Band Alignments of Atomic Layer Deposited ZrO2 and HfO2 High-k Dielectrics with (-201) β-Ga2O3
The energy band alignment between atomic layer deposited (ALD) high-k dielectrics of ZrO2 and HfO2 with n-type β-Ga2O3 was evaluated using x-Ray photoelectron spectroscopy. The valence band offset was found to be −0.3 ± 0.04 eV and −0.5 ± 0.04 eV for ZrO2and HfO2, respectively, which produced type I...
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Veröffentlicht in: | ECS journal of solid state science and technology 2017, Vol.6 (2), p.Q3052-Q3055 |
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Hauptverfasser: | , , , |
Format: | Artikel |
Sprache: | eng |
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Zusammenfassung: | The energy band alignment between atomic layer deposited (ALD) high-k dielectrics of ZrO2 and HfO2 with n-type β-Ga2O3 was evaluated using x-Ray photoelectron spectroscopy. The valence band offset was found to be −0.3 ± 0.04 eV and −0.5 ± 0.04 eV for ZrO2and HfO2, respectively, which produced type II, staggered gap alignments for both dielectrics with conduction band offsets greater than 1 eV. Capacitance-voltage measurements were conducted on metal-oxide-semiconductor (MOS) diodes and used to extract the dielectric constants (ɛ) of both oxides. ZrO2films had a nearly ideal ɛ of 24.7 (ɛ ∼ 25), while HfO2 exhibited a significantly lower ɛ of 14 (ɛ ∼ 25-30). These results, combined with the small hysteresis (≤0.09 eV) in the capacitance-voltage behavior for both films, is indicative of the high quality of these ALD oxides and their interface with the β-Ga2O3 making them potential candidates as gate dielectrics in power devices based on this relatively new ultra-wide bandgap material. |
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ISSN: | 2162-8769 |
DOI: | 10.1149/2.0131702jss |