Method of manufacturing a semiconductor device having a dual gate structure

摘要

A semiconductor device having a dual gate is formed on a substrate having a dielectric layer. A first metallic conductive layer is formed on the dielectric layer to a first thickness, and annealed to have a reduced etching rate. A second metallic conductive layer is formed on the first metallic conductive layer to a second thickness that is greater than the first thickness. A portion of the second metallic conductive layer formed in a second area of the substrate is removed using an etching selectivity. A first gate structure having a first metallic gate including the first and the second metallic conductive layers is formed in a first area of the substrate. A second gate structure having a second metallic gate is formed in the second area. A gate dielectric layer is not exposed to an etching chemical due to the first metallic conductive layer, so its dielectric characteristics are not degraded.