Method of forming self-aligned metal gate structure in a replacement gate process using tapered interlayer dielectric

摘要

A method for manufacturing a semiconductor device includes following steps. A substrate having at least a transistor embedded in an insulating material formed thereon is provided. The transistor includes a metal gate. Next, an etching process is performed to remove a portion of the metal gate to form a recess and to remove a portion of the insulating material to form a tapered part. After forming the recess and the tapered part of the insulating material, a hard mask layer is formed on the substrate to fill up the recess. Subsequently, the hard mask layer is planarized.