first contact material, and a contacting material such as W formed on the second contacting layer so as to substantially fill the contact hole. The first contacting layer in as formed state has a thickness of 4 nm or greater, while the second contacting layer as formed has a thickness of 1 nm or greater. The optimum thicknesses of the contacting layers are determined based on the pattern rule, e.g., 3.5 m rule, and the kinds of the materials such as Ti, TiN and W. Electrically stable ohmic contact can be obtained at a high yield.