Gate oxide prepared by nanometre silicon wet oxidation at low temperature for Si/SiGe PMOSFET application

摘要

A high-quality thin gate oxide for application in Si/SiGe heterostructure PMOSFETs is prepared by nanometre silicon wet oxidation at 750 deg.C by Taking full advantage of the peculiar phase in polysilicon thermal oxidation. The combination of low temperature and a short processing time prevents Strain relaxation and Ge outdiffusion in the compressively strained SiGe Channel. Its structural stability and interface quality are studied by x-ray Double-crystal diffraction. Results of C-V characteristics and breakdown Measurements indicate that the gate oxide exhibits a low fixed oxide charge Density and a high dielectric breakdown field.