Article
Chemistry, Multidisciplinary
Ryo Kagawa, Zhe Cheng, Keisuke Kawamura, Yutaka Ohno, Chiharu Moriyama, Yoshiki Sakaida, Sumito Ouchi, Hiroki Uratani, Koji Inoue, Yasuyoshi Nagai, Naoteru Shigekawa, Jianbo Liang
Summary: This study demonstrates the potential of fabricating GaN HEMTs on diamond substrates by successfully transferring AlGaN/GaN/3C-SiC layers to large diamond substrates and maintaining the integrity and high thermal conductivity of the substrate interface. It enables high-quality crystal growth and excellent heat dissipation performance.
Article
Materials Science, Multidisciplinary
Muhammad Dilawer Hayat, Harshpreet Singh, Kariappa Maletira Karumbaiah, Ying Xu, Xin-Gang Wang, Peng Cao
Summary: This study presents a modified process for depositing copper onto diamond particles, leading to a well-bonded interface and excellent thermal conductivity.
Article
Thermodynamics
Jason Velardo, Randeep Singh, Phan Thanh Long, Mladenko Kajtaz, Abhijit Date
Summary: In this study, a method for predicting the thermal resistance of a vapour chamber was developed and integrated into a thermal management system model. The model showed good agreement with experimental results and revealed that the vapour chamber accounted for 40% of the total thermal resistance. The spreading sub-model was found to have the largest contribution to the thermal resistance of the vapour chamber.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Materials Science, Multidisciplinary
Yiming Wang, Bing Zhou, Guoliang Ma, Jiaqi Zhi, Chao Yuan, Hui Sun, Yong Ma, Jie Gao, Yongsheng Wang, Shengwang Yu
Summary: The low TBReff at the GaN/diamond interface is crucial for high-power, high-frequency, and high-temperature GaN-on-diamond devices. This study proposed a bias enhanced nucleation technique to modulate TBReff by adjusting the nucleation of GaN/SiNx/diamond multilayer composites at different bias voltages. The results showed that the composite prepared under 700 V bias had the lowest TBReff, while the one prepared at 600 V bias had the highest TBReff.
MATERIALS CHARACTERIZATION
(2023)
Article
Engineering, Environmental
Jia-wan Peng, Feng-lin Zhang, Yu-mei Zhou, Ling-kang Xiong, Yao-jie Huang, Hong-qun Tang
Summary: This study proposes a novel method to fabricate a thin plate of diamond/copper composite based on the construction of a single-layer close packed diamond particles network. The composite exhibits high thermal conductivity, tunable coefficient of thermal expansion, and excellent mechanical properties. It also demonstrates better heat dissipation ability compared to pure copper plate.
CHEMICAL ENGINEERING JOURNAL
(2023)
Review
Chemistry, Analytical
Tianzhuo Zhan, Mao Xu, Zhi Cao, Chong Zheng, Hiroki Kurita, Fumio Narita, Yen-Ju Wu, Yibin Xu, Haidong Wang, Mengjie Song, Wei Wang, Yanguang Zhou, Xuqing Liu, Yu Shi, Yu Jia, Sujun Guan, Tatsuro Hanajiri, Toru Maekawa, Akitoshi Okino, Takanobu Watanabe
Summary: Wide-bandgap gallium nitride (GaN)-based semiconductors offer advantages in high-power and high-frequency operations, but self-heating effects (SHE) cause performance degradation. Reducing thermal boundary resistance (TBR) is necessary for better heat dissipation.
Article
Automation & Control Systems
Miquel Vellvehi, Xavier Perpina, Javier Leon, Oriol Avino-Salvado, Conrad Ferrer, Xavier Jorda
Summary: The thermal resistance of a high electron mobility transistor (HEMT) in a monolithic microwave integrated circuit (MMIC) was noninvasively extracted using infrared thermal imaging, with power dissipation inferred for each device thanks to heat source frequency modulation. This method allowed for obtaining reasonable values for the local thermal resistance of each individual HEMT in the MMIC.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2021)
Article
Materials Science, Ceramics
Mingkang Zhang, Zhouxi Tan, Ke Zhang, Xuejian Liu, Zhenren Huang, Yihua Huang
Summary: This study investigated the phase composition, microstructure, and properties of diamond/SiC composites. The results showed that the incorporation of α-SiC particles improved the uniformity of the microstructure. The acoustic mismatch model was used to analyze the samples before and after diamond graphitization and revealed an increased interfacial thermal resistance after graphitization. The correlation between diamond content and thermal/mechanical properties was also investigated.
