In-Ga-Zn-O thin-film transistors processed at 150 degrees C on laminated polyethylene naphthalate substrates exhibiting high electrical performances such as a saturation mobility of 24.26 cm(2)/(V . s), a subthreshold slope of 140 mV/dec, a turn-on voltage V(on) of -0.41 V, and an on-off ratio of 1.8 x 10(9) were fabricated. Cool-off-type adhesive was adopted to easily detach the plastic substrate from the carrier holder. Devices also showed highly uniform characteristics with a variation of 0.09 V in turn-on voltage. Stability characteristics under the positive gate bias stress can be enhanced by increasing the annealing time at 150 degrees C.