Comparison of Thermodynamic Databases for the Modeling of SiC Growth by PVT

2014 ◽  
Vol 778-780 ◽  
pp. 35-38 ◽  
Author(s):  
Kanaparin Ariyawong ◽  
Elisabeth Blanquet ◽  
Jean Marc Dedulle ◽  
Thierry Ouisse ◽  
Didier Chaussende
Keyword(s):  
Process Development ◽  
Growth Conditions ◽  
Point Of View ◽  
Vapor Transport ◽  
Equilibrium Partial Pressure ◽  
Crystal Shape ◽  
Bulk Growth ◽  
Rate Calculation ◽  
Thermodynamic Databases ◽  
Mass Transfers

The numerical modeling of the SiC bulk growth process by physical vapor transport has been established as the essential tool for the process development, especially for understanding and predicting the favorable growth conditions. An accurate computation of mass transfers is strongly dependent on the equilibrium partial pressure calculations. In this paper, we compare the relative impact of the different thermodynamic databases available on the full PVT process modeling. We found that whatever the database used, the trends regarding growth rate calculation, crystal shape, Si/C ratio are correctly described and none of the database would bring about unacceptable errors from the process development point of view even if some discrepancies in the absolute values could be obtained.

Fundamental Limitations of SiC PVT Growth Reactors with Cylindrical Heaters

2006 ◽  
Vol 527-529 ◽  
pp. 15-20 ◽  
Author(s):  
Roman Drachev ◽  
E. Deyneka ◽  
C. Rhodes ◽  
J. Schupp ◽  
Tangali S. Sudarshan
Keyword(s):  
Growth Conditions ◽  
Nonuniform Distribution ◽  
Vapor Transport ◽  
Structural Quality ◽  
Furnace Design ◽  
Bulk Growth ◽  
Fundamental Limitations ◽  
Conventional Furnace ◽  
Growth Technology

The ability to set and accurately control the desired growth conditions is crucial in order to attain high quality bulk growth of Silicon Carbide (SiC), especially when the ingot size is large (> 2” in diameter by > 2” long). However, these two aspects of SiC PVT (Physical Vapor Transport) growth technology are severely limited in “conventional” SiC PVT growth reactors with single cylindrical heaters. To overcome such shortcomings, an “alternative” furnace design with two plane resistive heaters is proposed. In order to verify benefits of this design, numerical modeling and comparative procedures have been employed. Detailed comparative analysis revealed two fundamental disadvantages of the conventional furnace design, attributed to (a) – significantly higher in magnitude and spatially nonuniform distribution of the thermal stress that consequently deteriorates structural quality of the growing SiC boule, and (b) – inability to grow long (> 2”) monocrystalline ingots of SiC. Furthermore, the potential of the alternative furnace design to overcome fundamental limitations of the conventional design is also analyzed, with particular attention being paid to the processes of source material recrystallization.

Microstructural study of GaAs epitaxial layers on Ge(100) substrates

1995 ◽  
Vol 10 (4) ◽  
pp. 843-852 ◽  
Author(s):  
N. Guelton ◽  
R.G. Saint-Jacques ◽  
G. Lalande ◽  
J-P. Dodelet
Keyword(s):  
Electron Microscopy ◽  
Surface Preparation ◽  
Growth Conditions ◽  
Vapor Transport ◽  
Threading Dislocations ◽  
Misfit Dislocations ◽  
Antiphase Boundaries ◽  
Microstructural Study ◽  
Mismatch Strain ◽  
Transmission Electron

GaAs layers grown by close-spaced vapor transport on (100) Ge substrates have been investigated as a function of the experimental growth conditions. The effects on the microstructure of the surface preparation, substrate misorientation, and annealing were studied using optical microscopy and transmission electron microscopy. Microtwins and threading dislocations are suppressed by oxide desorption before deposition. Single domain GaAs layers have been obtained using a 50 nm thick double domain buffer layer on an annealed Ge substrate misoriented 3°toward [011]. The mismatch strain is mainly accommodated by dissociated 60°dislocations. These misfit dislocations extend along the interface by the glide of the threading dislocations inherited from the substrate, but strong interaction with antiphase boundaries (APB's) prevents them from reaching the interface. These results are discussed and compared with previous reports of GaAs growth on Ge(100).

