Dynamic Time Evolutionary Aging Analysis for Device-Circuit Lifetime Estimation of Thin-Film Transistors

We present a new methodology to estimate the lifetime of thin-film-transistor (TFT)-based scan driver circuit in display application with the dynamic time evolutionary aging model. The proposed method not only enables more accurate device level estimation but also circuit level aging prediction given that the TFTs are stressed dynamically. To properly handle threshold voltage shift (AVth) of each TFTs in the scan driver under dynamic voltage stress patterns like the alternative voltage level and frequency, a time discretization strategy considering the voltage bias stress feedback is developed to be adaptable with SPICE transient simulation simply. The results show that ΔV
_th
of each TFTs in scan driver circuit can be evolved in real time accordingly under dynamic stress. What's more, an exponential relationship between the aging parameter β and the aging time is for the first time obtained, which has much importance for predicting lifetime of scan driver and other TFT-based circuit.