Growth of ultrathin SiO2 on Si by surface irradiation with an O-2+Ar electron cyclotron resonance microwave plasma at low temperatures

Ultrathin SiO2 films were grown by Si surface irradiation with an O-2+Ar el ectron cyclotron resonance (ECR) microwave plasma at low temperatures. Thes e films without hydrogen and silicon deposition were easily grown in a few minutes at low temperatures and at relatively low working pressures (1.0-3. 9 x 10(-1) Pa). The promoting growth process of an ultrathin oxidized layer (1-9 nm) was analyzed by in situ Fourier transform infrared reflective abs orption spectroscopy. By using the sputter erosion technique, the dependenc e of x-ray photoelectron spectroscopy on the depth profiling of the films w as obtained. The compositional deviations of the films from the stoichiomet ric SiO2 were also discussed in the interface region of Si/SiO2. This study indicated that an O-2 ECR microwave plasma was efficient to form controlle d ultrathin SiO2 dielectric films. The dependence of the film quality on th e working pressure and gas flow rate ratios of the O-2 to Ar was discussed. (C) 1999 American Institute of Physics. [S0021-8979(99)06203-9].