AN ELECTRON-SPIN-RESONANCE STUDY OF THE EFFECTS OF THERMAL NITRIDATION AND REOXIDATION ON P(B) CENTERS AT (111) SI SIO2 INTERFACES/

Electron spin resonance of P(b) centers is used to probe the dielectri c/silicon interface in NH3-nitrided oxide (NO) and reoxidized nitrided oxide (RNO) dielectrics. The P(b) spectra observed in the NO and RNO systems differ from Si/SiO2 systems only in the value of g(perpendicul ar-to) ; the DELTAg(perpendicular-to) suggests that the average value of the local strain at the defect site decreases upon nitridation, and is little changed by subsequent reoxidation. The relaxation of the P( b) center structure appears to coincide with a reduction of compressiv e stress in the dielectric and an increase of tensile stress in the si licon substrate. These results suggest that differences in atomic scal e strain due to nitrogen incorporation may be involved in the reduced radiation- and hot carrier-induced interface state generation that NO and RNO dielectrics exhibit.