bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Dielectric Science and Technology Division Poster Award, 1st Place) The Influence of Pad Micro-Features on Chemical Mechanical Polishing (CMP) Performance: Insights from Computational Fluid Dynamics (CFD)
Authors: Sadri Mofakham Atefeh , Cho Hanchul , Kim Hyongjae , Ahmadi Goodarz , Seo Jihoon 
Published: August 2024

With semiconductor chip dimensions shrinking below 7 nanometers, Chemical Mechanical Planarization (CMP) becomes more critical [1], [2]. To meet the increasing demand for precision and uniformity in the fabrication of wafers and chips, enhancements in CMP consumables and operating conditions are necessary. To address these requirements, novel pad designs have been developed, particularly those that do not require conditioning [3]. It is known that the CMP polishing rate depends on pressure, pad wafer relative velocity, and the distribution of pad asperities [4]. As conventional pads provide small and random contact areas, the external pressure applied by the head determines the material removal rate (MRR) [5] Advanced pads with micro-features provide more contact areas and help deliver consistent pressure and slurry distribution during Chemical Mechanical Polishing (CMP) [6], [7]. This study uses computational fluid dynamics (CFD) to simulate the flow between pad and wafer surfaces to determine how pad surface micro-features affect the CMP process. The abrasive residence time, total fluid pressure, and slurry flow velocity are evaluated for four distinct pad micro-feature geometries: square, square-circle, circle, and ellipse. Increasing the number of edges in the pad micro-feature patterns increases pressure drop, leading to more interaction between pad and slurry and enhancement of MRR. The findings of this study confirm the effectiveness of micro-featured pads in optimizing CMP processes and provide valuable insights into the influence of microfeature geometries on critical parameters for improving the semiconductor fabrication process.
[1] J. Seo, Journal of Materials Research, 36, 235–257, Jan, 2021.
[2] B. Suryadevara, Advances in Chemical Mechanical Planarization (CMP). Woodhead Publishing, 2021.
[3] S. Lee and E. Hwang, “Smart pad fabrication for CMP,” LMA Res Rep, vol. 10, pp. 100–104, 2002.
[4] G. Ahmadi and X. Xia, J Electrochem Soc, 148, G99, 2001.
[5] X. Xia and G. Ahmadi, Particulate Science and Technology, 20, 187–196, 2002.
[6] S. Lee, G. Kim, M. Mcgahay, H. Kim, and H. Cho, “Pad Designs-To navigate the fundamentals of CMP.”
[7] M. Mcgahay, G. Kim, S. Lee, H. Cho, and H. Kim, “Critical Feature Size of Polishing Pad and Its Performance.”
Bridging Technology and Environment: Sustainable Approaches in Semiconductor Chemical Mechanical Planarization (CMP)
Authors: Seo JIhoon 
Published: August 2024

As semiconductor technologies continue to advance in areas such as autonomous driving, artificial intelligence, 5G communications, the Internet of Things, and large-scale data processing, the demand for a reliable semiconductor industry is on the rise.(1) This growing demand necessitates the use of advanced device architectures, which heavily rely on two crucial processes: Chemical Mechanical Planarization (CMP) and post-CMP cleaning.(2)
This talk will focus on the development of CMP slurries and post-CMP cleaning solutions, emphasizing their vital roles in these processes. We will delve into the comprehensive development of CMP slurries and post-CMP cleaning solutions, highlighting how synthesis methods can significantly affect the surface chemistry of ceria abrasives and impact the removal rates of SiO2 surfaces during STI CMP.(3, 4)
Our research also demonstrates how our cleaning solutions can effectively remove even the most 10 nm-sized ceria particles from SiO2 surfaces,(5) thereby enhancing process efficiency. Furthermore, we will discuss the use of aliphatic amino acids as environmentally friendly corrosion inhibitors in CMP slurries, offering a sustainable alternative to the traditionally used benzotriazole (BTA) and addressing key environmental challenges.(6) In the context of the rapidly expanding semiconductor industry, it becomes critical to address global sustainability concerns and environmental health and safety (EHS) objectives. Our research proposes a comprehensive methodology for evaluating the sustainability of CMP consumables in semiconductor manufacturing, with a primary focus on CMP slurries due to their significant market share and shorter usage lifetimes. This research serves as a foundation for future CMP sustainability analyses, encouraging self-correction strategies within the CMP community to reduce environmental impact. We will also introduce a robust framework for the Life Cycle Assessment (LCA) of CMP consumables, marking a crucial step toward achieving these sustainability goals. In summary, this talk will explore the intricate details of CMP and post-CMP processes, their pivotal roles in the advancement of semiconductor manufacturing, and the imperative task of aligning these processes with environmental and sustainability objectives.
This talk is dedicated to the special session in honor of Prof. Babu.

