Metal Gate Structure and Fabricating Method thereof

A metal gate structure, comprising:

• a high-K gate dielectric layer, formed on a semiconductor substrate;
• a first metal-containing layer, formed on the gate dielectric layer, and having a surface away from the gate dielectric layer, the nitrogen content of the surface being greater than 50%;
• and
• a silicon layer, formed on the first metal-containing layer.

A metal gate structure, comprising:

• a high-K gate dielectric layer, formed on a semiconductor substrate;
• a first metal-containing layer, formed on the gate dielectric layer, and having a surface away from the gate dielectric layer, the nitrogen content of the surface being greater than 50%;
• a second metal-containing layer, formed on the surface of the first metal-containing layer and having a central indentation portion;
• and
• a conductive layer, filled into the central indentation portion.

A method of fabricating a metal gate structure, comprising:

• forming a high-K gate dielectric layer on a semiconductor substrate;
• forming a first metal-containing layer having a surface away from the gate dielectric layer on the gate dielectric layer;
• forming a silicon layer on the surface of the first metal-containing layer;
• and
• patterning the gate dielectric layer, the first metal-containing layer and the silicon layer to form a stacked structure;
• wherein forming the first metal-containing layer or the silicon layer comprises a surface-modifying process to improve the nitrogen content of the surface of the first metal-containing layer.