bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Dielectric Science & Technology Thomas Callinan Award) Materials and Processes As Enablers for Moore Moore and Beyond Moore Technologies
Authors: De Gendt Stefan 
Published: July 2022

In this presentation, an overview will be presented of historic and recent developments achieved w.r.t. materials and processes that enabled continued performance scaling of CMOS and beyond CMOS applications. Starting from early high-k work. For decades, thermal oxidation of crystalline Silicon into SiO2 has been the gate oxide material in CMOS technology. Miniaturization for performance improvement, required the gate dielectric to decrease in thickness to support the required increase in capacitance (per unit area) and drive current (per device width). Early 2000, the thickness scaled below 1.5 nm, causing drastically increased leakage currents, high power consumption and reduced device reliability. Replacing the SiO2 gate dielectric with a high-κ (dielectric constant) material allows increased gate capacitance without the associated leakage effects. Activities involved the unit process step development of dielectric and metal deposition processes, advanced interface preparation, electrical and physical characterization and wet and dry etch process development. In a second section, emphasis will be on emerging nanomaterials. Nanotechnology is defined as the manipulation of matter with at least one dimension sized from below 100nm, thus all CMOS activities are functional nanotechnology. The latter concentrated initially on Graphene, but extended further towards Transition Metal Dicalchogenide Materials. Emphasis of the work will be on growth, functionalization, dielectric passivation and doping of these materials. Lastly, expanding on the nanomaterial know-how also progress with regard to low-k dielectrics, area selective deposition processes (for bottom-up lithography) and application of nanochemistry research for photoresist material screening, where chemical interactions at the nanoscale, related to the EUV lithography (radiation chemistry) are hampering the pattern scaling.
Throughout the presentation, recognition will be given to people (PhD students) that contributed to this work and the presentation is also in honor of Prof Dolf Landheer and Professor Samares Kar with whom I organized my first ECS symposium.
(Digital Presentation) Silver Nanoparticles Coated Membrane Scaffolds and Fabric Materials as a New Generation of Antiviral Surface Protection Against COVID-19
Authors: Youssef Mohamed F. , Kalil Haitham , Samir Omar , Maher Shaimaa , El-falouji Abdullah I. , Gad Emad 
Published: July 2022

One of 2019's biggest scientific challenges is the coronavirus disease (COVID-19). The current COVID-19 epidemic is still a point of interest of all researchers from every field in the hope of finding a way to have it under control. COVID-19 vaccine development is a lengthy procedure that requires several clinical studies to prove its efficacy and overcome the virus mutations. Personal Protective Equipment (PPE) as masks and gloves are essential for moving the battle out of one's body. Developing a highly efficient PPE is crucial, not only to reduce the spread of virus, but also to protect people who work at the frontline.
Virus infection is one of the most serious public health problems facing the world today. Between now and then, several antiviral medicines have been tested to determine their effectiveness as prospective COVID-19 treatments. The rise of viral resistance, as well as the adverse effects associated with antiviral medications, are posing further hurdles, resulting in a decrease in their efficiency as antiviral treatments. This opens the possibility for developing an alternative antiviral material that is both safe and effective. When it comes to their potential to destroy a wide range of viruses, silver nanoparticles (Ag-NPs) laden fiber mats have emerged as a novel antiviral platform, according to the findings of the current study. In the past, Ag-NPs have been extensively examined for their antibacterial properties against a wide range of microorganisms. Their ability to combat hepatitis B and HIV has also been demonstrated to be encouraging, as has their ability to inhibit other viruses such as herpes simplex, monkey pox, and respiratory syncytial virus. Here, we tested the potential effect of silver nanoparticles as an alternative antiviral therapeutic based on their unique properties. When compared to imitative antivirals, elemental silver nanoparticles have the ability to attack many virus sites, reducing the likelihood of the virus developing resistance.
Our group has been developing silver nanoparticles loaded on toilet paper seat sheets, cellulose membranes, polymer dressings, and cotton textiles in response to the persistent issue. The new generation of fiber mats will be thoroughly described and tested against SARS-CoV-2 virus. SEM, EDS, TEM, and DLS will be utilized to identify the shape of our fibers and estimate the particle size of the embedded nanoparticles.
(Invited, Digital Presentation) High-κ Gate Oxide Integration and Ohmic Contact Development for AlGaN/GaN MISHEMTs
Authors: Seidel Sarah , Garbe Valentin , Schmid Alexander , Heitmann Johannes 
Published: July 2022

