Dynamics of SiO2/SiOx/Si multilayer growth and interfacial effects on silicon quantum well confinement properties

In this paper, we perform Monte Carlo simulations of SiO2 thin film growth on silicon. The results indicate the formation of non-stochiometric SiOx (0<x<2) transition layers 1.2–2.5 nm wide depending on the growth simulation parameters, and that the interfacial silicon molar content follows closely an error function profile. We study the role of the SiOx layers on the confinement properties of SiO2/Si/SiO2 single quantum wells by means of the effective mass theory. The electron and heavy-hole energy levels are shown to be strongly blue-shifted in comparison with those calculated when the existence of interfacial SiOx transition layers is disregarded. The recombination energy of the ground-state electron–hole pair is blue-shifted several hundred millielectronvolts when the graded interfaces in 3 nm wide SiO2/Si/SiO2 wells are as thin as a monolayer.