A Comparative Study on the Electrical Properties of Vertical ( $\bar{\sf2}01$ ) and (010) $\beta$ -Ga2O3 Schottky Barrier Diodes on EFG Single-Crystal Substrates
| Autor: | Jossue Montes, Xuanqi Huang, Hong Chen, Houqiang Fu, Tsung-Han Yang, Yuji Zhao, Izak Baranowski |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
010302 applied physics
Materials science Magnetoresistance Condensed matter physics Schottky barrier 02 engineering and technology Electron Activation energy 021001 nanoscience & nanotechnology 01 natural sciences Variable-range hopping Electronic Optical and Magnetic Materials Reverse leakage current Band bending 0103 physical sciences Electrical and Electronic Engineering 0210 nano-technology Single crystal |
| Zdroj: | IEEE Transactions on Electron Devices. 65:3507-3513 |
| ISSN: | 1557-9646 0018-9383 |
| Popis: | This paper reports a comprehensive study on the anisotropic electrical properties of vertical ( $\overline {\textsf {2}}01$ ) and (010) $\beta $ -Ga2O3 Schottky barrier diodes (SBDs). The devices were fabricated on single-crystal substrates grown by an edge-defined film-fed growth method. The temperature-dependent current–voltage (I–V) and capacitance–voltage (C–V) characteristics were systematically measured, analyzed, and compared. The ( $\overline {\textsf {2}}01$ ) and (010) SBDs exhibited on-resistances ( ${R}_{{ \mathrm{\scriptscriptstyle ON}}}$ ) of 0.56 and $0.77~\textsf {m}\Omega \cdot \textsf {cm}^{{\textsf {2}}}$ , turn- ON voltages ( ${V}_{{ \mathrm{\scriptscriptstyle ON}}}$ ) of 1.0 and 1.3 V, Schottky barrier heights (SBHs) of 1.05 and 1.20 eV, electron mobilities of 125 and 65 cm2/( $\textsf {V}\cdot ~\textsf {s}$ ), respectively, with an on-current of ~1.3 kA/cm2 and on/off ratio of ~109. The (010) SBD had a larger ${V}_{{ \mathrm{\scriptscriptstyle ON}}}$ and SBH due to anisotropic surface properties (i.e., surface Fermi level pinning and band bending), as supported by X-ray photoelectron spectroscopy measurements. Temperature-dependent I–V also revealed the inhomogeneous nature of the SBH in both devices, where the ( $\overline {\textsf {2}}01$ ) SBD showed a more uniform SBH distribution. The homogeneous SBH was also extracted: 1.33 eV for the ( $\overline {\textsf {2}}01$ ) SBD and 1.53 eV for the (010) SBD. The reverse leakage current of the devices was well described by the two-step trap-assisted tunnelingmodel and the 1-D variable range hopping conduction model. The ( $\overline {\textsf {2}}01$ ) SBD showed a larger leakage current due to its lower SBH and/or smaller activation energy, and thus a smaller breakdown voltage. These results indicate that the crystalline anisotropy of $\beta $ -Ga2O3 can affect the electrical properties of vertical SBDs and should be taken into consideration when designing $\beta $ -Ga2O3 electronics. |
| Databáze: | OpenAIRE |
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