Improving Device Characteristics of Dual-Gate IGZO Thin-Film Transistors with Ar-O2 Mixed Plasma Treatment and Rapid Thermal Annealing

In this study, high-performance indium-gallium-zinc oxide thin-film transistors (IGZO TFTs) with a dual-gate (DG) structure were manufactured using plasma treatment and rapid thermal annealing (RTA). Atomic force microscopy measurements showed that the surface roughness decreased upon increasing the O-2 ratio from 16% to 33% in the argon-oxygen plasma treatment mixture. Hall measurement results showed that both the thin-film resistivity and carrier Hall mobility of the Ar-O-2 plasma-treated IGZO thin films increased with the reduction of the carrier concentration caused by the decrease in the oxygen vacancy density; this was also verified using X-ray photoelectron spectroscopy measurements. IGZO thin films treated with Ar-O-2 plasma were used as channel layers for fabricating DG TFT devices. These DG IGZO TFT devices were subjected to RTA at 100 degrees C-300 degrees C for improving the device characteristics; the field-effect mobility, subthreshold swing, and I-ON/I-OFF current ratio of the 33% O-2 plasma-treated DG TFT devices improved to 58.8 cm(2)/V center dot s, 0.12 V/decade, and 5.46 x 10(8), respectively. Long-term device stability reliability tests of the DG IGZO TFTs revealed that the threshold voltage was highly stable.

Automated summary

In this study, high-performance indium-gallium-zinc oxide thin-film transistors (IGZO TFTs) with a dual-gate (DG) structure were manufactured using plasma treatment and rapid thermal annealing (RTA). The research found that increasing the O-2 ratio in the argon-oxygen plasma treatment mixture reduced surface roughness and improved thin-film resistivity and carrier Hall mobility. X-ray photoelectron spectroscopy measurements confirmed the decrease in carrier concentration due to the oxygen vacancy density reduction. The DG IGZO TFT devices showed enhanced characteristics after RTA, with improved field-effect mobility, subthreshold swing, and I-ON/I-OFF current ratio.