Article
Chemistry, Multidisciplinary
Naiyin Wang, Wei Wen Wong, Xiaoming Yuan, Li Li, Chennupati Jagadish, Hark Hoe Tan
Summary: There is a strong demand for III-V nanostructures of different geometries and interconnected networks in quantum science applications, which can be achieved through selective area epitaxy (SAE). This study investigates the shape evolution and crystal structure of InP nanostructures grown by SAE on InP substrates of different orientations, and establishes a unified understanding to explain these observations. The research reveals a strong correlation between growth direction and crystal phase, and explains the polarity-induced crystal structure difference by thermodynamic variations between different planes.
Article
Crystallography
Xingyu Zhao, Adam F. McKenzie, Connor W. Munro, Katherine J. Hill, Daehyun Kim, Sam L. Bayliss, Neil D. Gerrard, Donald A. MacLaren, Richard A. Hogg
Summary: We investigated the selective area growth of InGaAs/GaAs quantum wells using metalorganic vapour phase epitaxy. We studied the emission wavelength tuning range, growth enhancement, and material uniformity in square masked regions. Our results show a total wavelength tuning range of 86 nm and a typical tuning range of 30 nm for a given window width. The enhanced growth rate and indium concentrations calculated demonstrate the potential for future applications in multi-wavelength laser array fabrication.
JOURNAL OF CRYSTAL GROWTH
(2023)
Article
Chemistry, Multidisciplinary
Hua-Chiang Wen, Ssu-Kuan Wu, Cheng-Wei Liu, Jin-Ji Dai, Wu-Ching Chou
Summary: The nanotribological properties of AlxGa1-xN epitaxial films grown on low-temperature-grown GaN/AlN/Si substrates were investigated. It was found that the Al compositions played a crucial role in determining the strength of bonding forces and shear resistance. The measured friction coefficient (mu) values decreased with increasing Al compositions, indicating a transition from brittleness to ductility in the AlxGa1-xN system.
Article
Physics, Applied
Nemanja Peric, Corentin Durand, Maxime Berthe, Yan Lu, Kekeli N'Konou, Roland Coratger, Isabelle Lefebvre, Philipp Ebert, Louis Biadala, Ludovic Desplanque, Xavier Wallart, B. Grandidier
Summary: The knowledge of band alignment in semiconductor heterostructures is important for device performance. In this study, the direction of current flow in In0.53Ga0.47As/InP heterostructure nanowires was controlled, and the band offsets at the buried heterointerface were directly measured using low temperature multiple-probe tunneling spectroscopy. The results indicate the formation of an interface with a quality comparable to two-dimensional In0.53Ga0.47As/InP heterostructures.
APPLIED PHYSICS LETTERS
(2022)
Article
Chemistry, Physical
Pojung Lin, Jiazhe Liu, Hongche Lin, Zhiyuan Chuang, Wenching Hsu, Yiche Chen, Poliang Liu, Rayhua Horng
Summary: In this study, GaN-based epitaxial structures were grown on high-resistivity silicon (HRSi) substrates by met-alorganic chemical vapor deposition. The p-type parasitic channels generated at the interfaces of the aluminum nitride (AlN) nucleation layers and HRSi substrates were characterized. A 2-nm thick silicon nitride (SiNx) layer was used to suppress the Al diffusion and prevent the generation of p-type parasitic channels. The insertion loss of the optimized structure was only 0.04 dB/mm higher than that of the annealed HRSi substrate at 10 GHz.
SURFACES AND INTERFACES
(2023)
Article
Multidisciplinary Sciences
Kentaro Nagamatsu, Takumi Miyagawa, Atsushi Tomita, Hideki Hirayama, Yuusuke Takashima, Yoshiki Naoi
Summary: This article discusses the use of deep ultraviolet light-emitting diodes for virus inactivation applications. It was found that the growth temperature of the AlN underlying layer was limited in conventional MOVPE methods, and using a flat sapphire substrate led to a high density of dislocations in the AlN layer. By utilizing high temperature and gas flow velocity MOVPE, high-temperature crystal growth of AlN at 1700 degrees C was achieved. The study also observed a decrease in growth rate at AlN growth temperatures exceeding 1550 degrees C.
SCIENTIFIC REPORTS
(2023)
Article
Crystallography
Shining Xu, Shuqi Zhang, Huilong Gao, Jeremy Kirch, Dan Botez, Luke Mawst
Summary: This study investigated the properties of strained-layer InGaAs/AlInAs superlattices (SL) grown on metamorphic buffer layers on GaAs substrates. The results showed that tight control over the average net-strain of the SL is necessary for the growth of micron-thick structures, especially for quantum cascade laser (QCL) active regions. By achieving such conditions, strain-balanced InP-based QCLs were successfully grown on (001) GaAs, demonstrating comparable device performance to those grown on native InP substrate. The HR-XRD measurements of the strain-balanced QCL on GaAs showed well-aligned satellite peaks with their counterparts grown on InP.
