scholarly journals Nucleation Control in Physical Vapor Transport Growth of AlN Single Crystals on Polycrystal Tungsten Substrates

2019 ◽  
Vol 26 (2) ◽  
pp. 139-142
Author(s):  
Honglei WU ◽  
Zuoyan QIN ◽  
Xueyong TIAN ◽  
Zhenhua SUN ◽  
Baikui LI ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Temperature Field ◽  
High Temperature ◽  
Single Crystals ◽  
Thermal Gradient ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Heating Process ◽  
X Ray ◽  
Tungsten Substrate

The improved resistively-heated furnace with two heaters established a vertical thermal gradient to control nucleation during AlN single crystals Physical Vapor Transport (PVT) growth on polycrystal tungsten substrates. During the high temperature (> 1850 °C) heating process, the reverse temperature field (i.e., the temperature difference between the sublimation zone and the crystalline zone ΔT < 0) was obtained to reduce the number of nuclei on the tungsten substrate. During growth, the proper positive values of ΔT T were chosen to content the supersaturation values (0.25 < S < 0.3). The reverse temperature condition during high temperature (> 1850 °C) cooling was fulfilled to avoid recrystallization on grown AlN crystal. AlN single crystals made through the method were characterized by X-ray diffractions (XRD) and Raman spectroscopy.

Synchrotron X-ray Topography Studies of the Evolution of the Defect Microstructure in Physical Vapor Transport Grown 4H-SiC Single Crystals

2013 ◽  
Vol 58 (4) ◽  
pp. 315-324 ◽  
Author(s):  
M. Dudley ◽  
B. Raghothamachar ◽  
H. Wang ◽  
F. Wu ◽  
S. Byrappa ◽  
...  
Keyword(s):  
Single Crystals ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
X Ray ◽  
Defect Microstructure

PVT Growth of 6H SiC Crystals and Defect Characterization

2004 ◽  
Vol 815 ◽  
Author(s):  
Govindhan Dhanaraj ◽  
Feng Liu ◽  
Michael Dudley ◽  
Hui Zhang ◽  
Vish Prasad
Keyword(s):  
Numerical Modeling ◽  
Temperature Field ◽  
Single Crystals ◽  
Chemical Etching ◽  
Growth Parameters ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Defect Characterization ◽  
Sublimation Method ◽  
Hot Zone

AbstractSiC single crystals have been grown by seeded sublimation method using physical vapor transport (PVT) system designed and fabricated in our laboratory. A novel multi-segmented graphite insulation has been used for improved heat containment in the hot-zone. Numerical modeling was used to obtain the temperature field and predict various growth parameters. The grown crystals were characterized using AFM, SWBXT and chemical etching.

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

Parameters of substrates–single crystals of ZnTe and Cd1−xZnxTe (x<0.25), obtained by physical vapor transport technique (PVT)

1999 ◽  
Vol 197 (3) ◽  
pp. 423-426 ◽  
Author(s):  
A Mycielski ◽  
A Szadkowski ◽  
E Łusakowska ◽  
L Kowalczyk ◽  
J Domagała ◽  
...  
Keyword(s):  
Single Crystals ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Transport Technique

Modified Physical Vapor Transport Growth of SiC - Control of Gas Phase Composition for Improved Process Conditions

2005 ◽  
Vol 483-485 ◽  
pp. 25-30 ◽  
Author(s):  
Peter J. Wellmann ◽  
Thomas L. Straubinger ◽  
Patrick Desperrier ◽  
Ralf Müller ◽  
Ulrike Künecke ◽  
...  
Keyword(s):  
Temperature Field ◽  
Phase Composition ◽  
Gas Phase ◽  
Growth Conditions ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Process Conditions ◽  
Growth Technique ◽  
Experimental Implementation ◽  
P Type

We review the development of a modified physical vapor transport (M-PVT) growth technique for the preparation of SiC single crystals which makes use of an additional gas pipe into the growth cell. While the gas phase composition is basically fixed in conventional physical vapor transport (PVT) growth by crucible design and temperature field, the gas inlet of the MPVT configuration allows the direct tuning of the gas phase composition for improved growth conditions. The phrase "additional" means that only small amounts of extra gases are supplied in order to fine-tune the gas phase composition. We discuss the experimental implementation of the extra gas pipe and present numerical simulations of temperature field and mass transport in the new growth configuration. The potential of the growth technique will be outlined by showing the improvements achieved for p-type doping of 4H-SiC with aluminum, i.e. [Al]=9⋅1019cm-3 and ρ<0.2Ωcm, and n-type doping of SiC with phosphorous, i.e. [P]=7.8⋅1017cm-3.

Structural-phase transition in (Cu2Te)2−x(ZnTe)x at high temperature

2021 ◽  
pp. 2150113
Author(s):  
H. B. Gasimov ◽  
R. M. Rzayev
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
High Temperature ◽  
Single Crystals ◽  
Structural Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Range ◽  
Xrd Study ◽  
Xrd Method

Cu2Te single crystal was grown by the Bridgman method. X-ray diffraction (XRD) study of Cu2Te single crystals in the temperature range of 293–893 K was performed and possible phase transitions in the mentioned range of temperature have been investigated. (Cu2Te)[Formula: see text](ZnTe)[Formula: see text] single crystals also were grown with [Formula: see text], 0.05, 0.10 concentrations and structural properties of the obtained single crystals were investigated by the XRD method in the temperature range 293–893 K. Lattice parameters and possible phase transitions in the mention temperature range were determined for (Cu2Te)[Formula: see text](ZnTe)[Formula: see text] single crystals for [Formula: see text], 0.05, 0.10 concentrations.

Sign in / Sign up

Export Citation Format

Share Document