Hydrogen Incorporation and Crystallization of Nanocrystalline Silicon Deposited by Electron Cyclotron Resonance Plasmas

Nanocrystalline silicon layers have been deposited by electron cyclotron resonance chemical vapor deposition from silane as precursor. Although hydrogen was not deliberately introduced in the plasma it was incorporated in the grown layers as evidenced by the presence of a main infrared absorption band around 2100 cm21 with a shoulder at 2000 cm21. This suggests that most of the hydrogen is bonded to internal surfaces of microcavities instead of isolated Si–H bonds. In the first few hundreds, ,500 Å, of deposited layers, the estimated hydrogen concentration is rather low, below 5 atom %, and increases strongly for larger thicknesses. Solid phase crystallization at ,11008C occurs in thin layers close to the substrates in which the hydrogen concentration is below a certain critical value of ,5 atom %. © 1999 The Electrochemical Society. S0013-4651(98)05-047-2. All rights reserved.