To sharply reduce the diffusion of germanium to a gate dielectric.
A metal oxide semiconductor (MOS) transistor for an integrated circuit includes a gate area and a gate dielectric layer 32 positioned in the gate area. In this gate dielectric layer 32, germanium diffusing from an epitaxial Si1-xGex alloy layer 18 to the gate dielectric layer 32 is substantially made absent. This method comprises a process for building up a dummy displacement gate, a process for carrying out high temperature treatment to elements, a process for removing a dummy gate 28A, and a process for building-up dielectric materials to be turned into the gate dielectric layer 32 and final gate materials in the gate area. Thus, the dielectric materials to be turned into the gate dielectric layer 32 are built up after the high temperature treatment is carried out to the elements, and the quantity of germanium diffusing to the dielectric materials is ignorable.
TWEET DOUGLAS J
EVANS DAVID RUSSELL
