Mobility Anisotropy in Black Phosphorus MOSFETs With HfO2 Gate Dielectrics
| Autor: | P. Paul Ruden, Ryan J. Wu, Seon Namgung, Y. Liu, Steven J. Koester, Nazila Haratipour, K. Andre Mkhoyan, Sang Hyun Oh |
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| Rok vydání: | 2018 |
| Předmět: |
010302 applied physics
Electron mobility Materials science Magnetoresistance Condensed matter physics Scattering Center (category theory) 02 engineering and technology Electron 021001 nanoscience & nanotechnology 01 natural sciences Electronic Optical and Magnetic Materials Crystal Phosphorene chemistry.chemical_compound chemistry 0103 physical sciences Electrical and Electronic Engineering 0210 nano-technology Anisotropy |
| Zdroj: | IEEE Transactions on Electron Devices. 65:4093-4101 |
| ISSN: | 1557-9646 0018-9383 |
| DOI: | 10.1109/ted.2018.2865440 |
| Popis: | Precise measurements of the mobility anisotropy along high-symmetry crystal axes in black phosphorus (BP) MOSFETs are reported. Locally back-gated BP MOSFETs with 13-nm HfO2 dielectric and channel length ranging from 0.3 to 0.7 $\mu \text{m}$ are fabricated. A single BP flake of a uniform thickness is exfoliated and etched along armchair (AC) and zigzag (ZZ) crystal axes, and the orientations are confirmed using optical and transmission electron microscopy analyses. The hole and electron mobilities along each direction are extracted using the transfer length method. The AC-to-ZZ hole mobility ratio is found to increase from 1.4 (1.5) to 2.0 (2.9) as the sheet concentration increased from $5.1\times 10^{\textsf {11}}$ to $1.9\times 10^{\textsf {12}}$ cm−2 at room temperature (77 K). The room-temperature electron mobility anisotropy is found to be similar to that for holes with an AC-to-ZZ mobility ratio increasing from 1.4 to 2.1 from $5.1\times 10^{\textsf {11}}$ to $1.9\times 10^{\textsf {12}}$ cm−2 though electrons showed only a very weak temperature dependence. A Boltzmann transport model is used to explain the concentration- and temperature-dependent mobility anisotropies which can be well described using a charge center scattering model. |
| Databáze: | OpenAIRE |
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