JOURNAL OF CRYSTAL GROWTH
(2023)
Article
Chemistry, Multidisciplinary
Emmanuel Chereau, Vladimir G. Dubrovskii, Gabin Gregoire, Geoffrey Avit, Philipp Staudinger, Heinz Schmid, Catherine Bougerol, Pierre-Marie Coulon, Philip A. Shields, Agnes Trassoudaine, Evelyne Gil, Ray R. LaPierre, Yamina Andre
Summary: The selective area growth (SAG) of GaAs nanowires (NWs) by catalyst-free vapor-solid mechanism was achieved. Well-ordered GaAs NWs in perfect hexagonal shape were grown on GaAs (111)B substrates patterned with a dielectric mask using hydride vapor phase epitaxy (HVPE). The study investigated the impact of growth conditions and hole size on NW lengths and growth rates. High aspect ratio NWs were obtained by reducing As-4 partial pressure and decreasing the hole size, indicating the contribution of surface diffusion of Ga adatoms to axial growth rate.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Nanoscience & Nanotechnology
Katarzyna Ludwiczak, Aleksandra Krystyna Dabrowska, Johannes Binder, Mateusz Tokarczyk, Jakub Iwanski, Boguslawa Kurowska, Jakub Turczynski, Grzegorz Kowalski, Rafal Bozek, Roman Stepniewski, Wojciech Pacuski, Andrzej Wysmolek
Summary: Transition metal dichalcogenides (TMDs) are materials with intriguing optical properties, especially when thinned down to a monolayer. By transferring TMD onto hexagonal boron nitride (hBN), significant improvements in optical and electrical properties can be achieved. A new epitaxial technique has been developed to directly grow high optical quality MoSe2 on an entire 2-inch wafer.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Multidisciplinary
Jason Jung, Sander G. Schellingerhout, Markus F. Ritter, Sofieke C. ten Kate, Orson A. H. van der Molen, Sem de Loijer, Marcel A. Verheijen, Heike Riel, Fabrizio Nichele, Erik P. A. M. Bakkers
Summary: This study introduces a method for the growth of large-scale lead telluride networks using molecular beam epitaxy. Despite the lattice mismatch, different crystal structure, and diverging thermal expansion coefficient, the researchers were able to obtain high-quality single-crystalline nanowire networks. The resulting material exhibits high mobility and low-temperature phase coherence, indicating its high potential as a basis for topological networks.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Wouter Mortelmans, Stefan De Gendt, Marc Heyns, Clement Merckling
Summary: The application of new materials in nanotechnology, particularly 2D chalcogenides, holds promise for groundbreaking innovations in the semiconductor industry. However, the integration of these materials poses challenges, limiting their usage to research laboratories. Achieving epitaxial growth of large-area, single-crystalline 2D chalcogenides is crucial for meeting industry demands.
APPLIED MATERIALS TODAY
(2021)
Article
Chemistry, Physical
Zahra Azimi, Aswani Gopakumar, Amira S. Ameruddin, Li Li, Thien Truong, Hieu T. Nguyen, Hark Hoe Tan, Chennupati Jagadish, Jennifer Wong-Leung
Summary: Catalyst-free InGaAs nanowires grown by selective area epitaxy show promising potential for future optoelectronic devices in the infrared spectral region. The composition, microstructure, and optical properties of the nanowires are influenced by growth parameters and pattern geometry, with Ga content increasing with certain growth conditions. Understanding these factors can facilitate the engineering of nanowires for optoelectronic applications.
Review
Chemistry, Multidisciplinary
Sergey Nikishin, Ayrton Bernussi, Sergey Karpov
Summary: This article reviews the major issues affecting the performance of deep-UV (DUV) laser diodes (LDs) and discusses different approaches to improve their performance. The effects of threading dislocations, limitations on heavy n- and p-doping in Al-rich AlGaN alloys, electron leakage, implementation of tunnel junctions, and non-uniform hole injection are discussed. The current status of n- and p-type doping and threading dislocation density reduction is emphasized. Promising technological and design approaches, such as high-temperature face-to-face annealing and distributed polarization doping, are also discussed. The growth capabilities of MOVPE and MBE techniques for fabricating DUV-LD structures are compared.
Article
Materials Science, Multidisciplinary
Carl Reuterskiold Hedlund, Joao Martins De Pina, Akhil Kalapala, Zhonghe Liu, Weidong Zhou, Mattias Hammar
Summary: In this study, the fabrication of InP photonic-crystal surface-emitting lasers (PCSELs) using a buried airhole/InP photonic-crystal (PC) layer based on an epitaxial regrowth process is discussed. The formation of PC voids in the InP crystal structure requires precise tuning of MOVPE growth parameters, and with control of temperature, V/III ratio, and growth rate, the shape of the airholes can be altered. Low-threshold lasing is achieved from these encapsulated airhole regrown PCSELs using optical pumping.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Xu Zhang, Hanhan Han, Binxiao Fu, Naiyin Wang, Yuhuai Liu, Chih-Chung Yang
Summary: The study on the growth process of hexagonal InP NSs reveals that the evolution of NS morphology is influenced by the combined effect of thermodynamic and kinetic mechanisms, which interact with each other throughout the process. The concept of Uniform Diffusion effect for sidewall growth with different orientations is proposed, providing a kinetic explanation for shape transformation. Additionally, a general time-dependent growth model of self-catalyzed NSs in arbitrary shape is obtained under the restriction of the thermodynamic approach.
