A5003579890- Semiconductor materials and devices
- 2D Materials and Applications
- Graphene research and applications
- Advancements in Semiconductor Devices and Circuit Design
- Ferroelectric and Negative Capacitance Devices
- MXene and MAX Phase Materials
- Integrated Circuits and Semiconductor Failure Analysis
- Electronic and Structural Properties of Oxides
- Advanced Memory and Neural Computing
- Nanowire Synthesis and Applications
- Semiconductor materials and interfaces
- Quantum and electron transport phenomena
- Ga2O3 and related materials
- Surface and Thin Film Phenomena
- Semiconductor Quantum Structures and Devices
- Silicon Nanostructures and Photoluminescence
- Diamond and Carbon-based Materials Research
- Perovskite Materials and Applications
- Chalcogenide Semiconductor Thin Films
- Advanced Semiconductor Detectors and Materials
- Electron and X-Ray Spectroscopy Techniques
- GaN-based semiconductor devices and materials
- Silicon Carbide Semiconductor Technologies
- Copper Interconnects and Reliability
- Advanced MEMS and NEMS Technologies
Southern University of Science and Technology
2023-2025
TU Wien
2014-2024
Ioffe Institute
2015-2024
RWTH Aachen University
2024
Physico-Technical Institute
2011-2022
Physical and Technical Institute
2017-2020
Singapore Institute of Manufacturing Technology
2013-2014
KTH Royal Institute of Technology
2014
University of Siegen
2014
Institute of Microelectronics
2013
The commonly observed hysteresis in the transfer characteristics of MoS2 transistors is typically associated with charge traps gate insulator. Since Si technologies such can lead to severe reliability issues, we perform a combined study both as well arguably most important issue, bias-temperature instability. We use single-layer FETs SiO2 and hBN insulators demonstrate that phenomena are indeed due insulator time constants distributed over wide timescales, where faster ones slower...
Black phosphorus has been recently suggested as a very promising material for use in 2D field-effect transistors. However, due to its poor stability under ambient conditions, this not yet received much attention instance MoS2. We show that the demonstrated Al2O3 encapsulation leads highly stable devices. In particular, we report our long-term study on black transistors, which device characteristics at least eight months. This high allows us perform detailed analysis of their reliability with...
Electronic devices based on two-dimensional semiconductors suffer from limited electrical stability because charge carriers originating the interact with defects in surrounding insulators. In field-effect transistors, resulting trapped charges can lead to large hysteresis and device drifts, particularly when common amorphous gate oxides (such as silicon or hafnium dioxide) are used, hindering stable circuit operation. Here, we show that graphene-based transistors be improved by Fermi-level...
We report considerable improvement in the hysteresis and reliability of single-layer MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> field-effect transistors (FETs) achieved by chemical vapor deposition (CVD) dielectric encapsulation. Our results show that a high-quality 15-nm thick Al O xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> layer allows for an efficient protection devices from adsorbent-type trapping sites. Combined use...
Abstract The continuous miniaturization of field effect transistors (FETs) dictated by Moore's law has enabled enhancement their performance during the last four decades, allowing fabrication more powerful electronic products (e.g., computers and phones). However, as size FETs currently approaches interatomic distances, a general stagnation is expected, new strategies to continue trend are being thoroughly investigated. Among them, use 2D semiconducting materials channels in raised lot...
The performance of MoS2 transistors is strongly affected by charge trapping in oxide traps with very broad distributions time constants. These defects degrade the mobility and additionally lead to hysteresis gate transfer characteristics, which presents a crucial reliability issue for these new technologies. Here we perform detailed study double-gated FETs show that this nothing else than combination threshold voltage shifts resulting from positive negative bias-temperature instabilities....
Abstract Black phosphorus is considered a very promising semiconductor for two-dimensional field-effect transistors. Initially, the main disadvantage of this material was thought to be its poor air stability. However, recent studies have shown that problem can solved by suitable encapsulation. As such, long-term outstanding properties black devices become possible. In particular, here we examine highly-stable transistors and demonstrate they exhibit reproducible characteristics at least 17...
