SiC Solution Growth on Si Face with Extremely Low Density of Threading Screw Dislocations for Suppression of Polytype Transformation

2017 ◽  
Vol 897 ◽  
pp. 24-27 ◽  
Author(s):  
Kenta Murayama ◽  
Tsukasa Hori ◽  
S. Harada ◽  
S. Xiao ◽  
M. Tagawa ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Growth Temperature ◽  
Thick Layer ◽  
High Growth ◽  
Solution Growth ◽  
Threading Dislocation ◽  
Low Density ◽  
Screw Dislocations ◽  
Threading Dislocation Density ◽  
Polytype Transformation

In order to achieve a high-quality SiC crystal in solution growth, one of the most difficult issues is to grow a thick layer on Si face avoiding polytype transformation. In this case, two-dimensional nucleation, which leads to the polytype transformation, is frequently induced because a density of threading screw dislocations acting as a source of spiral step decreases and wide terraces form by step bunching as growth proceeds. Therefore, it is very difficult to stabilize the polytype of crystals grown with extremely low density of threading screw dislocations. In this study, we tried to overcome these problems by using specially designed seed crystal and optimizing growth temperature and temperature distribution. We successfully grew thick low-threading-dislocation density SiC crystal without polytype transformation under the condition of high growth temperature and homogeneous temperature distribution.

Solution Growth of 3C-SiC Single Crystals by Cold Crucible Technique

2008 ◽  
Vol 600-603 ◽  
pp. 191-194
Author(s):  
Takashi Tanaka ◽  
Nobuyoshi Yashiro ◽  
Kazuhiko Kusunoki ◽  
Kazuhito Kamei ◽  
Akihiro Yauchi
Keyword(s):  
Growth Rate ◽  
Single Crystals ◽  
Solution Method ◽  
High Growth ◽  
High Growth Rate ◽  
Solution Growth ◽  
Threading Dislocation ◽  
Cold Crucible ◽  
Threading Dislocation Density ◽  
Growth Method

We have successfully grown 3C-SiC(111) single crystals 10mm x 10mm in dimension on 6H-SiC(0001) substrate by the solution growth method using cold crucible technique. The growth rate of 60μm/hr was achieved. The use of Si-Ti-C ternary solution as well as the electromagnetic stirring are responsible for the relatively high growth rate in solution method. The threading dislocation density is low and the etch pit density amounts to 105-106 /cm2 at the lowest region. Polytype of the grown layer has changed from 3C to 6H with an increase in the dip depth of substrate. A mathematical model was applied to get better understanding of what happened in the crucible.

High-Speed Solution Growth of Single Crystal AlN from Cr-Co-Al Solvent

2016 ◽  
Vol 858 ◽  
pp. 1210-1213 ◽  
Author(s):  
Shota Watanabe ◽  
Masashi Nagaya ◽  
Yukihisa Takeuchi ◽  
Kenta Aoyagi ◽  
S. Harada ◽  
...  
Keyword(s):  
Growth Rate ◽  
Temperature Distribution ◽  
Numerical Analysis ◽  
Single Crystal ◽  
High Speed ◽  
Nitrogen Concentration ◽  
High Growth ◽  
High Growth Rate ◽  
Solution Growth ◽  
High Affinity

We achieved a high growth rate in solution growth of AlN single crystal by suppressing unintentional precipitations near the surface of solvent and by increasing the equilibrium nitrogen concentration in the solvent. In order to suppress unintentional precipitations, we made the solvent supersaturated just above the surface of the substrate by optimizing the composition of the solvent and the temperature distribution based on thermodynamic numerical analysis. In particular, we focused on interactions between nitrogen or aluminum and solvent elements, leading to the increase of the equilibrium nitrogen concentration. We selected chromium and cobalt due to their high affinity with nitrogen or aluminum. Consequently, we successfuly achieved growth rate as high as 200 μm/h in maximum.

Resistivity Control in Unintentionally Doped GaN Films Grown on Si (111) Substrates by MOCVD

2011 ◽  
Vol 415-417 ◽  
pp. 1959-1963 ◽  
Author(s):  
Yong Wang ◽  
Nai Sen Yu ◽  
Ming Li ◽  
Kei May Lau
Keyword(s):  
Sheet Resistance ◽  
Chemical Vapor ◽  
High Growth ◽  
Growth Conditions ◽  
Organic Chemical ◽  
Threading Dislocation ◽  
Growth Pressure ◽  
Initial Layer ◽  
Threading Dislocation Density ◽  
Metal Organic

Unintentionally doped GaN were grown on Si (111) substrates by metal organic chemical vapor deposition (MOCVD). The high-resolution X-ray diffraction (HRXRD) and Lehighton contactless sheet resistance measuring systems were employed to characterize the quality and sheet resistance (Rs) of GaN epilayer. The threading dislocation density (TDD) was estimated by calculating the full width at half maximum (FWHM) of GaN (0002) and (10-12) diffractions measured by HRXRD. The relationship between Rs and TDD in GaN epilayer was investigated. The influence of growth conditions of bottom GaN initial layer including carrier gas category (H2 or N2), growth temperatures, and growth pressures on the quality or resistivity of top GaN epilayer was discussed and analyzed. As a result, the improved resistivity was achieved in top GaN epilayer with low TDD by using H2 carrier, low growth temperature of 1050°C, and high growth pressure of 400mbar during the growth of bottom GaN initial layer.

