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

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 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$114.8~\pm ~9.4$ </tex-math></inline-formula> cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>/Vs, threshold voltage (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {TH}}\text {)}$ </tex-math></inline-formula> of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.2~\pm ~0.1$ </tex-math></inline-formula> V, and subthreshold swing of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$122~\pm ~20$ </tex-math></inline-formula> mV/dec. Moreover, remarkable reliability with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {TH}}$ </tex-math></inline-formula> shift (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Delta {V}_{\text {TH}}\text {)} \lt 0.1$ </tex-math></inline-formula> 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 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {TH}}$ </tex-math></inline-formula> shift of +2.2 (-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.