First Demonstration of Hysteresis-Free IGZO/SnO-Based Complementary Circuits and SRAM with Long-Term Reliability Using SU-8 Passivation

초록

Complementary logic and memory circuits based on n-type indium gallium zinc oxide (IGZO) and p-type tin monoxide (SnO) thin-film transistors (TFTs) were demonstrated with low-voltage, hysteresis-free operation. Optimization of IGZO channel thickness precisely tuned the inverter switching point to near VDD/2, achieving a high voltage gain of 146.6 V/V at VDD = 3 V and ultra-low static power consumption in the nanowatt range. SU-8 passivation effectively suppressed bias-stress-induced degradation in both IGZO and SnO TFTs, enhancing long-term stability and reducing device variation. Using these optimized devices, a 3-stage ring oscillator exhibited stable oscillations, and 6T-SRAM cells achieved tunable static noise margins by adjusting transistor strength ratios. This work represents one of the first implementations of IGZO/SnO-based 6T-SRAM and demonstrates the potential of oxide semiconductor complementary circuits for low-power and reliable system integration, with promising future applicability to non-volatile memory and on-device artificial intelligence hardware.

키워드