METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE WITH DUAL GATES

摘要

A method for manufacturing a semiconductor device is provided to restrain the degradation of dielectric characteristics and to control uniformly the thickness of first and second metallic gates using an enhanced dual gate structure. A dielectric film(102a,102b) is formed on a semiconductor substrate(100). A first metallic conductive layer with a first thickness is formed on the dielectric film. An etch rate of the first metallic conductive layer is decreased by annealing. A second metallic conductive layer with a second thickness larger than the first thickness is formed on the first metallic conductive layer. The second metallic conductive layer is selectively removed from a second region of the substrate by using an etch selectivity between the first and second metallic conductive layers. At this time, a first gate stack structure(115) with a first metallic gate(110) is formed on a first region of the substrate and a second gate stack structure(120) with a second metallic gate(104b) is formed on the second region of the substrate.