Large-Area Homoepitaxial Growth of Low-Doped Thick Epilayers for Power Devices with VBR > 4 kV

2009 ◽  
Vol 615-617 ◽  
pp. 77-80 ◽  
Author(s):  
Bernd Thomas ◽  
Christian Hecht ◽  
Birgit Kallinger
Keyword(s):  
Layer Thickness ◽  
Surface Quality ◽  
Doping Concentration ◽  
Epitaxial Layers ◽  
Power Devices ◽  
Large Area ◽  
Homoepitaxial Growth ◽  
Different Types ◽  
First Time

In this paper we present results on the growth of low-doped thick epitaxial layers on 4° off-oriented 4H-SiC using a commercially available hot-wall multi-wafer CVD system. For the first time we show results of a low-doped full-loaded 73” run on 4° off-oriented substrates with a layer thickness of more than 70 µm. The target doping concentration of 1.2×1015 cm-3 is suitable for blocking voltages > 6 kV. Results on doping, thickness and wafer-to-wafer homogeneities are shown. The surface quality of the grown layers was characterized by AFM. The density of different types of dislocations was determined by Defect Selective Etching.

Chloride-Based CVD at High Rates of 4H-SiC on On-Axis Si-Face Substrates

2011 ◽  
Vol 679-680 ◽  
pp. 59-62 ◽  
Author(s):  
Stefano Leone ◽  
Yuan Chih Lin ◽  
Franziska Christine Beyer ◽  
Sven Andersson ◽  
Henrik Pedersen ◽  
...  
Keyword(s):  
Epitaxial Growth ◽  
Doping Concentration ◽  
Epitaxial Layers ◽  
Power Devices ◽  
High Quality ◽  
Homoepitaxial Growth ◽  
Basal Plane Dislocation ◽  
Background Doping ◽  
Quality Material

The epitaxial growth at 100 µm/h on on-axis 4H-SiC substrates is demonstrated in this study. Chloride-based CVD, which has been shown to be a reliable process to grow SiC epitaxial layers at rates above 100 µm/h on off-cut substrates, was combined with silane in-situ etching. A proper tuning of C/Si and Cl/Si ratios and the combination of different chlorinated precursors resulted in the homoepitaxial growth of 4H-SiC on Si-face substrates at high rates. Methyltrichlorosilane, added with silane, ethylene and hydrogen chloride were employed as precursors to perform epitaxial growths resulting in very low background doping concentration and high quality material, which could be employed for power devices structure on basal-plane-dislocation-free epitaxial layers.

STRUCTURAL AND SEMANTIC CHARACTERISTICS OF THE NAMES AND DESCRIPTIONS OF DISHES IN GERMAN RESTAURANT DISCOURSE

2021 ◽  
Vol 7 (2) ◽  
pp. 96-119
Author(s):  
Nadezhda G. KANTYSHEVA ◽  
Inna V. Solovyova
Keyword(s):  
Discourse Analysis ◽  
Semantic Features ◽  
Institutional Discourse ◽  
The World ◽  
Different Types ◽  
Complex Words ◽  
First Time ◽  
Comprehensive Study

This article is devoted to a comprehensive study of the structural and semantic features of dish names and their descriptions in German in the field of restaurant discourse. The study employs cognitive discourse analysis, elements of comparative and contextological approaches, taking into account linguocultural parameters. The relevance of the comprehensive study of the names of dishes in restaurant discourse is due to an increased interest in the parameterization of lexical units in different types of institutional discourse. The scientific novelty of this work lies in the fact that for the first time, within the framework of a restaurant menu, not only the nomination of a dish is considered, but also the structural and semantic characteristics of its description are analysed. An attempt is made to analyse a connection between the nominations of dishes and their description in the restaurant menu, as well as to determine the semantic dominants of the genre under study. It is concluded that the text of the menu as a whole presents a combination of the language for special purposes and the language of advertising. In interaction with extralinguistic factors, the nominations of dishes and their descriptions not only document the culture of food in society, but also reflect the ethnocultural picture of the world. Based on the analysis of the menu texts, it is established that structurally the names of dishes are complex words or phrases, built mainly according to the attributive model. The description of dishes performs the function of verbalizing the sensations of taste and clarifying the method of preparing dishes, characterizing the quality of dishes, their ingredients, and the intensity of taste. Evaluative parameters in descriptions are expressed at the lexical, grammatical, syntactic and stylistic levels.