S. Babu, Advances in Chemical Mechanical Planarization (CMP), Woodhead Publishing (2021).

J. Seo, Journal of Materials Research, 36, 235 (2021).

J. Seo, J. W. Lee, J. Moon, W. Sigmund and U. Paik, ACS applied materials & interfaces, 6, 7388 (2014).

J. Seo, J. H. Kim, M. Lee, J. Moon, D. K. Yi and U. Paik, Journal of colloid and interface science, 483, 177 (2016).

J. Seo, A. Gowda and S. Babu, ECS Journal of Solid State Science and Technology, 7, P243 (2018).

H. T. T. Tran, J. Gichovi, E. J. Podlaha and J. Seo, in Electrochemical Society Meeting Abstracts 243, p. 1809 (2023).
Decoding CMP Challenges: A Metrospection Insight
Authors: Ramakrishnan Suresh 
Published: August 2024

We live in a digitally connected world with Global data to exceed 180 ZB by 2025 per some estimates1. Memory is the fiber connecting our world. New applications drive continued demand growth for memory and storage applications. Micron is a leader in the memory and storage industry, helping the world use information to enrich lives. As memory devices scale and new memory technologies arise, the requirements for Chemical Mechanical Planarization (CMP) processes are becoming tighter and more stringent node over node. Furthermore, memory scaling continues to become more dependent upon CMP, with not only a steady increase in the number of CMP steps but that of unique CMP steps as well node over node. In this presentation we focus on CMP challenges from a METROSPECTION (Metrology & Inspection) lens. We explore the critical role of inspection and metrology techniques in optimizing CMP for semiconductor memory fabrication. The ability and need for the integration of cutting-edge inspection techniques and metrology strategies emerges as a pivotal element in enhancing CMP cycles of learning and hence the reliability, yield, and overall quality of semiconductor memory devices.
1 - Statista
Dielectric Materials As Optical Emitters for Thermophotovoltaics
Authors: Leite Marina , Kopper Declan 
Published: August 2024

Thermophotovoltaics (TPV) are a promising route for converting heat generated as a byproduct into usable electricity through a clean energy paradigm. A primary challenge in the field is that the material options used to date for the optical emitters substantially constrain the power conversion efficiency of this process. Thus, we screened the optical response (i.e. permittivity) of >2,800 material combinations with melting point >2,000 oC, comprising refractory silicides, borides, carbides, nitrides, oxides, and metals [1]. Overall, the mismatch in permittivity allowed for emission control, key for the development of high performing TPV. We found a handful of emitters for TPV with theoretical efficiency >60% at 1800 oC, for GaSb solar cells. To complement our analysis, we also identified optimal material combinations for InGaAsSb, InGaAs, Ge, GaSb, and Si photovoltaic devices. The final down selection of materials is also based on their thermal expansion and thermochemical stability, which are frequently overlooked. The discussion of the best material options will be accompanied by the optical characterization of selected materials up to 1500 oC, using in situ reflection and transmission measurements [2]. Finally, we will discuss the specific case of SiC/AlN emitters for the abovementioned photovoltaic options [3].
References:
[1] M. R. S. Dias et al, Joule 7, 2209 (2023)
[2] T. Gong et al. ACS Appl. Optical Materials 1, 1615 (2023)
[3] M. Duncan, et al. In preparation (2024)
(Invited) Next-Generation Photonic Source Based on Lateral GaAs/AlgaAs Heterostructure Devices
Authors: Sfigakis Francois , Wasilewski Zbig , Reimer Michael , Baugh Jonathan D 
Published: August 2024

