Patent ID: 7449409

Claim:
A method of manufacturing a semiconductor device, the method comprising: providing a workpiece; forming an insulating material over the workpiece, the insulating material having a first top surface; forming at least one trench in the insulating material, the at least one trench extending below the first top surface of the insulating material and comprising sidewalls, the at least one trench having a second top surface disposed at the bottom of the at least one trench; forming a first barrier material covering the trench, said first barrier material inducing grain growth of a conductive material at a first growth rate including a portion directly over the second top surface; forming a second barrier material over the sidewalls, subsequent to forming said first barrier material, such that said portion of the first barrier material directly over the second top surface at the bottom of the trench is exposed and the second barrier material over the sidewalls is exposed, wherein the second barrier material comprises a different material than the first barrier material and said second barrier material causing grain growth of said conductive material at a second growth rate, said growth rate slower than said first growth rate; and filling the at least one trench with said conductive material.