GaN based devices are one of the main candidates for current power electronics and RF applications [1,2]. For optimizing device performance, a detailed understanding of the defects contained in the material and the passivation capability of dielectric layers, i.e., the interfacial defect states formed, is mandatory. Here, we will focus on the surface defect passivation and gate leakage current reduction by introducing thin dielectric films as gate insulator in a so-called MISHEMT (metal insulator semiconductor high electron mobility transistors) device using different materials. The impact of a fully amorphous dielectric (Al2O3), which was kept amorphous by the integration of a low thermal budget ohmic contact [3], was compared to an epitaxial dielectric film (GdScO3) [4]. Due to the band alignment and the high dielectric constant of GdScO3, the spillover effect as it was seen for Al2O3 [5] has been suppressed and a reduction of threshold voltage shift due to the additional capacitance by the dielectric layer has been achieved. In addition, AlTiOx films were investigated as gate dielectrics [6]. To avoid further deterioration of the dielectric layer by the ohmic contact formation anneal, a gate last integration scheme was carried out using Ti based gold free ohmic source and drain contacts [7]. By varying the Al content, the band alignment between the underlying GaN capping layer to the thin film dielectric was controlled. By this means and additional charge engineering in the dielectric layer, a gate leakage reduction with limited threshold voltage increase has been realized. All dielectric layers have been electrically characterized in detail. Interface trap densities were measured by photo-assisted capacitance voltage measurements and an in-depth comparison of the dielectric layers and their impact on the device performance will be given.
[1] Yole Developpement, RF GaN Market: Applications, Players, Technology and Substrates 2019, Market & Technology Report, (2019)
[2] T. Kimoto, Jpn. J. Appl. Phys. 54, 40103 (2015).
[3] Schmid, A.; Schröter, Ch.; Otto, R.; Schuster, M.; Klemm, V.; Rafaja, D.; Heitmann, J., Appl. Phys. Lett. 106, 053509 (2015)
[4] Seidel, S., Schmid, A., Miersch, C., Schubert, J., Heitmann, J. Appl. Phys. Lett., 118(5), 052902 (2021)
[5] P. Lagger, P. Steinschifter, M. Reiner, M. Stadtmüller, G. Denifl, A. Naumann, J. Müller, L. Wilde, J. Sundqvist, D. Pogany, C. Ostermaier, Appl. Phys. Lett. 105, 033412 (2014)
[6] N Siebdrath, S. Seidel, A. Schmid, J. Heitmann, Mikro-Nano-Integration; 8th GMM-Workshop, 2020, pp. 1-3.
[7] Garbe, V.; Schmid, A.; Seidel, S.; Abendroth, B; Stöcker, H.; Doering P.; Meyer, D.C.; Heitmann, J., Phys. Stat. Sol. (B), 2100312 (2021)
(Invited) Magneto-Ionic Control of Heterostructures and Interfaces
Authors: Liu Kai 
Published: July 2022

Magneto-ionics has shown promise for energy-efficient nanoelectronics, where ionic migration can be used to achieve atomic scale control of interfaces in magnetic nanostructures, and in turn modulate a wide variety of functionalities. Recently, we have discovered that chemisorbed oxygen and hydrogen on the surface of ferromagnetic films can induce significant Dzyaloshinskii–Moriya interaction (DMI) [1], a handle to introduce topology into nanoscale magnets. This has enabled direct tailoring of skyrmions winding number as well as wall type at room temperature via oxygen chemisorption. We have also demonstrated a sensitive and reversible chirality switching of magnetic domain walls [2] and writing/deleting of skyrmions [3] via hydrogen chemisorption/desorption. These chemisorption induced magnetic effects on controlled ferromagnet surfaces offer an ideal platform to gain quantitative understanding of magneto-ionics at buried interfaces, where the ionic motion can be further controlled by an electric field [4]. These effects are relevant for 3-dimensional information storage as a potentially contactless way to address spin textures, such as in interconnected nanowire networks [5]. Interestingly, nanoporous metal foams made of random assemblies of nanowires have found applications in deep-submicron particulate filtration, relevant to combatting COVID-19 and air pollution. Such foams are efficient, breathable, light-weight, robust, and can be reused and recycled [6]. Our mask design based on such foams has been selected by BARDA-NIOSH as a Phase 1 Winner of the Mask Innovation Challenge [7].
[1] Science Advances, 6, eaba4924 (2020).
[2] Physical Review X, 11, 021015 (2021).
[3] DOI: https://doi.org/10.21203/rs.3.rs-575830/v1
[4] ACS Applied Materials and Interfaces, 13, 38916−38922 (2021).
[5] Nano Letters, 21, 716-722 (2021).
[6] Nano Letters, 21, 2968-2974 (2021).
[7] https://drive.hhs.gov/mask_challenge.html.
This work has been supported by the NSF (DMR-1905468, DMR-2005108, ECCS-1933527), the nCORE SMART center through SRC/NIST, the University of California and Georgetown University.
(Digital Presentation) Evaluation of the O3 and H2o Oxidants in Downscaling Eot of Ferroelectric Hf0.5Zr0.5O2 on Silicon
Authors: Hernandez-Arriaga Heber , Mohan Jaidah , Jung Yong Chan , Kim Jin-Hyun , Rho Chang-Han , Choi Rino , Kim Jiyoung 
Published: July 2022

