Article
Chemistry, Physical
Yohei Kotsugi, Seung-Min Han, Youn-Hye Kim, Taehoon Cheon, Dip K. Nandi, Rahul Ramesh, Neung-Kyung Yu, Kirak Son, Tomohiro Tsugawa, Shigeyuki Ohtake, Ryosuke Harada, Young-Bae Park, Bonggeun Shong, Soo-Hyun Kim
Summary: The study reports the atomic layer deposition of high-quality Ru films using a metal-organic precursor, achieving efficient ALD process with significantly low resistivity at relatively low deposition temperatures. The thin Ru films exhibit good adhesion energy, regardless of the dielectric material and annealing treatment, making them suitable for replacing Cu-based interconnects in emerging electronic applications.
CHEMISTRY OF MATERIALS
(2021)
Article
Engineering, Electrical & Electronic
Rakshith Saligram, Suman Datta, Arijit Raychowdhury
Summary: This study measured the RC delays of BEOL elements on 22nm Fully Depleted Silicon on Insulator from room temperature to 4.2K, revealing a reduction in resistance for metal interconnect elements at low temperatures. By fitting the Fuchs-Sondheimer-Mayadas-Shatzkes (FS-MS) model and incorporating line-edge roughness in the analysis, the empirically fitted parameters matched well with literature and experimental results with an error of 3.7%.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Engineering, Mechanical
Muhammad Farooq-i-Azam, Muhammad Omar Farooq
Summary: This paper introduces a technique for analyzing circuits with partial information using probability methods. Circuit element parameters are treated as random variables, and probability models for desired parameters are derived using probability theory. The application of this technique is demonstrated using an example of a resistor capacitor circuit.
ENGINEERING FAILURE ANALYSIS
(2022)
Article
Physics, Applied
Ryan R. Gusley, Quintin Cumston, Kevin R. Coffey, Alan C. West, Katayun Barmak
Summary: The electrodeposition of Cu onto epitaxial Ru(0001) seed layers resulted in the growth of a bicrystal structure with an improvement in resistivity, despite the compressive misfit strain between the layers. The Cu initially grew as isolated islands before coalescing into a rough, contiguous film with large grain sizes. As the thickness increased, the film transitioned into a planar film with nanometric islands, but at thicknesses exceeding 200 nm, anisotropic growth led to increased surface roughness.
JOURNAL OF APPLIED PHYSICS
(2021)
Review
Energy & Fuels
Murat Ates, Achref Chebil
Summary: This work presents a state of the art review on energy storage systems, focusing on supercapacitors and batteries as alternative technologies for electrical energy generation. The review includes an analysis of the evolution of electroactive materials and a classical modeling approach based on electric equivalent circuits. The research aims to create circuits using physical models that represent conservation and diffusion interactions, and the suggested synthesis technique involves model discretization, linearization, model order reduction, and passive network synthesis. This comprehensive investigation is expected to lead to breakthrough developments in obtaining nanocomposites.
JOURNAL OF ENERGY STORAGE
(2022)
Article
Chemistry, Physical
Jiatao Zhou, Xiaowu Hu, Jialing Li, Xiongxin Jiang
Summary: The experimental results indicate that Cu doping can improve the electrical behavior of Ni-Co alloy coatings, reduce the activation energy of electron hopping, and inhibit the growth of oxide layers. The Ni-Co coatings doped with 9% Cu showed the best oxidation rate constant and electrical properties after the oxidation process.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Computer Science, Information Systems
Felipe Treviso, Riccardo Trinchero, Flavio G. Canavero
Summary: This work presents a novel approach based on machine learning techniques for accurately estimating multiple time-delays in distributed systems. The method constructs a metamodel using LS-SVM regression, identifies delays, and obtains the rational part of the model using a vector fitting algorithm. Results show the capability of the proposed approach in identifying dominant delays and constructing compact delayed rational models.
