Effect of the Seed Polarity for High Quality 4H-SiC Crystal Grown on 6H-SiC Seed by PVT Method

2011 ◽  
Vol 679-680 ◽  
pp. 44-47
Author(s):  
Im Gyu Yeo ◽  
Tae Woo Lee ◽  
Jong Hwi Park ◽  
Woo Sung Yang ◽  
Heui Bum Ryu ◽  
...  
Keyword(s):  
Growth Rate ◽  
Single Crystal ◽  
Seed Crystal ◽  
Crystal Quality ◽  
High Quality ◽  
Seed Crystals ◽  
Opposite Face ◽  
Crystal Region ◽  
Sublimation Technique

The single crystal ingots by using a sublimation technique were grown on 6H-SiC dual-seed crystals with opposite face polarities and then SiC crystal wafers sliced from the SiC ingot were systematically investigated to find out the polarity dependence of the crystal quality. The growth rate of the SiC crystal grown in this study was about 0.2mm/hr. N-type 2’’ SiC crystals exhibiting the 4H- and 6H-SiC polytype were successfully fabricated on C-face and Si-face, respectively. The incorporation of nitrogen donors in the SiC crystals grown on the C-face seed crystal was exhibited to be higher than in SiC crystals grown on a Si-face crystal. When the SiC crystal ingot proceeded to grow, the SiC crystal region grown on the C-face seed crystal was enlarged compared to the SiC crystal region on the Si-face seed crystal.

scholarly journals Simulation and Experiment for Growth of High-Quality and Large-Size AlN Seed Crystals by Spontaneous Nucleation

Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 3939
Author(s):  
Zuoyan Qin ◽  
Wenhao Chen ◽  
Danxia Deng ◽  
Zhenhua Sun ◽  
Baikui Li ◽  
...  
Keyword(s):  
Temperature Gradient ◽  
Single Crystal ◽  
Growth Surface ◽  
Inversion Method ◽  
High Quality ◽  
Radial Temperature ◽  
Heater Power ◽  
Seed Crystals ◽  
Spontaneous Nucleation ◽  
Large Size

Seed crystals are the prerequisite for the growth of high quality and large size aluminum nitride (AlN) single crystal boules. The physical vapor transport (PVT) method is adopted to grow AlN seed crystal. However, this method is not available in nature. Herein, the temperature field distribution in the PVT furnace was simulated using the numerical analysis method to obtain free-standing and large-size seeds. The theoretical studies indicate that the temperature distribution in the crucible is related to the crucible height. According to the theory of growth dynamics and growth surface dynamics, the optimal thermal distribution was achieved through the design of a specific crucible structure, which is determined by the ratio of top-heater power to main-heater power. Moreover, in our experiment, a sole AlN single crystal seed with a length of 12 mm was obtained on the tungsten (W) substrate. The low axial temperature gradient between material source and substrate can decrease the nucleation rate and growth rate, and the high radial temperature gradient of the substrate can promote the expansion of crystal size. Additionally, the crystallinity of the crystals grown under different thermal field conditions are analyzed and compared. The Raman results manifest the superiority of the thermal inversion method in the growth of high quality AlN single crystal.

Top-Seeded Solution Growth of 4H-SiC Bulk Crystal Using Si-Cr Based Melt

2012 ◽  
Vol 717-720 ◽  
pp. 61-64 ◽  
Author(s):  
Hironori Daikoku ◽  
M. Kado ◽  
H. Sakamoto ◽  
Hiroshi Suzuki ◽  
T. Bessho ◽  
...  
Keyword(s):  
Growth Rate ◽  
Seed Crystal ◽  
Solution Growth ◽  
Bulk Crystals ◽  
High Quality ◽  
Cross Sectional ◽  
Formation Technique ◽  
Top Seeded Solution Growth ◽  
Microscopy Images

We have grown high-quality long cylindrical (12 mm thick) 4H-SiC bulk crystals by the meniscus formation technique, which was first applied for the solution growth of bulk SiC. It enabled long-term growth by suppressing parasitic reactions such as polycrystal precipitation around the seed crystal. In addition, we could control the growth angle from −22° to 61° by adjusting the meniscus height. The thickness of the grown cylindrical crystals was 12 mm, which is the largest reported until now, and corresponded to a growth rate of 0.6 mm/h. Smooth morphology growth was maintained on the (000-1) C-face. In cross-sectional transmission optical microscopy images, few solvent inclusions and voids were observed. XRD measurements revealed that the FWHM values of the grown crystals were almost the same as those of the seed crystal.