Integrating the HfZrO2 (HZO) on silicon have attracted the attention of researches in the development of ferroelectric field effect transistor (FeFETs) for implementation in high-density memories and neuromorphic devices[1][2]. In this work, it has been investigated the thickness scalability of HZO thin films and the reduction of the equivalent-oxide-thickness (EOT) on Silicon using [(CH3)2N]4Hf and [(CH3)2N]4Zr as precursor and H2O and O3 as oxidants by means of atomic layer deposition. A TiN/HZO/Si structure was fabricated where the Si substrate has been prepared with a HF-last clean to remove the native oxide or SC1-last clean process to form a chemical oxide layer of 1.2nm. The EOT vs thickness analysis shows an interesting alteration in the dielectric constant which is understood as a phase formation in the HZO from the amorphous to the ferroelectric o-phase to be found in the 4 to 5nm region when annealed at 400 °C. Also, the interface thickness between silicon and HZO was reduced when the HZO is scaled down below the transition region and it is confirmed by transmission electron microscopy (TEM). This reduction in the interface is expressed as scavenging effects from the TiN top electrode when the samples are annealed at 400 °C.
[1] J. Y. Kim, M.-J. Choi, and H. W. Jang, “Ferroelectric field effect transistors: Progress and perspective” APL Mater., 9, 021102 (2021)
[2] E. T. Breyer, H. Mulaosmanovic, T. Mikolajick, and S. Slesazeck, “Perspective on ferroelectric, hafnium oxide based transistors for digital beyond von-Neumann computing,” Appl. Phys. Lett, 118, 050501 (2021)
(Invited, Digital Presentation) Exploring New Applications of Luminescent Silicon Nanocrystals
Authors: Pi Xiaodong 
Published: July 2022

The luminescence of silicon nanocrystals (Si NCs) has been traditionally studied for various applications such as light-emitting diodes, solar cells and bioimaging[1]. In the past few years we have started exploring the use of Si NCs for emerging optoelectronic synaptic devices[2,3]. As an important type of optoelectronic synaptic devices, electroluminescent synaptic devices have been fabricated by using Si NCs[4,5]. Under the stimulation of electrical spikes these devices give out electroluminescence that decays in the timeframe of tens of microseconds, enabling a series of synaptic functionalities and logic functions. In addition, we have synthesized Er-hyperdoped Si NCs, which emit light simultaneously at the wavelengths of 830 and 1540 nm. It is found that Er-hyperdoped Si NCs are a powerful ratiometric near-infrared fluorescent platform. The rationmetric near-infrared fluorescence may be well used for temperature sensing, which further enables the construction of logic gates[6].
[1] Z. Y. Ni, et al., Materials Science & Engineering R 138, 85-117 (2019).
[2] L. Yin, et al., Nano Letters 20, 5, 3378–3387 (2020).
[3] Y. Wang, et al., Advanced Functional Materials 2107973 (2021).
[4] S. Y. Zhao, et al., Nano Energy 54, 383-389 (2018)
[5] S. Y. Zhao, et al., Science China Materials 62, 1470-1478 (2019)
[6] K. Wang, et al., to be submitted.
(Invited) SiGe/SOI System: Mechanisms of Condensation and Strain Relaxation
Authors: Favre Luc , Bouabdellaoui Mohammed , Assaf Elie , Guelil Imene , Ronda Antoine , Berbezier Isabelle 
Published: July 2022

