Article
Chemistry, Physical
Po-Fan Lin, Dinh-Phuc Tran, Hung-Che Liu, Yi-Yi Li, Chih Chen
Summary: This study explores a new low-temperature method for copper-to-copper direct bonding and quantitatively evaluates the bonding quality through microstructural analysis. It is found that the bonding quality of chemically mechanically planarized (CMP) copper films is superior to electropolished copper films. This new method allows for shorter bonding time and has the potential to reduce the thermal budget and manufacturing cost of current 3D ICs packaging technology.
Article
Engineering, Electrical & Electronic
Mao Sun, Liang Jiang, Yuan Wu, Yushan Chen, Qiuyu Li, Linmao Qian
Summary: Electrochemical FABrication (EFAB) is capable of creating intricate metal microstructures. Chemical mechanical polishing (CMP) is crucial for achieving flatness and desired surface quality in EFAB. By tuning the concentration of K2S2O8 to 20 mM and using ethylenediamine sulfate as the complexing agent, benzotriazole and sodium dodecyl benzene sulfonate as corrosion inhibitors, a satisfactory material removal rate (MRR) selectivity and surface quality can be achieved. A two-step planarization method involving lapping and CMP was proposed to significantly reduce step height and improve surface roughness of Cu/Ni microstructures.
MICROELECTRONIC ENGINEERING
(2023)
Article
Chemistry, Physical
Yang Chen, Aoli Wei, Xiangyu Ma, Tianyu Wang, Ailian Chen
Summary: In this work, copper-incorporated dendritic mesoporous silica (D-mSiO(2)) nano-particles were synthesized, which resulted in defect-free and atomically planarized dielectric film surfaces and improved removal efficiency. The Cu2+/H2O2 heterogeneous Fenton-like system contributed to the formation of highly reactive species and enhanced material removal.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Seho Sun, Kangchun Lee, Ganggyu Lee, Yehwan Kim, Sungmin Kim, Junha Hwang, Hyungoo Kong, Kyung Yoon Chung, Ghulam Ali, Taeseup Song, Ungyu Paik
Summary: This article introduces an Fe-substituted SiO2 material that improves colloidal stability in low-defect tungsten CMP applications by controlling the dissolution-reprecipitation replacement process of Fe and Si ions in the lattice, thereby enhancing the performance of W CMP.
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
(2022)
Article
Engineering, Chemical
You-Sheng Lin, Kuen-Song Lin, Wei-Chin Tsai, Ndumiso Vukile Mdlovu, Cheng-Yan Tang, U-Ser Jeng
Summary: In this study, cubic CeO2 nanoparticles with uniform structure were synthesized using cetyltrimethylammonium bromide (CTAB) as a cationic surfactant, and these nanoparticles were used for silica wafer polishing. The results showed that the CTABx-CeO2 NPs reduced the roughness of the raw material by 70.7-74.5%.
JOURNAL OF THE TAIWAN INSTITUTE OF CHEMICAL ENGINEERS
(2023)
Article
Chemistry, Physical
Donggeon Kwak, Seungjun Oh, Juhwan Kim, Junho Yun, Taesung Kim
Summary: The study investigated the impact of ceria concentration on the removal rate of silicon oxide during chemical mechanical planarization. Results showed that the removal rate decreased with increasing abrasive concentration, while a wide adsorption layer was formed on the wafer surface with ceria abrasive. Understanding the adsorption between ceria and silicon oxide will aid in further research on post CMP cleaning processes and CMP processes.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2021)
Article
Chemistry, Multidisciplinary
Kangchun Lee, Jihoon Seo
Summary: A novel strategy involving the formation of coordination complex between picolinic acid and tungsten oxide suppresses tungsten dissolution and improves tungsten topography. Addition of 1.5 wt% picolinic acid as an inhibitor dramatically attenuates the dissolution rate of tungsten, leading to improved topography with an R-a value of 7.8 nm while validating CMP removal rate.
