The effect of ultrasound on the Si-SiO sub(2) system

The effect of ultrasonic treatment (UST) on the defect structure of the Si-SiO sub(2) 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 centers depended on the defect type and structure, and may be caused by dissipation of vibrational energy which is a function of the defect center type. The influence of the UST on the properties of the Si-SiO sub(2) interface depends on the oxide thickness and crystallographic orientation. The density of point defects and absorbed impurities at the Si-SiO sub(2) interface can be reduced and its electrical parameters improved by an appropriate choice of the UST and oxidation conditions. ( copyright 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)