Preparation and Properties of Ge Microcrystals Embedded in SiO₂ Glass Films

Ge microcrystals were successfully doped into SiO 2 glass films by the rf magnetron sputtering technique. The dependence of the average size of Ge microcrystals on substrate temperature and annealing time was discussed. The optical absorption spectra of Ge microcrystals clearly exhibited the blue shift compared with a bulk Ge crystal, which seems to be due to a quantum size effect.