APPLIED SCIENCES-BASEL
(2022)
Article
Engineering, Electrical & Electronic
Yinchan Zhang, Xinhuan Niu, Jiakai Zhou, Jianchao Wang, Yebo Zhu, Ziyang Hou, Han Yan, Fu Luo, Minghui Qu
Summary: This paper investigates the influence of the additive sarcosine on the chemical mechanical polishing (CMP) process of Cu film. Results show that sarcosine, as a complexing agent and functional reagent, can improve the planarization properties of Cu film. The adsorption and complexation mechanisms of sarcosine on the Cu film surface are analyzed through various experiments and tests. The synergistic effect of sarcosine and benzotriazole is also confirmed to effectively correct the step height and improve the surface quality of Cu patterned wafers.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2022)
Article
Chemistry, Multidisciplinary
Govinda Ghimire, Jing Guo, Robert Halmagian, Jin He
Summary: In this study, tunable, reliable, and efficient copper nanoelectrodes (CuNEs) were successfully fabricated, and the reversible chemical transformations between aromatic amine and nitro groups on the CuNE surface were comprehensively studied using time-resolved electrochemical surface-enhanced Raman spectroscopy. It was found that the plasmon-mediated chemical reactions (PMCRs) of CuNEs could be well-controlled by changing the surface roughness, oxidation states of copper, and the applied electrode potential. This study demonstrates the importance of Cu nanostructures in investigations of the interplays between PMCR, electrochemistry, and Cu catalysis.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Engineering, Electrical & Electronic
Chengxin Wang, Tongqing Wang, Fangxin Tian, Xinchun Lu
Summary: A study on real-time and accurate measurement of copper film thickness was conducted to improve global planarization during chemical mechanical polishing. The advantages and disadvantages of amplitude and phase methods were compared, and the effects of liftoff distance and excitation signal frequency on measurement performance were analyzed. The experimental results showed that the double-coil eddy current thickness measurement system achieved better measurement performance.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2022)
Article
Chemistry, Physical
Luji Li, Hongda Li, Jie Li, Hao Wu, Li Yang, Wenfeng Zhang, Haixin Chang
Summary: In this study, 2D alpha-MnTe nanosheets were successfully synthesized and exhibited excellent photoelectric properties in photodetectors. The thickness of the nanosheets can be controlled by adjusting reaction conditions, providing a new avenue for high-performance 2D optoelectronic devices.
CHEMISTRY OF MATERIALS
(2021)
Article
Engineering, Mechanical
Seungchul Hong, Deoksu Han, Keon-Soo Jang
Summary: The study focused on improving the planarization performance of dielectric layers by adjusting the zeta potential of particles and using surfactants, achieving a balance between performance and wafer defect density. High-quality wafer surfaces with rare defects, low roughness, and no contamination were achieved by tailoring the surface potential of colloidal silica nanoparticles and reducing defect concentration using fluorinated surfactant-induced intermolecular repulsion.
Article
Engineering, Electrical & Electronic
Sanghuck Jeon, Jungryul Lee, Seokjun Hong, Hyeonmin Seo, Yeongkwang Cho, Pengzhan Liu, Kihong Park, Taesung Kim
Summary: This paper investigates the tribological effects on the material removal rate using ceria and silica slurries and three types of pads. The study reveals that ceria and silica abrasives exhibit opposite behaviors as the pad texture changes, with ceria MRR increasing and silica MRR decreasing. The re-analysis of the Stribeck curve shows that two-body abrasion may be maintained for ceria CMP, while a transition to three-body abrasion is possible for silica CMP as the contact area increases. This research provides insights into the oxide CMP tribological mechanism and aids in optimizing consumables selection for CMP processes.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2022)
Article
Optics
Zhengming Yi, Weijiang Ding, Wei Lv
Summary: In this study, the drainage process of a landed soap bubble was investigated using large lateral shearing displacement interferometry. The measured results showed that the maximum film thickness, volume, and flow rate during drainage were 4.78 μm, 5.52 mm(3), and 0.234 mm(3)/s, respectively, and the drainage flow rate doubled after the drained zone formed. The simulated fringe patterns based on the measurement results agreed well with the experimental ones.
