Article
Materials Science, Multidisciplinary
Alexander Efremov, Ildar Amirov, Mikhail Izyumov
Summary: This study investigated the effects of Cl2/Ar and O2/Ar gas mixtures on plasma parameters and atomic species densities. It was found that Cl2/Ar mixture increases electron density and Cl atom density, while O2/Ar mixture can adjust O atom density.
Article
Nuclear Science & Technology
Cheng Wang, Jian-Hao Tan, Xiao-Xia Huang, Yi-Xing Lu, Lin Wang, Wen-Cheng Fang, Zhen-Tang Zhao
Summary: The article discusses the design, manufacturing, and performance testing of the first cryogenic RF gun in China, with focuses on RF design optimization, beam dynamics, and the results of cold testing under both room temperature and cryogenic conditions.
NUCLEAR SCIENCE AND TECHNIQUES
(2021)
Article
Materials Science, Coatings & Films
Simon Ruel, Patricia Pimenta-Barros, Frederic Le Roux, Nicolas Chauvet, Michel Massardier, Philippe Thoueille, Shirley Tan, Daniel Shin, Francois Gaucher, Nicolas Posseme
Summary: In this paper, the plasma-etching steps during the fabrication of a MOS-HEMT were investigated for their potential damage to GaN materials. The study compared the Cl-2-based atomic layer etching (ALE) process with He or Ar as the sputtering gas, examining the self-limiting synergy and process window of ALE. A comparison was also made to a steady-state process, evaluating roughness and electrical measurements to assess induced damage.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2021)
Article
Materials Science, Multidisciplinary
Clint D. Frye, Scott B. Donald, Catherine E. Reinhardt, Rebecca J. Nikolic, Lars F. Voss, Sara E. Harrison
Summary: The study demonstrates that SiO2 can serve as an effective mask material for deep etching of GaN devices with high selectivity, achieving GaN:SiO2 selectivities greater than those reported for metal hard masks. Introducing Al and AlCl into the plasma enables ultrahigh SiO2 selectivities, providing a low-contamination pathway for etching deep GaN microdevices.
MATERIALS RESEARCH LETTERS
(2021)
Article
Chemistry, Physical
Tongtong Zhu, Didi Luo, Andong Wu, Teng Tan, Hao Guo, Pingran Xiong, Zeqiang Lin, Shichun Huang, Qingwei Chu, Ziqin Yang, Feng Pan, Ming Lu, Kun Zhang, Yuan He
Summary: This study utilized a two-dimensional self-consistent model to quantitatively evaluate the physical sputtering process for SRF cavities by introducing the sputtering-yield probability distribution. It optimized the plasma distribution characteristics and established the correlation between ion flux and ion-energy distribution function, while also conducting a plasma physical sputtering experiment on small niobium samples to observe an etching and smoothing effect.
APPLIED SURFACE SCIENCE
(2022)
Article
Nuclear Science & Technology
Peng Sha, Wei-Min Pan, Song Jin, Ji-Yuan Zhai, Zheng-Hui Mi, Bai-Qi Liu, Chao Dong, Fei-Si He, Rui Ge, Liang-Rui Sun, Shi-Ao Zheng, Ling-Xi Ye
Summary: This study investigated two 650 MHz single-cell superconducting radio-frequency cavities used for the CEPC to achieve high accelerating gradient and high intrinsic quality factor. The combination of buffered chemical polishing and electropolishing showed promising results. Medium temperature furnace baking also demonstrated excellent performance in terms of ultrahigh Q(0) and extremely low BCS resistance.
NUCLEAR SCIENCE AND TECHNIQUES
(2022)
Article
Physics, Applied
Shohei Nakamura, Atsushi Tanide, Takahiro Kimura, Soichi Nadahara, Kenji Ishikawa, Osamu Oda, Masaru Hori
Summary: This study demonstrates damage-free atomic layer etching (ALE) of GaN using a cyclic process, where the chlorinated layer formed by Cl2 plasma exposure is removed by Ar plasma. A substrate temperature of 400 degrees C promotes etching even at lower ion energy, resulting in a higher ALE synergy of 62%. The proposed high temperature ALE method shows promise for achieving damage-free etching of GaN.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Engineering, Electrical & Electronic
Clint D. Frye, Catherine E. Reinhardt, Scott B. Donald, Lars F. Voss, Sara E. Harrison
Summary: This study investigates the effects of substrate temperature, RF power, and ICP power on GaN micropillar sidewall roughness and etch characteristics. The results show that adjusting these parameters can improve the sidewall etch morphology and produce extremely smooth surfaces suitable for GaN regrowth and new device structures.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2022)
Article
Instruments & Instrumentation
Cheng Wang, Jianhao Tan, Zihan Zhu, Xiaoxia Huang, Lin Wang, Wencheng Fang, Zhentang Zhao
Summary: This paper introduces a new cryogenic C-band photocathode electron gun and reports on the progress of experimental tests, showing that the RF characteristics at cryogenic temperatures are in good agreement with the design expectations. These results pave the way for practical operation of cryogenic electron guns and the design of other cryogenic structures.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT
(2021)
Article
Physics, Fluids & Plasmas
Young-Hee Joo, Jae-Won Choi, Bo Hou, Hyuck-In Kwon, Doo-Seung Um, Chang-Il Kim
Summary: In this study, the etching characteristics of indium gallium tin oxide (IGTO) thin films were investigated using Cl-2/Ar plasma. The results showed that the etch rate increased with an increase in Cl-2 proportion and radio-frequency power, with the highest etch rate observed in pure Cl-2 plasma. The etching process in Cl-2-containing plasma reduced surface roughness, while the etching process in pure Ar plasma increased surface roughness.