Quantum communications and remote sensing protocols rely on preparing individual quanta of light, or photons, as carriers of quantum information. While it is easy to generate many-photon classical states of light (e.g., a light bulb or a laser), it is challenging to generate single quanta or pairs of entangled quanta on-demand. Yet, only in this latter regime can the fundamentally quantum nature of light be exploited to achieve performance exceeding classical bounds.
We are developing a single-photon source based on combining a one-parameter single electron pump (Figure 1a,b) – an electrically controlled, on-demand, high-fidelity emitter of single electrons [1] – with a lateral p-n junction [2] (Figure 1c,d) in which injected single electrons recombine with holes to produce single photons. These devices are realized in undoped GaAs/AlGaAs heterostructures and designed to be ambipolar. Such a quantum light source could lead to a paradigm shift in metrology, providing a quantum redefinition of two of the seven SI base units, the ampere and the candela. It is also possible in principle to realize scalable source arrays on a single chip. I will discuss progress towards realizing and characterizing these sources, including work on optimizing collection efficiency and Purcell enhancement using a lateral distributed Bragg reflector in a concentric ring geometry. Beyond fundamental studies, the proposed photon source will find practical use in quantum communications protocols (QKD), where it can offer fast data transmission rates, and quantum sensing with LiDAR, where it could outperform laser-based systems in the few-photon regime for low-power, stealth applications.
[1] B. Buonacorsi et al, “Non-adiabatic single-electron pumps in a dopant-free GaAs/AlGaAs 2DEG”, Appl. Phys. Lett.
119, 114001 (2021).
[2] L. Tian et al, “Stable electroluminescence in ambipolar dopant-free lateral p-n junctions”, Appl. Phys. Lett.
123, 061102 (2023).

Figure 1
(Invited) Shape Engineering of Nanostructured III-V Semiconductor Lasers
Authors: Tan Hoe 
Published: August 2024

Group III-V semiconductors have revolutionised electronics and optoelectronics due to their superior physical and optoelectronic properties including high carrier mobility, direct bandgap and band structure engineering capability. Reducing the device size to nanoscale brings many unique properties, such as large surface-area-to-volume ratio, high aspect ratio, carriers and photons confinement effect. These nanostructures have already been demonstrated for potential applications in light emitters, photodetectors, solar cells and for photoelectrochemical water splitting. However, to date most efforts on the growth of these nanostructures have been limited to nanowires.
In this talk, we demonstrate selective area growth of III-V nanostructures, showing the possibility of obtaining other functional nanostructures, beyond the limitation of rod-like geometry. We demonstrate that by changing the pattern design on the mask and growth conditions, we are able to grow and control the shapes to form nanostructures such as membranes, flowers, rings, spirals, stars, ellipses etc. These shape-engineered nanostructures open up possibilities of new applications based on devices with novel geometries.
In particular, we will show the results of our InP micro-ring lasers which have excellent cavity due to the atomically flat facets. Micro-disk and micro-ring lasers are light emitting devices that operate in the whispering gallery mode. They are important components for integrated photonics applications as light from can these devices can be efficiently coupled to on-chip waveguides. By coupling the micro-ring laser to a nanowire antenna, we further demonstrate that we can tune the emission directionality to the device.
(Invited) Modeling Cyclic Voltammetry during Solid Electrolyte Interphase Formation
Authors: Steinruck Hans-Georg 
Published: August 2024

The solid electrolyte interphase (SEI) is an electronically insulating film on anode surfaces in Li-ion batteries (LIBs), formed by the reaction of Li-ions with reduced electrolyte species [1]. The SEI leads to a reduction of the electrochemical current in heterogeneous electrochemical redox reactions at the electrode-electrolyte interface, thereby passivating the electrode surface [2]. Accordingly, the growth of the SEI is, in principle, self-limited. However, under realistic conditions, these phenomena are much more complex and not well understood.
Towards a better understanding of SEI formation and passivation, we have developed a baseline quantitative model within Butler–Volmer electrode kinetics that describes the cyclic voltammetry (CV) of a flat macroelectrode during SEI formation [3]. We assumed that the SEI, which builds up electrochemically during CV, forms a homogeneous, single-phase, electronically insulating thin film due to the corresponding current. The model is based on a dynamically evolving electron tunneling barrier with increasing film thickness. Our framework allows both the qualitative, intuitive interpretation of the characteristic features of CV measurements and the quantitative extraction of physicochemical parameters through model fitting.
In this contribution, we will introduce the basic concepts and equations of our baseline model, illustrate several examples, discuss its limitations, and provide a brief outlook for improvements and for more complex scenarios. Finally, comparisons are presented to exemplary CVs from the literature relevant to LIB science and to self-inhibition phenomena.
References
[1] P. Verma, P. Maire, P. Novák, Electrochim. Acta 2010, 55, 6332
[2] F. T. Krauss, I. Pantenburg, B. Roling, Adv. Mater. Interfaces 2022, 2101891
[3] H.-G. Steinrück, J. Chem. Phys. 2021, 154, 174703
[4] I. Bhugun, J.-M. Savéant, J. Electroanal. Chem. 1995, 395, 127
Structural Characterization of Mixed Metal Cathodes via in Operando X-Ray Diffraction
Authors: Henderson Nathan , Jones Brian 
Published: August 2024

