Effects of deposition temperature on polycrystalline silicon films using plasma-enhanced chemical vapor deposition

The 200-nm-thick polycrystalline Si films were deposited by changing the deposition temperature (Td=150–750 °C) using plasma-enhanced chemical vapor deposition of monosilane–hydrogen mixtures. The structural and bonding properties were examined using techniques of Raman scattering, x-ray diffraction, infrared (IR) absorption, and electron spin resonance. Except for Td at 150 and 650 °C, crystallization of the films was observed, and the occurrence of two IR absorption bands around 850 and 1000 cm−1 and an increase in the density of Si dangling bonds were observed in the range of Td higher than 500 °C. These origins were discussed in connection with the mechanisms of disappearance of crystalline phases from the film at Td=650 °C.