ChemInform Abstract: The Effect of Fluorine Additions to the Oxidation of Silicon

ChemInform Abstract

is studied using two different fluorine sources, liquid dichlorofluoroethane (C₂H₃Cl₂F) and gaseous NF₃. The oxidation kinetics are found to be largely enhanced by the addition of very small amounts of fluorine (up to 0.11 vol.%). From the thermodynamic analysis of the oxidation ambient, it is concluded that HF and atomic fluorine are the major active species for O2/C2H3Cl2F and O2/NF3 oxidation, respectively. During oxidation, a local etching process competes with the growth process in the presence of HF. For HF concentrations exceeding a crucial amount, poor quality oxides are formed, in which pinholes and weakened structures are observed. The incorporation behavior of fluorine into the oxide is briefly discussed on the basis of SIMS results.