Article
Chemistry, Analytical
Huy-Binh Do, Quang-Ho Luc, Phuong V. Pham, Anh-Vu Phan-Gia, Thanh-Son Nguyen, Hoang-Minh Le, Maria Merlyne De Souza, Xiao Luo, Bo Yao, Parsian K. Mohseni
Summary: The impact of the work function of gate metals Ti, Mo, Pd, and Ni on defects in HfO2 and at HfO2/InGaAs interfaces was studied using capacitance-voltage measurements, TCAD simulations, and X-ray photoelectron spectroscopy. The highest density of interface and border traps was found at the Ti/HfO2 interface, while the Mo/HfO2 interface showed the smallest density of traps. The extracted values of D-it for acceptor-like traps and donor-like traps were the lowest reported to date.
Article
Physics, Applied
Bunichiro Mikake, Takuma Kobayashi, Hidetoshi Mizobata, Mikito Nozaki, Takayoshi Shimura, Heiji Watanabe
Summary: The effect of post-deposition annealing on the electrical characteristics of SiO2/GaN MOS devices was investigated. Oxygen annealing was used to form an interfacial GaO x layer and forming gas annealing was used to passivate the remaining defects. Care must be taken not to produce a fixed charge through reduction of the GaO x layer. By growing the GaO x layer with oxygen annealing at 800 degrees C and performing forming gas annealing at a low temperature of 200 degrees C, it became possible to suppress the reduction of GaO x and to reduce the interface traps, oxide traps, and fixed charge simultaneously.
APPLIED PHYSICS EXPRESS
(2023)
Article
Engineering, Electrical & Electronic
V. Volosov, S. Cascino, M. Saggio, A. Imbruglia, F. Di Giovanni, C. Fiegna, E. Sangiorgi, A. N. Tallarico
Summary: In this study, the role of interface/border defects in the threshold voltage drift of SiC power MOSFETs was investigated using various tests. The results showed that the temperature dependence of the drift was opposite depending on the applied gate bias and stress technique, indicating the presence of different mechanisms.
SOLID-STATE ELECTRONICS
(2023)
Proceedings Paper
Engineering, Electrical & Electronic
Gaspard Hiblot, Barry O'Sullivan, Nicolo Ronchi, Kaustuv Banerjee
Summary: The investigation focused on charging damage due to gate antennae on 65nm NMOS devices with a thick 9.5nm HfOx gate dielectric. It was found that charging caused different trap characteristics in plate-antenna and control transistors.
2021 IEEE INTERNATIONAL INTEGRATED RELIABILITY WORKSHOP (IIRW)
(2021)
Article
Materials Science, Multidisciplinary
Jun Lin, Scott Monaghan, Neha Sakhuja, Farzan Gity, Ravindra Kumar Jha, Emma M. Coleman, James Connolly, Conor P. Cullen, Lee A. Walsh, Teresa Mannarino, Michael Schmidt, Brendan Sheehan, Georg S. Duesberg, Niall McEvoy, Navakanta Bhat, Paul K. Hurley, Ian M. Povey, Shubhadeep Bhattacharjee
Summary: This study reports successful growth of MoS2 films on various substrates at low temperatures using chemical vapor deposition. The MoS2 films exhibited potential for BEOL logic, memory, and sensing applications.
Article
Nanoscience & Nanotechnology
Mircea Dragoman, Martino Aldrigo, Daniela Dragoman, Ian M. Povey, Sergiu Iordanescu, Adrian Dinescu, Andrea Di Donato, Mircea Modreanu
Summary: Research found that MoS2 behaves as a transparent piezoelectric material in the near infrared spectral region and as a strain-induced ferroelectric material. Experimental demonstration shows that SSDs can function as lateral memristors and photo-detectors in the visible spectrum.
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
(2021)
Article
Crystallography
Anya Curran, Agnieszka Gocalinska, Andrea Pescaglini, Eleonora Secco, Enrica Mura, Kevin Thomas, Roger E. Nagle, Brendan Sheehan, Ian M. Povey, Emanuele Pelucchi, Colm O'Dwyer, Paul K. Hurley, Farzan Gity
Summary: Polycrystalline indium arsenide thin films grown at 475 degrees C by MOVPE are studied as potential low-temperature-grown semiconducting materials, showing electron mobilities around 100 cm(2)/V.s at room temperature and reaching 155 cm(2)/V.s for a heterostructure. When used as channel material, poly InAs films exhibit transistor-type behavior with varying I-ON/I-OFF ratios at different temperatures.
