Interface strain in thermal Si/SiO 2 analysed by frequency-dependent electron spin resonance

Abstract

Thermal oxidation of Si gives intrinsically rise to the generation of Si dangling bond type defects at the Si/SiO 2 interface. In standard (1 1 1)Si/SiO 2 the dominant one observed by electron spin resonance (ESR) is the P b (Si 3Si ) center. It is generally accepted that the driving agent for these defects is the occurrence of interfacial strain. A frequency dependent ESR study on these P b defects has enabled the separation of the strain broadening component from other line broadening mechanisms, leading to a direct quantification of the associated interface stress. This resulted in the observation of thermal treatment induced variations in the strain broadening contribution indicating the existence of two different interfacial relaxation processes.