Effect of carbon on thermal oxidation of silicon and electrical properties of SiO₂-Si structures

Growth of thermal oxide on silicon implanted with carbon at low energies is studied and electrical characteristics of the resulting SiO₂-Si structures are evaluated. After excluding the effect of surface damage on the oxide growth kinetics, it was determined that for the carbon implant doses up to 10¹⁴ cm^-2 the effect on oxide growth kinetics is limited. At higher carbon doses significant retardation of oxide growth was observed. A clear correlation between carbon dose and electrical characteristics of SiO₂-Si structures has also been established. In the case of each parameter of concern in this study its degrActation with increased carbon dose above 10¹⁴cm^-2, which corresponds to carbon concentration in silicon of the order of 10¹⁹ cm³, was observed. These effects may come to play during thermal oxidation of silicon wafers subjected prior to oxidation to the reactive ion etching in carbon containing gases such as CF₄, CHF₃, and others.