Thin film transistors for displays on plastic substrates

We have successfully made thin film transistors on transparent, flexible po lymer substrates. These transistors have electrical properties suitable for driving the pixels in active matrix liquid crystal displays and also for b uilding integrated row driver circuits. The devices are fabricated on polye thylene naphthalate using a low temperature CdSe process at a maximum tempe rature of 150 degrees C, by evaporation and radio frequency sputtering onto unheated substrates. with pattern definition using standard photolithograp hy and etching. Electrical properties achieved include carrier field effect mobilities of >30 cm(2)/Vs, threshold voltages of similar to 2 V) switchin g ratio >10(6), an off-state leakage current of <10(-12) A and an on-state drive current of >1 mu A with a gate voltage swing of <10 V, and a sub-thre shold slope of 0.25 V/decade for devices of unity aspect ratio. The electri cal properties were found to scale with device channel length and width. (C ) 2000 Elsevier Science Ltd. All rights reserved.