Characterizing and solving imaging challenges in thick resists for wafer and panel based lithography applications

2016 ◽  
Vol 2016 (1) ◽  
pp. 000038-000043
Author(s):  
James E. Webb ◽  
Roger McCleary

Abstract Increasing volume using larger substrates with decreasing process margins continues to create new challenges for advanced packaging applications. Key step and repeat camera technology continues evolving for the mass production of microstructures used for 2.5D and 3D technologies. Printing dense arrays of smaller features with high aspect ratios requires higher sidewall angles in thick photoresists and polyimides. To help solve these imaging challenges we have leveraged resist modeling software and guided the adjustment of optical parameters needed for better performance. Higher contrast films have also been evaluated to help achieve the improvements in performance needed. Resist models that can include the effects of flare have been critical to understand the requirement for printing in thick negative resists and has aided in printing features on varying topography and film thicknesses. Special chucks help improve the flatness of warped wafers and real-time auto-focusing provides good image fidelity. Printing microstructures over larger formats with higher throughput has been accomplished using large magnification adjustment for improving overlay and validated by characterizing image placement errors over large substrates. Examples of resist models that are created using resist parameters and optimized using SEM images of printed features are compared. Extrapolations of the resist models have shown that guide improvements can be achieved by varying optical parameters. SEM images confirm that the modeled result of the optimal solution was achieved. Reduction in large substrate overlay error was achieved after the stage corrections were applied. Examples show that topographical errors of warped wafers can be reduced and how real-time auto-focusing for each exposure minimizes focus errors.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
François Stüder ◽  
Jean-Louis Petit ◽  
Stefan Engelen ◽  
Marco Antonio Mendoza-Parra

AbstractSince December 2019, a novel coronavirus responsible for a severe acute respiratory syndrome (SARS-CoV-2) is accountable for a major pandemic situation. The emergence of the B.1.1.7 strain, as a highly transmissible variant has accelerated the world-wide interest in tracking SARS-CoV-2 variants’ occurrence. Similarly, other extremely infectious variants, were described and further others are expected to be discovered due to the long period of time on which the pandemic situation is lasting. All described SARS-CoV-2 variants present several mutations within the gene encoding the Spike protein, involved in host receptor recognition and entry into the cell. Hence, instead of sequencing the whole viral genome for variants’ tracking, herein we propose to focus on the SPIKE region to increase the number of candidate samples to screen at once; an essential aspect to accelerate diagnostics, but also variants’ emergence/progression surveillance. This proof of concept study accomplishes both at once, population-scale diagnostics and variants' tracking. This strategy relies on (1) the use of the portable MinION DNA sequencer; (2) a DNA barcoding and a SPIKE gene-centered variant’s tracking, increasing the number of candidates per assay; and (3) a real-time diagnostics and variant’s tracking monitoring thanks to our software RETIVAD. This strategy represents an optimal solution for addressing the current needs on SARS-CoV-2 progression surveillance, notably due to its affordable implementation, allowing its implantation even in remote places over the world.


Author(s):  
Raquel Fernández

Research on dialogue deals with the study of language as it is used in spontaneous conversation. Dialogue is a multi-agent activity that takes place in real time, with speakers interacting with each other in an online fashion. This makes conversational language markedly different from the kind of language found in texts and brings in new challenges for computational linguistics. This chapter introduces the main phenomena that characterize language in dialogue interaction—including disfluencies, dialogue acts, alignment, grounding, and turn taking—and discusses some of the key approaches to modelling dialogue that are fundamental in computational research, such as dialogue act taxonomies and dynamic semantic theories of dialogue.


2015 ◽  
Vol 1752 ◽  
pp. 3-14
Author(s):  
Qiuhong Zhang ◽  
Betty T. Quinton ◽  
Bang-Hung Tsao ◽  
James Scofield ◽  
Neil Merrett ◽  
...  

