Patent ID: 9024299
Filing Date: 2015-05-05
Classification: H01L

Abstract:
1. A method of manufacturing a dual work function semiconductor device, the method comprising: providing a semiconductor substrate; providing a gate dielectric layer on and in contact with the semiconductor substrate; forming a metal layer having a thickness on and in contact with the gate dielectric layer, forming a first gate filling material on and in contact with the metal layer; patterning the gate dielectric layer, the metal layer and the first gate filling material to form a first gate stack and a second gate stack; after patterning, introducing dopants into substrate regions adjacent the first and second gate stacks and annealing to activate the dopants, thereby forming activated source/drain regions for both first and second gate stacks; after annealing, selectively removing the first gate filling material only from the second gate stack thereby exposing the underlying metal layer; after selectively removing, replacing the first gate filling material removed from the second gate stack with a second gate filling material formed of an oxygen-rich metal to form a replacement gate stack comprising the second gate filling material formed on the underlying metal layer; and thermally treating to supply oxygen atoms from the second gate filling material to the underlying metal layer to convert the underlying metal layer of the replacement gate stack into a metal oxide layer.