SEMICONDUCTOR DEVICE WITH DUAL WORKFUNCTION GATE STACK AND METHOD FOR FABRICATING THE SAME

摘要

The present invention provides a semiconductor device including a dual work function gate stack and a manufacturing method thereof capable of independently controlling each threshold voltage of an N-channel transistor and a P-channel transistor and preventing an effective work function of the gate stack from fluctuating due to a subsequent process. The semiconductor device manufacturing method according to the present invention comprises a step of forming a gate dielectric layer on the front surface of a substrate including a first region and a second region; a step of stacking a first metal containing layer containing a first effective work function adjustment specimen and an anti-reaction layer on the gate dielectric layer; a step of increasing the content of the first effective work function adjustment specimen; a step of removing the anti-reaction layer and the first metal containing layer on the second region; a step of forming a second metal containing layer containing a second effective work function adjustment specimen on the front surface of the second region including the gate dielectric layer; a step of forming a first gate stack on the first region by etching the second metal containing layer, the anti-reaction layer, the first metal containing layer, and the gate dielectric layer; and a step of forming a second gate stack on the second region by etching the second metal containing layer and the gate dielectric layer.