FinFETs with multiple threshold voltages

摘要

A device includes a substrate, a semiconductor fin over the substrate, and a gate dielectric layer on a top surface and sidewalls of the semiconductor fin. A gate electrode is spaced apart from the semiconductor fin by the gate dielectric layer. The gate electrode includes a top portion over and aligned to the semiconductor fin, and a sidewall portion on a sidewall portion of the dielectric layer. The top portion of the gate electrode has a first work function, and the sidewall portion of the gate electrode has a second work function different from the first work function.

主权项

1. A device comprising:
a substrate; a semiconductor fin over the substrate; a gate dielectric layer comprising a top portion overlapping the semiconductor fin, and a sidewall portion on a sidewall of the semiconductor fin; and a first metal layer contacting a top surface of the top portion of the gate dielectric layer, wherein the first metal layer does not extend to sides of the semiconductor fin; and a second metal layer contacting a sidewall of the sidewall portion of the gate dielectric layer, wherein the first metal layer and the second metal layer comprise different materials, and the second metal layer comprises a first portion over and aligned to the semiconductor fin, and second portions extending on the sides of the semiconductor fin.