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−10 V Threshold Voltage High-Performance Normally-OFF C–Si Diamond MOSFET Formed by p+-Diamond-First and Silicon Molecular Beam Deposition Approaches

MetadataDetails
Publication Date2022-03-23
JournalIEEE Transactions on Electron Devices
AuthorsYu Fu, Yu Hao Chang, Shozo Kono, Atsushi Hiraiwa, Kyotaro Kanehisa
InstitutionsUniversity of Electronic Science and Technology of China, Waseda University
Citations20

In this article, the normally- OFF oxidized Si-terminated (C-Si) diamond metal-oxide-semiconductor field-effect transistors (MOSFETs) with as-deposited 0.5-nm silicon on diamond annealed at high temperature as the subsurface p-channel were presented for the first time. A novel method utilizing both a metal mask to realize the regrown heavily boron-doped (001) diamond layer first (p <sup xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;+&lt;/sup> -diamond-first) and a molecular beam deposition (MBD) method to procure atomic-scale silicon deposition was achieved. Scanning transmission electron microscopy (STEM) and energy-dispersive X-ray spectroscopy (EDS) element mapping results suggest that the C-Si diamond/Al <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;2&lt;/sub> O <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;3&lt;/sub> interface is quite continuous and atomically flat. A remarkably high threshold voltage ( <inline-formula xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”> <tex-math notation=“LaTeX”>${V}{\text{TH}}$ </tex-math></inline-formula> ) of −10 V and a maximum drain 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”>${I}{D_{}{\text{MAX}}}$ </tex-math></inline-formula> ) of −156 mA/mm are simultaneously achieved in the fabricated devices. The devices with different source and drain (S/D) distances ( <inline-formula xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”> <tex-math notation=“LaTeX”>$L_{\text{SD}}$ </tex-math></inline-formula> ) deliver robust <inline-formula xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”> <tex-math notation=“LaTeX”>${V}{\text{TH}}$ </tex-math></inline-formula> results and feature low OFF-state S/D leakage current <inline-formula xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”> <tex-math notation=“LaTeX”>$\vert {I}{\text{leakage}}\vert $ </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”>$6\times10$ </tex-math></inline-formula> <sup xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;−6&lt;/sup> mA/mm at <inline-formula xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”> <tex-math notation=“LaTeX”>${V}_{\text{GS}}$ </tex-math></inline-formula> = 0 V. The extracted field-effect mobility is as high as 127 cm <sup xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;2&lt;/sup> <inline-formula xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”> <tex-math notation=“LaTeX”>$\cdot \text{V}$ </tex-math></inline-formula> <sup xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;−1&lt;/sup> <inline-formula xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”> <tex-math notation=“LaTeX”>$\cdot \text{s}$ </tex-math></inline-formula> <sup xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;−1&lt;/sup> and the interface state density is as low as <inline-formula xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”> <tex-math notation=“LaTeX”>$4.35\times10$ </tex-math></inline-formula> <sup xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;12&lt;/sup> eV <sup xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;−1&lt;/sup> <inline-formula xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”> <tex-math notation=“LaTeX”>$\cdot $ </tex-math></inline-formula> cm <sup xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;−2&lt;/sup> . These competitive results reveal that this first attempt of employing the combination of p <sup xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;+&lt;/sup> -diamond-first and MBD approaches promotes the integration of the advanced silicon manufacturing process with wide bandgap diamond material for power applications.