Status of Large Diameter SiC Single Crystals at II-VI

2008 ◽  
Vol 600-603 ◽  
pp. 35-38 ◽  
Author(s):  
Avinash K. Gupta ◽  
Ilya Zwieback ◽  
Andrew E. Souzis ◽  
Murugesu Yoganathan ◽  
Thomas Anderson
Keyword(s):  
Single Crystals ◽  
Large Diameter ◽  
Lattice Curvature ◽  
Rocking Curve ◽  
Si Substrates ◽  
Edge Defects ◽  
New Generation ◽  
Sublimation Growth ◽  
Lattice Matched

II-VI is developing large-diameter SiC crystals to be used as lattice-matched, high thermal conductivity substrates for new generation GaN-based and SiC-based semiconductor devices. Large-diameter 6H SiC single crystals are grown at II-VI using our Advanced PVT sublimation growth process. Stable SI properties are achieved by compensation with vanadium, which results in high and spatially uniform resistivity, on the order of 1011 Ohm-cm. The quality of the presently grown 100 mm 6H SI substrates has been dramatically improved [1], and they are free of edge defects. Micropipe density in the 100 mm 6H SI substrates ranges from 2 to 8 cm-2 and dislocation density from 3·104 to 6·104 cm-2. X-ray rocking curves measured on as-sawn 100 mm 6H wafers showed edge-to-edge lattice curvature () between 0.1° and 0.3° and FWHM of the rocking curve between 50 and 100 arc-seconds

Growth of Large Diameter 6H SI and 4H n+ SiC Single Crystals

2010 ◽  
Vol 1246 ◽  
Author(s):  
Avinash Gupta ◽  
Ping Wu ◽  
Varatharajan Rengarajan ◽  
Xueping Xu ◽  
Murugesu Yoganathan ◽  
...  
Keyword(s):  
Single Crystals ◽  
Growth Process ◽  
Large Diameter ◽  
Commercial Production ◽  
High Resistivity ◽  
Steady Growth ◽  
Vanadium Doping ◽  
Low Capacitance ◽  
Very High

AbstractSiC single crystals are grown at II-VI by the seeded sublimation technique. The process has been scaled up and optimized to support commercial production of high-quality 100 mm diameter, Semi-Insulating (SI) 6H substrates and 100 mm 4H n+ substrates. The growth process incorporates special elements aimed at achieving uniform sublimation of the source, steady growth rate, uniform doping and reduced presence of background impurities.Semi-insulating 6H substrates are produced using precise vanadium compensation. Vanadium doping is optimized to yield SI material with very high resistivity and low capacitance.Crystal quality of the substrates is evaluated using a wide variety of techniques. Specific defects, their interaction and evolution during growth are described with emphasis on micropipes and dislocations. The current quality of the 6H SI and 4H n+ crystals grown at II-VI is summarized.

Germanium-On-Insulator (GeOI) structure realized by the Smart Cut™ technology

2004 ◽  
Vol 809 ◽  
Author(s):  
F. Letertre ◽  
C. Deguet ◽  
C. Richtarch ◽  
B. Faure ◽  
JM Hartmann ◽  
...  
Keyword(s):  
Cross Sections ◽  
Large Diameter ◽  
Bonding Layer ◽  
Detailed Characterization ◽  
Si Substrates ◽  
First Results ◽  
Defect Densities ◽  
Technological Options ◽  
Roughness Measurements

ABSTRACTFirst results on formation of thin film GeOI structures by the Smart Cut™ technology are presented in this paper. Thin single crystal layers of Ge have been successfully transferred, via oxide bonding layer, onto standard Si substrates with diameters ranging from 100 to 200 mm. Compared to SOI manufacturing, the development of GeOI requires adaptation to the available germanium material, since the starting material can be either bulk Ge or an epitaxial layer. Some results will be presented for GeOI formation according to the different technological options. Germanium splitting kinetics will be discussed and compared to already published results. To show good quality of the GeOI structures, detailed characterization has been done by TEM cross sections for defect densities, interfaces abruptness and layers homogeneities evaluation. AFM was used for surface roughness measurements. These results help define procedures that are required to achieve large diameter high quality GeOI structures.

Growth and Characterization of Large Diameter 6H and 4H SiC Single Crystals

2006 ◽  
Vol 527-529 ◽  
pp. 43-46 ◽  
Author(s):  
A. Gupta ◽  
E. Semenas ◽  
Ejiro Emorhokpor ◽  
J. Chen ◽  
Ilya Zwieback ◽  
...  
Keyword(s):  
Single Crystals ◽  
Growth Process ◽  
Large Diameter ◽  
Growth Technique ◽  
Rocking Curve ◽  
X Ray ◽  
The Past ◽  
Type 3 ◽  
Insulating Properties

