High-Speed and Low-Voltage-Driven Shift Register With Self-Aligned Coplanar a-IGZO TFTs

We report a high-speed and low-voltage-driven shift register utilizing self-aligned coplanar amorphous-indium-gallium-zinc-oxide thin-film transistors (a -IGZO TFTs). The a-IGZO TFTs exhibit field-effect mobility, threshold voltage, and gate-voltage swing of 24.7 cm
²
/V·s, 0.2 V, and 118 mV/dec, respectively. The rise and fall times of the shift register at the supply voltage (
V
_DD
) of 1 V are 8 and 7 μs, respectively, and the output pulse is free from distortion or ripple. For a
V
_DD
of 15 V, the clock frequency of the shift register approaches 500 kHz, making it applicable to high-resolution active-matrix displays.