Article
Chemistry, Physical
V. Ratia-Hanby, E. Isotahdon, X. Yue, P. Malmberg, C. Leygraf, E. Huttunen-Saarivirta
Summary: The surface films formed on pre-oxidized copper in anoxic simulated groundwater with sulphide were characterized using various techniques. The results revealed that the sulphide content in the groundwater significantly influenced the morphology and composition of the surface film.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2023)
Article
Engineering, Chemical
Tianmao Lai, Mingli Guo, Yuguo Chen, Ting Zhu
Summary: This study investigated the dependence of adhesion force on contact time and surface hydrophilicity. It was found that hydrophobic graphene can shield the time-dependence and instability of adhesion forces at a silica/silica interface. Depending on surface hydrophilicity, there are three different adhesion force behaviors with dwell time for the silica/silica contact. The adhesion force at the silica/silica interface is greatly influenced by repeated contacts with an unstable behavior. On the other hand, adhesion forces on graphene do not depend on dwell time, and the factor of repeated contacts has little effect on the results. This research provides insights into the adhesion mechanism and can contribute to the design of anti-adhesion structures and devices in silicon-based systems.
JOURNAL OF ADHESION
(2023)
Article
Engineering, Multidisciplinary
Dongsheng Ji, Wenbo Zhang, Qianchuan Zhao, Wen Yang
Summary: This paper presents a method to calibrate circular pointer-type meters using the YOLOv5s network. The method utilizes a convolutional neural network framework for scale value detection and meter correction, resulting in accurate meter readings. By employing the weighted angle method, the accumulated error in meter images is eliminated, demonstrating the effectiveness of the proposed method.
MEASUREMENT SCIENCE AND TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Liang Yu, Zhanbo Xu, Xiaohong Guan, Qianchuan Zhao, Chunxia Dou, Dong Yue
Summary: This paper investigates the optimal operation problem of an HMES with building thermal dynamics and proposes an algorithm based on model-based optimization and data-driven learning. The algorithm transforms the long-term cost minimization problem into several single-slot subproblems and solves them using convex optimization and multi-agent attention-based deep deterministic policy gradient. Simulation results based on real-world traces demonstrate the effectiveness of the proposed algorithm.
IEEE TRANSACTIONS ON SMART GRID
(2023)
Article
Engineering, Multidisciplinary
Xinxin Li, Wenqing Chen, Xiaosong Li, Xin Hou, Qian Zhao, Yonggang Meng, Yu Tian
Summary: In this study, a new type of underactuated bionic microspines gripper is proposed for attaching to irregular, rough walls. The gripper, with its flexible structure and underactuated linkage mechanism, is capable of adapting to submillimeter-scale roughness and centimeter-scale geometry irregularity in both normal and tangential attachment. Experimental results and simulations confirm the effectiveness of the gripper in achieving rough wall attachment. The developed microspines gripper has demonstrated successful grasp of irregular objects, showcasing its dexterity and versatility in wall attachment applications.
Article
Automation & Control Systems
Ziyou Zhang, Qianchuan Zhao, Fa-An Dai
Summary: In this article, a warm-start point algorithm in interior point methods for shrinking horizon model predictive control with a variable discretization step is presented. The algorithm uses a convex combination of components of the earlier optimal solution to construct an interpolation point and obtains a warm-start point by using a convex combination of the modified interpolation point with the cold-start point. It is proven that the worst-case iteration complexity of this strategy is better than that of the cold-start. In the numerical experiment of fuel-optimal planetary powered-descent guidance problems, the strategy reduces the number of iterations of second-order cone programming by about 80% with the number of samples available in practical applications.
IEEE TRANSACTIONS ON AUTOMATIC CONTROL
(2023)
Article
Automation & Control Systems
Chen Hou, Qianchuan Zhao
Summary: This paper investigates a wireless powered edge computing system that enhances computing power and extends the lifetime of wireless devices through wireless power transfer technology. By optimizing the tradeoff between computation rate and energy harvested, an effective algorithm is proposed to maximize the sum of computation rates of all devices.
IEEE TRANSACTIONS ON AUTOMATION SCIENCE AND ENGINEERING
(2023)
Article
Automation & Control Systems
Chen Hou, Qianchuan Zhao
Summary: This paper investigates the task-offloading ordering problem in edge computing systems and proposes a discrete problem model and a novel algorithm OTOOA to find the optimal task-offloading orderings. Experimental results demonstrate the superiority of OTOOA.
