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Cheng C, Sun X, Gui Q, Wu G, Shen W, Dong F, Liu Y, Robertson J, Zhang Z, Guo Y, Liu S. Theoretical Insight into the Band Alignment at High-κ Oxide XO 2/Diamond (X = Hf and Zr) Interfaces with a SiO 2 Interlayer for MOS Devices. ACS APPLIED MATERIALS & INTERFACES 2024. [PMID: 38708910 DOI: 10.1021/acsami.4c03261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2024]
Abstract
Diamond has become a promising candidate for high-power devices based on its ultrawide bandgap and excellent thermoelectric properties, where an appropriate gate dielectric has been a bottleneck hindering the development of diamond devices. Herein, we have systematically investigated the structural arrangement and electronic properties of diamond/high-κ oxide (HfO2, ZrO2) heterojunctions by first-principles calculations with a SiO2 interlayer. Charge analysis reveals that the C-Si bonding interface attracts a large amount of charge concentrated at the diamond interface, indicating the potential for the formation of a 2D hole gas (2DHG). The diamond/HfO2 and diamond/ZrO2 heterostructures exhibit similar "Type II" band alignments with VBOs of 2.47 and 2.21 eV, respectively, which is consistent with experimental predictions. The introduction of a SiO2 dielectric layer into the diamond/SiO2/high-κ stacks exhibits the typical "Type I″ straddling band offsets (BOs). In addition, the wide bandgap SiO2 interlayer keeps the valence band maximum (VBM) and conduction band minimum (CBM) in the stacks away from those of diamond, effectively confining the electrons and holes in MOS devices. This work exhibits the potential of SiO2/high-κ oxide gate dielectrics for diamond devices and provides theoretical insights into the rational design of high-quality gate dielectrics for diamond-based MOS device applications.
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Affiliation(s)
- Chunmin Cheng
- The Institute of Technological Sciences, Wuhan University, Wuhan 430072, China
| | - Xiang Sun
- School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China
| | - Qingzhong Gui
- School of Electrical Engineering and Automation, Wuhan University, Wuhan 430072, China
| | - Gai Wu
- The Institute of Technological Sciences, Wuhan University, Wuhan 430072, China
| | - Wei Shen
- The Institute of Technological Sciences, Wuhan University, Wuhan 430072, China
- Hubei Key Laboratory of Electronic Manufacturing and Packaging Integration, Wuhan University, Wuhan 430072, China
| | - Fang Dong
- The Institute of Technological Sciences, Wuhan University, Wuhan 430072, China
| | - Yonghui Liu
- School of Electrical Engineering and Automation, Wuhan University, Wuhan 430072, China
| | - John Robertson
- School of Electrical Engineering and Automation, Wuhan University, Wuhan 430072, China
- Department of Engineering, University of Cambridge, CB2 1PZCambridge, U.K
| | - Zhaofu Zhang
- The Institute of Technological Sciences, Wuhan University, Wuhan 430072, China
- Hubei Key Laboratory of Electronic Manufacturing and Packaging Integration, Wuhan University, Wuhan 430072, China
| | - Yuzheng Guo
- The Institute of Technological Sciences, Wuhan University, Wuhan 430072, China
- School of Electrical Engineering and Automation, Wuhan University, Wuhan 430072, China
| | - Sheng Liu
- The Institute of Technological Sciences, Wuhan University, Wuhan 430072, China
- School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China
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Myint P, Woodward JM, Wang C, Zhang X, Wiegart L, Fluerasu A, Headrick RL, Eddy CR, Ludwig KF. Coherent X-ray Spectroscopy Elucidates Nanoscale Dynamics of Plasma-Enhanced Thin-Film Growth. ACS NANO 2024; 18:1982-1994. [PMID: 38194518 PMCID: PMC10811697 DOI: 10.1021/acsnano.3c07619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 12/07/2023] [Accepted: 12/12/2023] [Indexed: 01/11/2024]
Abstract
