As a next-generation electronics material, amorphous-InGaZnO (a-IGZO) film devices were investigated. In order to further utilize a-IGZO films, we carried out conventional ion of boron (B+) or neon (Ne+) implantations in a-IGZO thin films on glass and analyzed the implanted a-IGZO via Hall measurement with wet etching. In addition, a-IGZO thin film transistor processes with the implantation were carried out. As a result, we find that both ions drastically decrease a-IGZO sheet resistances. However, we observed oxygen vacancy area increase in the case of Ne+ implanted a-IGZO in 300 oC post annealing, which indicates Ne diffuses in a-IGZO film. On the other hand, B diffusion was not observed by depth profile comparison between the implanted samples with and without annealing. Furthermore, we extract key device parameters, such as effective channel length and ON/OFF current ratio, which can be applied to a-IGZO device processing.