Method for forming a borderless contact

摘要

A method of forming a borderless contact is described. An ion implantation process and a thermal process are performed on a device isolation structure to form a silicon nitride layer therein. During a process of forming a borderless contact window, the silicon nitride layer can serve as an etching stop layer to protect the device isolation structure from overetching. As a result, no recess is formed, and leakage current is avoided.