Ni reactions with surfaces: dependence of gettering efficiencies for Ni on crystal-growth conditions, back-side-gettering techniques, oxygen precipitates and thermal treatments

2002 ◽  
Vol 74 (5) ◽  
pp. 711-718 ◽  
Author(s):  
R. Hölzl ◽  
L. Fabry ◽  
K.-J. Range
Keyword(s):  
Crystal Growth ◽  
Growth Conditions ◽  
Thermal Treatments ◽  
Back Side ◽  
Oxygen Precipitates

Néel temperature of zinc-blende, MBE-grown MnTe layers: modification by the crystal growth conditions

2004 ◽  
Vol 1 (4) ◽  
pp. 953-956 ◽  
Author(s):  
W. Szuszkiewicz ◽  
E. Dynowska ◽  
J. Z. Domagala ◽  
E. Janik ◽  
E. Łusakowska ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Growth Conditions ◽  
Neel Temperature ◽  
Néel Temperature ◽  
Zinc Blende

Bulk laser damage of large-size KDP crystals obtained at various crystal growth conditions

1994 ◽  
Author(s):  
Marina I. Kolybayeva ◽  
Igor M. Pritula ◽  
Viacheslav M. Puzikov ◽  
Vitaly I. Salo ◽  
Serge V. Garnov ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Growth Conditions ◽  
Laser Damage ◽  
Large Size ◽  
Kdp Crystals

Optimization of Bulk Hgcdte Growth in a Directional Solidification Furnace by Numerical Simulation

1995 ◽  
Vol 398 ◽  
Author(s):  
A.V. Bune ◽  
D.C. Gillies ◽  
S.L. Lehoczky
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Finite Element ◽  
Crystal Growth ◽  
Numerical Model ◽  
Directional Solidification ◽  
Growth Conditions ◽  
Finite Element Code ◽  
Interface Shape ◽  
Solidification Furnace

ABSTRACTA numerical model of heat transfer by combined conduction, radiation and convection was developed using the FIDAP finite element code for NASA's Advanced Automated Directional Solidification Furnace (AADSF). The prediction of the temperature gradient in an ampoule with HgCdTe is a necessity for the evaluation of whether or not the temperature set points for furnace heaters and the details of cartridge design ensure optimal crystal growth conditions for this material and size of crystal. A prediction of crystal/melt interface shape and the flow patterns in HgCdTe are available using a separate complementary model.

scholarly journals Macrodefects in Cubic Silicon Carbide Crystals

2010 ◽  
Vol 645-648 ◽  
pp. 375-378 ◽  
Author(s):  
Valdas Jokubavicius ◽  
Justinas Palisaitis ◽  
Remigijus Vasiliauskas ◽  
Rositza Yakimova ◽  
Mikael Syväjärvi
Keyword(s):  
Growth Rate ◽  
Silicon Carbide ◽  
Crystal Growth ◽  
High Temperature ◽  
Temperature Gradient ◽  
Early Stage ◽  
Growth Conditions ◽  
Temperature Ramp ◽  
Cubic Silicon Carbide ◽  
Sublimation Growth

Different sublimation growth conditions of 3C-SiC approaching a bulk process have been investigated with the focus on appearance of macrodefects. The growth rate of 3C-SiC crystals grown on 6H-SiC varied from 380 to 460 μm/h with the thickness of the crystals from 190 to 230 μm, respectively. The formation of macrodefects with void character was revealed at the early stage of 3C-SiC crystal growth. The highest concentration of macrodefects appears in the vicinity of the domain in samples grown under high temperature gradient and fastest temperature ramp up. The formation of macrodefects was related to carbon deficiency which appear due to high Si/C ratio which is used to enable formation of the 3C-SiC polytype.

scholarly journals Optimization of the SiC Powder Source Material for Improved Process Conditions During PVT Growth of SiC Boules

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3272
Author(s):  
Ellefsen ◽  
Arzig ◽  
Steiner ◽  
Wellmann ◽  
Runde
Keyword(s):  
Crystal Growth ◽  
Size Distribution ◽  
Growth Conditions ◽  
Source Material ◽  
Process Time ◽  
Process Conditions ◽  
Powder Size ◽  
Growth Interface ◽  
X Ray

We have studied the influence of different SiC powder size distributions and the sublimation behavior during physical vapor transport growth of SiC in a 75 mm and 100 mm crystal processing configuration. The evolution of the source material as well as of the crystal growth interface was carried out using in situ 3D X-ray computed tomography (75 mm crystals) and in situ 2D X-ray visualization (100 mm crystals). Beside the SiC powder size distribution, the source materials differed in the maximum packaging density and thermal properties. In this latter case of the highest packaging density, the in situ X-ray studies revealed an improved growth interface stability that enabled a much longer crystal growth process. During process time, the sublimation-recrystallization behavior showed a much smoother morphology change and slower materials consumption, as well as a much more stable shape of the growth interface than in the cases of the less dense SiC source. By adapting the size distribution of the SiC source material we achieved to significantly enhance stable growth conditions.

