A Systematic Method for Predictive in-silico Chemical Vapour Deposition

A comprehensive systematic method for chemical vapour deposition modelling consisting of seven well defined steps is presented. The method is general in the sense that it is not adapted to a certain type of chemistry or reactor configuration. The method is demonstrated using silicon carbide (SiC) as model system, with accurate matching to measured data without tuning of the model. We investigate the cause of several experimental observations for which previous research only have had speculative explanations. In contrast to previous assumptions, we can show that SiCl₂ does not contribute to SiC deposition. We can confirm the presence of larger molecules at both low and high C/Si ratios, which have been thought to cause so-called step-bunching. We can also show that high concentrations of Si lead to other Si molecules than the ones contributing to growth, which also explains why the C/Si ratio needs to be lower at these conditions to maintain high material quality as well as the observed saturation in deposition rates. Due to its independence of chemical system and reactor configuration, the method paves the way for a general predictive CVD modelling tool.