Kinetics and mechanism of amorphous hydrogenated silicon growth by homogeneous chemical vapor deposition

A new method of amorphous hydrogenated silicon (a-Si) chemical vapor deposition is presented in which SiH4 is homogeneously decomposed at high temperature and pressure to produce films on low-temperature substrates having up to 30-at. % H and properties very similar to plasma-deposited material. Kinetic studies provide a film growth activation energy of 54 kcal/mole, confirming that SiH2 is the primary gas phase intermediate. A mechanism based on SiH2 chemistry is presented to account for the rapid surface reactions leading to a-Si growth and its possible relevance to the plasma deposition process is emphasized.