Over the past year, II-VI has transitioned from 2” to 3” commercial SiC substrates. Large-diameter semi-insulating 6H-SiC and n-type 4H-SiC single crystals are grown using the Advanced PVT growth process. Expansion of boule diameter from 2 to 3 and up to 4.25 inches has been carried out using a specially designed growth technique. Stable semi-insulating properties in 6H-SiC are achieved by precise vanadium compensation. The technique of compensation is optimized to produce a controlled and spatially uniform distribution of vanadium and high and spatially uniform electrical resistivity reaching 10 10 – 1011 ·cm. N-type 3-inch 4H-SiC crystals are grown using doping with nitrogen, and 3-inch 4H-SiC substrates show uniform resistivity of about 0.018 ·cm. The best quality semiinsulating (SI) 3” 6H-SiC substrates demonstrate micropipe density of 3 cm-2, and n-type 3” 4H-SiC substrates - about 1 cm-2. X-ray rocking curve topography of the produced 3” SiC substrates is used for evaluation of their crystal quality.

Status of Large Diameter SiC Single Crystals

2012 ◽  
Vol 717-720 ◽  
pp. 3-8 ◽  
Author(s):  
Avinash K. Gupta ◽  
Ping Wu ◽  
Varatharajan Rengarajan ◽  
Xue Ping Xu ◽  
Murugesu Yoganathan ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Dislocation Density ◽  
Single Crystals ◽  
Large Diameter ◽  
Crystal Quality ◽  
Commercial Products ◽  
X Ray ◽  
Si Substrates ◽  
Sublimation Technique ◽  
Made In

Large-diameter SiC single crystals are grown at II-VI by the sublimation technique. 100mm substrates of semi-insulating 6H SiC and n-type 4H SiC are produced as commercial products; in development, diameter expansion to 125mm has been achieved. Over the last two years, significant improvements have been made in crystal quality. The values of FWHM of x-ray rocking curves are typically 20-40 arc-seconds for 6H SI wafers and 12-30 arc-seconds for 4H n+ wafers. Micropipe density is less than 3 cm-2, and less than 0.1 cm-2 in best substrates. Electrical resistivity of SI substrates is, typically, of 1011 Ω•cm or above. For 4H n+ substrates, the typical dislocation density is about 9×103 cm-2 and the typical BPD density is less than 1×103 cm-2.

Pendeo Epitaxy Of 3C-SiC on Si Substrates

2000 ◽  
Vol 622 ◽  
Author(s):  
G.E. Carter ◽  
T. Zheleva ◽  
G. Melnychuck ◽  
B. Geil ◽  
K. Jones ◽  
...  
Keyword(s):  
Low Cost ◽  
Large Diameter ◽  
Side Wall ◽  
Cost Effective ◽  
Interface Layer ◽  
Lateral Epitaxial Overgrowth ◽  
Si Substrates ◽  
Device Applications ◽  
Sic Film

ABSTRACTPendeo Epitaxy is a type of Lateral Epitaxial Overgrowth (LEO) that instead of using a dielectric buffer layer, uses an etched substrate to grow laterally without an interface layer. We report the first successful growth of 3C-SiC on Si using Pendeo epitaxy. Rectangular stripes of 3C-SiC on (100) Si substrates were fabricated, along both the [110] and [100] directions. Pendeo epi was only observed for columns parallel to [001], indicating a preferred growth facet for Pendeo epi of 3C-SiC on Si. SEM and TEM investigations were performed to assess the material quality of the Pendeo 3C-SiC material. Films were grown for 60 min at 1310°C and film coalescence was achieved without evidence of voids where the growth fronts joined. TEM data indicate not only the growth of vertical and lateral 3C-SiC on the 3C-SiC seed layer but direct nucleation of 3C-SiC on the exposed Si columns side wall and trench bottom, despite the lack of a carbonization procedure. The quality of the Pendeo 3C-SiC film appears to be of high quality indicating that Pendeo epi of 3C-SiC on low-cost, large-diameter Si substrates may prove to be a cost effective way to grow device-grade SiC layers on Si substrates for device applications.

Modified Hot-Zone Design for Large Diameter 4H-SiC Single Crystal Growth

2019 ◽  
Vol 963 ◽  
pp. 18-21 ◽  
Author(s):  
Jung Woo Choi ◽  
Jung Gyu Kim ◽  
Byung Kyu Jang ◽  
Sang Ki Ko ◽  
Myung Ok Kyun ◽  
...  
Keyword(s):  
Single Crystal ◽  
Large Diameter ◽  
Edge Region ◽  
Rocking Curve ◽  
X Ray ◽  
Maximum Value ◽  
Actual Growth ◽  
Reduced Temperature ◽  
Hot Zone

6-inch 4H-SiC single crystal was grown with modified hot-zone design for large diameter crystal. The simulation data confirmed reduced temperature gradient between center and edge region of growing front, and actual growth experiment exhibited that SiC crystal with good quality was obtained with modified hot-zone design without any quality degradation in edge region of bulk crystal. Based on the mapping measurement of FWHM (Full width at half maximum) value in X-ray rocking curve, the crystal quality of SiC crystals from middle and top region of grown ingot was observed to be almost identical. Furthermore, various properties of SiC crystal grown with modified hot-zone design have been systematically investigated.

