Review
Physics, Applied
Chao Lu, Xueqiang Ji, Zeng Liu, Xu Yan, Nianpeng Lu, Peigang Li, Weihua Tang
Summary: This review summarizes recent research progress on beta-Ga2O3-metal contacts, including related theories, measurements, fabrication processes, and control methods. These studies provide important insights for both theoretical understanding of the metal/semiconductor interface and the fabrication process for engineering applications of Ga2O3-based devices.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Engineering, Electrical & Electronic
Sosorburam Boldbaatar, V. Janardhanam, Munkhsaikhan Zumuukhorol, Hoon-Ki Lee, Hae-Yong Lee, Hyo Jung Kim, Kyu-Hwan Shim, Chel-Jong Choi
Summary: We investigated Ni Schottky contacts on alpha-Ga2O3 epitaxial layers and studied their current-voltage characteristics at temperatures ranging from 100 to 425 K. The Ni/alpha-Ga2O3 Schottky diode showed excellent rectification with a high barrier height of 1.39 eV, a low leakage current of around 10-12 A, and a breakdown voltage of 215 V at room temperature. The temperature dependence of the barrier height and ideality factor indicated the presence of barrier inhomogeneity at the Schottky interface, with a transition occurring at 250 K.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2023)
Article
Physics, Applied
Yibo Wang, Wenhui Xu, Genquan Han, Tiangui You, Fengwen Mu, Haodong Hu, Yan Liu, Xinchuang Zhang, Hao Huang, Tadatomo Suga, Xin Ou, Xiaohua Ma, Yue Hao
Summary: The article reports on the interface performance of the beta-Ga2O3((2) over bar 01)/TiN Schottky barrier diode (SBD) on a heterogeneous integrated Ga2O3-Al2O3-Si (GaOISi) substrate. The SBD exhibits stable characteristics and consistent on-state to off-state current ratio at different temperatures. Additionally, the effective barrier height φ(B, eff) decreases with increasing temperature, leading to a decrease in V-on.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Physics, Applied
Hardhyan Sheoran, Rajendra Singh
Summary: This work presents the fabrication of high-performance Schottky barrier diodes (SBDs) on Ga2O3 epilayers using Cu as Schottky contacts (SCs). The fabricated SBDs displayed high Schottky barrier heights (SBHs) with values exceeding 1.0 eV, near-unity ideality factors, and a high rectification ratio (RR) at 300 K. Temperature-dependent measurements were conducted, revealing the increase and subsequent decrease in SBHs with temperature. The findings suggest the formation of a high-work-function copper oxide thin film, enabling the potential for low-cost mass production of power semiconductor devices based on oxide semiconductors.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Rishabh Raj, Himanshu Gupta, L. P. Purohit
Summary: In this study, vanadium pentoxide (V2O5) thin films were successfully grown on soda-lime glass using RF magnetron sputtering technique. The impact of different sputtered power on the growth, structural and optical properties of V2O5 films was systematically studied. The results showed that V2O5 films exhibited a preferred crystal orientation and good transmittance. The performance of the Schottky diode with V2O5 interface layer (IF) for solar cell applications was also investigated, which demonstrated the important role of the V2O5 layer in enhancing the diode's performance.