ABSTRACTCarbon nanotubes (CNTs) have unique thermal/electrical/mechanical properties and high aspect ratios. Growth of CNTs directly onto reactive material substrates (such as metals and carbon based foam structures, etc.) to create a micro-carbon composite layer on the surface has many advantages: possible elimination of processing steps and resistive junctions, provision of a thermally conductive transition layer between materials of varying thermal expansion coefficients, etc. Compared to growing CNTs on conventional inert substrates such as SiO2, direct growth of CNTs onto reactive substrates is significantly more challenging. Namely, control of CNT growth, structure, and morphology has proven difficult due to the diffusion of metallic catalysts into the substrate during CNT synthesis conditions. In this study, using a chemical vapor deposition method, uniform CNT layers were successfully grown on copper foil and carbon foam substrates that were pre-coated with an appropriate buffer layer such as Al2O3 or Al. SEM images indicated that growth conditions and, most notably, substrate surface pre-treatment all influence CNT growth and layer structure/morphology. The SEM images and pull-off testing results revealed that relatively strong bonding existed between the CNT layer and substrate material, and that normal interfacial adhesion (0.2‒0.5 MPa) was affected by the buffer layer thickness. Additionally, the thermal properties of the CNT/substrate structure were evaluated using a laser flash technique, which showed that the CNT layer can reduce thermal resistance when used as a thermal interface material between bonded layers.


Impact ◽  
2020 ◽  
Vol 2020 (8) ◽  
pp. 60-61
Author(s):  
Wei Weng

For a production system, 'scheduling' aims to find out which machine/worker processes which job at what time to produce the best result for user-set objectives, such as minimising the total cost. Finding the optimal solution to a large scheduling problem, however, is extremely time consuming due to the high complexity. To reduce this time to one instance, Dr Wei Weng, from the Institute of Liberal Arts and Science, Kanazawa University in Japan, is leading research projects on developing online scheduling and control systems that provide near-optimal solutions in real time, even for large production systems. In her system, a large scheduling problem will be solved as distributed small problems and information of jobs and machines is collected online to provide results instantly. This will bring two big changes: 1. Large scheduling problems, for which it tends to take days to reach the optimal solution, will be solved instantly by reaching near-optimal solutions; 2. Rescheduling, which is still difficult to be made in real time by optimization algorithms, will be completed instantly in case some urgent jobs arrive or some scheduled jobs need to be changed or cancelled during production. The projects have great potential in raising efficiency of scheduling and production control in future smart industry and enabling achieving lower costs, higher productivity and better customer service.


2006 ◽  
Vol 15 (05) ◽  
pp. 803-821 ◽  
Author(s):  
PING YAN ◽  
MINGYUE DING ◽  
CHANGWEN ZHENG

In this paper, the route-planning problems of Unmanned Aerial Vehicle (UAV) in uncertain and adversarial environment are addressed, including not only single-mission route planning in known a priori environment, but also the route replanning in partially known and mission-changeable environments. A mission-adaptable hybrid route-planning algorithm based on flight roadmap is proposed, which combines existing global and local methods (Dijkstra algorithm, SAS and D*) into a two-level framework. The environment information and constraints for UAV are integrated into the procedure of building flight roadmap and searching for routes. The route-planning algorithm utilizes domain-specific knowledge and operates in real time with near-optimal solution quality, which is important to uncertain and adversarial environment. Other planners do not provide all of the functionality, namely real-time planning and replanning, near-optimal solution quality, and the ability to model complex 3D constraints.


Author(s):  
Prasanna Lakshmi Kompalli

Data coming from different sources is referred to as data streams. Data stream mining is an online learning technique where each data point must be processed as the data arrives and discarded as the processing is completed. Progress of technologies has resulted in the monitoring these data streams in real time. Data streams has created many new challenges to the researchers in real time. The main features of this type of data are they are fast flowing, large amounts of data which are continuous and growing in nature, and characteristics of data might change in course of time which is termed as concept drift. This chapter addresses the problems in mining data streams with concept drift. Due to which, isolating the correct literature would be a grueling task for researchers and practitioners. This chapter tries to provide a solution as it would be an amalgamation of all techniques used for data stream mining with concept drift.