Sophisticated thin film growth techniques increasingly rely on the addition of a plasma component to open or widen a processing window, particularly at low temperatures. Taking advantage of continued increases in accelerator-based X-ray source brilliance, this real-time study uses X-ray Photon Correlation Spectroscopy (XPCS) to elucidate the nanoscale surface dynamics during Plasma-Enhanced Atomic Layer Deposition (PE-ALD) of an epitaxial indium nitride film. Ultrathin films are synthesized from repeated cycles of alternating self-limited surface reactions induced by temporally separated pulses of the material precursor and plasma reactant, allowing the influence of each on the evolving morphology to be examined. During the heteroepitaxial 3D growth examined here, sudden changes in the surface structure during initial film growth, consistent with numerous overlapping stress-relief events, are observed. When the film becomes continuous, the nanoscale surface morphology abruptly becomes long-lived with a correlation time spanning the period of the experiment. Throughout the growth experiment, there is a consistent repeating pattern of correlations associated with the cyclic growth process, which is modeled as transitions between different surface states. The plasma exposure does not simply freeze in a structure that is then built upon in subsequent cycles, but rather, there is considerable surface evolution during all phases of the growth cycle.
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Affiliation(s)
- Peco Myint
- X-ray
Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Lemont, Illinois 60439, United States
| | - Jeffrey M. Woodward
- Electronics
Science and Technology Division, U.S. Naval
Research Laboratory, 4555 Overlook Avenue SW, Washington, D.C. 20375, United States
| | - Chenyu Wang
- Department
of Physics, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
| | - Xiaozhi Zhang
- Department
of Physics and Materials Science Program, University of Vermont, 82 University Place, Burlington, Vermont 05405, United States
| | - Lutz Wiegart
- National
Synchrotron Light Source II, Brookhaven
National Laboratory, 744 Ring Road, Upton, New
York 11973, United States
| | - Andrei Fluerasu
- National
Synchrotron Light Source II, Brookhaven
National Laboratory, 744 Ring Road, Upton, New
York 11973, United States
| | - Randall L. Headrick
- Department
of Physics and Materials Science Program, University of Vermont, 82 University Place, Burlington, Vermont 05405, United States
| | - Charles R. Eddy
- Office of
Naval Research Global, 86 Blenheim Crescent, West Ruislip, Middlesex HA4 7HB, U.K.
| | - Karl F. Ludwig
- Department
of Physics and Division of Materials Science and Engineering, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
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Djaou C, Villeneuve-Faure C, Makasheva K, Boudou L, Teyssedre G. Analysis of the charging kinetics in silver nanoparticles-silica nanocomposite dielectrics at different temperatures. NANO EXPRESS 2021. [DOI: 10.1088/2632-959x/ac3886] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Abstract
Dielectric nanocomposite materials are now involved in a large panel of electrical engineering applications ranging from micro-/nano-electronics to power devices. The performances of all these systems are critically dependent on the evolution of the electrical properties of the dielectric parts, especially under temperature increase. In this study we investigate the impact of a single plane of silver nanoparticles (AgNPs), embedded near the surface of a thin silica (SiO2) layer, on the electric field distribution, the charge injection and the charge dynamic processes for different AgNPs-based nanocomposites and various temperatures in the range 25°C–110°C. The electrical charges are injected locally by using an Atomic Force Microscopy (AFM) tip and the related surface potential profile is probed by Kelvin Probe Force Microscopy (KPFM). To get deeper in the understanding of the physical phenomena, the electric field distribution in the AgNPs-based nanocomposites is computed by using a Finite Element Modeling (FEM). The results show a strong electrostatic coupling between the AFM tip and the AgNPs, as well as between the AgNPs when the AgNPs-plane is embedded in the vicinity of the SiO2-layer surface. At low temperature (25°C) the presence of an AgNPs-plane close to the surface, i.e., at a distance of 7 nm, limits the amount of injected charges. Besides, the AgNPs retain the injected charges and prevent from charge lateral spreading after injection. When the temperature is relatively high (110°C) the amount of injected charges is increased in the nanocomposites compared to low temperatures. Moreover, the speed of lateral charge spreading is increased for the AgNPs-based nanocomposites. All these findings imply that the lateral charge transport in the nanocomposite structures is favored by the closely situated AgNPs because of the strong electrostatic coupling between them, additionally activated by the temperature increase.