IEEE TRANSACTIONS ON AUTOMATION SCIENCE AND ENGINEERING
(2023)
Review
Chemistry, Analytical
Shuo Wang, Yongcai Wang, Deying Li, Qianchuan Zhao
Summary: This paper presents a detailed survey of the key methodologies designed for distributed relative localization for robot networks. The design methodologies, advantages, drawbacks, and application scenarios of different distributed localization algorithms are introduced and summarized. The research works supporting distributed localization are surveyed, including local network organization, communication efficiency, and the robustness of distributed localization algorithms. Popular simulation platforms are also summarized and compared to facilitate future research and experiments on distributed relative localization algorithms.
Article
Engineering, Mechanical
Renshui Cao, Hang Bai, Hui Cao, Yazhao Zhang, Yonggang Meng
Summary: Tapered roller bearings (TRBs) are commonly used in heavy-load rotating machinery, but they face the issue of sharp pressure spikes at the roller ends. This paper provides an asymmetric optimized profile solution for all TRBs to suppress the pressure spikes, using a numerical running-in method. The results show that the optimized profile performs better in smoothing contact pressure distribution compared to traditional profiles and is effective in eliminating sharp pressure spikes. The paper also analyzes the influences of different axial profiles under various conditions.
Article
Construction & Building Technology
Tian Xing, Kailai Sun, Qianchuan Zhao
Summary: Indoor temperature prediction is crucial for building control and energy saving. We propose a novel deep-learning framework, MITP-Net, for short-term indoor temperature prediction in multi-zone buildings, which improves the prediction accuracy and can be adjusted for different requirements. We provide the usage steps, operating data, and codes on GitHub for further research.
BUILDING AND ENVIRONMENT
(2023)
Article
Construction & Building Technology
Kailai Sun, Irfan Qaisar, Muhammad Arslan Khan, Tian Xing, Qianchuan Zhao
Summary: Buildings have a significant impact on global energy usage and carbon dioxide emissions. This study introduces a Transformer-based algorithm for building occupancy prediction, which outperforms other existing algorithms in the provided dataset.
BUILDING AND ENVIRONMENT
(2023)
Correction
Engineering, Chemical
Chenxu Liu, Weizi Li, Chuke Ouyang, Yu Tian, Yonggang Meng
Article
Chemistry, Multidisciplinary
Peixin Fang, Ming Wang, Jingzheng Li, Qianchuan Zhao, Xuehan Zheng, He Gao
Summary: With the rapid development of society, people's demands for lighting are increasing. However, most current lighting systems are inefficient and do not provide sufficient light comfort. To address this issue, this paper proposes an intelligent lighting control system based on a distributed architecture, which incorporates a dynamic shading system for adjusting the interior lighting environment. The system includes two subsystems: lighting and shading. The shading subsystem utilizes fuzzy control logic to achieve rapid control with fewer calculations based on the room's temperature and illumination. Meanwhile, the lighting subsystem employs a Deep Deterministic Policy Gradient (DDPG) algorithm to optimize luminaire dimming and achieve uniform illumination based on room illuminance, thus maximizing user convenience.
APPLIED SCIENCES-BASEL
(2023)
Article
Robotics
Ziyou Zhang, Qianchuan Zhao, Kailai Sun
Summary: Verifying the safety of states and designing a safety controller are crucial for safety critical systems, such as robotic and automotive systems. It is challenging to determine whether the current state will eventually enter the unsafe set, since calculating the reachable set online is difficult. Therefore, offline calculation of the forward invariant set is commonly used to obtain the safe set. Existing methods for computing control barrier functions have limitations, such as over-approximations or applicability only to problems without control constraints. This letter proposes a learning-based method that overcomes these limitations and significantly improves existing control barrier functions for nonlinear control affine systems with control constraints.
IEEE ROBOTICS AND AUTOMATION LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Maopeng Wu, Qian Zhao, Lei Kang, Mingze Weng, Zhonghai Chi, Ruiguang Peng, Jingquan Liu, Douglas H. Werner, Yonggang Meng, Ji Zhou
Summary: By using temporal topolectrical circuits as simulators, we demonstrate that the bulk states of an open system can be described by non-Bloch evolution and successfully confirm the existence of extended complex wave vectors. This work advances the investigation of dissipative topological modes and provides a versatile platform for exploring the unique evolution and topology for both closed and open systems.
