Oxygen partial-pressure dependence of the oxidation-induced surface stacking faults in (100) n silicon

Abstract

The effect of varying oxidation rates on the growth of the oxidation‐induced stacking faults (OISF) in (100) silicon has been investigated. Oxidation rates were varied by changing partial pressures of dry oxygen in the oxidizing ambient of oxygen‐nitrogen mixtures. For the first time, it has been shown that in addition to the conventionally observed dependence on time and temperature [i.e., L∝tⁿ exp(−Q/kT)], the length L of the OISF also depends on the partial pressure of oxygen and is given by L∝p^m_O2. Thus, the length of the OISF is given by L= (const) p^m_{O 2}tⁿ exp(−Q/kT), where m and n are number exponents. m was found to increase very slightly (from 0.28 at 1050 °C to 0.35 at 1150 °C) with temperature. n decrease very slightly with temperature and was 0.89 at 1050 °C and 0.76 at 1150 °C. At 1119 °C, n was found to increase from 0.78 to 0.84 by changing the oxygen content in the oxidizing ambient from 100 to 10%. The activation energy Q was found to be 2.30±0.05 eV in the temperature range 1050–1150 °C and was independent of variations in the oxygen partial pressures from 10 to 100%. The results have been discussed, and a mechanism incorporating excess of unoxidized silicon at the Si‐SiO₂ interface and vacancy mechanism of diffusion has been suggested to explain the experimental results.