Ms. Aida et al., THE OPTICAL-PROPERTIES OF SPUTTERED AMORPHOUS-SILICON NITRIDE FILMS -EFFECT OF RF POWER, Philosophical magazine. B. Physics of condensed matter. Statistical mechanics, electronic, optical and magnetic, 73(2), 1996, pp. 339-347
Recently great interest has been paid to amorphous silicon nitride thi
n films which have found a large range of applications. Certain device
processing requires a low temperature of film deposition, thus making
sputtering a potentially useful fabrication technique. In order to in
vestigate the influence of the radio frequency (RF) power on the optic
al properties of amorphous silicon nitride, films were deposited using
powers between 100 and 400 W. Infrared spectroscopic analysis indicat
es that the concentration of Si-N bonds is reduced with increase in th
e RF power. However, the concentrations of Si-Si bonds and = N-0 and =
Si-0 dangling bonds are enhanced. A decrease in the optical gap and a
n increase in the gap state density, refractive index and valence band
tail width are observed in films deposited at high RF power.