CRYSTAL GROWTH & DESIGN
(2021)
Article
Crystallography
Hironori Gamo, Katsuhiro Tomioka
JOURNAL OF CRYSTAL GROWTH
(2018)
Article
Crystallography
Yusuke Minami, Akinobu Yoshida, Junichi Motohisa, Katsuhiro Tomioka
JOURNAL OF CRYSTAL GROWTH
(2019)
Article
Nanoscience & Nanotechnology
Junichi Motohisa, Hiroki Kameda, Masahiro Sasaki, Katsuhiro Tomioka
Article
Nanoscience & Nanotechnology
Kohei Chiba, Akinobu Yoshida, Katsuhiro Tomioka, Junichi Motohisa
Article
Engineering, Electrical & Electronic
Hironori Gamo, Katsuhiro Tomioka
IEEE ELECTRON DEVICE LETTERS
(2020)
Article
Nanoscience & Nanotechnology
Tomoya Akamatsu, Katsuhiro Tomioka, Junichi Motohisa
Article
Multidisciplinary Sciences
Katsuhiro Tomioka, Junichi Motohisa, Takashi Fukui
SCIENTIFIC REPORTS
(2020)
Article
Physics, Applied
Katsuhiro Tomioka, Fumiya Ishizaka, Junichi Motohisa, Takashi Fukui
APPLIED PHYSICS LETTERS
(2020)
Article
Engineering, Electrical & Electronic
Keitaro Ikejiri, Yuichi Hiroyama, Kenji Kasahara, Chihiro Hirooka, Takenori Osada, Mitsuhiro Tanaka, Tomoyuki Takada, Takashi Egawa
Summary: Technologies for mass production of AlGaN/AlN/GaN HEMT structures on 200 mm diameter silicon substrates have been developed using a large-scale metal-organic chemical vapor deposition system. The inclusion of an AlN spacer layer between the AlGaN and GaN layers can lead to lower on-state resistance for power devices. The AlN spacer layer successfully fabricated in this study helps to suppress the alloy disorder scattering effect, resulting in high two-dimensional-electron-gas mobility in HEMT structures.
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2021)
Article
Nanoscience & Nanotechnology
S. Kimura, H. Gamo, Y. Katsumi, J. Motohisa, K. Tomioka
Summary: This study focuses on the characterization of wurtzite (WZ) InP nanowire (NW) light-emitting diodes (LEDs) with different pn junctions (axial and radial). The results show that NW-LEDs using core-shell InP NWs with a radial pn junction have smaller series resistance and better current injection performance. The electroluminescence (EL) analysis reveals that the EL peaks originate from the zinc-blende (ZB) phase, WZ phase, and ZB/WZ heterojunction.
Article
Multidisciplinary Sciences
Akinobu Yoshida, Hironori Gamo, Junichi Motohisa, Katsuhiro Tomioka
Summary: This study investigates the possibility of directly integrating nanometer-scale InGaAs nanowires (NWs) on Ge for heterogenous integration and creation of functional materials. It is found that by changing Ge to a specific polar surface, vertical InGaAs NWs can be successfully integrated, forming a tunnel junction with promising applications.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Multidisciplinary
Hironori Gamo, Chen Lian, Junichi Motohisa, Katsuhiro Tomioka
Summary: This article investigates the growth morphology of GaSb structures in selective-area growth (SAG) using InGaAs nanowires (NWs) grown on a Si template. The study shows that the dominant growth processes can be controlled by the GaSb growth temperature, resulting in smooth GaSb shell layers. The vertical diode of InGaAs/GaSb core-shell NWs on Si exhibits moderate rectifying properties, and specific dual-carrier modulation behaviors are observed in the same transistor architecture.
Article
Materials Science, Multidisciplinary
Katsuhiro Tomioka, Kazuharu Sugita, Junichi Motohisa
Summary: This study investigates the effect of vertical metal-clad architectures on the performance of vertical nano-light-emitting diodes (LEDs) using GaAs/GaAsP-related core-multishell nanowires integrated on silicon. The vertical metal-clad nanowires demonstrate suppression of carrier overflow effect and rapid enhancement of electrical luminescence. These nanowires are expected to be key components for next-generation Si photonics, bioimaging, on-chip microscopy, and light detection and ranging (LiDAR) techniques, despite the complexity in their integration on silicon and device process flow.
ADVANCED PHOTONICS RESEARCH
(2023)
Proceedings Paper
Engineering, Electrical & Electronic
Katsuhiro Tomiok, Junichi Motohisa
Summary: The study characterized several scaling effects on the III-V nanowire (NW)-channel VGAA-FETs on Si.
2021 SILICON NANOELECTRONICS WORKSHOP (SNW)
(2021)
Proceedings Paper
Engineering, Electrical & Electronic
Katsuhiro Tomioka, Hironori Gamo, Junichi Motohisa, Takashi Fukui
2020 IEEE INTERNATIONAL ELECTRON DEVICES MEETING (IEDM)
(2020)
