Abstract: Polycrystalline silicon (poly-Si) films were prepared by hot-wire chemical vapor deposition (HWCVD) at a low substrate temperature of 525 ℃. The influence of hydrogen on the epitaxial growth of ploy-Si films was investigated. Raman spectra show that the poly-Si films are fully crystallized at 525 ℃ with a different hydrogen dilution ratio (50%—91.7%). X-ray diffraction, grazing incidence X-ray diffraction and SEM images show that the poly-Si thin films present (100) preferred orientation on (100) c-Si substrate in the high hydrogen dilution condition. The P-type poly-Si film prepared with a hydrogen dilution ratio of 91.7% shows a hall mobility of 8.78 cm²/(V·s) with a carrier concentration of 1.3 × 10²⁰ cm^-3, which indicates that the epitaxial poly-Si film prepared by HWCVD has the possibility to be used in photovoltaic and TFT devices.

Key words: polycrystalline silicon, hot-wire chemical vapor deposition, low temperature epitaxial growth