Improving surface quality of polyethylene terephthalate film for large area flexible electronic applications

2015 ◽  
Vol 20 (7) ◽  
pp. 1895-1902 ◽  
Author(s):  
Florencia Edith Wiria ◽  
Chu Long Tham ◽  
Alamelu Suriya Subramanian ◽  
Ju Nie Tey ◽  
Xiaoying Qi ◽  
...  
Keyword(s):  
Surface Quality ◽  
Polyethylene Terephthalate ◽  
Large Area ◽  
Polyethylene Terephthalate Film ◽  
Flexible Electronic

Properties of 4H-SiC by Sublimation Close Space Technique

1999 ◽  
Vol 572 ◽  
Author(s):  
S. Nishino ◽  
K. Matsumoto ◽  
Y. Chen ◽  
Y. Nishio
Keyword(s):  
Schottky Diode ◽  
Source Material ◽  
Epitaxial Layers ◽  
Power Devices ◽  
High Quality ◽  
Substrate Quality ◽  
Space Technique ◽  
P Type ◽  
Type Conduction

ABSTRACTSiC is suitable for power devices but high quality SiC epitaxial layers having a high breakdown voltage are needed and thick epilayer is indispensable. In this study, CST method (Close Space Technique) was used to rapidly grow thick epitaxial layers. Source material used was 3C-SiC polycrystalline plate of high purity while 4H-SiC(0001) crystals inclined 8° off toward <1120> was used for the substrate. Quality of the epilayer was influenced significantly by pressure during growth and polarity of the substrate. A p-type conduction was obtained by changing the size of p-type source material. The carrier concentration of epilayer decreased when a lower pressure was employed. Schottky diode was also fabricated.

Challenges in Large-Area Multi-Wafer SiC Epitaxy for Production Needs

2006 ◽  
Vol 527-529 ◽  
pp. 135-140 ◽  
Author(s):  
Bernd Thomas ◽  
Christian Hecht ◽  
René A. Stein ◽  
Peter Friedrichs
Keyword(s):  
System Stability ◽  
Market Development ◽  
Process Conditions ◽  
Epitaxial Layers ◽  
Large Area ◽  
Homoepitaxial Growth ◽  
The Past ◽  
Active Layers ◽  
Wafer Size ◽  
Drift Of Parameters

The rapid market development for SiC-devices during the last years can be attributed particularly to the success in supplying high-quality SiC wafers and corresponding epitaxial layers. The device quality could be enhanced and the costs were reduced by enlarging the wafer size as well as by a significant progress in epitaxial growth of active layers by using multi-wafer CVD systems. In this paper we want to give an overview of CVD multi-wafer systems used for SiC growth in the past and today. We present recent results of SiC homoepitaxial growth using our multi-wafer hot-wall CVD system. This equipment exhibits a capacity of 5×3” wafers per run and can be upgraded to a 7×3” or 5×4” setup. By optimizing the process conditions epitaxial layers with excellent crystal quality, purity and homogeneity of doping and thickness have been grown. Issues like reproducibility, drift of parameters and system stability over several runs will be discussed.

Influence of the CAM Parameters and Selection of End-Mill Cutter when Assessing the Resultant Surface Quality in 3D Milling

2014 ◽  
Vol 474 ◽  
pp. 267-272 ◽  
Author(s):  
Michal Fabian ◽  
Peter Ižol ◽  
Dagmar Draganovská ◽  
Miroslav Tomáš
Keyword(s):  
Ball Milling ◽  
Surface Quality ◽  
End Mill ◽  
Machined Surface ◽  
Machined Surface Quality ◽  
Different Types ◽  
Mill Cutter ◽  
Milling Tools ◽  
Selection Of

The paper deals with the effects of CAM data needed to produce desired quality of shaped surfaces in forming dies making. In general, the input CAM data have strong influence to the final surface quality. The shaped surfaces 3D milling has been modeled as end ball milling of the surfaces with defined inclination. The end ball milling is the most common way to finish shaped surfaces. Directions of the milling tools motion and applied cutting conditions have been used to simulate data when setting milling strategies. The resultant machined surface quality has been identified in terms of the surface roughness. The paper introduces recommendations applicable to the programming of the different types of milling strategy when producing form surfaces.

Method for assessing the surface quality of copper cathodes

1970 ◽  
Author(s):  
E.V. Shulga ◽  
A.I. Yurev ◽  
M.I. Bazanov
Keyword(s):  
Surface Quality ◽  
Cathode Surface ◽  
Special Technique ◽  
Practical Application ◽  
European Standard ◽  
Cathode Copper ◽  
Current Production ◽  
Polar Division ◽  
First Time

One of the criteria for the quality of high-purity copper, which makes it possible to evaluate its mechanical properties and, accordingly, its suitability for use by consumers, is the spiral elongation number which, in accordance with the requirements of the European Standard EN 12893, must be at least 400 mm.  In order to stabilize spiral elongation number at the required level, an estimate is made of its distribution along the cathode web.  Experimentally obtained results, processed using mathematical statistics methods, showed significant discrepancies between the spiral elongation values in the central and other parts of the cathode (upper, lower, side), which indicates an uneven distribution of the spiral elongation number along the cathode web.  It was found that in order to form a representative analytical sample under cathode copper cathode production of the Polar Division of MMC «Norilsk Nickel», cathode testing should be performed using methods that include all areas of the cathode web, including edges and ears. To determine the dependence of the spiral elongation number on the surface quality of copper cathodes, a special technique has been developed, based on the detection of the most frequently encountered defects in the surface of the cathode web, which is assigned a certain numerical value in accordance with the ranking results.  The proposed scoring system for the quality of cathodes in appearance allowed us to establish for the first time that stabilization of the spiral elongation number at a level of at least 400 mm is possible if the defectiveness of the cathode surface does not exceed 17 points per bath.  The technique has found practical application for assessing the surface quality of copper cathodes under current production conditions. 

