Crystallography of In-Ga-Zn-O thin film having CAAC structure

We succeeded in fabricating an In-Ga-Zn-O (IGZO) thin film which has a novel structure. We have shown that the IGZO thin film has a c-axis aligned crystalline structure (abbreviated below to CAAC-IGZO) as the detailed structural analysis. Besides, we have shown that the crystalline plane of the CAAC-IGZO structure is c-axis aligned over the entire area in the nano-order analysis. In addition, the results have shown that a clear crystalline grain boundary was not observed regardless of the result that, over the entire area of the CAAC-IGZO thin film is c-axis aligned and has high crystallinity and there is no orientation on average in the directions of the a-axis and the b-axis. It is found that the CAAC-IGZO structure is a completely novel crystalline structure, which is different from a polycrystalline structure obtained by laser annealing, a nanocrystalline structure and an amorphous structure, which were previously reported in silicon TFT and so on.