PLASMA SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Physical
Hee Ju Kim, Long Wen, Doo San Kim, Ki Hyun Kim, Jong Woo Hong, Won Jun Chang, Soo Namgoong, Dong Woo Kim, Geun Young Yeom
Summary: The etch characteristics of silicon trenches masked with various SiO2/Si3N4 pattern distances were investigated using different pulse modes in Ar/Cl-2 inductively coupled plasmas. The results showed that using synchronously and asynchronously pulse modes instead of continuous wave (CW) mode increased the selectivity between Si and the mask layer and reduced the etch rate differences between wide and narrow pattern distance patterns (ARDE). The improvements in etch selectivity and reduction of ARDE were attributed to the increased conduction of Cl radicals/byproducts and time separated etch cycle composed of Cl chemical adsorption and removal of chemisorbed species.
APPLIED SURFACE SCIENCE
(2022)
Article
Engineering, Electrical & Electronic
Andrzej Taube, Maciej Kaminski, Marek Ekielski, Renata Kruszka, Joanna Jankowska-Sliwinska, Pawel P. Michalowski, Joanna Zdunek, Anna Szerling
Summary: The study focuses on the development of selective etching of p-GaN over Al0.25Ga0.75N for fabrication of AlGaN/GaN HEMTs with a p-GaN gate, achieving high etching selectivity and good electrical performance of the devices.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2021)
Article
Physics, Fluids & Plasmas
A. Mukherjee, M. Chakraborty, N. Sharma, P. K. Saha
Summary: The behaviour of nitrogen plasma mixed with varying proportions of argon was investigated under different RF discharge conditions. The dissociation fraction of nitrogen increased with the growing concentration of argon at low RF power, while it rapidly fell at high RF power. The electron density, temperature, and energy probability function were obtained using a Langmuir probe, and the vibrational and rotational temperatures were evaluated using optical emission spectroscopy.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2023)
Article
Nanoscience & Nanotechnology
Nayeon Lee, Ohyung Kwon, Chin-Wook Chung
Summary: The study analyzed the correlation of RF impedance with Ar plasma parameters in semiconductor etch equipment, finding that the corrected plasma resistance had a coefficient of determination over 0.9 with the theoretical formula for bulk plasma resistance. This suggests that the corrected RF impedance can help monitor plasma status and maintain etch process quality in semiconductor mass production lines.
Article
Nuclear Science & Technology
Zhen-Yu Ma, Shen-Jie Zhao, Xu-Ming Liu, Yue-Chao Yu, Hong-Ru Jiang, Xiang Zheng, Qiang Chang, Zi-Gang Zhang, Kai Xu, Yan Wang, Yu-Bin Zhao, Hong-Tao Hou
Summary: This paper describes the 1.3 GHz power couplers used in the Shanghai High Repetition Rate XFEL and Extreme Light Facility (SHINE) project and their testing results, which demonstrate that these couplers are capable of handling high power continuous waves.
NUCLEAR SCIENCE AND TECHNIQUES
(2022)
Article
Physics, Applied
J. Upadhyay, Do Im, S. Popovic, A. -M. Valente-Feliciano, L. Phillips, L. Vuskovic
JOURNAL OF APPLIED PHYSICS
(2015)
Article
Materials Science, Coatings & Films
Janardan Upadhyay, Do Im, Svetozar Popovic, Leposava Vuskovic, Anne-Marie Valente-Feliciano, Larry Phillips
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2015)
Article
Instruments & Instrumentation
J. Upadhyay, Do Im, J. Peshl, M. Basovic, S. Popovic, A. -M. Valente-Feliciano, L. Phillips, L. Vuskovic
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT
(2016)
Article
Physics, Applied
S. Popovic, J. Upadhyay, J. Mammosser, M. Nikolic, L. Vuskovic
JOURNAL OF APPLIED PHYSICS
(2014)
Article
Materials Science, Coatings & Films
M. Raskovic, S. Popovic, J. Upadhyay, L. Vuskovic, L. Phillips, A. -M. Valente-Feliciano
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2009)
Article
Physics, Nuclear
M. Raskovic, J. Upadhyay, L. Vuskovic, S. Popovic, A-M. Valente-Feliciano, L. Phillips
PHYSICAL REVIEW SPECIAL TOPICS-ACCELERATORS AND BEAMS
(2010)
Article
Physics, Nuclear
J. Upadhyay, Do Im, S. Popovic, A. -M. Valente-Feliciano, L. Phillips, L. Vuskovic
PHYSICAL REVIEW SPECIAL TOPICS-ACCELERATORS AND BEAMS
(2014)
Article
Physics, Fluids & Plasmas
M. Nikolic, S. Popovic, J. Upadhyay, L. Vuskovic, R. Leiweke, B. Ganguly
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2012)
Article
Nanoscience & Nanotechnology
J. Upadhyay, J. Peshl, S. Popovic, A. -M. Valente-Feliciano, L. Vuskovic
Article
Materials Science, Coatings & Films
Ch. Chakrapani, S. K. Sharma, A. K. Chakraborty, M. J. Singh, G. B. Patel, S. Rambabu, B. Prajapati, J. Upadhyay, S. K. Mattoo
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2007)