High Mobility Field-Effect Thin Film Transistor Using Room-Temperature High-<formula formulatype="inline"><tex Notation="TeX">$\kappa$</tex> </formula> Gate Dielectrics

Abstract

This paper reports an InGaZnO thin-film transistor (TFT) that involves using fully room-temperature gate dielectrics on a flexible substrate. The wide bandgap dielectrics of <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\hbox{HfO}}_{2}$</tex> </formula> and <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\hbox{Y}}_{2}{\hbox{O}}_{3}$</tex> </formula> exhibited favorable adhesion properties on a flexible substrate compared with conventional low- <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\kappa$</tex> </formula> <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\hbox{SiO}}_{2}$</tex> </formula> film. Based on the experimental results, the room-temperature <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\hbox{ IGZO/HfO}}_{2}$</tex></formula> TFTs demonstrated effective device integrity, and achieve a low drive voltage of <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$&lt; {\hbox{2}}$</tex></formula> V, a low threshold voltage of <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\hbox{0.46}} \pm {\hbox{006}}$</tex></formula> V, a low sub-threshold swing of <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\hbox{110}} \pm {\hbox{6}}$</tex> </formula> mV/decade and an extremely high mobility of <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">${\hbox{60.2}} \pm {\hbox{32}}$</tex></formula> cm <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$^{2}/{\hbox{V}}\cdot{\hbox{s}}$</tex> </formula> . The excellent performance of this TFT indicated that it demonstrates considerable potential for active-matrix liquid crystal display applications requiring low power consumption and a high driving current.