Crystal structure of Si1−xCx films by plasma-enhanced chemical vapor deposition at 700 °C

Using x-ray diffraction and electron-spin-resonance measurements, the crystal structure and bonding configurations of Si1−xCx films by plasma-enhanced chemical vapor deposition at 700 °C are shown to change abruptly at around x=0.5. At around this composition, a polycrystalline film with a cubic SiC 〈111〉 preferred orientation and an average grain size of 95 nm is grown on a fused silica substrate under high hydrogen dilution. The structural change can be attributed to an increase in the probability of occurrence of a Si- C4 tetrahedron in a chemically ordered network.