YIELDS OF THE PLASMA OXIDATION OF SILICON BY NEUTRAL OXYGEN-ATOMS AND NEGATIVE OXYGEN ATOM IONS

The yield for the plasma oxidation of silicon is defined for both ground state oxygen atoms (O3P) and oxygen atom ions (O−). On the basis of these yields it is shown that the role of oxygen atoms is negligible compared to the negative oxygen atom ions in plasma oxidation. The negative ion oxidation yield as a function of temperature follows an Arrhenius behavior with an apparent temperature coefficient of 0.20 ± 0.033 eV. Other factors such as the oxygen pressure, the silicon bias voltage, or the reactor geometry have only a minor effect on the oxidation yields. Calculated negative ion fluxes from the plasma toward the silicon substrate seem to be too low to explain the observed initial silicon dioxide growth rates, which supports a surface-catalyzed formation path for the negative oxygen atom ions. © 1990, The Electrochemical Society, Inc. All rights reserved.