Dynamic characteristics of MICC polycrystalline thin film transistors

Abstract We studied the DC bias-induced changes in the performance of the PMOS ring oscillator made of poly-Si TFT. The poly-Si was prepared by metal-induced crystallization of amorphous silicon through a cap layer (MICC). The p-channel MICC poly-Si TFT exhibited the field-effect mobility of 31 cm 2 /V s, on/off current ratio of ∼10 7 and threshold voltage of −2.8 V. A 41-stage PMOS inverter chain exhibited an operation frequency of 1.2 MHz at an applied voltage of V DD = −18 V. The degradation of the ring oscillator made of MICC poly-Si TFT is much less than that of ELA TFT by DC bias stress. The difference appears to be due to the smooth surface of MICC poly-Si as compared with a typical excimer laser annealing (ELA) poly-Si.