THERMAL-BEHAVIOR OF FLUORINE IN SIO2 AND SI INVESTIGATED BY THE F-19(P,ALPHA-GAMMA) O-16 REACTION AND SECONDARY-ION MASS-SPECTROMETRY

Thermal changes of implanted fluorine distributions in a SiO2 film and a (100)-oriented Si single crystal were investigated by the F-19(p, alpha-gamma) O-16 reaction and secondary-ion mass spectrometry. Fluorine in the Si accumulates to a damaged region (consistent with a Monte Carlo simulation) after annealing above 700-degrees-C for 30 min. This effect is not observed in the SiO2. Once the fluorine is trapped by the damaged region, nearly 80% of the fluorine stays in the silicon after annealing at 800-degrees-C. In contrast, only 10% of implanted fluorine remains in the SiO2 after annealing at 800-degrees-C. These effects are explained by assuming the difference in the natures of imperfections in these samples. Above 1000-degrees-C, most of the fluorine diffuses out of both systems.