Reliable high-voltage amorphous InGaZnO TFT for monolithic 3D integration

The wide band-gap a-IGZO is a promising channel material to realize high-voltage transistors that can be easily integrated on logic ICs by low-temperature 3D stacking. This monolithic 3D integration would enable on-chip power management to improve power consumption and integration density. We report a high-voltage a-IGZO TFT with the high-k Al2O3 gate dielectric. By using a low-temperature process below 200 oC, excellent transistor characteristics, including a current on/off ratio of 109, steep subthreshold swing of 0.1 V/decade, high breakdown voltage of 45 V, and robust bias stress reliability have been demonstrated.