Adjustable emissions from silicon-rich oxide films prepared by plasma-enhanced chemical-vapor deposition

Observation of sequentially adjustable, intense, and stable emissions at room temperature from amorphous silicon-rich oxide thin films without any thermal annealing is reported. Hydrogenated amorphous silicon-rich oxide (SiOx:N:H, 0<x<2) thin films were deposited by plasma-enhanced chemical-vapor deposition with a mixture of 5% silane in argon and nitrous oxide gases. The strong naked-eye-seeing photoluminescence (blue-white-orange) could be adjusted by changing the process gases flow rate ratio Gamma (=[SiH4]/[N2O]). The degree of silicon richness was determined from secondary ion mass spectrometry. The microstructure-bonding configuration was examined by Fourier transform infrared spectroscopy. The implications of these studies for understanding the origins of silicon-based luminescence are discussed. (C) 1999 American Institute of Physics. [S0003-6951(99)01512-0].