Crystallization of μc-Si on plastic substrate by using a pulsed double-frequency YAG laser

Abstract:

Thin film transistors (TFTs) of microcrystalline silicon (μc-Si) can provide higher mobility and stability than that of a-Si and better uniformity than that of poly-Si TFTs, and it would be more suitable to be applied to larger-area AMOLEDs. By using 2ωYAG laser annealing, crystalline μc-Si thin film on plastic substrate has been investigated and the proper laser energy needed for crystallization has been indicated. It has been found that the dehydrogenation process at 300–450 °C for a few of hours could be omitted by decreasing the H content in the crystallization precursor, which is suitable for laser crystallization on plastic substrates. The crystalline volume fraction (Xc) and the grain size of the resulted μc-Si could be adjusted by controlling the laser energy. By this method, the μc-Si on plastic substrate with Xc and grain size is respectively 85% (at the maximum) and 50 nm. This work has been supported by “863” Project of National Ministry of Science and Technology (No. 2004AA33570), Key Project of NSFC (No. 60437030) and Tianjin Natural Science Foundation (No.05YFJMJC01400)