A growth model for the carbonization of silicon surfaces

The kinetics of carbonization of (111)Si by rapid thermal processing with C3H8 diluted in H2 were investigated and compared with published results on (100)Si. A mathematical description for the saturation behaviour was developed and fitted with the data received by ellipsometry and atomic force microscopy. These parameters are nucleation density, silicon diffusion flux and a ratio between vertical and horizontal growth. The model agrees in the estimation of saturation thickness and time as a function of concentration and temperature. A boundary concentration around 0.1% was found where the surface is already sealed off after heating up. Above this concentration the model failed.