High-frequency hydrogen-related infrared modes in silicon grown in a hydrogen atmosphere

High-frequency vibrational modes have been observed at liquid-helium temper ature in silicon samples grown in a H-2 or D-2 atmosphere. The highest-freq uency ones are due to the overtones and combination modes of SiH fundamenta ls. Others are CH modes due to (C,H) complexes, but the simultaneous presen ce of NH modes due to (N,H) complexes cannot be excluded. The present resul ts seem to show also the existence of centers including both SiH and CH or NH bonds. One sharp mode at 4349 cm-l is related to a weak SiH fundamental at 2210 cm(-1). The related center is ascribed to a vacancy fully decorated with hydrogen with a nearest-neighbor C atom. [S0163-1829(99)00911-X].