Silicon-Germanium strain engineering has been used for more than two decades in silicon based devices and has contributed to the scaling down of a transistor’s size and to significant improvements in device performance. However, while conventional silicon-germanium based electronics has experienced rapid and steady growth, thanks to this continuous miniaturization of transistors, this trend cannot continue indefinitely. Industry has already moved to alternate methods such as FinFET devices, in which a thin silicon channel is placed vertically, and the FD-SOI (FD-SGOI) design consisting of a thin film Si(SiGe) channel placed horizontally. For nodes scaled down below 28 nm, low power operation will be inherently hindered by both the imperfect interface, non-uniformity of ultra-thin films and quantum confinement effects, which increase the effective bandgap. In these devices, despite the intense research activity on the strained SiGe ultra-thin body, which accounts for a large portion of such microelectronic devices (below the 45 nm node), we still fail to properly understand the mechanisms that limit hole and electron mobilities in SGOI layers. In addition, one of the main challenges for Si based devices remains the fabrication of efficient group-IV photon sources / photon detectors compatible with the microelectronic industry, which would usefully replace the integration of III-V heterostructures on Si. The major bottleneck is that group-IV semiconductor elements have indirect bandgaps, but with possibilities of being transformed to direct bandgaps using strain engineering strategies.
In this presentation, we will review the formation mechanism of Ge-rich layers on SOI by condensation at different temperatures. TEM cross-section and GPA analysis of the heterostructures will be presented. We will also report the physical and optical properties of these heterostructures. Special attention is devoted to the influence of the SiGe thickness reduction (up to few MLs), where quantum confinement is prominent in the optical properties of the layers. Raman and PL results will be presented to better explain such confinement behavior. We show that novel SGOI substrates could represent a key strategy for the fabrication of future photonic devices.
Electrodeposition of Cu-Zn and Cu-Mn Films As Precursors for Nanoporous Copper Synthesis
Authors: Castillo Ezer , Dimitrov Nikolay 
Published: July 2022

An all-electrochemical approach for the synthesis of fine-structured nanoporous copper (np-Cu) films has been developed which involves the initial electrodeposition of Cu-containing alloys followed by a selective dissolution or dealloying of the less noble metal via anodization. This process leaves a nanoporous, three-dimensional spongy structure. Among these alloys are Cu-Zn and Cu-Mn that are commonly used as protective and decorative coatings. These types of coatings are typically rich in Cu; however, precursor alloys for dealloying purposes must contain high atomic percentages (at%) of the less noble metal. Here, we present the controlled electrodeposition of Cu-Zn and Cu-Mn alloys with Zn and Mn contents of ≥ 60 at% and ≥ 70 at%, respectively, as precursors for np-Cu synthesis.
The co-electrodeposition of Cu-Zn and Cu-Mn alloys were achieved in baths containing pyrophosphate and ammonium sulfate, respectively. These electrolytes serve as a source of ligands that form complexes with Cu (i.e. [Cu(P2O7)]2- and [Cu(NH3)
n
]2+). The use of the complexing agent is necessary to shift the reduction potential of Cu2+ negatively towards that of Zn2+ or Mn2+, thereby decreasing the large deposition potential difference between the two respective metals. The complexation of Cu in either bath was confirmed by voltammetric and spectroscopic studies.
A systematic potentiostatic electrodeposition study revealed that the optimal plating potential for Cu-Zn is at -2.0 V vs. Hg/HgSO4 with an efficiency of 63–73%. At this potential, the alloy composition is tunable by adjusting the respective percent compositions of the Cu2+ and Zn2+ salts in the deposition bath, thereby producing highly crystalline, Zn-rich alloys that are suitable for dealloying purposes (1). For Cu-Mn, galvanostatic deposition at current densities of 100–200 mA⋅cm-2 gave crystalline deposits with low plating efficiencies (<30%) due to the concurrent hydrogen evolution reaction. Nonetheless, Mn-rich alloys were obtained by also varying the concentration ratio of the Cu2+ and Mn2+ salts in the ammine bath (2). The optimization of the Cu-Zn and Cu-Mn alloy plating parameters and conditions including the structural and compositional characterization will be discussed in detail.
References:

Castillo and N. Dimitrov, “Electrodeposition of Zn-Rich CuxZn(1-x) Films with Controlled Composition and Morphology” J. Electrochem. Soc., 2021, 168, 062513.