CERAMICS INTERNATIONAL
(2023)
Article
Materials Science, Coatings & Films
Su-Hwan Choi, Hyun-Jun Jeong, TaeHyun Hong, Yong Hwan Na, Chi Kwon Park, Myung Yong Lim, Seong Hoon Jeong, Jun Hyung Lim, Jin-Seong Park
Summary: Plasma-enhanced atomic layer deposited indium oxide (InOx) films using a new liquid precursor DATI exhibit high growth efficiency and purity, making them a promising choice for indium oxide semiconductors, particularly in backplane TFTs.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2021)
Review
Engineering, Electrical & Electronic
Markus Mueller, Vincenzo D'Alessandro, Sophia Falk, Christoph Weimer, Xiaodi Jin, Mario Krattenmacher, Pascal Kuthe, Martin Claus, Michael Schroeter
Summary: This review evaluates and discusses several widely used methods for extracting the thermal resistance of heterojunction bipolar transistors (HBTs), including the underlying assumptions, suitable operating point range, and necessary measurement effort. The accuracy of each method is determined by applying it to data based on circuit simulations and experimental data from advanced SiGe and III-V HBT technologies. A guideline for selecting the most suitable method in practice is also provided.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Engineering, Electrical & Electronic
Youngjun Im, Seong-In Cho, Jingyu Kim, Namgyu Woo, Jong Beom Ko, Sang-Hee Ko Park
Summary: This research proposes a solution to the trade-off relationship between mobility and turn-on voltage (V-on) in oxide thin-film transistors (TFTs) by introducing a buffer layer engineered trench-TFT (T-TFT). The T-TFT, which incorporates both Al2O3 and SiO2 buffer layers, demonstrates a high mobility and suitable V-on value by selectively utilizing the advantages of different planar-TFTs.
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Nanoscience & Nanotechnology
Mohamadali Malakoutian, Daniel E. Field, Nicholas J. Hines, Shubhra Pasayat, Samuel Graham, Martin Kuball, Srabanti Chowdhury
Summary: The implementation of SG-and-beyond networks requires faster, high-performance, and power-efficient semiconductor devices, with gallium nitride (GaN) power amplifiers playing a crucial role in providing high frequency and power output. Cooling GaN devices with diamond has gained significant momentum in overcoming heat removal challenges, achieving record-low thermal boundary resistance at the diamond/GaN interface. Integration of diamond within close proximity to the GaN channel layer without degrading electrical behavior, along with the growth of isotropic polycrystalline diamond, has led to an efficient heat spread in both vertical and lateral directions. The impressive combination of thermal conductivity and low thermal boundary resistance marks a leading-edge achievement in this field.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Physical
Wen-Hao Chang, Chun- Lu, Tilo H. Yang, Shu-Ting Yang, Kristan Bryan Simbulan, Chih-Pin Lin, Shang-Hsien Hsieh, Jyun-Hong Chen, Kai-Shin Li, Chia-Hao Chen, Tuo-Hung Hou, Ting-Hua Lu, Yann-Wen Lan
Summary: The study reveals that negative differential resistance (NDR) can be observed in monolayer MoS2 by introducing a specific amount of sulfur vacancy defects. This finding is significant for the development of new electronic devices based on defect engineering in two-dimensional materials.
NANOSCALE HORIZONS
(2022)
Article
Chemistry, Physical
Zijun Qi, Wei Shen, Rui Li, Xiang Sun, Lijie Li, Qijun Wang, Gai Wu, Kang Liang
Summary: This paper investigates the influence of nanopillars on the thermal boundary resistance of AlN/diamond interfaces using Non-equilibrium Molecular Dynamics method. The optimal AlN/diamond interface with nanopillar structures can reduce the thermal boundary resistance by 28%. The analysis of vibrational density of states reveals that the enhancement of AlN intermediate frequency phonons and the shift of diamond VDOS towards lower frequency contribute to the optimization of interfacial thermal transport.
APPLIED SURFACE SCIENCE
(2023)
Article
Nanoscience & Nanotechnology
L. Lei, L. Bolzoni, F. Yang
Summary: Copper/diamond composites fabricated using a cost-effective hot forging process show different morphology and thermal conductivity due to the influence of diamond facets on B4C nucleation, highlighting the potential for future high-power electronic devices.