2013 ◽  
Vol 4 (3) ◽  
pp. 80-93
Author(s):  
Venkata S. Inampudi ◽  
Russell Kondaveti ◽  
Aura Ganz

In this paper, the authors introduce a real time web based tool for resource allocation (RETRA) that can assist the incident commanders and resource managers in the complex task of emergency resource deployment for multiple simultaneous incidents that occur in close geographical proximity. RETRA real time inputs include the location of the emergency sites and the required resources with associated priorities. It generates an optimal deployment plan so that emergency sites with highest priorities for a resource are assigned that resource in the least amount of time. The optimal solution is presented graphically using Google Maps. RETRA can be used for emergency resource deployment at the initial response stage of a disaster. 1


Membranes ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 70 ◽  
Author(s):  
Nancy Li ◽  
Jackie Zheng ◽  
Pejman Hadi ◽  
Mengying Yang ◽  
Xiangyu Huang ◽  
...  

Despite the advantages of membrane processes, their high energy requirement remains a major challenge. Fabrication of nanocomposite membranes by incorporating various nanomaterials in the polymer matrix has shown promise for enhancing membrane flux. In this study, we embed functionalized cellulose nanofibers (CNFs) with high aspect ratios in the polymer matrix to create hydrophilic nanochannels that reduce membrane resistance and facilitate the facile transport of water molecules through the membrane. The results showed that the incorporation of 0.1 wt % CNF into the polymer matrix did not change the membrane flux (~15 L · m − 2 · h − 1 ) and Bovine Serum Albumin (BSA) Fraction V rejection, while increasing the CNF content to 0.3 wt % significantly enhanced the flux by seven times to ~100 L · m − 2 · h − 1 , but the rejection was decreased to 60–70%. Such a change in membrane performance was due to the formation of hydrophilic nanochannels by the incorporation of CNF (corroborated by the SEM images), decreasing the membrane resistance, and thus enhancing the flux. When the concentration of the CNF in the membrane matrix was further increased to 0.6 wt %, no further increase in the membrane flux was observed, however, the BSA rejection was found to increase to 85%. Such an increase in the rejection was related to the electrostatic repulsion between the negatively-charged CNF-loaded nanochannels and the BSA, as demonstrated by zeta potential measurements. SEM images showed the bridging effect of the CNF in the nanochannels with high CNF contents.


2020 ◽  
Vol 89 (1) ◽  
pp. 10303
Author(s):  
Mustafa Anutgan ◽  
Tamila Anutgan ◽  
Ismail Atilgan

An ordinary amorphous silicon nitride-based p-i-n diode was electroformed under optimized process conditions, which led to its instant transformation to a semiconductor device with two-in-one properties: a bright visible light emitting diode and a resistive memory switching device; i.e. light emitting memory (LEM). In the present work, for a thorough understanding of the changes that occur during electroforming, SEM images and EDX analyses were performed on both top-view and cross-section of both as-deposited and electroformed diodes. It was seen from the top-view images that while the diode surface of the as-deposited diode had a smooth and homogeneous ITO top electrode, the electroformed diode exhibited a rough ITO surface. EDX analyses showed that ITO was completely removed from many point-like regions on the diode surface. Cross-sectional SEM images showed no clue of any material diffusion through the diode structure during electroforming, which was one of the suspected situations about our model. EDX results also showed no considerable increase of any of the ingredients of the ITO alloy (In, Sn or O) across the semiconductor (p-i-n) layers of the electroformed diode. In contrast to the roughened surface of the electroformed diode, the silicon-based layers of the diode below the ITO electrode seemed to be well-preserved. Real-time optical microscopy showed that the light is emitted through the regions of the diode surface where the residual ITO top electrode is present.


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