Change of the Characterization Techniques as Progress of CuInSe2-Based Thin-Film PV Technology

2012 ◽  
Vol 725 ◽  
pp. 165-170
Author(s):  
Katsumi Kushiya ◽  
Hiroki Sugimoto ◽  
Yoshiyuki Chiba ◽  
Yoshiaki Tanaka ◽  
Hideki Hakuma
Keyword(s):  
Thin Film ◽  
Integrated Circuits ◽  
Limited Information ◽  
Large Area ◽  
Area Efficiency ◽  
Characterization Techniques ◽  
First Time ◽  
Film Form ◽  
Comprehensive Characterization

In the CuInSe2(CIS)-based thin-film PV technology, various characterization techniques have been applied to measure the composition, crystal structure, depth profile and defect chemistry and so on, since Boeing Aerospace, for the first time, has come to the 10 % milestone in a thin-film form in 1980 by fabricating a very small single cell with top grids. More advanced and comprehensive characterization techniques are being applied after over 18 % total-area efficiency was consistently achieved employing the “three stage method”, which was developed by National Renewable Energy Laboratory (NREL). Comparing to the CIS-based absorber, there are not so many researches to investigate the absorber/buffer interface because the buffer is too thin to analyse separately and precisely and there are quite limited information on reaction pathways and composition of the buffer layer. However, in order to achieve the aperture-area efficiency of over 18 % on over 800cm2-sized large-area integrated circuits, it is remarkably important how to enhance the quality of absorber/buffer interface. Therefore, analytical works to understand how to improve the FF should tend to be more and more important.

SiC Warm-Wall Planetary VPE Growth on Multiple 100-mm Diameter Wafers

2006 ◽  
Vol 527-529 ◽  
pp. 159-162 ◽  
Author(s):  
Albert A. Burk ◽  
Michael J. O'Loughlin ◽  
Michael J. Paisley ◽  
Adrian R. Powell ◽  
M.F. Brady ◽  
...  
Keyword(s):  
Layer Thickness ◽  
Epitaxial Layer ◽  
High Throughput ◽  
Layer Growth ◽  
Experimental Results ◽  
Epitaxial Layers ◽  
Large Area ◽  
Low Background ◽  
Total Range ◽  
Background Doping

Experimental results are presented for SiC epitaxial layer growth employing a large-area, up to 8x100-mm, warm-wall planetary SiC-VPE reactor. This high-throughput reactor has been optimized for the growth of uniform 0.01 to 80-micron thick, specular, device-quality SiC epitaxial layers with low background doping concentrations of <1x1014 cm-3 and intentional p- and n-type doping from ~1x1015 cm-3 to >1x1019 cm-3. Intrawafer layer thickness and n-type doping uniformity (σ/mean) of ~2% and ~8% have been achieved to date in the 8x100-mm configuration. The total range of the average intrawafer thickness and doping within a run are approximately ±1% and ±6% respectively.

Novel Scanning Immersion Lithography for 3D Microfabrication

2012 ◽  
Vol 249-250 ◽  
pp. 747-751
Author(s):  
Yi Cheng Chen ◽  
Shi Chang Tseng
Keyword(s):  
Surface Quality ◽  
Experimental Results ◽  
Mask Pattern ◽  
Large Area ◽  
Immersion Lithography ◽  
3D Microstructure ◽  
Smooth Movement ◽  
Optical Applications ◽  
First Time ◽  
Lithography Technique

We propose the first time combining the merit of scanning and immersion lithography to fabricate 3D microstructure in this study. Via applying a matching liquid to reduce the diffraction error, the gap between the mask/resist becomes more tolerable. In addition, the liquid also act as a lubricant and a buffer for smooth movement of the mask/substrate. These advantages will benefit the performance of scanning lithography technique. The experimental results show that the large-area, 3D microstructure with excellent surface quality (Ravg<10 nm) can be successively fabricated based on this method. Besides, 3D microstructures with various geometries and functionalities can be generated by altering the shape of the mask pattern, or changing the scanning directions. The proposed SIL technique seems to be a promising way for fabricating 3D microstructure for optical applications.

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