Sublimation Growth of Bulk AlN Crystals on SiC Seeds

2013 ◽  
Vol 740-742 ◽  
pp. 95-98 ◽  
Author(s):  
E.N. Mokhov ◽  
A.A. Wolfson ◽  
A.O. Avdeev ◽  
S.S. Nagalyuk ◽  
D. P. Litvin ◽  
...  
Keyword(s):  
Surface Layer ◽  
Dislocation Density ◽  
High Purity ◽  
Bulk Crystals ◽  
Considerable Decrease ◽  
Vapor Source ◽  
X Ray ◽  
Low Dislocation Density ◽  
Sandwich Method ◽  
Sublimation Growth

AlN bulk crystals were grown by the sublimation “sandwich method” on the SiC substrates. Two types of containers were used: (i) Ta container with a surface layer of TaC created by the special annealing in contact with carbon, (ii) TaC container created by pressing of TaC powder. Cryptocrystalline AlN wafers grown by oversublimation of the original industrial high purity AlN powder were used as a vapor source. So a considerable decrease of oxygen concentration in the source (10 – 30 times) was achieved. 4H and 6H SiC bulk crystals grown by Nitride Crystals, Ltd., which were used as wafers, were crack-free, micropipe-free and have a low dislocation density (1- 4.103cm-2). The method allowed to grow thick AlN bulk crystals up to 5mm height and up to two inches in diameter with smooth mirror-like surface. X-ray diffractometry and topography of the grown AlN layers show that FWHMs of the rocking curves in ω-scan lie in the range of 60-120 arcsec.

Determination of the type of stacking faults in single-crystal high-purity diamond with a low dislocation density of <50 cm−2by synchrotron X-ray topography

2016 ◽  
Vol 55 (4) ◽  
pp. 040303 ◽  
Author(s):  
Satoshi Masuya ◽  
Kenji Hanada ◽  
Takumi Uematsu ◽  
Tomoya Moribayashi ◽  
Hitoshi Sumiya ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Single Crystal ◽  
High Purity ◽  
Stacking Faults ◽  
X Ray ◽  
Low Dislocation Density

Single-Crystal Aluminum Nitride Substrate Preparation from Bulk Crystals

2001 ◽  
Vol 680 ◽  
Author(s):  
J. Carlos Rojo ◽  
Leo J. Schowalter ◽  
Kenneth Morgan ◽  
Doru I. Florescu ◽  
Fred H. Pollak ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Analysis ◽  
Dislocation Density ◽  
Single Crystal ◽  
High Strain ◽  
Bulk Crystals ◽  
Scanning Thermal Microscopy ◽  
Substrate Preparation ◽  
X Ray ◽  
Differential Expansion

ABSTRACTLarge (15mm diameter) single-crystal AlN boules have been prepared using sublimationrecondensation growth. X-ray topography shows that the dislocation density averages less than 103 cm2 in some of the substrates but also that the dislocations are not uniformly distributed. Also, strain due to the differential expansion with the crucible walls seems to cause severe cracking in the periphery of the crystal and high-strain regions. Thermal analysis using the Scanning Thermal Microscopy (SThM) reveals a thermal conductivity of 3.4 ± 0.2 W/K-cm, which is the largest value ever reported for AlN.

scholarly journals Gallium nitride films grown on AlN/sapphire templates

2020 ◽  
Author(s):  
Jin Wu
Keyword(s):  
Gallium Nitride ◽  
Dislocation Density ◽  
Carrier Concentration ◽  
Hall Mobility ◽  
High Quality ◽  
Rocking Curve ◽  
X Ray ◽  
Low Dislocation Density

High-quality GaN films were grown on AlN/c-sapphire templates by MOVPE with Hall mobility of 802 cm2/V.s and carrier concentration of 8.1x1016/cm3 at 300K have achieved. The film low dislocation density of 5x107 cm-2 and X-ray rocking curve FWHM of 101 and 250 arcsec for the (0004) and (20-24) reflections were also obtained, respectively.

Detailed Characterisations of GaAs Films on Si Obtained by Conformal Growth.

1992 ◽  
Vol 280 ◽  
Author(s):  
B. Gerard ◽  
D. Pribat ◽  
R. Bisaro ◽  
E. Costard ◽  
J. Nagle ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Dislocation Density ◽  
The Self ◽  
Epitaxial Lateral Overgrowth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lateral Overgrowth ◽  
State Of Stress ◽  
Low Dislocation Density ◽  
Gaas Films

ABSTRACTConformal growth is a confined epitaxial lateral overgrowth technique capable of yielding low dislocation density GaAs films on Si. This technique makes extensive use of selective epitaxy and crystal growth is confined by a dielectric cap as well as by the self-passivated Si surface itself.In this paper, we have performed a detailed characterisation of the state of stress of the GaAs films in various configurations (after conformal growth and removal of the seed regions, and after the regrowth of an MBE layer) by photoluminescence measurements at 5K and X-ray diffraction experiments. Although the as-grown conformal films are found in the same state of stress than reference MOCVD GaAs epilayers on Si, we report a significant decrease of this stress after MBE regrowth on conformal films.

