scholarly journals The Physical Vapor Transport Method for Bulk AlN Crystal Growth

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1562 ◽  
Author(s):  
Wen-Hao Chen ◽  
Zuo-Yan Qin ◽  
Xu-Yong Tian ◽  
Xu-Hui Zhong ◽  
Zhen-Hua Sun ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Temperature Gradient ◽  
Single Crystals ◽  
Low Cost ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Inverse Temperature ◽  
Seeded Growth ◽  
Perforated Sheet

In this report, the development of physical vapor transport (PVT) methods for bulk aluminum nitride (AlN) crystal growth is reviewed. Three modified PVT methods with different features including selected growth at a conical zone, freestanding growth on a perforated sheet, and nucleation control with an inverse temperature gradient are discussed and compared in terms of the size and quality of the bulk AlN crystals they can produce as well as the process complexity. The PVT method with an inverse temperature gradient is able to significantly reduce the nucleation rate and realize the dominant growth of only one bulk AlN single crystal, and thus grow centimeter-sized bulk AlN single crystals. X-ray rocking curve (XRC) and Raman spectroscopy measurements showed a high crystalline quality of the prepared AlN crystals. The inverse temperature gradient provides an efficient and relatively low-cost method for the preparation of large-sized and high-quality AlN seed crystals used for seeded growth, devoted to the diameter enlargement and quality improvement of bulk AlN single crystals.

The Effect of Modified Crucible Design and Seed Attachment on SiC Crystal Grown by PVT

2013 ◽  
Vol 740-742 ◽  
pp. 77-80
Author(s):  
Jung Young Jung ◽  
Sang Il Lee ◽  
Mi Seon Park ◽  
Doe Hyung Lee ◽  
Hee Tae Lee ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Temperature Gradient ◽  
Single Crystals ◽  
Crystal Quality ◽  
Full Width ◽  
Half Maximum ◽  
Radial Temperature Gradient ◽  
Radial Temperature ◽  
Better Than

The present research was focused to investigate the effect of internal crucible design that influenced the 4H-SiC crystal growth onto a 6H-SiC seed by PVT method. The crucible design was modified to produce a uniform radial temperature gradient in the growth cell. The seed attachment was also modified with a use of polycrystalline SiC plate. The crystal quality of 4H-SiC single crystals grown in modified crucible and grown with modified seed attachment was revealed to be better than that of crystal grown in conventional crucible. The full width at half maximum (FWHM) values of grown SiC crystals in the conventional crucible, the modified seed attachment and the modified crucible were 285 arcsec, 134 arcsec and 128 arcsec, respectively. The micropipe density (MPD) of grown SiC crystals in the conventional crucible, the modified seed attachment and the modified crucible were 101ea/cm^2, 81ea/cm^2 and 42ea/cm^2, respectively.

Seeded growth of AlN single crystals by physical vapor transport

2006 ◽  
Vol 287 (2) ◽  
pp. 372-375 ◽  
Author(s):  
D. Zhuang ◽  
Z.G. Herro ◽  
R. Schlesser ◽  
Z. Sitar
Keyword(s):  
Single Crystals ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Seeded Growth

Effect of Temperature Gradient on AlN Crystal Growth by Physical Vapor Transport Method

2019 ◽  
Vol 19 (11) ◽  
pp. 6736-6742 ◽  
Author(s):  
Guodong Wang ◽  
Lei Zhang ◽  
Yong Wang ◽  
Yongliang Shao ◽  
Chengmin Chen ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Temperature Gradient ◽  
Vapor Transport ◽  
Effect Of Temperature ◽  
Physical Vapor Transport ◽  
Transport Method ◽  
Vapor Transport Method

Grain Expansion and Subsequent Seeded Growth of AlN Single Crystals

2004 ◽  
Vol 831 ◽  
Author(s):  
Dejin Zhuang ◽  
Raoul Schlesser ◽  
Zlatko Sitar
Keyword(s):  
Single Crystals ◽  
Growth Process ◽  
Surface Preparation ◽  
Nitrogen Atmosphere ◽  
Vapor Transport ◽  
Growth Surface ◽  
Seeded Growth ◽  
Single Crystalline ◽  
High Temperature Reactor

ABSTRACTOngoing efforts of growing large AlN single crystals at NCSU using an induction-heated, high-temperature reactor are based on (1) engineered expansion of single crystalline grains with increasing boule length, as well as (2) the development of a growth process that enables seeded growth on AlN surfaces previously exposed to air. The growth process is based on physical vapor transport (PVT), where AlN powder is sublimed in a high purity nitrogen atmosphere. The growth temperature was typically in the range of 2250 to 2300 °C. In this study, tungsten crucibles were used in combination with graphite insulation and were found to be durable for AlN growth. Boule growth was interrupted several times in order to refill the AlN powder source and the growth surface was subjected to surface preparation to facilitate epitaxial re-growth. Grain expansion was studied as a function of process parameters. Crystalline quality of large single crystalline grains was correlated with their surface morphology.

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
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