Modified Physical Vapor Transport Growth of SiC - Control of Gas Phase Composition for Improved Process Conditions

2005 ◽  
Vol 483-485 ◽  
pp. 25-30 ◽  
Author(s):  
Peter J. Wellmann ◽  
Thomas L. Straubinger ◽  
Patrick Desperrier ◽  
Ralf Müller ◽  
Ulrike Künecke ◽  
...  
Keyword(s):  
Temperature Field ◽  
Phase Composition ◽  
Gas Phase ◽  
Growth Conditions ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Process Conditions ◽  
Growth Technique ◽  
Experimental Implementation ◽  
P Type

We review the development of a modified physical vapor transport (M-PVT) growth technique for the preparation of SiC single crystals which makes use of an additional gas pipe into the growth cell. While the gas phase composition is basically fixed in conventional physical vapor transport (PVT) growth by crucible design and temperature field, the gas inlet of the MPVT configuration allows the direct tuning of the gas phase composition for improved growth conditions. The phrase "additional" means that only small amounts of extra gases are supplied in order to fine-tune the gas phase composition. We discuss the experimental implementation of the extra gas pipe and present numerical simulations of temperature field and mass transport in the new growth configuration. The potential of the growth technique will be outlined by showing the improvements achieved for p-type doping of 4H-SiC with aluminum, i.e. [Al]=9⋅1019cm-3 and ρ<0.2Ωcm, and n-type doping of SiC with phosphorous, i.e. [P]=7.8⋅1017cm-3.

Bulk Growth of Low Resistivity n-Type 4H-SiC Using Co-Doping

2017 ◽  
Vol 897 ◽  
pp. 3-6 ◽  
Author(s):  
Hiromasa Suo ◽  
Kazuma Eto ◽  
Tomohisa Kato ◽  
Kazutoshi Kojima ◽  
Hiroshi Osawa ◽  
...  
Keyword(s):  
Vapor Deposition ◽  
Chemical Vapor ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
X Ray ◽  
Co Doping ◽  
Bulk Growth ◽  
Dislocation Densities ◽  
Growth Method ◽  
Co Doped

The growth of n-type 4H-SiC crystal was performed by physical vapor transport (PVT) growth method by using nitrogen and aluminum (N-Al) co-doping. Resistivity of N-Al co-doped 4H-SiC was as low as 5.8 mΩcm. The dislocation densities of N-Al co-doped substrates were evaluated by synchrotron radiation X-ray topography (SXRT). In addition, epitaxial growth was performed on the N-Al co-doped substrates by chemical vapor deposition (CVD). No double Shockley type stacking fault was observed in the epitaxial layer.

Uniformity Control of 3-Inch GaN/InGaN Layers Grown in Planetary Reactors®

2000 ◽  
Vol 618 ◽  
Author(s):  
H. Protzmann ◽  
M. Luenenbuerger ◽  
M. Bremser ◽  
M. Heuken ◽  
H. Juergensen
Keyword(s):  
Process Development ◽  
Growth Control ◽  
Growth Conditions ◽  
Nitride Layer ◽  
Group Iii ◽  
Production Type ◽  
Reactor Geometry ◽  
Simple Scaling ◽  
Group Iii Nitride

ABSTRACTWe report on recent results obtained using an AIX 2400G3HT production type Planetary Reactor® in the 5×3 inch configuration for growth of typical group-III nitride layer structures consisting of GaN, InGaN and AlGaN. The optimum reactor geometry has been found by extensive modeling of the reactor design. Increased thermal management allows maximum reactor temperatures above 1400°C. As a consequence of extensive reactor modeling, the process transfer from 6×2 inch to 5×3 inch configuration was carried out by simple scaling of the corresponding process parameters of the 6×2 inch configuration. The scaling factor is calculated with respect to the changed reactor geometry. We used optical reflectrometry for in-situ growth control during this process development and could confirm the theoretical scaling requirements for obtaining identical growth conditions as compared to the 6×2 inch reactor configuration. This is verified by the generation of identical reflectance spectrum features. This important issue of in-situ control is discussed in detail. The TMGa efficiency could be kept at about 17%. Switching to the 8×3 inch configuration the efficiency increases up to about 27%, which is an improvement of 63% as compared to the 6×2 inch configuration

