VISIBLE LUMINESCENCES FROM THERMALLY GROWN SILICON DIOXIDE THIN-FILMS

We introduce visible photoluminescences (PL) of violet (432 nm) and ye llow (561 nm) at room temperature from thermally treated silicon dioxi de thin films, These luminescences were very strong with a near infini te degradation time. At an oxide layer thickness less than 200 nm, the se luminescences were not seen, even with high temperature annealing a t about 1000 degrees C. As a result of photoluminescence, x-ray photoe lectron spectroscopy, Fourier transform infrared, and high-resolution transmission electron microscopy measurements, we conclude that the vi olet PL originates from the nanocrystalline silicon formed in the sili con oxide film by the thermal strain effect between the silicon substr ate and the silicon dioxide film, while the yellow PL originates from the radiative decay of self-trapped excitons that are confined to oxyg en sufficient structures. (C) 1996 American Institute of Physics.