Method of locally forming metal silicide layers

Abstract

The present invention mainly provides a method to locally form metal silicide on an integral circuit and to avoid the phenomenon of leakage current which is caused by metal silicide formed between the memory cells on the same word line. The method of present invention achieve above objectives by principally using a design rule to adequately arrange elements in proper distance. In an embodiment, in order to form metal silicide layers on an integral circuit and to avoid metal silicide formed between two neighboring memory cell on the same word line, a dielectric layer is previously formed in the spaced region between the two neighboring memory cells and is used as a mask. Thus, in a following selective etching process, a part of silicon substrate within the above spaced region can be protected and not exposed. Therefore, no metal silicide is formed in the spaced region, and the above objectives is achieved.