Article
Engineering, Electrical & Electronic
Haodong Hu, Yibo Wang, Xiaole Jia, Yuewen Li, Bochang Li, Zhengdong Luo, Xiangyu Zeng, Cizhe Fang, Yan Liu, Jinggang Hao, Yiyang Shan, Hong Dong, Yue Hao, Genquan Han
Summary: We propose a method to enhance the electrical performance of Pt/beta-Ga2O3 Schottky barrier diodes (SBDs) by treating the surface with low-temperature O-2 gas annealing. The pretreatment of beta-Ga2O3 surface with O-2 gas for 5 minutes at 400 degrees C increases the breakdown voltage (Vbr) by 18% and improves power figure-of-merit (PFOM) by 42% compared to control devices. X-ray photoelectron spectroscopy (XPS) analysis reveals that O-2 gas pretreatment leads to oxidation of Ga2+ states on the surface, resulting in increased Schottky barrier height (q phi(b)) and improved ideality factor of the SBDs. However, prolonging the pretreatment time to 15 minutes leads to reduction of the oxidized Ga2+, causing degraded Vbr and reduced qfb of the SBDs. Overall, our study demonstrates the promising potential of low-temperature O-2 gas annealing for optimizing the Schottky interface of beta-Ga2O3 SBDs and enhancing their performance.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Engineering, Electrical & Electronic
Qiming He, Weibing Hao, Xuanze Zhou, Yu Li, Kai Zhou, Chen Chen, Wenhao Xiong, Guangzhong Jian, Guangwei Xu, Xiaolong Zhao, Xiaojun Wu, Junfa Zhu, Shibing Long
Summary: This work demonstrates vertical beta-Ga2O3 Schottky barrier diodes (SBDs) breaking through the power figure of merit of 1 GW/cm(2) without edge termination. The unreliable surface on the top of the drift region, which naturally formed in air, was removed by inductively coupled plasma etching. The repaired surface was exposed to ambient air for less than 10 minutes during the entire preparation process. Compared with the excessive air exposure samples, the leakage current was well suppressed for the Ni/beta-Ga2O3 SBDs fabricated on a clean surface. Moreover, the blocking voltage reaches a maximum value of 1720 V, and the forward/reverse characteristics of the diodes on the same wafer show good uniformity. These results pave the way for further improving the performance of beta-Ga2O3 devices and verify the potential of beta-Ga2O3 SBDs for power applications.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Qiming He, Xuanze Zhou, Qiuyan Li, Weibing Hao, Qi Liu, Zhao Han, Kai Zhou, Chen Chen, Jinlan Peng, Guangwei Xu, Xiaolong Zhao, Xiaojun Wu, Shibing Long
Summary: Selective high-resistance zones were successfully achieved on beta-Ga2O3 wafers using a high-temperature oxygen annealing process. Polysilicon was employed as an annealing cap layer to prevent local carrier concentration changes during annealing. Additionally, a high-resistance anode edge termination of Schottky barrier diodes was demonstrated, leading to reduced leakage current and increased breakdown voltage.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Materials Science, Multidisciplinary
V. Manjunath, Nanda Kumar Reddy Nallabala, C. Yuvaraj, Chandramohan Kukkambakam, Venkata Krishnaiah Kummara, Suresh Kumar, Shivani Sharma, M. V. Lakshmaiah, Vasudeva Reddy Minnam Reddy
Summary: This study investigated the influence of incorporating a Ta2O5 thin film at the Au/GaN interface, analyzing the fabricated Au/Ta2O5/n-GaN MIS junctions using I-V measurements and evaluating Schottky diode parameters. Different methods were used to extract the electrical parameters and compare them, showing good agreement. The conduction mechanisms under different bias conditions were identified, with the study attributing the superior rectification ratio and high Schottky barrier height to the deposition of an undoped GaN buffer layer.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Tamer Guzel, Andac Batur Colak
Summary: This study investigates the usability of machine learning algorithms in determining important electrical parameters of Schottky diodes and develops a multi-layer artificial neural network model that can predict the parameters with high accuracy.
MATERIALS TODAY COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Min-Yeong Kim, Dong-Wook Byun, Geon-Hee Lee, Sujitra Pookpanratana, Qiliang Li, Sang-Mo Koo
Summary: The Schottky contact plays a crucial role in the electrical properties of Schottky barrier diodes (SBDs). This study investigated the carrier transport mechanisms and electrical characteristics of SBDs with pre-treated Ga2O3 thin films and Ni or Au Schottky contacts. The results showed that the pre-treated Ni SBDs exhibited the highest on/off ratio at room temperature and stable ideality factors and Schottky barrier heights between 298 K and 523 K. Additionally, SBDs with Ni as the anode material had lower Schottky barrier heights compared to those with Au.
