Ablation Free Dicing of 4H-SiC Wafers with Feed Rates up to 200 mm/s by Using Thermal Laser Separation

2012 ◽  
Vol 1433 ◽  
Author(s):  
Dirk Lewke ◽  
Matthias Koitzsch ◽  
Martin Schellenberger ◽  
Lothar Pfitzner ◽  
Heiner Ryssel ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
State Of The Art ◽  
Separation Process ◽  
Back Side ◽  
Current State ◽  
Edge Quality ◽  
First Time ◽  
Metal Layers ◽  
Laser Separation ◽  
Street Width

ABSTRACTThis paper presents Thermal Laser Separation (TLS) as a novel dicing technology for silicon carbide (SiC) wafers. Results of this work will play an important role in improving the SiC dicing process regarding throughput and edge quality. TLS process parameters were developed for separating 4H-SiC wafers. Separated SiC dies were analyzed and compared with results produced with current state of the art blade dicing technology. For the first time, fully processed 100 mm 4H-SiC wafers with a thickness of 450 μm, including epi-layer and back side metal layers, could be separated with feed rates up to 200 mm/s. Besides the vastly improved dicing speed, the TLS separation process results in two important features of the separated SiC devices: First, edges are free of chipping and therefore of higher quality than the edges produced by blade dicing. Second, the TLS process is kerf free, which allows for reducing the necessary dicing street width and hence increasing the number of devices per wafer.

High quality and high speed cutting of 4H-SiC JFET wafers including PCM structures by using Thermal Laser Separation

2014 ◽  
Vol 1693 ◽  
Author(s):  
Dirk Lewke ◽  
Matthias Koitzsch ◽  
Karl Otto Dohnke ◽  
Martin Schellenberger ◽  
Hans-Ulrich Zuehlke ◽  
...  
Keyword(s):  
High Speed ◽  
Metal Layer ◽  
Back Side ◽  
The Novel ◽  
Metal Structures ◽  
High Speed Cutting ◽  
Current State ◽  
Current Transition ◽  
First Time ◽  
Laser Separation

ABSTRACTThe silicon carbide (SiC) market is gaining momentum hence productivity in device manufacturing has to be improved. The current transition from 100 mm SiC-wafers to 150 mm SiC-wafers requires novel processes in the front-end as well as the back-end of SiC-chip production. Dicing of fully processed SiC-wafers is becoming a bottleneck process since current state-of-the-art mechanical blade dicing faces heavy tool wear and achieves low throughput due to low feed rates in the range of only a few mm/s. This paper presents latest results of the novel dicing technology Thermal Laser Separation (TLS) applied for separating SiC-JFETs. We demonstrate for the first time that TLS is capable of dicing fully processed 4H-SiC wafers, including back side metal layer stacks, process control monitoring (PCM), and metal structures inside the dicing streets with feed rates up to 200 mm/s. TLS thus paves the way to efficient dicing of 150 mm SiC-wafers.

scholarly journals Electro-Quasistatic Animal Body Communication for Untethered Rodent Biopotential Recording

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shreeya Sriram ◽  
Shitij Avlani ◽  
Matthew P. Ward ◽  
Shreyas Sen
Keyword(s):  
Lower Energy ◽  
Sensor Node ◽  
State Of The Art ◽  
The Body ◽  
Animal Body ◽  
Current State ◽  
Communication Modalities ◽  
First Time ◽  
Biopotential Recording

AbstractContinuous multi-channel monitoring of biopotential signals is vital in understanding the body as a whole, facilitating accurate models and predictions in neural research. The current state of the art in wireless technologies for untethered biopotential recordings rely on radiative electromagnetic (EM) fields. In such transmissions, only a small fraction of this energy is received since the EM fields are widely radiated resulting in lossy inefficient systems. Using the body as a communication medium (similar to a ’wire’) allows for the containment of the energy within the body, yielding order(s) of magnitude lower energy than radiative EM communication. In this work, we introduce Animal Body Communication (ABC), which utilizes the concept of using the body as a medium into the domain of untethered animal biopotential recording. This work, for the first time, develops the theory and models for animal body communication circuitry and channel loss. Using this theoretical model, a sub-inch$$^3$$ 3 [1″ × 1″ × 0.4″], custom-designed sensor node is built using off the shelf components which is capable of sensing and transmitting biopotential signals, through the body of the rat at significantly lower powers compared to traditional wireless transmissions. In-vivo experimental analysis proves that ABC successfully transmits acquired electrocardiogram (EKG) signals through the body with correlation $$>99\%$$ > 99 % when compared to traditional wireless communication modalities, with a 50$$\times$$ × reduction in power consumption.

scholarly journals A Step by Step Methodology for Building Sustainable Cementitious Matrices

2020 ◽  
Vol 10 (8) ◽  
pp. 2955 ◽  
Author(s):  
Styliani Papatzani ◽  
Kevin Paine
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Silica Fume ◽  
Carbon Footprint ◽  
State Of The Art ◽  
Cost Effective ◽  
Strength Development ◽  
Low Carbon ◽  
Current State ◽  
First Time

