We have fabricated fully patterned transparent oxide/organic hybrid transistors on glass substrates that contain In-Ga-Zn-O as the active layer and a poly(4-vinyl phenol-comethyl methacrylate) copolymer as the dielectric layer. These devices exhibit a saturation mobility of 6.04 cm(2)/V s, a threshold voltage value of 3.53 V, a subthreshold slope of 360 mV/decade, and an on-off ratio of 1.0 x 10(9) at a maximum processing temperature of 200 degrees C. We found that the bias stability characteristics of the hybrid transistors are dependent on the ambient conditions, but can also be dramatically improved by applying a hydrophobic organic passivation layer to the gate insulator. (C) 2011 American Institute of Physics. [doi:10.1063/1.3551536]