Article
Energy & Fuels
M. Ignacia Devoto Acevedo, Stephan Grosser, Karl Wienands, Tudor Timofte, Andreas Halm, Ralph Gottschalg, Daniel Tune
Summary: The contact resistivity plays a significant role in the performance of solar module interconnects. However, accurately measuring the contact resistivity for interconnects based on electrically conductive adhesive (ECA) is challenging. This study demonstrates that transmission line method (TLM) test structures based on ECA exhibit non-negligible inhomogeneities, leading to inaccuracies in determining the contact resistivity. The analysis of four commercially available ECAs used in solar modules reveals that even without macroscale inhomogeneities, microscopic structural effects affect the sheet and contact resistance, particularly due to variations in filler distribution.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2023)
Article
Engineering, Electrical & Electronic
Bin Wang, Chaohui Wang, Zhiyu Wang, Hong Xue, Siliang Ni
Summary: This letter presents a variable first-order resistance-capacitance equivalent circuit for dynamic modeling of supercapacitors, a real-time voltage state observer for estimating variable internal capacitance and resistance, three different energy estimation methods, and simulated and experimental validations of an adaptive energy estimation method. The proposed adaptive method improves estimated state-of-energy accuracy by over 0.75% compared to conventional methods when applied to electric vehicle applications.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Arup K. George, Wooyoon Shim, Jaeha Kung, Ji-Hoon Kim, Minkyu Je, Junghyup Lee
Summary: This paper introduces a digital-intensive, reconfigurable RC-to-digital converter that can readout multiple sensors in a time-interleaved fashion, achieving high resolution and low temperature drift. Implemented in a standard CMOS process, the converter demonstrates excellent performance, occupying a small footprint and effectively sensing femto-farad capacitances.
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS
(2022)
Article
Engineering, Electrical & Electronic
Sunil Jadav, Shubham Tayal, Rajeevan Chandel, Munish Vashishath
Summary: This study introduces a novel mathematical delay model for global VLSI interconnects based on characteristic impedance. The model's accuracy and superiority are verified through simulative sweep analysis techniques and SPICE simulations.
MICROELECTRONICS JOURNAL
(2021)
Article
Multidisciplinary Sciences
Muhammad Farooq-i-Azam, Zeashan Hameed Khan, Arfan Ghani, Asif Siddiq
Summary: In this research, we analyze a resistor capacitor electric circuit with an exponentially decaying transient response. The capacitance is treated as a continuous uniformly distributed random variable. A probability model for the response current is derived, and its validity is verified. The model is further used to analyze the transient current probabilistically, and to determine the probability of reaching a specific value.
Article
Computer Science, Hardware & Architecture
Nicholas A. Lanzillo, Albert Chu, Prasad Bhosale, Dan Dechene
Summary: The study evaluates the performance impact of cobalt interconnect metallization in advanced logic technologies with a minimum metal pitch of 32 nm or less. Cobalt interconnects may reduce line resistance in narrow signal lines, but significant performance penalties are associated with using cobalt in wide lines, including delay and parasitic voltage drop. The authors discuss design strategies to minimize the impact of cobalt metallization and highlight critical differences between low-power and high-performance design points for power delivery.
IEEE TRANSACTIONS ON VERY LARGE SCALE INTEGRATION (VLSI) SYSTEMS
(2022)
Article
Engineering, Electrical & Electronic
Sonal Agrawal, Anurag Srivastava, Gaurav Kaushal
Summary: This study analyzed the impact of halogen passivation on zigzag graphene nanoribbons (ZGNRs) in terms of structural stability, electron transport, thermal conductivity, and interconnect performance. It found that chlorine-passivated ZGNRs exhibited better characteristics in terms of current-voltage behavior, interconnect parameters, and power consumption, making them a favorable choice for interconnect applications.
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
R. Mathur, M. Bhargava, B. Cline, S. Salahuddin, A. Gupta, P. Schuddinck, J. Ryckaert, J. P. Kulkarni
Summary: The study explores a new method of using buried interconnects in SRAM to improve performance and address the issue of resistance increase, showing that buried interconnects can significantly improve SRAM access time, write time, and dynamic power.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Engineering, Electrical & Electronic
Shuzhen You, Xiangdong Li, Karen Geens, Niels Posthuma, Ming Zhao, Hu Liang, Guido Groeseneken, Stefaan Decoutere
Summary: This work introduces a MIT virtual source GaNFET model for GaN IC design, successfully simulating the evolution of output waveforms in a monolithically integrated GaN driver circuit under switching stress, and demonstrating the significant impact of gate leakage on the gate voltage redistribution of power p-GaN gate HEMTs controlled by the integrated GaN driver.
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Zhicheng Wu, Jacopo Franco, Anne Vandooren, Philippe Roussel, Ben Kaczer, Dimitri Linten, Nadine Collaert, Guido Groeseneken
Summary: Low thermal budget junction-less transistors with back-gate were fabricated for 3-D sequential integration. The study showed that back-gate bias can modulate carrier mobility and BTI reliability. Applying back-gate bias during ON-state can adjust device performance without reliability penalty, while applying it during both ON- and OFF-states can improve BTI reliability without performance loss.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Physics, Applied
Y. C. Wu, W. Kim, S. Van Beek, S. Couet, R. Carpenter, S. Rao, S. Kundu, J. Van Houdt, G. Groeseneken, D. Crotti, G. S. Kar
Summary: The voltage control of magnetic anisotropy (VCMA) effect enables a voltage-mediated mechanism for magnetization switching with lower power applications. This study experimentally investigates VCMA-induced switching, observing a clear decrease in critical switching voltage (Vc) at elevated temperatures, with a 50% reduction when ambient temperature (T) is increased from 300K to 360K. The temperature dependence of these characteristics is well explained by variations in saturation magnetization (MS), interfacial anisotropy (Ki), and VCMA coefficient (xi).
