Effect of ultrasonic treatment on the defect structure of the Si–SiO2 system

The effect of ultrasonic treatment (UST) on the defect structure of the Si–SiO₂ system by means of electron spin resonance (ESR), metallography, MOS capacitance technique and secondary ions mass-spectroscopy (SIMS) is presented. The non-monotonous dependence of the defect densities on the US wave intensity has been observed. The influence of the UST frequency on the ESR signal intensity of the defect centres has been studied. It is shown that observed changes in the ESR intensity are caused by vibrational dissipative mechanisms which are a function of defect centre type and crystallographic orientation. The influence of the UST on the Si–SiO₂ interface properties depends on the time of oxidation. The density of point defects at the Si–SiO₂ interface can be reduced and its electrical parameters improved by an appropriate choice of the UST and oxidation conditions.