Modeling of the PVT Growth Process of Bulk 3C-SiC - Growth Process Development and Challenge of the Right Materials Data Base

2019 ◽  
Vol 963 ◽  
pp. 157-160 ◽  
Author(s):  
Michael Schöler ◽  
Philipp Schuh ◽  
Johannes Steiner ◽  
Peter J. Wellmann
Keyword(s):  
Electrical Conductivity ◽  
Growth Process ◽  
Process Development ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Temperature Dependency ◽  
Free Standing ◽  
Growth Interface ◽  
Materials Properties ◽  
The Right

We report on the modeling of the temperature field and supersaturation in front of the SiC crystal growth interface of a physical vapor transport growth configuration. The data are compared with experimental results, like the growth of free standing 3C-SiC wafers with a diameter of 50 mm and a thickness of 870 µm. Special emphases is put on the precise handling of the materials properties which include the temperature dependency of the heat and electrical conductivity of the graphite parts at temperatures above 2000 °C.

Resistivity Distribution in Undoped 6H-SiC Boules and Wafers

2006 ◽  
Vol 527-529 ◽  
pp. 51-54 ◽  
Author(s):  
Qiang Li ◽  
A.Y. Polyakov ◽  
Marek Skowronski ◽  
Edward K. Sanchez ◽  
Mark J. Loboda ◽  
...  
Keyword(s):  
Cross Section ◽  
Growth Process ◽  
Growth Direction ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Growth Axis ◽  
Compensation Mechanisms ◽  
The Cross ◽  
Electron And Hole Traps

For undoped 6H-SiC boules grown by physical vapor transport the variations of resistivity, of the type and density of deep electron and hole traps, and of the concentration of nitrogen and boron were studied as a function of position in the cross section normal to the growth axis and along the growth direction. It was observed that the concentrations of all deep electron and hole traps decreased when moving from seed to tail of the boule and from the center to the edge of the wafers. Modeling of the growth process suggests that the C/Si ratio increases in a similar fashion and could be responsible for observed changes. We also discuss the implications of such stoichiometry changes on compensation mechanisms rendering the crystals semi-insulating and on electrical uniformity of SI-SiC wafers.

Free Standing AlN Single Crystal Grown on Pre-Patterned and In Situ Patterned 4H-SiC Substrates

2010 ◽  
Vol 645-648 ◽  
pp. 1187-1190 ◽  
Author(s):  
Gholam Reza Yazdi ◽  
Konstantin Vassilevski ◽  
José M. Córdoba ◽  
Daniela Gogova ◽  
Irina P. Nikitina ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Free Standing ◽  
Patterned Substrate ◽  
Low Dislocation Density ◽  
Temperature Ramp ◽  
Transport Method ◽  
Vapor Transport Method

Free standing AlN wafers were grown on pre-patterned and in situ patterned 4H-SiC substrates by a physical vapor transport method. It is based on the coalescence of AlN microrods, which evolve from the apex of SiC pyramids grown on the SiC substrate during a temperature ramp up for in situ patterned substrate and SiC pyramids formed by reactive ion etching (RIE). This process yields stress-free (according XRD and Raman results) AlN single crystals with a thickness up to 400 µm and low dislocation density.

Hydrogen Effect on SiC Single Crystal Prepared by the Physical Vapor Transport Method

2007 ◽  
Vol 556-557 ◽  
pp. 25-28 ◽  
Author(s):  
Jung Gon Kim ◽  
Joon Ho An ◽  
Jung Doo Seo ◽  
Jung Kyu Kim ◽  
Myung Ok Kyun ◽  
...  
Keyword(s):  
Single Crystal ◽  
Carrier Concentration ◽  
Growth Process ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Hydrogen Effect ◽  
Hydrogen Addition ◽  
Bulk Growth ◽  
Transport Method ◽  
Concentration Levels

We investigated the effects of hydrogen addition to the growth process of SiC single crystal using sublimation physical vapor transport (PVT) techniques. Hydrogen was periodically added to an inert gas for the growth ambient during the SiC bulk growth. Grown 2”-SiC single crystals were proven to be the polytype of 6H-SiC and carrier concentration levels of about 1017/cm3 was determined from Hall measurements. As compared to the characteristics of SiC crystal grown without using hydrogen addition, the SiC crystal grown with periodically modulated hydrogen addition definitely exhibited lower carrier concentration and lower micropipe density as well as reduced growth rate.

