Compositional and structural properties of hydrogenated amorphous silicon-carbon films prepared by ultra-high-vacuum plasma-enhanced chemical vapour deposition with different carbon sources

Abstract

Hydrogenated amorphous siliconxarbon films were deposited by ultra-highvacuum plasma-enhanced chemical vapour deposition in silane + methane and silane + acetylene gas mixtures. Both types of film were compared with respect to their compositional, optical and structural properties. They have an optical gap in the range 2.3-3.3eV for [C]/[C + Si] between 0.2 and 0.1 and possess high uniformity. The deposition rate of CzHz-based films is 4-5As-', one order of magnitude higher than CH4-based films having large bandgap. By infrared (IR) spectroscopy, marked differences in carbon and hydrogen incorporation have been found for the films grown using the two different carbon sources. Analysis of the IR spectra reveals, among the most important structural characteristics, that the films grown from the S i b + C€& plasma have a higher concentration of SikC bonds than those grown from SiH4 + C2H2, and that CzH2-based alloys allow the formation of carbon clusters during the growth of the films. Considerations of the average coordination number, the chemical bonding and the degree of chemical order are also reported and discussed.

Photoluminescence and electronic density of states in a-C:H films

“…͑5͒. N is computed by using the sp 2 fraction, obtained from IR spectroscopy 19 and the film atomic density given by nuclear measurements, 20 for the samples of the present work. N values for literature samples 17 were estimated following Ref.…”

Influence of Growth Conditions of Hydrogenated Amorphous Silicon Carbide on Optical Properties of the Interfacial Layer in SiC-Based Photodevice

“…In this work, Au-SiC interface has been modified by a thin layer of metal sulfide, MS (PbS specifically). Synthesis of luminescent nanocrystalline MS (M = Pb, Cd) thin films were done in order to introduce them as interfacial layer [5]. Lead sulfide (PbS) is an important member of the chalcogenides which offers large tenability.…”

Thermal modification of wide-bandgap hydrogenated amorphous silicon-carbon alloy films grown by plasma-enhanced chemical vapour deposition from C2H2+SiH4 mixtures

“…The deposition parameters were optimized to obtain device-quality films (Demichelis, Giorgis, Pirri and Tresso 1995b). The fihn thicknesses were in the range of 0.5-1.2 pm.…”