FABRICATION OF ULTRATHIN SILICON DIOXIDE LAYERS IN ULTRA-HIGH-VACUUM

Silicon dioxide layers of thickness 1-10 nm have been manufactured by the plasma oxidation of silicon in ultra high vacuum (UHV). UHV chambe r is a very clean environment, temperature and molecular fluxes are ea sily controllable and in situ device processing is possible. In the te mperature range 700-850 degrees C the oxidation is very slow in the be ginning. After an uniform layer is developed on the surface, the growt h rate increases. Increasing temperature also clearly increases the gr owth rate, as the temperature dependence of the initial growth phase i s probably less. Our measurements predict, that to get a good quality layer, the processing temperature should be at least 700 degrees C.