Microstructure of poly-Si thin films prepared at low temperatures

Microstructures of hydrogenated polycrystalline silicon (poly-Si) and micro crystalline silicon (mu c-Si:H) thin films prepared by hot wire chemical va por deposition (HWCVD) with hydrogen dilution of silane have been studied. The columnar crystal growth of the film was clearly visible tarting from su bstrate. The transmission electron diffraction (TED) showed the typical por ycrystalline material with small crystals. The (1 1 1) preferential grain w as observed in poly-Si films. The 2100 cm(-1) stretching vibration mode spl its into two modes centered at around 2082 and 2098 cm(-1) which are sugges ted to be the Si-H modes at the nanocrystalline Si (1 1 1) and (1 1 0)surfa ces, respectively. (C) 2000 Elsevier Science B.V. All rights reserved.