Complex metal oxides used in lithium-based energy storage technologies undergo distinct crystallographic changes based on chemical composition, specific voltage and current states, degree of lithiation, and more. Crystallographic studies via X-ray diffraction (XRD) are a critical part of understanding structure-property relationships and engineering devices to meet specific performance requirements. For the raw electrode materials, XRD provides information about exact crystal structure (e.g. symmetry, unit cell parameters, atomic site mixing) as well as the presence of impurity phases that might arise from a poor sintering process or non-stoichiometric starting reagents. For formed devices such as button- or pouch-cells, XRD can be used in operando to measure changes in phase composition, phase quantification, and crystal lattice expansion/contraction as a function of charge state. This can provide useful information such as the level of reversibility of a device or the onset of impurity phases during aging and long cycling.
In this presentation, we will review diffraction data for case studies based on NMC electrodes and highlight key insights into reversible structural changes during device cycling. The figure attached to this abstract shows diffraction data as a function of charge state during a single charge/discharge cycle. The observed peaks show modifications to the crystalline lattice (expansion in one direction, contraction in another orthogonal direction).

Figure 1
Voltammetric Study of Phase Separating Anode Materials in Li-Ion Battery Using Phase Field Model
Authors: Hussain Umair , Swaminathan Narasimhan , Phanikumar Gandham 
Published: August 2024

The increasing demand for higher energy capacity in lithium-ion batteries has underscored the significance of modeling lithiation with alternative electrode materials, such as silicon (Si) and tin (Sn). This research addresses the need for comprehensive insights into the (dis)charging process, particularly focusing on the intricate phase transformations in the anode. Phase-field modeling has proven effective in capturing these transformations [2], revealing volumetric deformations of up to 300% during (dis)charging cycles [1]. Unfortunately, these deformations compromise material integrity, leading to reduced battery cycle life and reliability.
To address these challenges, our work presents a novel framework for modeling lithiation in materials exhibiting two-phase diffusion using phase field modeling. Unlike previous models limited to single-phase diffusion, our framework provides a more realistic representation of the diffusion process. This realism is achieved by incorporating the time-dependent voltage applied to the anode, a crucial factor in understanding the electrochemical response during lithiation [3].
Furthermore, we leverage the currents generated during the lithiation and delithiation processes to conduct a comprehensive voltammetric study. This study goes beyond existing research by considering the impact of phase separation on the currents developed during Li-ion battery operation. Our findings aim to contribute valuable insights into optimizing battery performance and addressing challenges associated with phase transformations, ultimately advancing the development of high-capacity anodes for lithium-ion batteries.

REFERENCES

[1] McDowell M. T., Lee S. W., Nix W. D., Cui Y. 25th Anniversary Article: Understanding the Lithiation of Silicon and Other Alloying Anodes for Lithium-Ion Batteries. Adv. Mater., Vol. 25 (36), pp. 4966–4985, 2013.
[2] Chen L., Fan F., Hong L., Chen J., Ji Y. Z., Zhang S. L., Zhu T., Chen L. Q. A Phase-Field Model Coupled with Large Elasto-Plastic Deformation: Application to Lithiated Silicon Electrodes. J. Electrochem. Soc., Vol. 161 (11), pp. F3164–F3172, 2014.
[3] Swaminathan, N., Balakrishnan, S., & George, K. Elasticity and Size Effects on the Electrochemical Response of a Graphite, Li-Ion Battery Electrode Particle. Journal of The Electrochemical Society, 163(3), A488–A498, 2016.

