High-Performance Short-Channel Top-Gate Indium-Tin-Oxide Transistors by Optimized Gate Dielectric

Abstract

In this work, high-performance top-gate indium-tin-oxide (ITO) transistors with high carrier mobility of 60 cm2/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{V}\cdot \text{s}$ </tex-math></inline-formula> have been successfully demonstrated using optimized atomic layer deposited (ALD) La-doped HfO2 as the top-gate dielectric. The scaled device with a channel length of 50 nm exhibits a high current on/off ratio over <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${7} \times {10} ^{{9}}$ </tex-math></inline-formula> owing to the excellent electrostatic control. A maximum output current of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1680~\mu \text{A}/\mu \text{m}$ </tex-math></inline-formula> with a remarkable carrier velocity of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${0}.{87} \times {10} ^{{7}}$ </tex-math></inline-formula> cm/s has also been achieved due to the record low contact resistance of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$180~\Omega \cdot \mu \text{m}$ </tex-math></inline-formula> . The on- and off-state performance of our ITO transistors are the highest among previous top-gate amorphous oxide semiconductors.