Fabry-Perot interference characteristics of the photoluminescence in nanoclustered SiNx : H thick films

Abstract

Thick films (3 similar to 4 pm) of nanoclustered SiNx:H on p-type Si (100) substrates were fabricated by using an rf plasma-enhanced chemical vapor deposition (PECVD) method under flows of hydrogen-diluted silane and nitrogen gas. The photoluminescence (PL) of the SiNx:H films at room temperature showed broad emission bands modulated by the Fabry-Perot interference patterns at a wavelength of 400 similar to 600 nm. The Fabry-Perot interference characteristics in the visible ranges was discussed in view of the refractive index variations of the interface layers between films and the Si substrates and of the near-air surface layers of the thick films. A consideration of the thick films as Fabry-Perot microcavity structures is quite successful in explaining the modulated PL emission spectra, where the refractive indices of the thick films are observed to be in the range of 1.8 similar to 2.5 for SiNx:H films with x = 1.0 similar to 1.2. These results suggest that nanoclustered SiNx:H films would be a probable material for further applications such as microcavities, resonators, filters, and gain media over wide ranges of visible wavelengths.