MATERIALS RESEARCH EXPRESS
(2023)
Review
Materials Science, Multidisciplinary
Chowdam Venkata Prasad, You Seung Rim
Summary: Beta-Gallium oxide (beta-Ga2O3) has emerged as a promising semiconductor material for power electronic devices due to its ultra-wide bandgap and diverse material systems. This review article discusses recent investigations on the interface engineering of beta-Ga2O3-based power devices, summarizing different methods for improving performances and addressing challenges such as p-type doping difficulty and low thermal conductivity. The study also highlights the potential of ion-cutting process for achieving full potential of beta-Ga2O3 in power electronics.
MATERIALS TODAY PHYSICS
(2022)
Article
Engineering, Electrical & Electronic
Ailing Pan, Yingzhe Wang, Xuefeng Zheng, Yuehua Hong, Fang Zhang, Xiangyu Zhang, Ling Lv, Yanrong Cao, Xiaohua Ma, Yue Hao
Summary: The transformation of current transport mechanism and defect behavior in beta-gallium oxide Schottky barrier diodes (SBDs) under constant forward bias stress is investigated in this study. It is found that the predominant transport mechanism for both forward and reverse leakage current changes from thermionic emission to trap-assisted tunneling after stress. The generation of shallow-level defects and ionization of newly generated shallow donors contribute to the enhancement of trap-assisted tunneling.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Materials Science, Multidisciplinary
Chowdam Venkata Prasad, Joon Hui Park, Ji Young Min, Wonjin Song, Madani Labed, Yusup Jung, Sinsu Kyoung, Sangmo Kim, Nouredine Sengouga, You Seung Rim
Summary: In this study, a p-type copper aluminum oxide (p-CuAlO2) interlayer was proposed for improved breakdown voltage and low leakage current of beta-Ga2O3 Schottky barrier diodes (SBDs). XPS and TEM analysis confirmed the composition and properties of RF sputtered p-CuAlO2 thin films on beta-Ga2O3. Electrical characterization of Pt/beta-Ga2O3 SBD and Pt/p-CuAlO2/beta-Ga2O3 heterojunction (HJ) revealed that the HJ exhibited better rectification behavior, lower leakage current, and higher barrier height compared to the SBD. The p-CuAlO2 interlayer also reduced the interface state density and altered the conduction mechanisms of the SBD and HJ. These findings highlight the potential of p-CuAlO2 as a material for forming heterojunctions with beta-Ga2O3.
MATERIALS TODAY PHYSICS
(2023)
Review
Engineering, Electrical & Electronic
Hardhyan Sheoran, Vikram Kumar, Rajendra Singh
Summary: This study comprehensively reviews the recent development of metal-semiconductor contacts on ultrawide bandgap beta-gallium oxide (beta-Ga2O3). The study starts by introducing the basic concepts of metal-semiconductor contacts and then summarizes the current literature on ohmic and Schottky contacts on beta-Ga2O3. Finally, the status of high-power Schottky diode contact on beta-Ga2O3 is presented.