New Crucible Design for SiC Single Crystal Growth by Sublimation

2000 ◽  
Vol 640 ◽  
Author(s):  
Shin-ichi Nishizawa ◽  
Hirotaka Yamaguchi ◽  
Tomohisa Kato ◽  
M. Nasir Khan ◽  
Kazuo Arai ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Growth Rate ◽  
Crystal Growth ◽  
Single Crystal ◽  
Flat Surface ◽  
Single Crystal Growth ◽  
Crystal Growth Rate ◽  
Bulk Single Crystal ◽  
High Quality ◽  
Better Than

ABSTRACTSiC bulk single crystal growth by sublimation was investigated. A new crucible design, double-walled crucible, was proposed, and its effect was confirmed numerically and experimentally. On the point of heat transfer in a growth cavity, double-walled crucible is better than conventional crucible. With a double-walled crucible, temperature of seed and source surfaces could be kept constant with better uniformity than that with a conventional crucible. It was deduced that a crystal growth rate could be kept constant with flat surface. Furthermore, in case of a double walled crucible, crystal enlarged rapidly with less inclusion. As the results, a double-walled crucible is useful to grow high quality SiC single crystal by sublimation.

Polytype and Crystal Quality of SiC Crystals Grown on 3C-SiC by Seeded Solution Method

2009 ◽  
Vol 615-617 ◽  
pp. 27-30 ◽  
Author(s):  
Kazuaki Seki ◽  
Ryo Tanaka ◽  
Toru Ujihara ◽  
Yoshikazu Takeda
Keyword(s):  
Growth Process ◽  
Solution Method ◽  
Grown Crystal ◽  
Stacking Faults ◽  
High Density ◽  
Seed Crystal ◽  
Solution Growth ◽  
Crystal Quality ◽  
Seed Crystals

We investigated the effects of the solution growth process on the polytype and crystal quality of the crystals grown on (111) 3C-SiC seed crystals. In spite of the use of 3C-SiC seed crystals, the polytype of the grown crystal changed from 3C-SiC to 6H-SiC, because the stacking errors easily occur due to the similarity of the (111) face of 3C-SiC and the (0001) face of 6H-SiC. Moreover, the grown 6H-SiC crystal affected the crystal quality of the seed crystal, i.e., high-density stacking faults were induced in the seed crystal after the growth process.

Towards Large Area Diamond Substrates: The Mosaic Process

1995 ◽  
Vol 416 ◽  
Author(s):  
Ger Janssen ◽  
John J. Schermer ◽  
L. J. Giling
Keyword(s):  
Growth Rate ◽  
Single Crystal ◽  
Diamond Growth ◽  
Large Area ◽  
Severe Problem ◽  
Step Process ◽  
Seed Crystals ◽  
Combustion Flame ◽  
Single Crystal Diamond ◽  
Hot Filament

ABSTRACTA method has been developed for producing large area single-crystal diamond plates, suitable for optical and electronic applications. It starts with orienting and closely packing a set of diamond seed crystals with (001) top faces. This assembly, or mosaic, is then joined by a single-crystal overgrowth using a CVD process. A number of assembling techniques have been tested for compatibility with homoepitaxial diamond growth by hot filament assisted CVD and/or growth and etching by the acetylene-oxygen combustion flame. Furthermore a two-step process is described. First an initial layer (20-50/μm) is deposited by hot filament assisted CVD at a low growth rate in order to bridge the gap between the seeds. Subsequently the fast growth rate of the acetylene-oxygen combustion flame is employed to increase the layer thickness (>250,μm). It was found that both the basic mosaic process as well as the two step process can produce a single-crystal diamond layer on top of mosaics consisting of seed crystals with well aligned crystallographic directions. The width of the gaps between the seed crystals (up to 25 μm) was found to be less critical, while the orientation of the side faces and the direction of the misorientation (i.e. the step flow direction) seem not to effect the successful overgrowth. Apart from the alignment of the seed crystals the most severe problem, which has to be overcome in order to obtain one single-crystal overgrowth, is the occurrence of penetration twins in the joint regions. The largest mosaic structure -up to now- overgrown by CVD consists of seven seed crystals and has a surface area slightly in excess of 1 cm2

An Inserted Epitaxial Layer for SiC Single Crystal Growth by the Physical Vapor Transport Method

2007 ◽  
Vol 556-557 ◽  
pp. 9-12 ◽  
Author(s):  
Jung Doo Seo ◽  
Joon Ho An ◽  
Jung Gon Kim ◽  
Jung Kyu Kim ◽  
Myung Ok Kyun ◽  
...  
Keyword(s):  
Growth Rate ◽  
Single Crystal ◽  
Carrier Concentration ◽  
Epitaxial Layer ◽  
Vapor Transport ◽  
Seed Surface ◽  
Bulk Growth ◽  
Seed Material ◽  
Transport Method

