INFRARED-SPECTROSCOPY DURING HYDROGEN EFFUSION OF A-SI-H, A-SIGE-H AND A-GE-H

The effusion of hydrogen from a-Si:H, a-SiGe:H and a-Ge:H was studied in-situ by infrared spectroscopy. This allows monitoring of Si-H (Ge-H) bond breaking in different configurations. Additional information is obtained from changes in refractive index and from the wavelength shift of absorption bands upon tempering. Already before the onset on H-effusion changes in hydrogen binding are observed. During effusion film density increases as a result of crosslinking in voids. Information on bond angle distribution and crystallisation is obtained from Raman measurements.