Electrical quality of low-temperature (Tdep≤800 °C) epitaxial silicon: The effect of deposition temperature

The results of an investigation of the effects of temperature, during both the in situ argon sputter clean and the deposition, on the electrical properties of low-temperature (Tdep≤800 °C) expitaxial silicon films are presented. The data indicate that the electrical quality does not depend on the sputter temperature, at least for temperatures in the 750–800 °C temperature range. The electrical quality is a strong function of the deposition temperature, however. Epitaxial layers deposited at 800 °C have electrical characteristics comparable or superior to bulk silicon. However, reducing the deposition temperature to 750 °C results in a significant degradation in the film electrical properties. The electrical quality is stable to further annealing for temperatures in the 750–950 °C range. The mechanism responsible for the dependence of the film electrical quality on the deposition temperature is described.