NEW DEFECT IN AS-GROWN THERMAL SIO2 INHERENT TO THE GROWTH-PROCESS

A defect, intrinsic to the SiO2 thermal growth process, has been obser ved by electron spin resonance (ESR) in thin (50 to 150 angstrom) SiO2 films grown on (111)Si at temperatures ranging from 720 to 930-degree s-C. Analysis of its ESR features at 4.3 K in combination with etch ba ck experiments show the defect to reside in the top half of the amorph ous SiO2 layer. The defect concentration - as sensed in the ESR-active state - is found to depend critically on the oxide thickness d(ox), t he local spin concentrations reaching values as high as 10(18) cm-3 in Si/SiO2 structures optimized for d(ox). The same defect appears in eq ual intensities when growing SiO2 films of comparable thicknesses on ( 100)Si.