Optimized O2/Ar mixed plasma treatment for hydrogen-resistant and high-reliability IGZO thin-film transistors

초록

This study demonstrates that optimized O-2/Ar mixed plasma treatment effectively enhances both electrical performance and hydrogen resistance of indium-gallium-zinc oxide (IGZO) thin-film transistors. At the optimal 4-minute condition, a subthreshold swing of 80 mV dec(-1) and hysteresis of 0.07 V were achieved, with the FGA-induced threshold voltage shift (Delta V-TH) suppressed from -5.34 V to -0.28 V, confirming substantial hydrogen tolerance improvement. These improvements are attributed to oxygen radical activation promoted by the O-2/Ar plasma, which passivates oxygen vacancies and densifies the metal-oxygen-metal bonding network. X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry analyses attribute this enhancement to the suppression of stable substitutional hydrogen formation via vacancy passivation. Conversely, excessive treatment (10 min) leads to over-oxidation-induced defect states that degrade reliability. These findings establish O-2/Ar plasma treatment as a process-compatible strategy for engineering hydrogen-resilient, high-reliability IGZO thin-film transistors for next-generation displays and 3D integration applications.

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