MoS2 has received a lot of attention lately as semiconducting channel material for electronic devices, in part due to its large band gap compared that other 2D materials. Yet, the performance and reliability these devices are still severely limited by defects which act traps charge carriers, causing reduced mobilities, hysteresis, long-term drift. Despite their importance, only poorly understood. One fundamental problem defect characterization is concentration average response bias changes...
Abstract Mechanically exfoliated 2D hexagonal boron nitride (h‐BN) is currently the preferred dielectric material to interact with graphene and transition metal dichalcogenides in nanoelectronic devices, as they form a clean van der Waals interface. However, h‐BN has low constant (≈3.9), which ultrascaled devices results high leakage current premature breakdown. Furthermore, synthesis of using scalable methods, such chemical vapor deposition, requires very temperatures (>900 °C) ,...
Even though the hysteresis in gate transfer characteristics of two-dimensional (2D) transistors is a frequently encountered phenomenon, physics behind it are up to now only barely understood, let alone modeled. Here, we demonstrate that phenomenon can be captured accurately by previously established non-radiative multiphonon model describing charge capture and emission events surrounding dielectrics. The embedded into drift-diffusion based TCAD simulation environment, which was adapted 2D...
2D photodetectors can considerably outperform their Si counterparts and thus appear promising for contemporary optoelectronic circuits. However, limited charge separation efficiency poor optical absorption make it complicated to create ultrasensitive broad response using a single material. While hybrid heterostructures combining 1D materials could be solution, previously used binary/binary 1D/2D have performance that is merely satisfactory at best. To address these limitations, here we the...
We present a detailed analysis of the bias-temperature instability (BTI) single-layer graphene field-effect transistors. Both negative BTI and positive can be benchmarked using models developed for Si technologies. In particular, recovery follows universal relaxation trend described established capture/emission time map approach. thereby propose general methodology assessing reliability graphene/dielectric interfaces, which are essential building blocks devices.
Two-dimensional (2D) semiconductors are currently considered a very promising alternative to Si for channel applications in next-generation field-effect transistors of sub-5 nm designs. However, their huge potential cannot be fully exploited owing lack competitive insulators which required effectively separate the from gate, while being scalable down few nanometers thicknesses. Recently we have made an attempt at addressing this issue by using crystalline CaF2 and demonstrated MoS2 devices...
Abstract Recent advances in fabricating field-effect transistors with MoS 2 and other related two-dimensional (2D) semiconductors have inspired the industry to begin integration of these emerging technologies into FAB-compatible process flows. Just like lab research on 2D devices performed last decade, focus during development is typically put pure technology-related issues, such as low-temperature growth methods large-area films target substrates, damage-free transfer from sacrificial...
Abstract Graphene is a promising material for applications as channel in graphene field-effect transistors (GFETs) which may be used building block optoelectronics, high-frequency devices and sensors. However, these require gate insulators ideally should form atomically flat interfaces with at the same time contain small densities of traps to maintain high device stability. Previously amorphous oxides, such SiO 2 Al O 3 , however, typically suffer from oxide dangling bonds interface, surface...
For optimal integration of 2D materials into fab-compatible processes, it is essential to grow them directly onto suitable insulating substrates, thereby avoiding error-prone transfer procedures. In the present paper, ultrathin films WS2 were grown on Al2O3 using laser molecular beam epitaxy (LMBE). By applying our advanced 3D reciprocal space mapping technique, presence long-range order in growing layers during growth process could be identified. We observed a strong influence pre-growth...
Metal/CaF2/p-Si(111) capacitors with the improved-quality several-nanometer-thick epitaxial fluorite films are examined, aiming at solidifying a candidacy of this material for barrier layers in silicon devices. Structural and transport properties thin crystalline dielectric characterized by different experimental techniques. The measured current-voltage characteristics accompanied simulation results demonstrate that elastic tunneling electron injection takes place considered structures. same...