Article
Nanoscience & Nanotechnology
Nazar Farid, Adam Brunton, Phil Rumsby, Scott Monaghan, Ray Duffy, Paul Hurley, Mingqing Wang, Kwang-Leong Choy, Gerard M. O'Connor
Summary: A new process of crystallizing amorphous silicon without melting is proposed, which includes adding a molybdenum layer to control crystallite size and achieve high-quality crystallization at low temperature. Simulations show that the transfer of energy from the molybdenum layer to the silicon film can lead to crystallization of amorphous silicon at temperatures lower than its melting point.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Engineering, Electrical & Electronic
E. Coleman, G. Mirabelli, P. Bolshakov, P. Zhao, E. Caruso, F. Gity, S. Monaghan, K. Cherkaoui, V Balestra, R. M. Wallace, C. D. Young, R. Duffy, P. K. Hurley
Summary: This study investigates inverted metal-oxide semiconductor (MOS) structures formed by mechanically exfoliating MoS2 flakes onto Al2O3 or SiO2 layers on degenerately doped p-type silicon substrates. Multi-frequency capacitance and conductance characterization is performed to study electrically active defects in the MoS2/oxide structures, paired with physics-based ac simulations indicating close to ideal interfacial properties.
SOLID-STATE ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
E. Caruso, J. Lin, S. Monaghan, K. Cherkaoui, L. Floyd, F. Gity, P. Palestri, D. Esseni, L. Selmi, P. K. Hurley
Summary: The study investigates the interaction between the series and parallel equivalent circuit representations of the MOS system conductance and capacitance, finding five independent values for magnitude and frequency of maxima and minima points. By interpreting the measured data in both series and parallel modes, the significance and application of this approach is presented and discussed.
SOLID-STATE ELECTRONICS
(2021)
Article
Engineering, Environmental
Frank Riedewald, Edward Wilson, Yunus Patel, Daniel Vogt, Ian Povey, Killian Barton, Liam Lewis, Tom Caris, Silvia Santos, Maria O'Mahoney, Maria Sousa-Gallagher
Summary: This paper presents experimental results on pilot plant trials of recycling aluminium laminated pouches and Tetra-Pak cartons. The study shows that both package formats can be recycled and clean aluminium can be recovered. However, mechanical cleaning may be necessary for recovered aluminium from pouches due to carbon residue. The pyrolysis of the polypropylene plastic layer in the packaging showed excellent kinetics, with over 90% converting into waxes. Economic analysis of a commercial-scale plant demonstrated the viability of a molten metal aluminium recycling plant, achieving an internal rate of return (IRR) of over 20%.
Article
Crystallography
Bienlo Flora Zerbo, Mircea Modreanu, Ian Povey, Jun Lin, Antoine Letoublon, Alain Rolland, Laurent Pedesseau, Jacky Even, Bruno Lepine, Pascal Turban, Philippe Schieffer, Alain Moreac, Olivier Durand
Summary: This study presents the development of MoS2/c-silicon heterojunction solar cells and examines the characteristics of MoS2 through experiments and numerical simulations. The results show that MoS2 is sensitive to oxidation and has a bandgap suitable for the targeted application. The MoS2/Si heterojunction could potentially improve quantum efficiency compared to standard solar cells.
Article
Chemistry, Physical
Aein Babadi, Scott Monaghan, Christopher O'Rourke, Michael Braun, Lindsey Brock, Huikai Cheng, Ted Tessner, Paul K. Hurley, Andrew Mills, Paul C. McIntyre
Summary: TiO2-IrOx alloys synthesized by atomic layer deposition (ALD) were used as anodes for water and chloride oxidation. The effects of alloy composition on their electrochemical activity and nanoscale structures were investigated. The TiO2-IrOx alloy with 38% iridium showed the highest electronic conductivity and electrochemical performance, with the lowest activation overpotentials for both oxygen and chloride evolution reactions. It also exhibited the largest photovoltage during water oxidation experiments.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Physics, Applied
Emma Coleman, Scott Monaghan, Farzan Gity, Gioele Mirabelli, Ray Duffy, Brendan Sheehan, Shashank Balasubramanyam, Ageeth A. A. Bol, Paul Hurley
Summary: In this study, the physical and electrical properties of WS2 thin films grown by plasma-enhanced atomic layer deposition were investigated. The films exhibited the desired orientation and p-type behavior, with a carrier concentration of 1.31 x 10^17 cm(-3). The temperature-dependent analysis revealed similar activation energies for the specific contact resistivity and WS2 resistivity, indicating that both are affected by the temperature dependence of the WS2 hole concentration. Changes in material properties after device fabrication were attributed to various chemical and thermal treatments associated with the process.