APPLIED PHYSICS LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Michiel Vandemaele, Jacopo Franco, Stanislav Tyaginov, Guido Groeseneken, Ben Kaczer
Summary: This study presents measurements of multiple hot-carrier stress and high-temperature anneal cycles on the same nFETs in a commercial 40-nm bulk CMOS technology. It models the degradation anneal process assuming Si-H bond breakage during stress and bond passivation during anneal, with the bond dissociation and passivation energies following a bivariate Gaussian distribution. The research finds no correlation between bond dissociation and passivation energies, and notes that repeated HC stress and anneal cycles change the shape of the distribution of bond passivation energies from Gaussian to non-Gaussian.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Engineering, Electrical & Electronic
Y. Xiang, M. Garcia Bardon, B. Kaczer, Md Nur K. Alam, L-A Ragnarsson, K. Kaczmarek, B. Parvais, G. Groeseneken, J. Van Houdt
Summary: The study presents a hardware-validated FeFET compact model that addresses key aspects of MFIS electrostatics, laying the groundwork for memory and logic applications.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Engineering, Electrical & Electronic
Wei-Min Wu, Ming-Dou Ker, Shih-Hung Chen, Arturo Sibaja-Hernandez, Sachin Yadav, Uthayasankaran Peralagu, Hao Yu, AliReza Alian, Vamsi Putcha, Bertrand Parvais, Nadine Collaert, Guido Groeseneken
Summary: Gallium nitride (GaN) technologies play an important role in commercial advanced RF systems, but face challenges in reliability due to electrostatic discharge (ESD). A mis-correlation between standard-defined human body model (HBM) ESD robustness and commonly used transmission line pulse (TLP) failure current was observed in GaN high electron mobility transistors (HEMTs). A discharge model is proposed to explain the mechanism, and simulations confirm that the mis-correlation is due to 2-dimensional electron gas (2DEG) resistance modulation in response to HBM ESD transient voltage waveforms.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Engineering, Electrical & Electronic
Zhicheng Wu, Jacopo Franco, Anne Vandooren, Hiroaki Arimura, Lars-Ake Ragnarsson, Philippe Roussel, Ben Kaczer, Dimitri Linten, Nadine Collaert, Guido Groeseneken
Summary: This article proposes a method to improve the reliability of high-k/metal gate structures by inserting defect decoupling layers between SiO2 and HfO2. The study shows that LaSiOx has little impact on carrier mobility, while Al2O3 can improve both positive and negative BTI reliability. Furthermore, the simplified dual gate-stack integration strategy is explored, indicating that the pMOS gate-stack is more tolerant to the presence of a residual LaSiOx layer.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Engineering, Electrical & Electronic
Wen-Chieh Chen, Shih-Hung Chen, Thomas Chiarella, Geert Hellings, Dimitri Linten, Guido Groeseneken
Summary: The electrostatic discharge (ESD) reliability of OFF- and ON-state NMOS field-effect transistors in a bulk FinFET technology is investigated in this study. The study focuses on the impacts of gate pitch (GP) and gate length (L-g) on the epitaxy of source and drain regions. It is found that a large GP leads to nonuniform epitaxy and high power density localization in the device, while a large L-g improves the ESD performance. Additionally, the study reveals that the clamping voltage and ON-resistance of the ON-state NMOSFET are influenced by L-g and GPs, with shorter L-g and the same gate space achieving better ESD performance.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Engineering, Electrical & Electronic
M. Vandemaele, B. Kaczer, S. Tyaginov, J. Franco, E. Bury, A. Chasin, A. Makarov, G. Hellings, G. Groeseneken
Summary: We simulate the spatial profile of trapped charge in the forksheet FET wall under hot-carrier stress and find that the charge trapping occurs above and below the horizontal projection of the sheet. The charge profile is independent of the sheet width, and the trapping in the forksheet FET wall is significantly smaller than the trapping in the gate stack.
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Wei-Min Wu, Shih-Hung Chen, Chun-An Shih, Bertrand Parvais, Nadine Collaert, Ming-Dou Ker, Tian-Li Wu, Guido Groeseneken
Summary: Gallium nitride (GaN)-on-Si technologies for advanced RF applications have been drawing attention in the semiconductor industry, along with challenges in RF electrostatic discharge (ESD) reliability. Investigating both positive and negative ESD stress polarities is equally important. In this study, four scenarios of positive and negative human body model (HBM) stresses were conducted on GaN-on-Si (MIS-HEMTs) with gate-tied-to-source and gate-tied-to-drain configurations. It was found that the negative GS MIS-HEMT exhibited a failure mechanism different from the constant-power 2DEG failure mechanism in the typical positive GS (MIS-HEMT).
