Influence of Ultra-Thin Ge3N4 Passivation Layer on Structural, Interfacial, and Electrical Properties of HfO2/Ge Metal-Oxide–Semiconductor Devices
| Autor: | Youngkuk Kim, Minkyu Ju, S. V. Jagadeesh Chandra, Eun-Chel Cho, Kumar Mallem, Junsin Yi, Shahzada Qamar Hussain, Young Hyun Cho, Ch. V. V. Ramana, Jinjoo Park, Subhajith Dutta |
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| Rok vydání: | 2020 |
| Předmět: |
Materials science
Passivation Annealing (metallurgy) Gate dielectric Biomedical Engineering Analytical chemistry Oxide Bioengineering Equivalent oxide thickness General Chemistry Dielectric Nitride Condensed Matter Physics chemistry.chemical_compound chemistry X-ray photoelectron spectroscopy General Materials Science |
| Zdroj: | Journal of Nanoscience and Nanotechnology. 20:1039-1045 |
| ISSN: | 1533-4880 |
| Popis: | We report the effects of the nitride passivation layer on the structural, electrical, and interfacial properties of Ge metal-oxide-semiconductor (MOS) devices with a hafnium oxide (HfO₂) gate dielectric layer deposited on p-type 〈100〉 Ge substrates. X-ray photoelectron spectroscopy analysis confirmed the chemical states and formation of HfO₂/Ge₃N₄ on Ge. The interfacial quality and thickness of the layers grown on Ge were confirmed by high-resolution transmission electron microscopy. In addition, the effects of post-deposition annealing (PDA) on the HfO₂/Ge₃N₄/Ge and HfO₂/Ge samples at 400 °C in an (FG+O₂) ambient atmosphere for 30 min were studied. After PDA, the HfO₂/Ge₃N₄/Ge MOS device showed a higher dielectric constant (k) of ~21.48 and accumulation capacitance of 1.2 nF, smaller equivalent oxide thickness (EOT) of 1.2 nm, and lower interface trap density (Dit) of 4.9×1011 cm-2 eV-1 and oxide charges (Qeff) of 7.8×1012 cm-2 than the non-annealed sample. The I-V analysis showed that the gate leakage current density of the HfO₂/Ge₃N₄/Ge sample (0.3-1 nA cm-2 at Vg = 1 V) was half of that of the HfO₂/Ge sample. Moreover, the barrier heights of the samples were extracted from the Fowler-Nordheim plots. These results indicated that nitride passivation is crucial to improving the structural, interfacial, and electrical properties of Ge-based MOS devices. |
| Databáze: | OpenAIRE |
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