| Hydrogenated, amorphous silicon nitride (a-SiN:H) is used extensively in semiconductor device technology. It is commonly used as a gate dielectric in a-Si:H thin film transistors and as a passivation layer for integrated circuits. When exposed to light, defects are induced in the material which have been associated with under-coordinated Si dangling bonds. The light-induced defects are capable of trapping mobile charges and causing a degradation in the electrical properties of the material. This, of course, would adversely affect device stability due to charge accumulating in the nitride. Therefore, it is of importance to understand the properties of these light-induced defects and their behavior under illumination.;Electron spin resonance (ESR) spectroscopy is an excellent method for monitoring paramagnetic centers in insulating materials. The light-induced defects are paramagnetic in the electrically neutral state and are detectable using ESR. ESR is used to study the production and photo-bleaching of neutral defects as a function of illumination time, photon energy and temperature. Included in this thesis is a physical model to explain the light-induced phenomena. |