ACS APPLIED ELECTRONIC MATERIALS
(2022)
Article
Physics, Applied
Asanka Jayawardena, Rahul P. Ramamurthy, Ayayi C. Ahyi, Dallas Morisette, Sarit Dhar
APPLIED PHYSICS LETTERS
(2018)
Article
Engineering, Electrical & Electronic
Asanka Jayawardena, X. Shen, P. M. Mooney, Sarit Dhar
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2018)
Article
Engineering, Electrical & Electronic
S. Uprety, D. Hanggi, K. Yapabandara, V. Mirkhani, M. P. Khanal, B. Schoenek, S. Dhar, M. Park, M. Hamilton, S. Wang, W. E. Hames, M. H. Sk
ELECTRONICS LETTERS
(2018)
Article
Materials Science, Multidisciplinary
Vahid Mirkhani, Kosala Yapabandara, Shiqiang Wang, Min Prasad Khanal, Sunil Uprety, Muhammad Shehzad Sultan, Burcu Ozden, Ayayi Claude Ahyi, Michael C. Hamilton, Mobbassar Hassan Sk, Minseo Park
Article
Physics, Applied
I. U. Jayawardhena, R. P. Ramamurthy, D. Morisette, A. C. Ahyi, R. Thorpe, M. A. Kuroda, L. C. Feldman, S. Dhar
Summary: Silicon carbide (4H) based metal-oxide-semiconductor field-effect transistors offer capabilities in high power and high temperature that silicon cannot achieve. This research investigates the use of deposited Al2O3 dielectrics instead of thermal oxidation, resulting in improved electronic properties. The optimal structure involves preparation of a nitrided surface through NO annealing, hydrogen exposure, and Al2O3 deposition, leading to high inversion layer field-effect mobilities. Leakage currents and interface breakdown are also observed in various Al2O3/4H-SiC MOS structures.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Physics, Applied
Christopher J. Klingshirn, Asanka Jayawardena, Sarit Dhar, Rahul P. Ramamurthy, Dallas Morisette, Tsvetanka Zheleva, Aivars Lelis, Lourdes G. Salamanca-Riba
Summary: Analytical electron microscopy was used to investigate the chemical and structural features of (201) beta-Ga2O3 interfaces with SiO2 and Al2O3 gate oxides. The study revealed issues with the processing methods of the gate oxide affecting the interface quality and performance.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Engineering, Electrical & Electronic
Vahid Mirkhani, Shiqiang Wang, Kosala Yapabandara, Muhammad Shehzad Sultan, Min Prasad Khanal, Sunil Uprety, Burcu Ozden, Ehsan Hassani, Benjamin Schoenek, Dong-Joo Kim, Tae-Sik Oh, Ayayi Claude Ahyi, Sarit Dhar, Michael C. Hamilton, Mobbassar Hassan Sk, Minseo Park
Summary: Solution-based bottom-gate zinc oxide thin film transistors were fabricated and remained functional and stable under extreme gamma irradiation conditions. The removal of the channel surface due to the cumulative effect of displacement damage near the ZnO surface was observed through thickness measurements and optical images. The impact of displacement damage on the device characteristics was discussed in terms of surface/bulk effects.
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2021)
Article
Physics, Applied
Suman Das, Tamara Isaacs-Smith, Ayayi Ahyi, Marcelo A. Kuroda, Sarit Dhar
Summary: Nitridation of the gate oxide can enhance the performance of p-channel 4H-SiC MOSFETs at high temperatures, resulting in more reliable operation. The incorporation of nitrogen at the interface reduces trap density and improves the threshold voltage behavior with increasing temperature.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Physics, Applied
Suman Das, Hengfei Gu, Lu Wang, Ayayi Ahyi, Leonard C. Feldman, Eric Garfunkel, Marcelo A. Kuroda, Sarit Dhar
Summary: We propose an N-2 based annealing treatment to eliminate interface traps in 4H-SiC. The treatment shows potential as a safer and more cost-effective alternative to nitric oxide. The effectiveness of the treatment varies between n- and p-type devices, with N-2 annealing being more effective for p-type devices. The breakdown voltages of the devices also differ between the two treatments, with N-2 annealed devices having lower breakdown voltages.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Multidisciplinary Sciences
Hao Deng, Asanka Jayawardena, Jianxiong Chan, Sher Maine Tan, Tuncay Alan, Patrick Kwan
Summary: The portable point-of-care nucleic acid amplification test developed for rapid detection of active COVID-19 infection is easy to operate, provides results in approximately 35 minutes, and has the potential for effective testing in community settings.
SCIENTIFIC REPORTS
(2021)
Proceedings Paper
Thermodynamics
Bikramjit Chatterjee, Jacob H. Leach, Sarit Dhar, Sukwon Choi
PROCEEDINGS OF THE 17TH IEEE INTERSOCIETY CONFERENCE ON THERMAL AND THERMOMECHANICAL PHENOMENA IN ELECTRONIC SYSTEMS (ITHERM 2018)
(2018)