ADVANCED COMPOSITES AND HYBRID MATERIALS
(2022)
Article
Physics, Condensed Matter
Lisa Liborius, Jan Bieniek, Alexander Possberg, Franz-Josef Tegude, Werner Prost, Artur Poloczek, Nils Weimann
Summary: In this study, the leakage mechanisms in epitaxially grown nanowire heterojunction bipolar transistors were analyzed in detail. Tunneling was identified as the dominant leakage mechanism in highly doped nanowire pn-junctions, and by adjusting the tunneling barrier width, the junction leakage current density was successfully reduced. This suppression of tunneling also increased the number of electrons injected from the n-emitter into the p-base, enabling the functionality of bipolar transistors.
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2021)
Article
Engineering, Electrical & Electronic
Michael Hrobak, Karsten Thurn, Jochen Moll, Maruf Hossain, Amit Shrestha, Thualfiqar Al-Sawaf, Dimitri Stoppel, Nils G. Weimann, Adam Raemer, Wolfgang Heinrich, Javier Martinez, Martin Vossiek, Tom K. Johansen, Viktor Krozer, Marion Resch, Jurgen Bosse, Michael Sterns, Kai Loebbicke, Stefan Zorn, Mohamed Eissa, Marco Lisker, Frank Herzel, Robert Miesen, Klaus Vollmann
Summary: This article presents the design and prototyping of components for a modular multiple-input-multiple-output (MIMO) millimeter-wave radar for space applications, utilizing SiGe and InP semiconductor technologies. The radar features comparatively low complexity of the TX/RX units and optimized process maturity for space qualification.
JOURNAL OF INFRARED MILLIMETER AND TERAHERTZ WAVES
(2021)
Article
Engineering, Electrical & Electronic
Matteo Villani, Simone Clochiatti, Werner Prost, Nils Weimann, Xavier Oriols
Summary: A novel time-dependent displacement current coefficient is proposed to replace the traditional transmission coefficient for frequencies above a certain limit. The study shows that tunneling electron devices exhibit intrinsic nonlinearity at high frequencies, leading to potential advantages in THz applications.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Quang Huy Le, Dang Khoa Huynh, Steffen Lehmann, Zhixing Zhao, Thomas Kampfe, Matthias Rudolph
Summary: This article introduces a systematic empirical modeling approach for large-signal simulation in FDSOI CMOS for power amplifier applications, constructed from multibias S-parameter measurements to address frequency dispersions. Load-pull measurements verified the accuracy of the model in predicting nonlinear characteristics and harmonic components of the device under test. Time-domain waveforms also showed excellent agreement with the simulation results.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Engineering, Electrical & Electronic
S. Krause, F. Michler, A. Koelpin, M. Rudolph, W. Heinrich
Summary: This study demonstrates a digital correction method for extending the dynamic range of a six-port radar system, which effectively compensates for phase errors generated under large-signal and high-power operation. The concept has been validated using Si Schottky diodes operating at 24 GHz in conjunction with power detectors in a six-port junction.
IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Matthias Rudolph, Anisha M. Apte
IEEE MICROWAVE MAGAZINE
(2021)
Article
Chemistry, Multidisciplinary
Juliane Koch, Lisa Liborius, Peter Kleinschmidt, Nils Weimann, Werner Prost, Thomas Hannappel
Summary: This study investigates the conductivity channels of III-V semiconductor nanowires at the nanoscale using a ultrahigh-vacuum based multi-tip scanning tunneling microscope. Advanced analysis techniques reveal significant differences in electrical performance between freestanding and detached nanowires, providing important insights for the study of nanoelectronic devices.
ADVANCED MATERIALS INTERFACES
(2022)
Proceedings Paper
Simone Clochiatti, Parya Yavari, Robin Schmidt, Patrick Hauser, Enes Mutlu, Christian Preuss, Werner Prost, Nils Weimann
Summary: This study presents the design, fabrication, and characterization of a monolithically integrated epitaxial thin-film resistor for THz applications. The resistor shows a flat frequency response and exhibits stability at high temperatures.
2022 FIFTH INTERNATIONAL WORKSHOP ON MOBILE TERAHERTZ SYSTEMS (IWMTS)
(2022)
Proceedings Paper
R. Kress, E. Mutlu, T. Kubiczek, J. Kossmann, C. Preuss, T. Schultze, J. C. Balzer, W. Prost, N. Weimann
Summary: This paper presents an assembly process using HRFZ-Si transfer substrate for precise alignment of THz oscillators with hyper-hemispherical silicon lenses. The bonding process and THz-TDS measurements were conducted to analyze the losses within the setup, and the process was verified with experiments on a 300 GHz triple barrier (TB)-RTD oscillator.
