Large V TH of Normally-OFF Field Effect Transistor With Yttrium Gate Material Directly Deposited on Hydrogen-Terminated Diamond
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2022-05-24 |
| Journal | IEEE Transactions on Electron Devices |
| Authors | Minghui Zhang, Wei Wang, Feng Wen, Fang Lin, Genqiang Chen |
| Institutions | Xi’an Jiaotong University |
| Citations | 12 |
Abstract
Section titled “Abstract”A normally- OFF field effect transistor (FET) with 20-nm yttrium (Y) gate material directly deposited on hydrogen-terminated (H-terminated) diamond surface has been successfully fabricated and characterized. The threshold voltage’s absolute value ( <inline-formula xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”> <tex-math notation=“LaTeX”>$\vert {V}{TH}\vert $ </tex-math></inline-formula> ) varies from 1.62 to 2.12 V with the variation of different gate lengths ( <inline-formula xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”> <tex-math notation=“LaTeX”>${L}{G}$ </tex-math></inline-formula> ), which demonstrates an obviously normally- OFF characteristic. 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”>$\vert {V}{TH}\vert $ </tex-math></inline-formula> could be greatly attributed to the fixed positive charge in the Al <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”>2</sub> O <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”>3</sub> layer and the large work function difference between Y and H-terminated diamond. The maximum drain-source current density ( <inline-formula xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”> <tex-math notation=“LaTeX”>${I}{Dmax}$ </tex-math></inline-formula> ) is −6.26 mA/mm. In addition, their Schottky barrier height is evaluated to be 0.71 eV. 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”>$\vert {V}_{TH}\vert $ </tex-math></inline-formula> could avoid the device failure from gate voltage overdrive. The technique exhibits the merits of uncontaminated interface in gate material and simple fabrication process, which is meaningful to the development of normally- OFF H-terminated diamond FET.