APPLIED PHYSICS LETTERS
(2023)
Article
Biochemistry & Molecular Biology
Aaron O'Donoghue, Micheal Shine, Ian M. Povey, James F. Rohan
Summary: This work demonstrates the improved electrochemical performance of sputter-deposited, binder-free lithium cobalt oxide thin films with an alumina coating deposited via atomic layer deposition. The Al2O3 coating enhances charge-discharge kinetics and suppresses phase transition, leading to minimal irreversible capacity loss. By analyzing the electrochemical performance at different upper potential limits, the study finds that a 3 nm Al2O3 coating delivers high-rate capability and cycling benefits with a capacity retention of 87% and 70% at cycle 100 and 400, respectively.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Engineering, Electrical & Electronic
Christopher P. P. Murray, Daniyar Mamyraimov, Mugahid Ali, Clive Downing, Ian M. M. Povey, David McCloskey, David D. D. O'Regan, John F. F. Donegan
Summary: This study compares the thermal stability of Au thin films with different thicknesses of Al and AlOx capping films. It is found that 0.5-1 nm of Al or AlOx capping films are most effective in reducing the dewetting of Au thin films, while thicker Ta and AlOx capping films fail to completely prevent dewetting. A simple model is developed to explain how thinner capping layers can better protect the metal from laser-induced damage.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Multidisciplinary Sciences
Frank Riedewald, Ian Povey, Maria O'Mahoney, Maria Sousa-Gallagher
Summary: This paper describes the design features and operational details of a molten metal pyrolysis reactor, and presents experimental results on biomass, plastic composites, carbon fiber materials, and printed circuit boards. The reactor allows for pyrolysis experimentation on various materials.
Article
Materials Science, Multidisciplinary
Shona Doyle, Louise Ryan, Melissa M. McCarthy, Mircea Modreanu, Michael Schmidt, Fathima Laffir, Ian M. Povey, Martyn E. Pemble
Summary: In this study, layered ZnO and TiO2 nanolaminates were deposited using combinatorial atomic layer deposition (C-ALD) on different substrates to investigate their structure and photocatalytic activity. ZnO was found to have a templating influence on the subsequent TiO2 layer, and the nanolaminate structures remained stable after high-temperature annealing. In terms of photocatalytic activity, ZnO deposited on glass substrates showed the best performance.
MATERIALS ADVANCES
(2022)
Article
Engineering, Electrical & Electronic
Bruno Galizia, Patrick Fiorenza, Corrado Bongiorno, Bela Pecz, Zsolt Fogarassy, Emanuela Schiliro, Filippo Giannazzo, Fabrizio Roccaforte, Raffaella Lo Nigro
Summary: This study demonstrates the growth of oriented AlN thin films on 4H-SiC substrates using PE-ALD technique, and investigates the impact of NH3 plasma pulsing on the microstructure and orientation degree of the AlN layers. The structural characterization reveals different polymorphic structures depending on the NH3 plasma pulsing time, and electrical nanoscopic characterization shows a correlation between the AlN crystalline phases and the insulating properties.
MICROELECTRONIC ENGINEERING
(2024)
Article
Engineering, Electrical & Electronic
Theo Levert, Alter Zakhtser, Julien Duval, Chloe Raguenez, Stephane Verdier, Delphine Le Cunff, Jean-Herve Tortai, Bernard Pelissier
Summary: In this study, the robustness of optical constants and optical band gap determination of three different materials is compared using a combination of spectroscopic ellipsometry and energy loss signal of X-ray photoelectron spectroscopy. The hybridization of these two techniques provides a new robust method for determining the band gap of the studied materials and other optical properties over a wide energy range.
MICROELECTRONIC ENGINEERING
(2024)
