METHODS FOR FORMING METAL GATE TRANSISTORS

摘要

A method for cleaning a diffusion barrier over a gate dielectric of a metal-gate transistor over a substrate is provided. The method includes cleaning the diffusion barrier with a first solution including at least one surfactant. The amount of the surfactant of the first solution is about a critical micelle concentration (CMC) or more. The diffusion barrier is cleaned with a second solution. The second solution has a physical force to remove particles over the diffusion barrier. The second solution is substantially free from interacting with the diffusion barrier.