This paper reviews analysis methods of hydrogenated amorphous silicon thin films by using thermal desorption spectroscopy and spectroscopic ellipsometry. Amorphous silicon has disordered atomic structure, and consists of dangling bonds, which work as ...
This paper reviews analysis methods of hydrogenated amorphous silicon thin films by using thermal desorption spectroscopy and spectroscopic ellipsometry. Amorphous silicon has disordered atomic structure, and consists of dangling bonds, which work as electronically active defects. These defects can be passivated by hydrogen, and the material is called hydrogenated amorphous silicon. Hydrogen exodiffusion provides information on Si-H bonding and microstructure of the material. Therefore, Si-H bonding property and microstructure of the films can be analyzed in detail. Spectroscopic ellipsometry is a powerful tool for analyzing optical properties of material. Ellipsometry measurement results is usually given by change of polarization state of probe light, so the measured result should be properly treated and transformed to meaningful parameters by transformation and modeling of the measurement result. In case of hydrogenated amorphous silicon, Tauc-Lorentz dispersion is usually used to model the measured ellipsometry spectrum. Modeling of spectroscopic ellipsometry result of hydrogenated amorphous silicon using Tauc-Lorentz dispersion is discussed.