Fast Low-Temperature Plasma Process for the Application of Flexible Tin-Oxide-Channel Thin Film Transistors

Abstract

In this study, we demonstrated a <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</i> -type and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> -type SnO TFTs on flexible polyimide substrate. The fabricated <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</i> -type SnO TFT showed a high <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX"> $I_{\rm on}/ I_{\rm off}$</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">$ \text{5.7}\, \times \,\text{10}^{5}$</tex-math></inline-formula> and a high <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\mu _{{\rm{FE}}}$</tex-math></inline-formula> of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${\text{10.7 cm}}^{2}\,{\text{V}}^{-1}\,{\text{s}}^{-1}$</tex-math></inline-formula> . Through optimizing the oxygen plasma condition, the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> -type channel TFT transfered from prime <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</i> -type channel exhibits excellent characteristics, including a high on/off current ratio of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX"> $\rm{6.6}\,\times\,10^{3}$</tex-math></inline-formula> , a low threshold voltage of −0.13 V, and a very high 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">${\text{28 cm}}^{2}\,{\text{V}}^{-1}\,{\text{s}}^{-1}$</tex-math></inline-formula> . This proposed low-temperature oxygen plasma treatment shows the potential in simplification of TFT process that can achieve <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> -type and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p </i> -type TFTs under the same device process.