The bonding configuration, H evolution, and defect content of rapid thermally annealed SiOx:H films of different compositions were studied. Infra-red absorption measurements showed that all the H present in the films was lost at annealing temperatures below 600C without any change in the O to Si ratio of the films. The activation energy of the H release was in the 0.21 to 0.41eV range independently of film composition, suggesting that the process occurred via network bond reactions. For annealing temperatures higher than 700C, a change in the Si–O–Si stretching wave number from the initial unannealed value to the 1070 to 1080/cm range was promoted, independently of the initial film composition. Electron spin resonance measurements showed that all the films contain two type of bulk paramagnetic defects: the E’ center (•Si ≡ O3) and the Si dangling bond center (•Si ≡ Si3). The rapid thermal annealing process promotes a general decrease of defect concentration for annealing temperatures below 400C. At higher temperatures, E’ center disappeared, and the •Si ≡ Si3 center increased its concentration up to the 1017 to 1018/cm3 range. This suggested that the rapid thermal annealing at higher temperatures promotes the formation of a high-quality, almost defect-free, SiO2 matrix in which highly defective Si nanocrystals were also formed, where the •Si ≡ Si3 centers were located.

Thermally Induced Modifications of Bonding Configuration and Density of Defects in Plasma Deposited SiOx:H Films. E.San Andrés, A.del Prado, I.Mártil, G.González-Díaz, D.Bravo, F.J.López: Journal of Applied Physics, 2002, 92[4], 1906-13