In an effort to produce cost-effective and environmentally friendly cementitious binders. mainly ternary (Portland cement + limestone + pozzolanas) formulations have been investigated so far. Various proportions of constituents have been suggested, all, however, employing typical Portland cement (PC) substitution rates, as prescribed by the current codes. With the current paper a step by step methodology on developing low carbon footprint binary, ternary and quaternary cementitious binders is presented (PC replacement up to 57%). Best performing binary (60% PC and 40% LS (limestone)) and ternary formulations (60% PC, 20% LS, 20% FA (fly ash) or 43% PC, 20% LS 37% FA) were selected on the grounds of sustainability and strength development and were further optimized with the addition of silica fume. For the first time a protocol for successfully selecting and testing binders was discussed and the combined effect of highly pozzolanic constituents in low PC content formulations was assessed and a number of successful matrices were recommended. The present paper enriched the current state of the art in composite low carbon footprint cementitious binders and can serve as a basis for further enhancements by other researchers in the field.

scholarly journals Regularized Evolution for Image Classifier Architecture Search

2019 ◽  
Vol 33 ◽  
pp. 4780-4789 ◽  
Author(s):  
Esteban Real ◽  
Alok Aggarwal ◽  
Yanping Huang ◽  
Quoc V. Le
Keyword(s):  
Neural Network ◽  
Learning Algorithm ◽  
State Of The Art ◽  
Simple Method ◽  
Current State ◽  
Network Topologies ◽  
Comparable Accuracy ◽  
Tournament Selection ◽  
Complex Architecture ◽  
First Time

The effort devoted to hand-crafting neural network image classifiers has motivated the use of architecture search to discover them automatically. Although evolutionary algorithms have been repeatedly applied to neural network topologies, the image classifiers thus discovered have remained inferior to human-crafted ones. Here, we evolve an image classifier— AmoebaNet-A—that surpasses hand-designs for the first time. To do this, we modify the tournament selection evolutionary algorithm by introducing an age property to favor the younger genotypes. Matching size, AmoebaNet-A has comparable accuracy to current state-of-the-art ImageNet models discovered with more complex architecture-search methods. Scaled to larger size, AmoebaNet-A sets a new state-of-theart 83.9% top-1 / 96.6% top-5 ImageNet accuracy. In a controlled comparison against a well known reinforcement learning algorithm, we give evidence that evolution can obtain results faster with the same hardware, especially at the earlier stages of the search. This is relevant when fewer compute resources are available. Evolution is, thus, a simple method to effectively discover high-quality architectures.

scholarly journals Electrode-free visual prosthesis/exoskeleton control using augmented reality glasses in a first proof-of-technical-concept study

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Simon Hazubski ◽  
Harald Hoppe ◽  
Andreas Otte
Keyword(s):  
Augmented Reality ◽  
State Of The Art ◽  
Visual Prosthesis ◽  
Control Mechanisms ◽  
Proof Of Concept ◽  
End Effector ◽  
Concept Study ◽  
Current State ◽  
First Time ◽  
Robust Systems

Abstract In the field of neuroprosthetics, the current state-of-the-art method involves controlling the prosthesis with electromyography (EMG) or electrooculography/electroencephalography (EOG/EEG). However, these systems are both expensive and time consuming to calibrate, susceptible to interference, and require a lengthy learning phase by the patient. Therefore, it is an open challenge to design more robust systems that are suitable for everyday use and meet the needs of patients. In this paper, we present a new concept of complete visual control for a prosthesis, an exoskeleton or another end effector using augmented reality (AR) glasses presented for the first time in a proof-of-concept study. By using AR glasses equipped with a monocular camera, a marker attached to the prosthesis is tracked. Minimal relative movements of the head with respect to the prosthesis are registered by tracking and used for control. Two possible control mechanisms including visual feedback are presented and implemented for both a motorized hand orthosis and a motorized hand prosthesis. Since the grasping process is mainly controlled by vision, the proposed approach appears to be natural and intuitive.

TLS-Dicing for SiC - Latest Assessment Results

2018 ◽  
Vol 924 ◽  
pp. 547-551
Author(s):  
Dirk Lewke ◽  
Mercedes Cerezuela Barreto ◽  
Karl Otto Dohnke ◽  
Hans Ulrich Zühlke ◽  
Christian Belgardt ◽  
...  
Keyword(s):  
State Of The Art ◽  
Semiconductor Devices ◽  
The State ◽  
Electrical Performance ◽  
European Project ◽  
Edge Quality ◽  
Volume Production ◽  
Laser Separation ◽  
Assessment Results

With the gaining demand for SiC semiconductor devices it is more and more challenging to meet the requirements for SiC volume production with the state of the art wafer dicing technology. In order to overcome this challenge the laser based dicing technology Thermal Laser Separation (TLS-DicingTM) was assessed for SiC volume production within the European project SEA4KET. This paper presents the key results of this project. It could be demonstrated that the demand of SiC volume production regarding throughput and cost as well as edge quality and electrical performance of diced chips can be met with TLS-DicingTM.

