Effect of buried Si-SiO2 interfaces on oxidation and implant-enhanced dopant diffusion in thin silicon-on-insulator films

Abstract

The diffusion behavior of phosphorus and boron was used to study point defect kinetics in silicon-on-insulator (SOI) material. Phosphorus marker layers were used to study oxidation enhanced diffusion in bulk and bonded and etched-back silicon-on-insulator (BESOI) material under oxidizing conditions at 750, 800, and 850 °C. An effective interstitial recombination velocity Kox for the buried Si-SiO2 interface in the BESOI material was extracted by fitting the experimentally obtained phosphorus profiles with suprem−iv simulation results. The data can be modeled with a time-independent interface recombination velocity. The same parameter set incorporating this extracted recombination velocity was used to accurately model the implant enhanced diffusion of boron marker layers at 750 and 800 °C in thin SOI films, implying the recombination velocity is independent of the interstitial supersaturation. The expression Kox/DI=4.7×10−3 exp(+1.34/kT) fits this work and also a wide range of literature results at higher temperatures.