The Effect of High-Pressure Hydrogen or Deuterium Annealing on Electrical Performance of Indium Gallium Zinc Oxide Thin-Film Transistors
An Hoang-Thuy Nguyen, Manh-Cuong Nguyen, Anh-Duy Nguyen, No-Hwal Park, Seung Joon Jeon, Daewoong Kwon, Rino Choi
Abstract
This study examined the effects of hydrogen ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{H}_{{2}}$ </tex-math></inline-formula> ) or deuterium ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{D}_{{2}}$ </tex-math></inline-formula> ) annealing on indium gallium zinc oxide (IGZO) channels for the staggered bottom-gate thin-film transistor (TFT). High-pressure annealing (HPA) at 10 bar was used to diffuse and control the amount of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{H}_{{2}}$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{D}_{{2}}$ </tex-math></inline-formula> atoms in IGZO thin films. <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{H}_{{2}}$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{D}_{{2}}$ </tex-math></inline-formula> doping samples were compared with Ar annealed samples to exclude the thermal effects. The performance of both <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{H}_{{2}}$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{D}_{{2}}$ </tex-math></inline-formula> annealed devices was superior to that of the Ar annealed device. The reliability of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{H}_{{2}}$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{D}_{{2}}$ </tex-math></inline-formula> doping devices under positive bias stress was improved due to the defect passivation of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{H}_{{2}}$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{D}_{{2}}$ </tex-math></inline-formula> . Larger degradation of the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{H}_{{2}}$ </tex-math></inline-formula> -annealed sample under negative illumination bias stress (NIBS) was observed compared to the Ar-annealed sample, which was explained by the release of positive <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{H}_{{2}}$ </tex-math></inline-formula> ions from O–H bonding by the light radiation. With <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{D}_{{2}}$ </tex-math></inline-formula> doping, the stability under the NIBS and field-effect mobility was improved significantly compared to the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{H}_{{2}}$ </tex-math></inline-formula> and Ar annealed TFTs (11.2 and 10.6 cm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{{2}}\text{V}^{-1}\text{s}^{-1}$ </tex-math></inline-formula> ). The large <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{D}_{{2}}$ </tex-math></inline-formula> isotope for slow diffusive ability significantly improves the performance and stability of IGZO TFTs.