P-70: Active Matrix OLED Displays Using Simple Poly-Si TFT Process

We have suggested and developed a novel 6 photo-mask process for the p-channel poly-Si thin film transistor TFT panel fabrication of active matrix organic light-emitting diode AMOLED. By removing power line Vdd and bank photo process, we simplified the fabrication process from 8 to 6 mask steps. The p-channel TFT fabricated by the 6 photo-mask process had a field effect mobility of ∼80 cm2/Vsec, a sub-threshold voltage swing of ∼0.3 V/dec., and a threshold voltage of ∼−2 V. Using the 6 photo-mask process, we have successfully realized a 7-inch WVGA 720×480 AMOLED panel, which is controlled by the voltage driving method.