Comparison between computational modeling and experiment for a CVD growth process of silicon films

摘要

Silicon growth at high growth rates is e.g. interesting for the production of solar cells. The thermal chemical vapor deposition of silicon was systematically studied experimentally and by computational modeling. Model calculations were used to define the field of starting parameters, i.e. temperature, pressure, and flow rates as well as to evaluate different reaction gas compositions. Monosilane was chosen as starting material on silicon carbide ceramics as the substrate. The calculations show that substrate temperatures around 1100 K should be used with short residence times to avoid pre-reactions and gas phase nucleation. Small amounts of hydrogen (2-10%) help further to avoid gas phase decomposition. The experimental setup consists of a cold-wall CVD reactor with a stagnation point geometry. The influence of hydrogen and nitrogen upon growth rate was investigated. Silicon growth rates of more than 6 μm/min were achieved, similar to modeling predictions.