Optimum growth conditions for the epitaxy of GaAs on Ge by close-spaced vapor transport

1994 ◽  
Vol 72 (5-6) ◽  
pp. 225-232 ◽  
Author(s):  
G. Lalande ◽  
N. Guelton ◽  
D. Cossement ◽  
R. G. Saint-Jacques ◽  
J. P. Dodelet
Keyword(s):  
Growth Rate ◽  
Solar Cells ◽  
Water Vapor ◽  
Substrate Temperature ◽  
Growth Conditions ◽  
Vapor Transport ◽  
Temperature Evolution ◽  
Threading Dislocations ◽  
Optimum Growth ◽  
Antiphase Boundaries

GaAs epitaxial layers are grown by close-spaced vapor transport (CSVT) on (100)Ge substrates and (100)Ge substrates misoriented 1.5° and 3° toward (011). Water vapor is used as the transport agent. When the temperatures of the GaAs source (T1) and of the Ge substrate (T2) are 800 and 750 °C, respectively, the growth rate is about 3 μm h−1. When an optimum source–substrate temperature evolution is followed, it is possible to grow specular layers of GaAs/Ge that contain only a small number (< 105 cm−2) of threading dislocations. All antiphase boundaries (APBs) annihilate close to the interface (from about 230 nm for (100)Ge substrates to about 65 nm for vicinal (3° off) (100)Ge substrates). The GaAs growth occurs via the coalescence of 3D nuclei that are formed on an arsenic prelayer n-type GaAs layers are always obtained. By encapsulating the Ge substrate, it is possible to drastically decrease the autodoping resulting from the transport of Ge by water vapor in the same growth conditions as those prevailing for GaAs. After encapsulation, uncompensated doping densities ND – NA in the order of 5 × 1016 cm−3 are easily obtained for GaAs/Ge films grown from undoped semi-insulating GaAs sources. These GaAs/Ge layers can be used as bases for solar cells.

Growth dynamics of cyclomaltodextrin glucanotransferase producing Bacillus circulans var. alkalophilus

1990 ◽  
Vol 36 (3) ◽  
pp. 176-182 ◽  
Author(s):  
Mauri J. Mäkelä ◽  
Sari K. Paavilainen ◽  
Timo K. Korpela
Keyword(s):  
Time Course ◽  
Growth Parameters ◽  
Growth Dynamics ◽  
Point Of View ◽  
Bacillus Circulans ◽  
Amylolytic Enzyme ◽  
Bulk Growth ◽  
Atcc Strain ◽  
Total Carbohydrates ◽  
Cyclomaltodextrin Glucanotransferase

The time course of the growth of cyclomaltodextrin glucanotransferase (EC 2.4.1.19; CGTase) producing Bacillus circulans var. alkalophilus (ATCC 21783) was studied using shaking-flask cultivations. The growth curve was diauxic and during the initial phase the pH decreased sharply by 1.3–1.5 units. Most of the total carbohydrates disappeared prior to the bulk growth, which corresponded to a transient peak of amylolytic enzyme activity and of reducing sugars followed by acid production. During active cell growth the pH recovered by about 0.5 units and 65% of the final CGTase appeared in the medium. Another 20% was produced during the stationary phase and 15% was produced in the death phase. The growth dynamics of two randomly selected alkalophilic Bacillus strains (ATCC 27647 and 27557) were compared with those of ATCC-strain 21783. The reference strains showed related growth behavior with the exception that the timing and magnitudes of the changes in the growth parameters measured were different. The effects of carbon source (starch), nitrogen source (yeast extract plus Bacto-pantone), sodium carbonate, and temperature were studied from the point of view of CGTase production. Key words: cyclomaltodextrin glucanotransferase; alkalophilic bacilli; cyclodextrins.

SiC-bulk growth by physical-vapor transport and its global modelling

1997 ◽  
Vol 174 (1-4) ◽  
pp. 669-674 ◽  
Author(s):  
D. Hofmann ◽  
R. Eckstein ◽  
M. Kölbl ◽  
Y. Makarov ◽  
St.G. Müller ◽  
...  
Keyword(s):  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Bulk Growth ◽  
Global Modelling
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