Nucleation and Growth of Poly-Si Films Deposited Directly on Glass Substrate in Reactive Thermal CVD at 450℃
In order to elucidate why the reactive thermal CVD provides us with device grade poly-Si thin films when the source gasses of Si2 H6 and F2 were employed, the very thin films deposited at different process pressures were investigated. Atomic force microscopy (AFM) study revealed mat the nucleation of the films was totally different from that of the films deposited in a conventional low pressure CVD (LPCVD). Nucleation densities were higher and nuclei sizes were smaller at a coalescence point of nuclei for films deposited at low pressure than for those deposited at high pressure, in the range of 4 -6 torr. In addition, incubation time was considerably shorter than 30 seconds, which is comparable to that of a conventional rapid thermal CVD (RTCVD). The crystalline volume fraction of films grown at low pressures was over 90％ , while it was decreased abruptly when the pressure was increased over 5.5 torr. This change in me polycrystalline growth is due to how the F2 plays on the growing surface and in the gas phase where the F2 takes part in the chemical reactions.
Poly-Si Nucleation Reactive Thermal CVD TFT Low Temperature
Cheolhyun Lim Junichi Hanna
Imaging Science and Engineering Lab., Tokyo Institute of Technology,Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
国际会议
上海
英文
528-531
2007-03-12（万方平台首次上网日期，不代表论文的发表时间）