Optimization of SiGe Graded Buffer Defectivity and Throughput by Means of High Growth Temperature and Pre-Threaded Substrates

2005 ◽  
Vol 891 ◽  
Author(s):  
Matthew Erdtmann ◽  
Matthew T. Currie ◽  
Joseph C. Woicik ◽  
David Black
Keyword(s):  
Growth Temperature ◽  
High Growth ◽  
Dislocation Nucleation ◽  
Threading Dislocation ◽  
Threading Dislocations ◽  
Trade Off ◽  
Dislocation Glide ◽  
Si Substrates ◽  
High Growth Temperature ◽  
Dislocation Densities

ABSTRACTDislocation glide kinetics dictate in relaxed graded buffers a fundamental opposition between the defectivity and throughput. For state-of-the-art Si-based applications, the trade-off between defect level and wafer cost (inversely related to throughput) has made the insertion of SiGe graded buffers into production difficult. We aim to mitigate the trade-off by reporting two advances that enable simultaneous improvements in both defectivity and throughput. The first is use of a high growth temperature to allow very fast dislocation glide velocities and growth rates as high as 1.0 μm/min. The second is the use of “pre-threaded” Si substrates, substrates with an elevated density of threading dislocations. By having dislocation nucleation controlled by uniformly distributed substrate threading dislocations, instead of unpredictable heterogeneous sources, impediments to dislocation glide, such as dislocation bundles and pile-ups, are reduced. By incorporating both advances into SiGe graded buffer epitaxy, dislocation pile-up densities are reduced by nearly three orders of magnitude, threading dislocation densities are reduced by a factor of 7.4×, and wafer throughput is increased at least 33%.

Reduction of Threading Screw Dislocation Utilizing Defect Conversion during Solution Growth of 4H-SiC

2013 ◽  
Vol 740-742 ◽  
pp. 189-192 ◽  
Author(s):  
S. Harada ◽  
Yuji Yamamoto ◽  
Kazuaki Seki ◽  
Toru Ujihara
Keyword(s):  
Screw Dislocation ◽  
Seed Crystal ◽  
Solution Growth ◽  
Spiral Growth ◽  
High Quality ◽  
Special Shape ◽  
Screw Dislocations ◽  
Step Flow ◽  
Polytype Transformation ◽  
Step Flow Growth

Reduction of threading screw dislocation without polytype transformation from 4H-SiC was performed by the combination of step-flow growth and spiral growth. On a vicinal 4H-SiC seed crystal, threading screw dislocations are converted to Frank-type stacking faults by step-flow during solution growth. As the growth proceeds, the defects are excluded to the crystal. Thus utilizing the conversion, high quality SiC crystal growth without threading screw dislocations is expected to achieve. However, at the same time, polytype transformation is caused by the occurrence of 2D nucleation. By using the special shape of seed crystal, we successfully grew high quality 4H-SiC crystal without threading screw dislocation and polytype transformation.

High-Irradiance Degradation Studies of Metamorphic 1eV GaInAs Solar Cells

2012 ◽  
Vol 1432 ◽  
Author(s):  
Ryan M. France ◽  
Myles A. Steiner
Keyword(s):  
Solar Cells ◽  
Active Region ◽  
Dislocation Density ◽  
Dark Current ◽  
Degradation Mechanism ◽  
Control Cell ◽  
High Irradiance ◽  
Threading Dislocation ◽  
Threading Dislocation Density ◽  
Degradation Studies

ABSTRACTInitial tests are performed regarding the degradation of lattice-mismatched GaInAs solar cells. 1eV metamorphic GaInAs solar cells with 1-2×106 cm-2 threading dislocation density in the active region are irradiated with an 808 nm laser for 2 weeks time under a variety of temperature and illumination conditions. All devices show a small degradation in Voc that is logarithmic with time. The absolute loss in performance after 2 weeks illuminated at 1300 suns equivalent and 125°C is 7 mV Voc and 0.2% efficiency, showing these devices to be relatively stable. The dark current increases with time and is analyzed with a two-diode model. A GaAs control cell degrades at the same rate, suggesting that the observed degradation mechanism is not related to the additional dislocations in the GaInAs devices.

Relationship between misfit-dislocation formation and initial threading-dislocation density in GaInN/GaN heterostructures

2015 ◽  
Vol 54 (11) ◽  
pp. 115501 ◽  
Author(s):  
Motoaki Iwaya ◽  
Taiji Yamamoto ◽  
Daisuke Iida ◽  
Yasunari Kondo ◽  
Mihoko Sowa ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Misfit Dislocation ◽  
Threading Dislocation ◽  
Threading Dislocation Density ◽  
Dislocation Formation

Enhanced reduction in threading dislocation density in Ge grown on porous silicon during annealing due to porous buffer reconstruction

2015 ◽  
Vol 213 (1) ◽  
pp. 96-101
Author(s):  
G. Calabrese ◽  
S. Baricordi ◽  
P. Bernardoni ◽  
D. De Salvador ◽  
M. Ferroni ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Dislocation Density ◽  
Threading Dislocation ◽  
Threading Dislocation Density

Defect-Engineered Graded GexSi1-x Buffers on Si (001) with Extreme Low Threading Dislocation Density

1995 ◽  
Vol 378 ◽  
Author(s):  
G. Kissinger ◽  
T. Morgenstern ◽  
G. Morgenstern ◽  
H. B. Erzgräber ◽  
H. Richter
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Atomic Force Microscopy ◽  
Dislocation Density ◽  
Threading Dislocation ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Dislocation Densities ◽  
Threading Dislocation Density

AbstractStepwise equilibrated graded GexSii-x (x≤0.2) buffers with threading dislocation densities between 102 and 103 cm−2 on the whole area of 4 inch silicon wafers were grown and studied by transmission electron microscopy, defect etching, atomic force microscopy and photoluminescence spectroscopy.

Sign in / Sign up

Export Citation Format

Share Document