Castillo and N. Dimitrov, “Electrodeposition of Cu-Mn Films as Precursor Alloys for Nanoporous Cu Synthesis” Electrochem, 2021, 2 (3), 520-533.
Glassy Carbon Electrode Modified with Au Nanoparticles Electrodeposited from Au(III) Dissolved in a Deep Eutectic Solvent and Its Analytical Performance Towards Dopamine Quantification
Authors: Godoy-Colin Estefania , Corona-Avendaño Silvia , Vázquez-Huerta Gerardo , Ramírez-Silva María Teresa , Aldana-González Jorge , Romero-Romo Mario , Palomar-Pardave Manuel Eduardo 
Published: July 2022

In this work, the surface of a glassy carbon electrode (GCE) was modified with gold nanoparticles (AuNPs), by potentiostatic electrodeposition, from Au (III) ions dissolved in a deep eutectic solvent formed by choline chloride and urea (reline) at 70 °C. Using electrochemical techniques, both potentiodynamic and potentiostatic, the mechanism and kinetics of the AuNPs nucleation and growth was determined. It was found that the experimental total current density transients jtotal(t) can be adequately describe by a model that Involves adsorption, jad(t), and 3D nucleation and diffusion-controlled growth, j
3D-dc(t),1 see Figure 1a. Furthermore, the modified electrode (GCE/AuNPs) was used in the evaluation of the electrochemical response of dopamine (DA) by means of cyclic voltammetry (CV) and differential pulse voltammetry (PDV) techniques. The results obtained showed that GCE/AuNPs electrode has a greater catalytic activity towards the electrochemical oxidation of DA, with a sensitivity of 129 , see Figure 1b, which is greater than that shown by the bare GCE and comparable to the performance reported for an ITO/AuNPs electrode.2 As well as the presence of a displacement of the oxidation peak towards lower potentials when using the GCE/AuNPs with respect to the bare GCE, which is indicative that GCE/AuNPs requires less energy for the oxidation of DA.

References

[1] C. Ramírez, E.M. Arce, M. Romero-Romo, M. Palomar-Pardavé. The effect of temperature on the kinetics and mechanism of silver electrodeposition. Solid State Ionics. 169 (2004) 81–85.
[2] J. Aldana-González, M. Palomar-Pardavé, S. Corona-Avendaño, M.G. Montes de Oca, M.T. Ramírez-Silva, M. Romero-Romo, Gold nanoparticles modified-ITO electrode for the selective electrochemical quantification of dopamine in the presence of uric and ascorbic acids, Journal of Electroanalytical Chemistry 706 (2013) 69–75

Figure 1
(Invited) Epitaxial Electrodeposition of Wide Bandgap Semiconductors for Transparent and Flexible Electronics
Authors: Switzer Jay , Banik Avishek , Luo Bin 
Published: July 2022

Single-crystal silicon is the bedrock of semiconductor devices due to the high crystalline perfection that minimizes electron-hole recombination, and the dense SiOx native oxide that minimizes surface states. One issue with the material is that it is both brittle and opaque. There is interest in moving beyond the planar structure of conventional Si-based chips to produce flexible and transparent electronic devices such as wearable solar cells, sensors, and flexible displays. In this talk we will discuss the electrodeposition of transparent, wide bandgap semiconductors such as ZnO, CuI, and CuSCN that can be produced as epitaxial films on single-crystal and single-crystal-like substrates. These epitaxial films have an orientation that is controlled by the substrate, with electronic properties that mimic those of single crystals. The talk will emphasize the electrodeposition of the wide bandgap hole conductors CuI and CuSCN. They are electrodeposited by electrochemically reducing Cu(II)EDTA to Cu(I) in the presence of either iodide or thiocyanate anions. Cubic CuI deposits as dense films on Si(111), and CuSCN deposits as nanowires on Au(111). The CuI is epitaxial on the Si(111) in spite of a 2.4 nm thick interfacial SiOx layer. The rectifying p-CuI/SiOx/n-Si heterojunction diode shows an ideality factor of 1.5, a built-in voltage of 0.67 V, and a barrier height of 0.91 eV. The crystal structure and morphology of the CuSCN nanowires can be controlled by varying the SCN-/Cu(II) ratio in solution (see Fig. 1). We also show that the epitaxial films can be removed by a simple lift-off procedure to produce single-crystal-like flexible foils of transparent semiconductors.
Fig. 1 – Controlling the crystal structure and morphology of CuSCN nanowires through the SCN-/Cu(II) ratio in solution. Top micrographs are of rhombohedral CuSCN deposited using SCN-/Cu(II) = 4, and the bottom micrographs are of hexagonal CuSCN deposited using SCN-/Cu(II) = 2. The nanowires were both on Au(111), and were deposited at a potential of -0.4 V vs. Ag/AgCl.

Figure 1