Reliability-Aware SPICE Compatible Compact Modeling of IGZO Inverters on a Flexible Substrate

Abstract

Accurate circuit simulation reflecting physical and electrical stress is of importance in indium gallium zinc oxide (IGZO)-based flexible electronics. In particular, appropriate modeling of threshold voltage (VT) changes in different bias and bending conditions is required for reliability-aware simulation in both device and circuit levels. Here, we present SPICE compatible compact modeling of IGZO transistors and inverters having an atomic layer deposition (ALD) Al2O3 gate insulator on a polyethylene terephthalate (PET) substrate. Specifically, the modeling was performed to predict the behavior of the circuit using stretched exponential function (SEF) in a bending radius of 10 mm and operating voltages ranging between 4 and 8 V. The simulation results of the IGZO circuits matched well with the measured values in various operating conditions. It is expected that the proposed method can be applied to process improvement or circuit design by predicting the direct current (DC) and alternating current (AC) responses of flexible IGZO circuits.