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Hsu B, Farid S, Averion-Puttrich J, Sumant AV, Stroscio MA, Dutta M. High performance ionic-liquid-gated air doped diamond field-effect transistors. NANOTECHNOLOGY 2021; 32:135205. [PMID: 33276348 DOI: 10.1088/1361-6528/abd0b6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We report successful fabrication of high performance ion-gated field-effect transistors (FETs) on hydrogenated diamond surface. Investigations on the hydrogen (H)-terminated diamond by Hall effect measurements shows Hall mobility as high as ∼200 cm2 V-1 s-1. In addition we demonstrate a rapid fabrication scheme for achieving stable high performance devices useful for determining optimal growth and fabrication conditions. We achieved H-termination using hydrogen plasma treatment with a sheet resistivity as low as ∼1.3 kΩ/sq. Conductivity through the FET channel is studied as a function of bias voltage on the liquid ion-gated electrode from -3.0 to 1.5 V. Stability of the H-terminated diamond surface was studied by varying the substrate temperature up to 350 °C. It was demonstrated that the sheet resistance and carrier densities remain stable over 3 weeks in ambient air atmosphere even at substrate temperatures up to 350 °C, whereas increasing temperature beyond this limit has effected hydrogenation. This study opens new avenues for carrying out fundamental research on diamond FET devices with ease of fabrication and high throughput.
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Affiliation(s)
- Bo Hsu
- Department of Electrical and Computer Engineering, University of Illinois at Chicago, Chicago, IL 60607, United States of America
| | - Sidra Farid
- Department of Electrical and Computer Engineering, University of Illinois at Chicago, Chicago, IL 60607, United States of America
| | - Joseph Averion-Puttrich
- Department of Electrical and Computer Engineering, University of Illinois at Chicago, Chicago, IL 60607, United States of America
| | - Anirudha V Sumant
- Center for Nanoscale Materials, Argonne National Labs, Lemont, IL 60493, United States of America
| | - Michael A Stroscio
- Department of Electrical and Computer Engineering, University of Illinois at Chicago, Chicago, IL 60607, United States of America
- Department of Physics, University of Illinois at Chicago, Chicago, IL 60607, United States of America
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, United States of America
| | - Mitra Dutta
- Department of Electrical and Computer Engineering, University of Illinois at Chicago, Chicago, IL 60607, United States of America
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, United States of America
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James MC, May PW, Allan NL. Ab initio study of negative electron affinity from light metals on the oxygen-terminated diamond (1 1 1) surface. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:295002. [PMID: 30978712 DOI: 10.1088/1361-648x/ab18ef] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Recent computational work has shown that light metals adsorbed onto the oxygenated diamond (1 0 0) surface have the potential to give diamond a temperature-stable negative electron affinity (NEA). Here, we use density functional theory to study three of these metals, lithium, magnesium and aluminium, on the (1 1 1) surface. We show that all three of these metals adsorbed onto the ketone O-terminated diamond surface can possess a large NEA and adsorption energies above that of H-termination at monolayer (ML) or sub-ML coverages. Adsorption onto the ether O-terminated surface gives similarly large NEAs but lower adsorption energies. These results are promising for the development of novel NEA surfaces such as those required for thermionic devices.
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Affiliation(s)
- Michael C James
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, United Kingdom. HH Wills Physics Laboratory, Bristol Centre for Functional Nanomaterials, University of Bristol, Tyndall Avenue, Bristol, BS8 1TL, United Kingdom
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