SiC single crystal ingots were prepared onto different seed material using sublimation PVT techniques and then their crystal quality was systematically compared. In this study, the conventional SiC seed material and the new SiC seed material with an inserted SiC epitaxial layer on a seed surface were used as a seed for SiC bulk growth. The inserted epitaxial layer was grown by a sublimation epitaxy method called the CST with a low growth rate of 2μm/h. N-type 2”-SiC single crystals exhibiting the polytype of 6H-SiC were successfully fabricated and carrier concentration levels of below 1017/cm3 were determined from the absorption spectrum and Hall measurements. The slightly higher growth rate and carrier concentration were obtained in SiC single crystal ingot grown on new SiC seed materials with the inserted epitaxial layer on the seed surface, maintaining the high quality.

Relation of Heat Transfer with the Growth Rate of InSb based Bulk Crystals Grown by VDS and its Effect on the Crystal Quality

2020 ◽  
Vol 12 (2) ◽  
pp. 02012-1-02012-5
Author(s):  
Dilip Maske ◽  
◽  
Manisha Deshpande ◽  
Dattatray Gadkari ◽  
◽  
...  
Keyword(s):  
Heat Transfer ◽  
Growth Rate ◽  
Crystal Quality ◽  
Bulk Crystals

ФОРМИРОВАНИЕ ПЕРЕХОДНОГО СЛОЯ ALN НА ТЕМПЛЕЙТАХ 3С-SIC/SI(111) МЕТОДОМ АММИАЧНОЙ МОЛЕКУЛЯРНО-ЛУЧЕВОЙ ЭПИТАКСИИ

2020 ◽  
Vol 96 (3s) ◽  
pp. 148-153
Author(s):  
С.Д. Федотов ◽  
А.В. Бабаев ◽  
В.Н. Стаценко ◽  
К.А. Царик ◽  
В.К. Неволин
Keyword(s):  
Crystal Structure ◽  
Growth Rate ◽  
Low Temperature ◽  
Surface Morphology ◽  
Single Crystal ◽  
Root Mean Square Roughness ◽  
Rate Variation ◽  
Mean Square ◽  
Nucleation Layer ◽  
Low Temperature Epitaxy

Представлены результаты изучения морфологии поверхности и структуры слоев AlN, сформированных аммиачной МЛЭ на темплейтах 3C-SiC/Si(111) on-axis- и 4° off-axis-разориентации. Опробован технологический режим низкотемпературной эпитаксии зародышевого слоя AlN на поверхности 3C-SiC(111). Среднеквадратичная шероховатость поверхности (5 х 5 мкм) слоев AlN толщиной 150 ± 50 нм составила 2,5-3,5 нм на темплейтах 3C-SiC/Si(111) on-axis и 3,3-3,5 нм на 4° off-axis. Показано уменьшение шероховатости смачивающего слоя AlN при изменении скорости роста. Получены монокристаллические слои AlN(0002) со значениями FWHM (ω-геометрия) 1,4-1,6°. The paper presents the surface morphology and crystal structure of AlN layers formed by ammonia MBE on 3C-SiC/Si(111) on-axis and 4° off-axis disorientation. It offers the technological approach of low-temperature epitaxy of the AlN nucleation layer on the 3C-SiC (111) surface. Root mean square roughness (5 х 5 |xm) of AlN layers with thickness of 150 ± 50 nm was 2,5-3,5 nm onto on-axis templates and 3.3-3.5 nm onto 4° off-axis. It appears that the RMS roughness of the AlN surface is changing with the growth rate variation. Single-crystal AlN(0002) layers with FWHM values (ω-geometry) of 1.4-1.6° have been obtained.

Measurement of growth rates for single crystals and pressed tablets of CuSO4.5 H2O on a rotating disc

1989 ◽  
Vol 54 (11) ◽  
pp. 2951-2961 ◽  
Author(s):  
Miloslav Karel ◽  
Jaroslav Nývlt
Keyword(s):  
Growth Rate ◽  
Single Crystal ◽  
Single Crystals ◽  
Growth Rates ◽  
Diffusion Coefficients ◽  
Preferred Orientation ◽  
Rotating Disc ◽  
Dissolution Rates ◽  
Rates Of Growth ◽  
Good Agreement

Measured growth and dissolution rates of single crystals and tablets were used to calculate the overall linear rates of growth and dissolution of CuSO4.5 H2O crystals. The growth rate for the tablet is by 20% higher than that calculated for the single crystal. It has been concluded that this difference is due to a preferred orientation of crystal faces on the tablet surface. Calculated diffusion coefficients and thicknesses of the diffusion and hydrodynamic layers in the vicinity of the growing or dissolving crystal are in good agreement with published values.

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