Figure 1
Designing High Stability Fluorinated Materials to Replace Carbonate Additives in Li-Ion Batteries Under Extreme Test Conditions
Authors: Usrey Monica Lee , Du Peng , Johnson Tobias , Kerber Brian M , Zhou Liu (Amy) , Guillot Sarah Lucienne , Homa Arthur , Sriramulu Suresh 
Published: August 2024

Graphite-based Li-ion batteries require the formation of a solid electrolyte interphase (SEI) on the surface of the anode to prevent solvent co-intercalation and graphite exfoliation. Materials such as vinylene carbonate (VC) and fluoroethylene carbonate (FEC) that have been successfully deployed as SEI layer forming additives show limited utility under high voltage and high temperature conditions due to low electrochemical and/or thermal stability.1-3 Development of Li-ion batteries that meet the needs of automotive and other electrification applications require advanced electrolyte additives that can support operation under extreme conditions.
Koura has developed fluorinated additives that demonstrate improved stability and performance over conventional SEI layer forming additives under the high temperature and high voltage conditions relevant to the automotive industry. In this study, the performance of Koura’s fluorinated additives was compared to common commercial additives in the multiple cell designs, including 4.3V Gr/NMC811, to identify candidates to replace VC and FEC. Testing included 45°C cycling and 60°C storage. It has been found that these materials reduce gassing and increase capacity retention during high-temperature battery operation.
To gain a fundamental understanding of how these molecules function in the battery, including mechanisms of solvation, interfacial behavior, and bulk reactivity; and how the structure of the molecule contributes to its properties and behavior, comprehensive post-test analysis was conducted, including gas composition analysis and quantification via gas chromatography, bulk electrolyte composition analysis via NMR spectroscopy, and surface layer characterization via XPS and SEM. Also, performance of multiple structural variants was examined to develop a structure-property relationship to guide rational design of additives for advanced Li-ion batteries.
This presentation will summarize Koura’s efforts to supply advanced fluorinated materials for Li-ion batteries that satisfy the arduous demands of current and future applications. Specifically, we will present data showing the capability of fluorinated Koura materials to replace and/or enable existing Li-ion additives under extreme operating conditions, specifically high temperature and/or voltage. Multiple structures will be compared, where appropriate, to highlight our fundamental understanding of the structure-property relationships critical to designing next generation materials.
References:

Tobias Teufl et al 2023 J. Electrochem. Soc. 170 020531

Daniel Pritzl et al 2017 J. Electrochem. Soc. 164 A2625

Hiroshi Haruna et al 2017 J. Electrochem. Soc. 164 A6278
Addressing the Key Challenges of Lithium-Sulfur Batteries: A Comprehensive Overview and Future Perspectives
Authors: Gedif Elmineh Tsegahun 
Published: August 2024

Introduction: Lithium-sulfur (Li-S) batteries represent a pioneering technology with the potential to revolutionize energy storage due to their high theoretical energy density and cost-effectiveness. Nevertheless, their practical implementation encounters various challenges, hindering widespread commercialization. This abstract aims to explore the critical hurdles facing Li-S batteries and proposes strategies to advance their development into a sustainable and efficient energy storage solution. The primary obstacles for Li-S batteries encompass issues related to the polysulfide shuttle effect, sulfur's poor conductivity, limited cycle life, and significant volume changes during charge-discharge cycles. Moreover, achieving stable and efficient sulfur cathodes and electrolytes remains a crucial concern for ensuring prolonged battery performance. This review focuses on a range of strategies and innovations addressing these challenges, including advanced material design, conductive additives, novel electrolytes, and modified separator designs, all aimed at enhancing electrochemical performance. Advanced techniques such as computational modeling and machine learning play a pivotal role in accelerating the discovery and optimization of materials and architectures for Li-S batteries. These methodologies enable precise prediction, design, and evaluation of materials, expediting breakthroughs in overcoming limitations. The future of Li-S batteries relies on multidisciplinary research encompassing material science, electrochemistry, engineering, and computational methodologies.
Keywords: Li – S batteries, Energy density, Cycle life, electrolyte design, cost-effectiveness