Semiconductor structure and method for forming the same

A semiconductor structure, comprising:

• a first fin structure, a second fin structure, and a third fin structure separated from each other;
• a plurality of nanosheets separated from the first fin structure, the second fin structure and the third fin structure;
• a high-k gate dielectric layer over each of the first fin structure, the second fin structure and third fin structure, and surrounding each of the nanosheets;
• a first work function metal layer over the high-k gate dielectric layer and the first fin structure;
• a second work function metal layer over the high-k gate dielectric layer and the second fin structure;
• a third work function metal layer over the high-k gate dielectric layer and the third fin structure;
• and
• a fourth work function metal layer over the high-k gate dielectric layer and surrounding each of the nanosheets.

A method for forming a semiconductor structure, comprising:

• forming a first fin structure, a second fin structure, a third fin structure and a nanosheet stack over a substrate, wherein the nanosheet stack comprises a plurality of nanosheets separated from each other;
• forming a high-k gate dielectric layer over the first fin structure, the second fin structure and the third fin structure, and surrounding each of the nanosheets;
• forming a first work function metal layer to surround each of the nanosheets;
• forming a first passivation layer to wrap each of the nanosheets;
• and
• forming a second work function metal layer to cover the first fin structure, the third fin structure and the nanosheet stack,
• wherein the first work function metal layer is complementary to the second work function metal layer.