Photoluminescence characteristics from amorphous SiC thin films with various structures deposited at low temperature

Hydrogenated amorphous SiC thin films deposited at low substrate temperature (100degreesC) show the different bonding configurations and microstructures which depend on the carbon concentrations in the films controlled by the gas ratio R of methane to silane during the deposition. Photoluminescence characteristics are investigated for these samples with different structures. A strong luminescence in red light region can be observed for samples deposited with low gas ratio R which is significantly reduced its intensity with increasing the carbon concentrations in the films. On the other hand, the luminescence bands located at blue-green light region are detected under UV light excitation for samples deposited with high gas ratio R, which can be associated with the existence of amorphous SiC clusters in the films. (C) 2004 Elsevier Ltd. All rights reserved.