Si-C-H bonding in amorphous Si1-xCx: H film/substrate interfaces determined by real time infrared absorption during reactive magnetron sputter deposition

We determine the evolution of Si–H and C–H bonding during the growth of hydrogenated amorphous silicon carbide films by reactive magnetron sputtering of a Si target in (Ar+H2+CH4). Si–H and C–H modes are observed by infrared reflectance spectroscopy. An optical cavity substrate is used to enhance the sensitivity. We identify Si–H stretching modes at 2110 and 2145 cm−1 due to Si–H clusters in microvoids and Si–H back‐bonded to carbon, respectively. C–H stretching modes are identified at 2870, 2900, and 2950 cm−1. These indicate dominant sp3 bonding configuration for C. During initial growth, a transition layer rich in H and C is observed. Steady state growth is not achieved until ≳250 A on SiO2 substrates, and ∼70 A on a‐Si:H substrates.