scholarly journals Bundle-specific fornix reconstruction for dual-tracer PET-tractometry

2018 ◽  
Author(s):  
Francois Rheault ◽  
Maggie Roy ◽  
Stephen Cunnane ◽  
Maxime Descoteaux
Keyword(s):  
State Of The Art ◽  
Emission Tomography ◽  
Hippocampal Atrophy ◽  
Current State ◽  
Positron Emission ◽  
Spatial Coverage ◽  
Before And After ◽  
Position And Orientation ◽  
First Time ◽  
Dual Tracer

AbstractTractography is known to have problems reconstructing white matter bundles that are narrow, have high curvature, or go through partial volume voxels contaminated by CSF or gray matter. One such bundle is the fornix, the major output tract of the hippocampus, which is especially problematic with aging. Hippocampal atrophy and ventricular expansion make the fornix even harder (often impossible) to track with current state-of-the-art techniques. In this work, a bundle-specific tractography algorithm is proposed to fully reconstruct the fornix. By injecting shape, position, and orientation priors, fornix reconstruction is markedly is improved. We report an increase in spatial coverage and better reproducibility across test-retest. These improvements over classical tractography algorithms also enable tractometry of the fornix to be combined with dual-tracer positron emission tomography (PET) data in participants with mild cognitive impairment (MCI). MCI participants underwent a multi-modal brain imaging before and after a 6-month daily ketogenic supplement. We report, for the first time, significant diffusion measures and 18F-fluorodeoxyglucose (FDG) uptake differences in specific sub-sections of the fornix after the ketogenic supplement.

scholarly journals Self-attentive Biaffine Dependency Parsing

2019 ◽  
Author(s):  
Ying Li ◽  
Zhenghua Li ◽  
Min Zhang ◽  
Rui Wang ◽  
Sheng Li ◽  
...  
Keyword(s):  
Error Analysis ◽  
Machine Translation ◽  
State Of The Art ◽  
Contextual Information ◽  
The Self ◽  
Dependency Parsing ◽  
Benchmark Data ◽  
Current State ◽  
Model Ensembles ◽  
First Time

The current state-of-the-art dependency parsing approaches employ BiLSTMs to encode input sentences.Motivated by the success of the transformer-based machine translation, this work for the first time applies the self-attention mechanism to dependency parsing as the replacement of the BiLSTM-based encoders, leading to competitive performance on both English and Chinese benchmark data. Based on the detailed error analysis, we then combine the power of both BiLSTM and self-attention via model ensembles, demonstrating their complementary capability of capturing contextual information. Finally, we explore the recently proposed contextualized word representations as extra input features, and further improve the parsing performance.

scholarly journals Extension of the Stoney Equation for a Taiko Wafer (Si and SiC)

2020 ◽  
Author(s):  
Antonio Landi ◽  
Vincenzo Vinciguerra
Keyword(s):  
Silicon Carbide ◽  
Band Gap ◽  
Wide Band ◽  
Theory Of Elasticity ◽  
Back Side ◽  
Wide Band Gap ◽  
Elastic Regime ◽  
Stoney Formula ◽  
Metal Layers ◽  
Strong Extension

An extension of the Stoney formula for the case of a back side metallized 8” silicon taiko wafer has been developed, in the elastic regime, within the frame of the theory of elasticity. A good correlation between the calculated warpage, determined by the stress released by a given back side metallization (BSM), and the corresponding experimental warpages of the same thick metal layers deposited on an 8” silicon taiko wafer provides evidences of the correctness of the developed theory. This development suggests the possibility to extend this approach to the case of 8” taiko wafers based on a wide band gap semiconductor such as silicon carbide (SiC).

scholarly journals State-of-the-Art Management of Patients Suffering from Chronic Lymphocytic Leukemia

2012 ◽  
Vol 6 ◽  
pp. CMO.S6201 ◽  
Author(s):  
Ruth Clifford ◽  
Anna Schuh
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
State Of The Art ◽  
Late Phase ◽  
Clinical Intervention ◽  
Response Prediction ◽  
Lymphocytic Leukemia ◽  
New Agents ◽  
Current State ◽  
History Of ◽  
First Time

The management of chronic lymphocytic leukemia (CLL) has evolved dramatically in the last decade. For the first time, clinical intervention has been shown to alter the natural history of the disease. Considerable efforts are focussing on better patient selection and response prediction, and it is expected that the publication of the first 200 CLL genomes will spark new insights into risk stratification of CLL patients. Besides, many new agents are being evaluated on their own and in combination therapy in early and late Phase clinical studies. Here, we provide a general clinical introduction into CLL including diagnosis and prognostic markers followed by a summary of the current state-of-the-art treatment. We point to areas of continued clinical research in particular for patients with co-morbidities and highlight the challenges in managing refractory disease.

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