Anomalous x-ray transmission study of low-dislocation-density aluminum crystals

1972 ◽  
Vol 11 (1) ◽  
pp. 263-274 ◽  
Author(s):  
B. Nøst ◽  
B. C. Larson ◽  
F. W. Young
Keyword(s):  
Dislocation Density ◽  
X Ray ◽  
Low Dislocation Density ◽  
Transmission Study

Sublimation Growth of AlN and GaN Bulk Crystals on SiC Seeds

2013 ◽  
Vol 740-742 ◽  
pp. 81-84 ◽  
Author(s):  
E.N. Mokhov ◽  
A.A. Wolfson ◽  
H. Helava ◽  
Yu. Makarov
Keyword(s):  
Semiconductor Devices ◽  
Crystal Quality ◽  
Bulk Crystals ◽  
High Quality ◽  
Temperature Range ◽  
Sandwich Method ◽  
Kinetic Mechanisms ◽  
Sublimation Growth

Growth techniques of high quality AlN and GaN bulk crystals on SiC seeds by sublimation sandwich method are presented. GaN crystals were grown in the temperature range of 1100-1250 °C and with addition of ammonia (NH3) to prevent GaN decomposition. GaN powder or metallic Ga was used as the source. AlN crystals up to 2 inch diameter have been grown on SiC seeds in the temperature range of 1950 -2050 0С. Kinetic mechanisms and transport features in the sandwich cell are discussed. The achieved high crystal quality has allowed producing semiconductor devices on their basis, in particular, ultraviolet LEDs

scholarly journals High quality gallium nitride films grown on epitaxial AlN/sapphire templates

2020 ◽  
Author(s):  
Jin Wu
Keyword(s):  
Gallium Nitride ◽  
Dislocation Density ◽  
Carrier Concentration ◽  
Hall Mobility ◽  
High Quality ◽  
Rocking Curve ◽  
X Ray ◽  
Low Dislocation Density

High-quality GaN films were grown on AlN/c-sapphire templates by MOVPE with Hall mobility of 802 cm2/V.s and carrier concentration of 8.1x1016/cm3 at 300K have achieved. The film low dislocation density of 5x107 cm-2 and X-ray rocking curve FWHM of 101 and 250 arcsec for the (0004) and (20-24) reflections were also obtained, respectively.

Preparation Method of High Purity Aluminum Single Crystals with Low Dislocation Density

1978 ◽  
Vol 17 (4) ◽  
pp. 611-616 ◽  
Author(s):  
Yasuhiko Deguchi ◽  
Nobuo Kamigaki ◽  
Kenji Kashiwaya ◽  
Takao Kino
Keyword(s):  
Dislocation Density ◽  
Single Crystals ◽  
High Purity ◽  
Preparation Method ◽  
Low Dislocation Density ◽  
High Purity Aluminum

Trials of Solution Growth of Dislocation-Free 4H-SiC Bulk Crystals

2016 ◽  
Vol 858 ◽  
pp. 19-22 ◽  
Author(s):  
Katsunori Danno ◽  
Satoshi Yamaguchi ◽  
Hiroyuki Kimoto ◽  
Kazuaki Sato ◽  
Takeshi Bessho
Keyword(s):  
Dislocation Density ◽  
Grown Crystal ◽  
Seed Crystal ◽  
Solution Growth ◽  
Growth Surface ◽  
Threading Dislocation ◽  
Bulk Crystals ◽  
Low Dislocation Density ◽  
Crystal Diameter ◽  
Growth Dislocation

Solution growth of high-quality 4H-SiC bulk crystals has been performed by using Si-Cr based melt at 2000°C. Through enlargement of crystal diameter which is controlled by meniscus height during growth, dislocation free area has been successfully obtained on the periphery of the crystal. However, the threading dislocations in the seed crystal have penetrated into the grown crystal and have been located around the center of the crystal. To reduce dislocation density in the grown crystals, we have used threading-dislocation-free seedcrystals prepared by solution growth on (1-100). The solution growth on the seed crystal sliced from the (1-100) crystal has resulted in very low dislocation density of grown crystals. In an area of 16 mm2 for the growth surface, no dislocation has been detected.

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