scholarly journals Current status of GaN crystal growth by sublimation sandwich technique

1998 ◽  
Vol 3 ◽  
Author(s):  
P. G. Baranov ◽  
E. N. Mokhov ◽  
A. O. Ostroumov ◽  
M. G. Ramm ◽  
M. S. Ramm ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Growth Process ◽  
Growth Conditions ◽  
Current Status ◽  
Gaseous Species ◽  
Double Crystal ◽  
Paramagnetic Resonance ◽  
Sandwich Technique ◽  
Microscopy Technique ◽  
Gan Crystal

The current status of GaN crystal growth using the Sublimation Sandwich Technique is discussed in the paper. We use modeling to analyze gas dynamics in the reactor and the supply of the main gaseous species into the growth cell under growth conditions used in experiments. Important features of growth process — non-equilibrium cracking of ammonia, partial sticking of ammonia at the growing surface and kinetic limitation of GaN thermal decomposition — are taken into account in the model. Growth is carried out on sapphire and 6H-SiC substrates in ammonia atmosphere using a Ga/GaN mixture as the group-III element source. Single crystals of GaN of size 15×15 mm and up to 0.5 mm thick are normally grown with the optimized growth rates of 0.25-0.35 mm/h. The GaN crystals are characterized by photoluminescence, by the Color Cathodoluminescence Scanning Electron Microscopy technique, by differential double-crystal and triple-crystal X-ray diffractometry, and by electron paramagnetic resonance. Mechanisms of sublimation growth of GaN and physical limitations of the growth process are discussed.

Correlation between ZnSe Crystal Growth Conditions from Melt and Generation of Large-Angle Grain Boundaries and Twins

1994 ◽  
Vol 33 (Part 1, No. 4A) ◽  
pp. 1991-1994 ◽  
Author(s):  
Peter Rudolph ◽  
Kazuyuki Umetsu ◽  
Han Jun Koh ◽  
Tsuguo Fukuda
Keyword(s):  
Crystal Growth ◽  
Grain Boundaries ◽  
Large Angle ◽  
Growth Conditions ◽  
Znse Crystal

The Effect of D-Defect in Silicon Single Crystal on Oxygen Precipitation

1992 ◽  
Vol 262 ◽  
Author(s):  
I. Fusegawa ◽  
N. Fujimaki ◽  
H. Yamagishi
Keyword(s):  
Crystal Growth ◽  
Single Crystal ◽  
Single Crystals ◽  
Thermal Process ◽  
Flow Patterns ◽  
Optical Microscope ◽  
Silicon Single Crystal ◽  
Thermal Treatments ◽  
Oxygen Precipitation ◽  
Predominant Factor

ABSTRACTWe investigated the effect of D-defect in CZ silicon single crystals on the oxygen precipitation by two-step thermal treatments consisting of the first annealing in nitrogen ambient at 1073K and the second annealing in dry oxygen ambient at 1273K. The density of D-defect was measured by counting ‘flow patterns’ using an optical microscope after preferential etching in Secco's solution for 30 minutes. It was found that the amount of oxygen precipitation along the growth axis was not affected by D-defect. The predominant factor of the oxygen precipitation after the two-step thermal process is the nuclei of oxygen precipitation generated around 723K during CZ crystal growth.

Intrinsic Point Defects in Silicon Crystal Growth

2011 ◽  
Vol 178-179 ◽  
pp. 3-14 ◽  
Author(s):  
Vladimir V. Voronkov ◽  
Robert Falster
Keyword(s):  
Crystal Growth ◽  
Point Defects ◽  
Vacancy Concentration ◽  
Silicon Crystal ◽  
Growth Conditions ◽  
Intrinsic Point Defects ◽  
Silicon Crystals ◽  
Low Concentrations ◽  
Different Populations ◽  
Vacancy Concentrations

In dislocation-free silicon, intrinsic point defects – either vacancies or self-interstitials, depending on the growth conditions - are incorporated into a growing crystal. Their incorporated concentration is relatively low (normally, less than 1014 cm-3 - much lower than the concentration of impurities). In spite of this, they play a crucial role in the control of the structural properties of silicon materials. Modern silicon crystals are grown mostly in the vacancy mode and contain many vacancy-based agglomerates. At typical grown-in vacancy concentrations the dominant agglomerates are voids, while at lower vacancy concentrations there are different populations of joint vacancy-oxygen agglomerates (oxide plates). Larger plates – formed in a narrow range of vacancy concentration and accordingly residing in a narrow spatial band – are responsible for the formation of stacking fault rings in oxidized wafers. Using advanced crystal growth techniques, whole crystals can be grown at such low concentrations of vacancies or self-interstitials such that they can be considered as perfect.

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