ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
We analyze the effect of thermal processes on the optical properties (refractive index, optical gap, Tauc coefficient, and Urbach energy) of SiNx:H films. Films with three different nitrogen to silicon ratios (x=0.97, x=1.43, and x=1.55, respectively) were deposited by a chemical vapor deposition technique assisted by an electron cyclotron resonance generated plasma. After deposition they were subjected to rapid thermal annealing at temperatures ranging from 300 °C to 1050 °C. We found that the percolation threshold for Si–Si bonds (at x=1.1) separates films with different response to thermal treatments. The changes of the Tauc coefficient and the Urbach energy at moderate annealing temperatures indicate a structural relaxation of the network for the films with x above the percolation threshold, while at higher temperatures the trends are inverted. In the case of x below the percolation limit the inversion point is not observed. These trends are well correlated with the width of the Si–N infrared stretching absorption band. Additionally the samples with as-grown x=1.43 show a good correlation between the Urbach energy and the density of unpaired spins in silicon dangling bonds. © 1999 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.371008