2022 FIFTH INTERNATIONAL WORKSHOP ON MOBILE TERAHERTZ SYSTEMS (IWMTS)
(2022)
Proceedings Paper
K. Mueller, A. Possberg, M. Coers, H. Zhang, N. Weimann
Summary: This study focuses on the causes and improvements of the non-linear behavior of InP DHBTs through physical simulations. The simulated devices have triple mesa structures with type-I band alignment and utilize a carbon-doped In53.2Ga46.8As base, 0.5 μm emitter width, and InGaAsP material in the collector region for enhanced electron transport. The simulations showed a 5 dB difference in OIP3 values between two devices, and a significant discrepancy in RF performance in terms of transit frequency and maximum frequency of oscillation. The improved design also demonstrated better electron transport across the collector region, highlighting the collector design's high sensitivity to device performance.
2022 FIFTH INTERNATIONAL WORKSHOP ON MOBILE TERAHERTZ SYSTEMS (IWMTS)
(2022)
Article
Materials Science, Multidisciplinary
Davide Cimbri, Nils Weimann, Qusay Raghib Ali Al-Taai, Afesomeh Ofiare, Edward Wasige
Summary: This paper introduces a simple test structure for accurately extracting the specific contact resistivity of metal-n++ InGaAs-based low-resistance Ohmic contacts. The structure is designed to avoid common measurement artifacts and microfabrication was optimised to achieve a short minimum gap spacing required for reliable rho(c) estimation. The Ohmic contacts fabricated and characterised using this structure yielded a extracted rho(c) of approximately 1.37x10(-7) Omega cm(2) = 13.7 Omega mu m(2), which can improve the quality of Ohmic contacts in high-power InGaAs/AlAs double-barrier resonant tunnelling diodes and enhance the output power capability of RTD-based oscillators at terahertz frequencies.
INTERNATIONAL JOURNAL OF NANOELECTRONICS AND MATERIALS
(2021)
Proceedings Paper
Engineering, Electrical & Electronic
Meng Zhang, Peng-Yuan Wang, Andreas Rennings, Simone Clochiatti, Werner Prost, Nils Weimann, Daniel Erni
Summary: This study presents a 1 to 4 subarray element for wireless subharmonic injection in on-chip antennas, achieving a maximum radiation efficiency better than 50% through optimizing the positions and distances between FOS and SIS antennas.
2021 FOURTH INTERNATIONAL WORKSHOP ON MOBILE TERAHERTZ SYSTEMS (IWMTS)
(2021)
Proceedings Paper
Engineering, Electrical & Electronic
R. Kress, C. Preuss, E. Mutlu, S. Clochiatti, W. Prost, N. Weimann
Summary: This study investigates the impact of alignment accuracy requirements for hyper-hemispherical silicon lenses at THz frequencies. Experimental results demonstrate that hyper-hemispherical silicon lenses have relaxed alignment accuracy needs compared to hemispherical lenses, and design rules and concepts for a heterointegrated system are proposed based on consecutive observations.
2021 FOURTH INTERNATIONAL WORKSHOP ON MOBILE TERAHERTZ SYSTEMS (IWMTS)
(2021)
Proceedings Paper
Engineering, Electrical & Electronic
S. Clochiatti, E. Mutlu, C. Preuss, R. Kress, W. Prost, N. Weimann
Summary: A broadband THz detector using a triple-barrier InP Resonant Tunneling Diode and a monolithically integrated circularly polarized spiral antenna was designed, fabricated, and measured at room temperature. The detector achieved high responsivity and low noise equivalent power in the 220-330 GHz band, making it suitable for various applications.
2021 FOURTH INTERNATIONAL WORKSHOP ON MOBILE TERAHERTZ SYSTEMS (IWMTS)
(2021)
Proceedings Paper
Engineering, Electrical & Electronic
M. Hossain, T. Shivan, M. Hrobak, T. Al-Sawaf, D. Stoppel, H. Yacoub, N. Weimann, W. Heinrich, V Krozer
Summary: This paper presents a W-band transceiver chip using InP-DHBT technology, including a transceiver switch, a medium power amplifier, and a low noise amplifier with good performance parameters. The entire circuit consumes low power and exhibits high isolation, suitable for future 5G communication.
2020 15TH EUROPEAN MICROWAVE INTEGRATED CIRCUITS CONFERENCE (EUMIC)
(2021)
