Local vibrational mode bands of V-O-H complexes in silicon

H-2 molecules, which are introduced into moderately doped silicon crystals by high-temperature in-diffusion from H-2 gas ambient followed by fast cooling to room temperature, are found to interact effectively with the defects induced by irradiation of the crystals with fast electrons. In Czochralski-grown silicon crystals, the interaction of the mobile H-2 molecules with vacancy-oxygen defects (A centers) leads to the creation of V-O-H-2 complexes. This complex gives rise to infrared (IR) absorption lines at 943.5, 2126.4, and 2151.5 cm(-1). Ab initio calculations showed that the most stable configuration of V-O-H-2 consists of one oxygen and two hydrogen atoms sharing a vacancy site. It is suggested that the interaction of the V-O-H-2 complexes with interstitial oxygen atoms results in the formation of V-O-2-H-2 complexes, which are responsible for the IR absorption line at 891.5 cm(-1). (C) 1999 Elsevier Science B.V, All rights reserved.