METAL GATE STRUCTURE OF A SEMICONDUCTOR DEVICE

摘要

The present invention relates to the manufacturing of an integrated circuit, and more particularly to a metal gate structure. An exemplary structure of a semiconductor device comprises a substrate including an isolation region separating and surrounding both P-active region and N-active region; a P-work function metal layer of a P-gate structure on the P-active region wherein the P-work function metal layer includes a first bottom part and a first side walls and the first bottom part includes a first metal compound layer having first thickness; and a N-work function metal layer of a N-gate structure on the N-active region wherein the N-work function metal layer includes a second bottom part and second sidewalls and the second bottom part includes a second metal compound layer having second thickness less than the first thickness. [Reference numerals] (102) Providing a device including a separation area separating and surrounding both an active area and a N-active area; (104) Forming P-trench on the P-active area and N-trench on the N-active area at a dielectric layer; (106) Forming a metal compound layer on all layers and in the P-trench and N-trench; (108) Forming a first sacrificial layer on the layer of the metal compound; (110) Forming a second sacrificial layer on the first sacrificial layer for filling the P-trench and N-trench; (112) Forming a phtosensitive layer on the second sacrificial layer; (114) Exposing the second sacrificial layer on the N-trench and patterning the photosensitive layer to cover the second sacrificial layer on the P-trench; (116) Removing the second sacrificial layer on the N-trench; (118) Removing the first sacrificial layer on the N-trench; (120) Removing the metal compound layer of the N-trench partially