Ultra-clean interface between high k dielectric and 2D MoS2
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| Main Authors: | , , , , , , , , , , |
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| Format: | Preprint |
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2025
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| _version_ | 1866912499264126976 |
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| author | Yan, Han Wang, Yan Li, Yang Phuyal, Dibya Liu, Lixin Guo, Hailing Guo, Yuzheng Lee, Tien-Lin Kim, Min Hyuk Jeong, Hu Young Chhowalla, Manish |
| author_facet | Yan, Han Wang, Yan Li, Yang Phuyal, Dibya Liu, Lixin Guo, Hailing Guo, Yuzheng Lee, Tien-Lin Kim, Min Hyuk Jeong, Hu Young Chhowalla, Manish |
| contents | Atomically thin transition metal dichalcogenides (TMDs) are promising candidates for next-generation transistor channels due to their superior scaling properties. However, the integration of ultra-thin gate dielectrics remains a challenge, as conventional oxides such as SiO2, Al2O3, and HfO2 tend to unintentionally dope 2D TMDs and introduce interfacial defect states, leading to undesirable field-effect transistor (FET) performance and unstable threshold voltages. Here, we demonstrate that zirconium oxide (ZrO2), a high-k dielectric compatible with semiconductor processing, forms an ultra-clean interface with monolayer MoS2. Using soft and hard X-ray photoelectron spectroscopy and density functional theory, we find that ZrO2 does not measurably interact with MoS2, in contrast to significant doping observed for SiO2 and HfO2 substrates. As a result, back-gated monolayer MoS2 FETs fabricated with ZrO2 dielectrics exhibit stable and positive threshold voltages (0.36 plus/minus 0.3 V), low subthreshold swing (75 mV per decade), and high ON currents exceeding 400 microamperes. We further demonstrate p-type WSe2 FETs with ON currents greater than 200 microamperes per micrometer by suppressing electron doping with ZrO2 dielectrics. Atomic-resolution imaging confirms a defect-free ZrO2/MoS2 interface, which enables top-gate FETs with an equivalent oxide thickness of 0.86 nanometers and subthreshold swing of 80 mV per decade. Moreover, the ultraclean ZrO2/MoS2 interface allows for effective threshold voltage modulation in top-gate FETs via gate metal work function engineering. These findings establish ZrO2 as a highly promising, industry-compatible high-k dielectric for scalable 2D TMD-based electronics. |
| format | Preprint |
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arxiv_https___arxiv_org_abs_2507_18010 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Ultra-clean interface between high k dielectric and 2D MoS2 Yan, Han Wang, Yan Li, Yang Phuyal, Dibya Liu, Lixin Guo, Hailing Guo, Yuzheng Lee, Tien-Lin Kim, Min Hyuk Jeong, Hu Young Chhowalla, Manish Materials Science Applied Physics Atomically thin transition metal dichalcogenides (TMDs) are promising candidates for next-generation transistor channels due to their superior scaling properties. However, the integration of ultra-thin gate dielectrics remains a challenge, as conventional oxides such as SiO2, Al2O3, and HfO2 tend to unintentionally dope 2D TMDs and introduce interfacial defect states, leading to undesirable field-effect transistor (FET) performance and unstable threshold voltages. Here, we demonstrate that zirconium oxide (ZrO2), a high-k dielectric compatible with semiconductor processing, forms an ultra-clean interface with monolayer MoS2. Using soft and hard X-ray photoelectron spectroscopy and density functional theory, we find that ZrO2 does not measurably interact with MoS2, in contrast to significant doping observed for SiO2 and HfO2 substrates. As a result, back-gated monolayer MoS2 FETs fabricated with ZrO2 dielectrics exhibit stable and positive threshold voltages (0.36 plus/minus 0.3 V), low subthreshold swing (75 mV per decade), and high ON currents exceeding 400 microamperes. We further demonstrate p-type WSe2 FETs with ON currents greater than 200 microamperes per micrometer by suppressing electron doping with ZrO2 dielectrics. Atomic-resolution imaging confirms a defect-free ZrO2/MoS2 interface, which enables top-gate FETs with an equivalent oxide thickness of 0.86 nanometers and subthreshold swing of 80 mV per decade. Moreover, the ultraclean ZrO2/MoS2 interface allows for effective threshold voltage modulation in top-gate FETs via gate metal work function engineering. These findings establish ZrO2 as a highly promising, industry-compatible high-k dielectric for scalable 2D TMD-based electronics. |
| title | Ultra-clean interface between high k dielectric and 2D MoS2 |
| topic | Materials Science Applied Physics |
| url | https://arxiv.org/abs/2507.18010 |