In metal-gate stack formation replacement gate technology

摘要

A method comprising:Forming a first metal gate electrode material layer, which via a gate dielectric layer a dielectric constant of 10 or more;Subjecting the first metal gate electrode material layer a oxygen diffusion process;Forming a second metal gate electrode material layer over the first metal gate electrode material layer according to the subject of the first metal gate electrode material layer the oxygen diffusion process; andSetting a oxygen concentration gradient and a nitrogen concentration gradient in at least the first metal gate electrode material layer and the gate dielectric layer in the layer thickness direction by means of a thermal treatment.