X-Ray Rocking Curve Characterization of SiC Substrates

2008 ◽  
Vol 600-603 ◽  
pp. 361-364
Author(s):  
Murugesu Yoganathan ◽  
Ping Wu ◽  
Ilya Zwieback
Keyword(s):  
Growth Process ◽  
Crystal Quality ◽  
Nondestructive Technique ◽  
Lattice Curvature ◽  
Rocking Curve ◽  
X Ray ◽  
Typical Variation

X-ray rocking curve characterization is a relatively fast and nondestructive technique that can be utilized to evaluate the crystal quality of SiC substrates. The contribution of lattice curvature to rocking curve broadening is estimated, and shown to be the major contribution to the measured broadening (FWHM). The feedback on lattice quality is used to optimize our SiC growth process. In the optimized growth runs, the typical variation in rocking curve sample angle Ω across the entire 3” diameter wafer is about 0.2 degrees. Possible mechanisms leading to changes in the lattice curvature are discussed.

Current Progress in Biomedical Applications of Chitosan-Carbon Nanotube Nanocomposites: A Review

2020 ◽  
Vol 20 (16) ◽  
pp. 1619-1632
Author(s):  
Katarzyna Pieklarz ◽  
Michał Tylman ◽  
Zofia Modrzejewska
Keyword(s):  
Carbon Nanotube ◽  
Medical Science ◽  
Antimicrobial Properties ◽  
Polymer Materials ◽  
Biological Macromolecules ◽  
Medical Sciences ◽  
New Generation ◽  
High Degree ◽  
Dressing Materials

The currently observed development of medical science results from the constant search for innovative solutions to improve the health and quality of life of patients. Particular attention is focused on the design of a new generation of materials with a high degree of biocompatibility and tolerance towards the immune system. In addition, apart from biotolerance, it is important to ensure appropriate mechanical and technological properties of materials intended for intra-body applications. Knowledge of the above parameters becomes the basis for considerations related to the possibilities of choosing the appropriate polymer materials. The researchers' interest, as evidenced by the number of available publications, is attracted by nanobiocomposites based on chitosan and carbon nanotubes, which, due to their properties, enable integration with the tissues of the human body. Nanosystems can be used in many areas of medicine. They constitute an excellent base for use as dressing materials, as they exhibit antimicrobial properties. In addition, they can be carriers of drugs and biological macromolecules and can be used in gene therapy, tissue engineering, and construction of biosensors. For this reason, potential application areas of chitosan-carbon nanotube nanocomposites in medical sciences are presented in this publication, considering the characteristics of the system components.

scholarly journals Measuring Key Quality Indicators in Cloud Gaming: Framework and Assessment Over Wireless Networks

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1387
Author(s):  
Oswaldo Sebastian Peñaherrera-Pulla ◽  
Carlos Baena ◽  
Sergio Fortes ◽  
Eduardo Baena ◽  
Raquel Barco
Keyword(s):  
Communication Networks ◽  
Mobile Networks ◽  
Video Game ◽  
Know How ◽  
Fifth Generation ◽  
New Generation ◽  
Graphics Rendering ◽  
The Impact

Cloud Gaming is a cutting-edge paradigm in the video game provision where the graphics rendering and logic are computed in the cloud. This allows a user’s thin client systems with much more limited capabilities to offer a comparable experience with traditional local and online gaming but using reduced hardware requirements. In contrast, this approach stresses the communication networks between the client and the cloud. In this context, it is necessary to know how to configure the network in order to provide service with the best quality. To that end, the present work defines a novel framework for Cloud Gaming performance evaluation. This system is implemented in a real testbed and evaluates the Cloud Gaming approach for different transport networks (Ethernet, WiFi, and LTE (Long Term Evolution)) and scenarios, automating the acquisition of the gaming metrics. From this, the impact on the overall gaming experience is analyzed identifying the main parameters involved in its performance. Hence, the future lines for Cloud Gaming QoE-based (Quality of Experience) optimization are established, this way being of configuration, a trendy paradigm in the new-generation networks, such as 4G and 5G (Fourth and Fifth Generation of Mobile Networks).

Giant power density produced by PIN–PMN–PT ferroelectric single crystals due to a pressure induced polar-to-nonpolar phase transformation

2021 ◽  
Author(s):  
Sergey I. Shkuratov ◽  
Jason Baird ◽  
Vladimir G. Antipov ◽  
Christopher S. Lynch ◽  
Shujun Zhang ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Energy Storage ◽  
Single Crystals ◽  
Power Density ◽  
Ferroelectric Materials ◽  
Power Supplies ◽  
Energy Storage Devices ◽  
Storage Devices ◽  
New Generation ◽  
Power Densities

The search for ferroelectric materials capable of producing high electric charge and power densities is important for developing a new generation of ultrahigh-power-density ferroelectric energy storage devices and autonomous megawatt power supplies.

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