Hydrogen incorporation and crystallization of nanocrystalline silicon deposited by electron cyclotron resonance plasmas

Nanocrystalline silicon layers have been deposited by electron cyclotron re sonance chemical vapor deposition from silane as precursor. Although hydrog en was not deliberately introduced in the plasma it was incorporated in the grown layers as evidenced by the presence of a main infrared absorption ba nd around 2100 cm(-1) with a shoulder at 2000 cm(-1). This suggests that mo st of the hydrogen is bonded to internal surfaces of microcavities instead of isolated Si-H bonds. In the first few hundreds, similar to 500 Angstrom, of deposited layers, the estimated hydrogen concentration is rather low, b elow 5 atom So, and increases strongly for larger thicknesses. Solid phase crystallization at similar to 1100 degrees C occurs in thin layers close to the substrates in which the hydrogen concentration is below a certain crit ical value of similar to 5 atom %. (C) 1999 The Electrochemical Society. S0 013-4651(98)05-047-2. AU rights reserved.