Aluminum P-Type Doping of Bulk SiC Single Crystals by Tri-Methyl-Aluminum

2008 ◽  
Vol 600-603 ◽  
pp. 19-22 ◽  
Author(s):  
Philip Hens ◽  
Ulrike Künecke ◽  
Peter J. Wellmann
Keyword(s):  
Carrier Mobility ◽  
Growth Process ◽  
Charge Carrier Mobility ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Crystal Growth Process ◽  
Conductivity Increase ◽  
A Charge ◽  
P Type ◽  
Dopant Precursor

We present p-type doping of bulk SiC crystals by the modified physical vapor transport (M-PVT) technique using TMA (Tri-Methyl-Aluminum). Using TMA as a dopant precursor allows a quite well defined crystal growth process control. The issue of improvement of conductivity (reduction of substrate resistivity) by reduction of unintentional acceptor compensation by nitrogen is addressed. It is shown that a decrease of compensation from approx. 3%...10% to approx. 0.5%...2.5% leads to a charge carrier mobility and, hence, conductivity increase of about factor two.

Knoop Hardness on the (0001) Plane of 4H and 6H SiC Single Crystals Fabricated by Physical Vapor Transport

2014 ◽  
Author(s):  
Jeffrey J. Swab ◽  
James W. McCauley ◽  
Brady Butler ◽  
Daniel Snoha ◽  
Donovan Harris ◽  
...  
Keyword(s):  
Single Crystals ◽  
Knoop Hardness ◽  
Vapor Transport ◽  
Physical Vapor Transport

High thermal conductivity of pure dense SiC ceramics prepared via HTPVT

2019 ◽  
Vol 12 (03) ◽  
pp. 1950032 ◽  
Author(s):  
Yuchen Deng ◽  
Yaming Zhang ◽  
Nanlong Zhang ◽  
Qiang Zhi ◽  
Bo Wang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Silicon Carbide ◽  
Grain Size ◽  
Phase Composition ◽  
Room Temperature ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Growth Substrate ◽  
Sic Ceramics ◽  
Evolution Of Microstructure

Pure dense silicon carbide (SiC) ceramics were obtained via the high-temperature physical vapor transport (HTPVT) method using graphite paper as the growth substrate. The phase composition, the evolution of microstructure, the thermal diffusivity and thermal conductivity at RT to 200∘C were investigated. The obtained samples had a relative density of higher than 98.7% and a large grain size of 1[Formula: see text]mm, the samples also had a room-temperature thermal conductivity of [Formula: see text] and with the temperature increased to 200∘C, the thermal conductivity still maintained at [Formula: see text].

scholarly journals In Pursuit of the Perfect Dancer’s Ballet Foot. The Footprint, Stabilometric, Pedobarographic Parameters of Professional Ballet Dancers

Biology ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 435
Author(s):  
Joanna Gorwa ◽  
Robert Michnik ◽  
Katarzyna Nowakowska-Lipiec
Keyword(s):  
Reference Group ◽  
Mean Value ◽  
Free Standing ◽  
Foot Pressure ◽  
Ballet Dancers ◽  
Professional Career ◽  
Foot Length ◽  
Weekly Training ◽  
Rear Part ◽  
The Right

This work aims to assess footprint parameters in a group of professional ballet dancers and to determine the correlation between the aforementioned parameters and lateralization, stabilometric parameters, pedobarographic parameters and work environment conditions. A group subjected to tests consisted of 44 elite professional ballet dancers and the reference group was composed of 44 students. The test of balance and thrust under feet involved 30 s-long free standing with open eyes on a podographic platform. The research-related analysis was concerned with footprint parameters (foot length and width, Clarke angle, and Weissflog index), stabilometric parameters (path length and ellipse field, mean value of the velocity and deflection of the displacement of the center of the foot pressure on the ground) and pedobarographic parameters (percentage thrust on the right, left foot as well as the front and rear part the foot). Statistically significant differences between the groups were observed in relation to the stabilometric parameters, the percentage pressure of the left forefoot and the right heel, as well as the value of the Clarke angle (p ≤ 0.05). The longitudinal arch of the foot and the width of the foot in ballet dancers are not dependent on the total and professional career duration and weekly training volume

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