METAL GATE TRANSISTOR AND METHOD FOR FORMING THE SAME

摘要

Various embodiments provide metal gate transistors and methods for forming the same. In an exemplary method, a substrate having a top surface and a back surface can be provided. A dummy gate can be formed on the top surface. A first interlayer dielectric layer can be formed on the top surface and planarized to expose the dummy gate. The dummy gate can be removed to form a trench. A metal gate stack can be formed to cover the first interlayer dielectric layer and to fill the trench. The metal gate stack can be planarized to remove a portion of the metal gate stack from the first interlayer dielectric layer to form a metal gate electrode in the trench. A remaining edge portion of the metal gate stack can exist over an annular region of the substrate and can be removed from the annular region by an edge cleaning process.

主权项

1. A method for forming a metal gate transistor, comprising:
providing a substrate having a top surface and a back surface; forming a dummy gate on the top surface of the substrate; forming a first interlayer dielectric layer on the top surface of substrate; planarizing the first interlayer dielectric layer to expose the dummy gate; removing the dummy gate to form a trench; forming a metal gate stack to cover the first interlayer dielectric layer and to fill the trench; planarizing the metal gate stack to remove a portion of the metal gate stack from the first interlayer dielectric layer to form a metal gate electrode in the trench and to leave a remaining edge portion of the metal gate stack over an annular region of the substrate; and performing an edge cleaning process on the top surface of the substrate to remove the remaining edge portion of the metal gate stack from the annular region of the substrate.