Beneficial Hydrogen Doping in Single Spinel Phase Crystallized IZTO Thin-Film Transistors

초록

This study demonstrates different hydrogen (H) behavior in InZnSnO (IZTO) semiconductor depending on its crystalline structure. H-doped single spinel phase-IZTO (c-IZTO) thin-film transistors (TFTs) show exceptional device performances, with field-effect mobility of 114.8 &#x00B1; 9.4 cm2/Vs, threshold voltage (<italic>V</italic>TH) of 0.2 &#x00B1; 0.1 V, and subthreshold swing of 122 &#x00B1; 20 mV/dec. Moreover, remarkable reliability with <italic>V</italic>TH shift (&#x0394;<italic>V</italic>TH) < 0.1 V against external harsh bias temperature stresses is revealed in the c-IZTO TFTs, which is quite different from H-doped amorphous IZTO (a-IZTO) TFTs showing significant <italic>V</italic>TH shift of +2.2 (&#x2212;3.5) V under positive (negative) bias temperature stress. This considerably higher reliability in the c-IZTO TFTs could be attributed to inhibited local transition of substitutional H by crystallization, unlike the a-IZTO TFTs, which were supported by density functional theory calculations.

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