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Oxidized-Silicon-Terminated Diamond p-FETs With SiO2-Filling Shallow Trench Isolation Structures

MetadataDetails
Publication Date2023-09-26
JournalIEEE Electron Device Letters
AuthorsYu Fu, Te Bi, Yu Hao Chang, Ruimin Xu, Yuehang Xu
InstitutionsUniversity of Electronic Science and Technology of China, Waseda University
Citations7

Herein, excellent electrical performances were achieved for the oxidized-silicon-terminated (C-Si-O) diamond metal-oxide-semiconductor field-effect transistors (MOSFETs) using chemical-vapor-deposition grown SiO2 as the filling insulator of shallow-trench-isolation (STI) structures and gate oxide. The C-Si-O interface was formed under the initial SiO2 layer ( <inline-formula xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”> <tex-math notation=“LaTeX”>$1^{\text {st}}$ </tex-math></inline-formula> SiO <inline-formula xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”> <tex-math notation=“LaTeX”>${{2}}{)}$ </tex-math></inline-formula> as a mask during heavily boron-doping growth. The surface carbon-rich layer formed on the mask during selective diamond regrowth was removed using the oxygen plasma ashing treatment. The device having a 130-nm-thick SiO2 gate insulator exhibited subthreshold slopes (S S) of 220-710 mV/dec between 473 and 673 K. A normally-off operation was confirmed at 673 K. The SiO2filling insulator ( <inline-formula xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”> <tex-math notation=“LaTeX”>$2^{\text {nd}}$ </tex-math></inline-formula> SiO <inline-formula xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”> <tex-math notation=“LaTeX”>${{2}}{)}$ </tex-math></inline-formula> containing positive fixed charges can block the hole transport channels, and the active regions of the device are out of one plane using the STI structures. Accordingly, OFF-state drain leakage current was successfully suppressed. Consequently, high on-off ratios of <inline-formula xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”> <tex-math notation=“LaTeX”>$10^{{6}}$ </tex-math></inline-formula> - <inline-formula xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”> <tex-math notation=“LaTeX”>$10^{{7}}$ </tex-math></inline-formula> that cannot be realized in hydrogen-terminated (C-H) diamond FETs were confirmed up to 673 K. To summarize, results of this study provide new strategies for advancing diamond devices from the laboratory to industrial applications.

  1. 2014 - Wide temperature (10 K&#x2013;700 K) and high voltage (~1000 V) operation of C-H diamond MOSFETs for power electronics application