Crystallization of amorphous silicon thin films: The effect of rapid thermal processing pretreatment

In the present work, the effect of low temperature short-time rapid thermal processing (RTP) pretreatment on the average grain size and the crystallinity of the polycrystalline silicon thin films, fabricated by subsequent solid phase crystallization (SPC) of amorphous silicon (a-Si) thin films grown by radio-frequency plasma-enhanced chemical vapor deposition (RF-PECVD) at high temperature has been studied. The average grain size and the crystallinity results were estimated using X-ray diffraction (XRD) and Raman spectroscopy, respectively. It was found that RTP at 800 degrees C for 60s resulted in slightly larger average grain size and higher crystallinity than those without the RTP pretreatment after SPC at 800 degrees C for 5, 10 and 22h. The results suggest that the low-temperature short-time RTP pretreatment can promote the crystallization process of the as-deposited a-Si thin films during the following SPC and then improve their crystallinity. Finally, the mechanism is also discussed in detail in the paper. (c) 2005 Elsevier Ltd. All rights reserved.