Performance improvements of IGZO and ZnO thin-film transistors by laser-irradiation treatment

Zinc oxide (ZnO) and indium gallium zinc oxide (IGZO) thin films subjected to laser irradiation were investigated. The structural, optical, and electrical properties of the as-deposited and laser-irradiated films at different laser dosages were studied. The crystallinity of the structure increased after laser treatment. The transmittances without/with laser irradiation had a net rise of 85-92% and 80-95% (@ 550 nm) for 250-nm ZnO and IGZO films, respectively. Thin-film transistors (TFTs) with ZnO and IGZO as the active layer were fabricated. The as-deposited ZnO/IGZO TFT devices had a field-effect mobility of 0.19 and 1.3 cm(2)/V-sec, respectively. The electrical characteristics increased by more than 2.8 times for ZnO and by 5.8 times for IGZO with laser treatment. The field-effect mobility of ZnO and IGZO are 0.5 and 7.65 cm(2)/V-sec.