We proposed high‐energy green laser irradiation as a new technique for the activation of amorphous indium gallium zinc oxide thin film transistors (a‐IGZO TFTs). Compared with IGZO TFTs fabricated at 300°C, green laser‐activated IGZO TFTs without any thermal annealing process showed superior characteristics: field effect mobility of 6.88 cm2/Vs, subthreshold swing of 0.29 V/dec, and on/off ratio of 6.95 x 109. Although a‐IGZO films are hardly absorb green laser due to large bandgap (> 3 eV), a‐IGZO TFTs could be activated by selective heat absorption only for gate, source, and drain metal electrodes with selective green laser irradiation. The thermal energy converted by the laser irradiation selectively activated the channel layer without thermal damage on substrates.
