Boiling KOH Etching Behavior of GaN Buffer and Epitaxial Layers on Sapphire Substrate– Effects of Substrate-Surface Nitridation and Carrier Gas

AbstractThe synthesis of thin silver films by the gas-jet deposition method is experimentally and theoretically studied. When the metal is deposited onto silicon substrates from a supersonic jet of silver vapor with a helium carrier gas, nanostructured films with a 3−30 nm size of nanostructures are obtained for a 1230−1380 K range of jet source temperatures. The data on Ag–He gas-jet dynamics when it is expanded into vacuum (velocity, temperature, concentration, flux of particles onto a substrate) depending on parameters at the source (vapor temperature, flow rate of a carrier gas) are obtained by the method of direct simulation Monte Carlo. The range of optimal helium flow rates, when the efficiency of a gas-jet source is maximal, is determined. It is established that the presence of a background gas in a deposition chamber at pressure higher than 1 Pa decreases the flow of particles onto a substrate, and a simple way of its evaluation is proposed. Conditions for formation of silver clusters in the jet are determined by using the simulation. It is shown that for experimental deposition regimes there are no clusters in the jet, and the observed silver nanostructures are formed on the substrate surface.

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The study of spray impact on the heated sapphire plate

Journal of Physics Conference Series ◽

10.1088/1742-6596/2119/1/012172 ◽

2021 ◽

Vol 2119 (1) ◽

pp. 012172

Author(s):

T G Gigola ◽

V V Cheverda

Keyword(s):

Heat Transfer ◽

Sapphire Substrate ◽

Substrate Surface ◽

Heated Surface ◽

Local Heat ◽

Heat Fluxes ◽

Transfer Coefficients ◽

Heat Transfer Coefficients ◽

Liquid Spray ◽

Sapphire Plate

Abstract The process of the liquid spray impact on the heated surface is studied experimentally using the IR-transparent sapphire plate method. The spatiotemporal distribution of the temperature field on the sapphire substrate surface during impacting spray is received. The obtained experimental data are an important step in a study of the local characteristics of heat transfer in the areas of the contact lines during liquid spray impact on the heated surface. Further, the local heat fluxes and heat transfer coefficients will be determined by solving the problem of thermal conductivity in the sapphire substrate.

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Reciprocal Space Mapping of X-Ray Diffraction Intensity of GaN-Based Laser Diodes Grown on GaN Substrates

MRS Proceedings ◽

10.1557/proc-798-y5.40 ◽

2003 ◽

Vol 798 ◽

Cited By ~ 2

Author(s):

K. Tachibana ◽

Y. Harada ◽

S. Saito ◽

S. Nunoue ◽

H. Katsuno ◽

...

Keyword(s):

Output Power ◽

Sapphire Substrate ◽

Light Output ◽

Space Mapping ◽

Reciprocal Space ◽

Epitaxial Layers ◽

X Ray Diffraction ◽

Light Output Power ◽

Reciprocal Space Mapping ◽

X Ray

ABSTRACTCharacterization by reciprocal space mapping of x-ray diffraction (XRD) intensity was carried out for epitaxial layers of GaN-based laser structures on two GaN substrates: GaN substrate and GaN template on sapphire substrate. The difference between these two substrates was shown clearly. The distribution of XRD intensity of the epitaxial layers on GaN substrate was smaller than that of the epitaxial layers on GaN template on sapphire substrate. In the lasers with the epitaxial structure on GaN substrate, the light output power was as high as 200 mW under continuous-wave operation at room temperature. Excellent noise characteristics with relative intensity noise of -132 dB/Hz were also obtained at a low light output power of 3 mW without any high-frequency modulation. These results support that GaN substrates are promising for realizing GaN-based lasers with high performance.

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Effects of substrate surface preparation on chemical vapor deposition growth of 4H-SiC epitaxial layers

Journal of Electronic Materials ◽

10.1007/s11664-001-0021-3 ◽

2001 ◽

Vol 30 (3) ◽

pp. 228-234 ◽

Cited By ~ 29

Author(s):

S. E. Saddow ◽

T. E. Schattner ◽

J. Brown ◽

L. Grazulis ◽

K. Mahalingam ◽

...

Keyword(s):

Chemical Vapor Deposition ◽

Vapor Deposition ◽

Substrate Surface ◽

Surface Preparation ◽

Chemical Vapor ◽

Epitaxial Layers ◽

Chemical Vapor Deposition Growth

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Semipolar (112¯2) GaN Films Improved by in situ SiN x Pretreatment of m‐Sapphire Substrate Surface

physica status solidi (a) ◽

10.1002/pssa.201900001 ◽

2019 ◽

Vol 216 (7) ◽

pp. 1900001

Author(s):

Zhengyuan Wu ◽

Zhuoxun Jiang ◽

Shiqiang Lu ◽

Jinchai Li ◽

Ran Liu ◽

...

Keyword(s):

Sapphire Substrate ◽

Substrate Surface

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Influence of 6H–SiC(0001) substrate surface morphology on the growth of AlN epitaxial layers

Applied Physics Letters ◽

10.1063/1.123431 ◽

1999 ◽

Vol 74 (7) ◽

pp. 985-987 ◽

Cited By ~ 34

Author(s):

V. M. Torres ◽

J. L. Edwards ◽

B. J. Wilkens ◽

David J. Smith ◽

R. B. Doak ◽

...

Keyword(s):

Surface Morphology ◽

Substrate Surface ◽

Epitaxial Layers

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A Study of MOCVD-Grown Gallium Nitride Nucleation Layers on Sapphire

MRS Proceedings ◽

10.1557/proc-280-355 ◽

1992 ◽

Vol 280 ◽

Cited By ~ 1

Author(s):

A. Estes Wickenden ◽

D. K. Wickenden ◽

T. J. Kistenmacher ◽

S. A. Ecelberger ◽

T. O. Poehler

Keyword(s):

Gallium Nitride ◽

Sapphire Substrate ◽

Low Temperatures ◽

Carrier Gas ◽

Mocvd Reactor ◽

Nucleation Sites

ABSTRACTNucleation layers of GaN have been deposited in an MOCVD reactor on (0001) sapphire, over a range of temperatures and layer thicknesses, using either N2 or H2 carrier gas. The layers have been found to be continuous, textured films as deposited at low temperatures (600°C), but to reorder upon annealing, segregating into nucleation sites which exhibit the normal heteroepitaxial relationship with the sapphire substrate.

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