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Engineering, Electrical & Electronic
K. Kaczmarek, M. Garcia Bardon, Y. Xiang, N. Ronchi, L. -A. Ragnarsson, U. Celano, K. Banerjee, B. Kaczer, G. Groeseneken, J. Van Houdt
Summary: We investigate the origins of threshold voltage (V-TH) variability in planar ferroelectric FETs (FeFETs) by considering both process variations and source-drain channel percolation. By using a percolation-aware physics-based multidomain FeFET model, we are able to accurately capture the measured V-TH statistics across various channel dimensions in fabricated devices. Our findings suggest that the bimodal V-TH distribution observed in large devices can be explained by percolation, while the transition to a monomodal distribution in scaled devices is qualitatively reproduced by the overlapping Pelgrom-type and percolative variabilities in the model. Furthermore, we demonstrate that the percolation-related FeFET V-TH variability is minimized when the channel aspect ratio is equal to 1 in terms of device geometry.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Proceedings Paper
Engineering, Multidisciplinary
Michiel Vandemaele, Ben Kaczer, Erik Bury, Jacopo Franco, Adrian Chasin, Alexander Makarov, Hans Mertens, Geert Hellings, Guido Groeseneken
Summary: We present TCAD simulation studies on the hot-carrier reliability of nanowire (NW), nanosheet (NS), and forksheet (FS) FETs. The simulations involve solving the Boltzmann transport equation, calculating interface state generation and bulk defect charging, and evaluating the impact of generated/trapped charges on FET characteristics. We discuss the models used in hot-carrier simulation flows, anneal measurements, and validate the simulation models by comparing with NW FET measurements, providing insights for NS and FS FETs.
2023 IEEE INTERNATIONAL RELIABILITY PHYSICS SYMPOSIUM, IRPS
(2023)
Proceedings Paper
Engineering, Electrical & Electronic
S. Abhinay, W. -M. Wu, C. -A. Shih, S. -H. Chen, A. Sibaja-Hernandez, B. Parvais, U. Peralagu, A. Alian, T. -L. Wu, M. -D. Ker, G. Groeseneken, N. Collaert
Summary: This paper presents an extensive experimental study and simulations on the impact of different stress scenarios on the ESD robustness of GaN RF HEMTs. The study highlights the importance of different current discharge paths for each stress scenario and verifies the contribution of the on-state gate Schottky diode to the robustness of the HEMTs. Additionally, three types of HBM failure mechanisms are identified under different stress scenarios.
2022 INTERNATIONAL ELECTRON DEVICES MEETING, IEDM
(2022)
Proceedings Paper
Engineering, Multidisciplinary
Michiel Vandemaele, Ben Kaczer, Stanislav Tyaginov, Erik Bury, Adrian Chasin, Jacopo Franco, Alexander Makarov, Hans Mertens, Geert Hellings, Guido Groeseneken
Summary: Forksheet (FS) FETs are a new transistor architecture that utilizes vertically stacked nFET and pFET sheets with a dielectric wall, reducing p-to-n separation. Hot-carrier degradation (HCD) simulations show that both FS FETs and NS FETs can reduce HCD with increasing sheet width when considering interface state generation. Furthermore, an initial assessment suggests that the impact of oxide defect charging in the FS wall can be controlled under operating conditions.
2022 IEEE INTERNATIONAL RELIABILITY PHYSICS SYMPOSIUM (IRPS)
(2022)
Proceedings Paper
Engineering, Multidisciplinary
Ping-Yi Hsieh, Artemisia Tsiara, Barry O'Sullivan, Didit Yudistira, Marina Baryshnikova, Guido Groeseneken, Bernardette Kunert, Marianna Pantouvaki, Joris Van Campenhout, Ingrid De Wolf
Summary: This study reports for the first time a reliability study on degradation of InGaAs/GaAs nano-ridge p-i-n diodes monolithically integrated on Si by nano-ridge engineering (NRE). The results show that current crowding and Joule heating near the p-contact are responsible for the degradation in forward bias region, while the electrical stress-induced leakage current indicates the degradation of crystal quality in reverse bias region. The study also demonstrates that a sintering process can lower the p-contact resistance and improve electrical stability, and the high aspect-ratio of the trenches leads to effective threading dislocation trapping.
2022 IEEE INTERNATIONAL RELIABILITY PHYSICS SYMPOSIUM (IRPS)
(2022)