Cone Kinetics Model for Two-Phase Film Silicon Deposition

We study quantitatively the morphology of nanocrystalline silicon (nc-Si:H) cones that appear during amorphous silicon (a-Si:H) film growth by chemical vapor deposition from hydrogen-diluted silane. The shapes of the nc-Si:H inclusions are found to be spherical cones, consistent with our "cone kinetics" model for silicon film growth. This model predicts cone development when growth is isotropic and there is sparse nucleation of a second material phase with a higher growth rate. Application of the cone kinetics model provides insights into the deposition of technologically important thin film materials, including protocrystalline silicon, highly P-doped nc-Si:H, silicon heterojunctions, and silicon epitaxy.