Patent ID: 7592270
Filing Date: 2009-09-22
Classification: H01L

Abstract:
1. A method of fabricating a semiconductor device comprising: Providing a substrate prepared with a transistor of a first transistor type, the transistor having a gate with a gate electrode; forming a stress layer of a first stress type over the transistor, the stress layer having a first stress value, the first stress type improves carrier mobility of the first transistor type; implanting ions into the stress layer, wherein implanting ions relaxes stress in the stress layer, resulting in a second stress value which is less than the first stress value; annealing the substrate, to increase stress in the stress layer to result in a third stress value of the first stress type, which is greater than the second stress value, wherein annealing crystallizes the gate electrode and imparts the increased stress of the stress layer to the gate electrode; and removing the stress layer after annealing.