METHOD FOR FORMING SILICON GERMANIUM GATE POLY OF MOS TRANSISTOR AND CMOS TRANSISTOR USING THE SAME

摘要

PURPOSE: A formation method of a silicon germanium gate poly is provided to prevent a boron depletion and operational problems by quickly implanting lots of germanium on a gate polysilicon layer and by reliably controlling the density of the implanted germanium. CONSTITUTION: A gate insulating layer(11) is formed on a substrate(10). Then, a polysilicon layer(23) is formed on the gate insulating layer(11). After forming a plasma having a germanium in a processing chamber, a plasma doping process for implanting ions including the germanium is performed on the polysilicon layer(23) by supplying a voltage to the substrate(10). At this time, the density of the implanted germanium is constant and the germanium intensifies a solubility of boron, thereby preventing a boron depletion. Then, a boron doping process is performed on the germanium plasma doping performed structure.