Time Evolution of a High-temperature GaN Epilayer Grown on a Low-temperature GaN Buffer Layer using a Low-pressure MOCVD

ABSTRACTHigh quality GaN films are grown on sapphire(0001) substrates by low pressure MOCVD using TMG and NH3 as source materials. Effects of surface nitridation and buffer layer thickness on the quality of over-grown GaN films are investigated. It is revealed by atomic force microscope (AFM) observations that surface roughness of the annealed buffer layers strongly depends on the nitridation time. Dislocation density and surface morphology of the high temperature GaN layer depend on the buffer layer thickness. It is found that sufficient surface nitridation of sapphire makes the buffer layer just prior to the high temperature growth very smooth, which is essential to obtain flat thick-GaN on it. It is also found that thickness of the buffer layer largely influences the dislocation density in the over-grown thick GaN. In order to obtain good surface morphology and low dislocation density at the same time, both nitridation time and buffer layer thickness must be optimized.

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Effect of low-temperature GaN buffer layer on the crystalline quality of subsequent GaN layers grown by MOVPE

Journal of Crystal Growth ◽

10.1016/j.jcrysgro.2006.10.189 ◽

2007 ◽

Vol 298 ◽

pp. 232-234 ◽

Cited By ~ 21

Author(s):

K. Hoshino ◽

N. Yanagita ◽

M. Araki ◽

K. Tadatomo

Keyword(s):

Low Temperature ◽

Buffer Layer ◽

Crystalline Quality ◽

Gan Buffer Layer

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The Influence of Growth Temperature on Oxygen Concentration in GaN Buffer Layer

MRS Proceedings ◽

10.1557/proc-1068-c03-09 ◽

2008 ◽

Vol 1068 ◽

Cited By ~ 1

Author(s):

Ewa Dumiszewska ◽

Wlodek Strupinski ◽

Piotr Caban ◽

Marek Wesolowski ◽

Dariusz Lenkiewicz ◽

...

Keyword(s):

High Temperature ◽

Buffer Layer ◽

Oxygen Concentration ◽

Growth Temperature ◽

Low Temperatures ◽

Buffer Layers ◽

Crystalline Quality ◽

Temperature Growth ◽

Gan Buffer Layer

ABSTRACTThe influence of growth temperature on oxygen incorporation into GaN epitaxial layers was studied. GaN layers deposited at low temperatures were characterized by much higher oxygen concentration than those deposited at high temperature typically used for epitaxial growth. GaN buffer layers (HT GaN) about 1 μm thick were deposited on GaN nucleation layers (NL) with various thicknesses. The influence of NL thickness on crystalline quality and oxygen concentration of HT GaN layers were studied using RBS and SIMS. With increasing thickness of NL the crystalline quality of GaN buffer layers deteriorates and the oxygen concentration increases. It was observed that oxygen atoms incorporated at low temperature in NL diffuse into GaN buffer layer during high temperature growth as a consequence GaN NL is the source for unintentional oxygen doping.

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Effects of ZnO buffer layer thickness on properties of ZnO thin films deposited by low-pressure MOCVD

Journal of Crystal Growth ◽

10.1016/j.jcrysgro.2003.10.079 ◽

2004 ◽

Vol 262 (1-4) ◽

pp. 456-460 ◽

Cited By ~ 42

Author(s):

Yuantao Zhang ◽

Guotong Du ◽

Boyang Liu ◽

HuiChao Zhu ◽

Tianpeng Yang ◽

...

Keyword(s):

Thin Films ◽

Buffer Layer ◽

Layer Thickness ◽

Low Pressure ◽

Zno Thin Films ◽

Low Pressure Mocvd ◽

Buffer Layer Thickness ◽

Zno Buffer Layer

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Influence of substrate polarity on the low-temperature GaN buffer layer growth on GaAs (111)A and (111)B surfaces

Journal of Crystal Growth ◽

10.1016/s0022-0248(02)01979-6 ◽

2003 ◽

Vol 247 (3-4) ◽

pp. 245-250 ◽

Cited By ~ 9

Author(s):

Hisashi Murakami ◽

Yoshinao Kumagai ◽

Hisashi Seki ◽

Akinori Koukitu

Keyword(s):

Low Temperature ◽

Buffer Layer ◽

Layer Growth ◽

Influence Of Substrate ◽

Gan Buffer Layer

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Morphology and surface reconstructions of m-plane GaN

MRS Proceedings ◽

10.1557/proc-743-l4.1 ◽

2002 ◽

Vol 743 ◽

Cited By ~ 1

Author(s):

C. D. Lee ◽

R. M. Feenstra ◽

J. E. Northrup ◽

L. Lymperakis ◽

J. Neugebauer

Keyword(s):

Molecular Beam Epitaxy ◽

Low Temperature ◽

Surface Morphology ◽

Buffer Layer ◽

Molecular Beam ◽

Structural Quality ◽

Surface Reconstructions ◽

Gan Buffer Layer

ABSTRACTM-plane GaN(1100) is grown by plasma assisted molecular beam epitaxy on ZnO(1100) substrates. A low-temperature GaN buffer layer is found to be necessary to obtain good structural quality of the films. Well oriented (1100) GaN films are obtained, with a slate like surface morphology. On the GaN(1100) surfaces, reconstructions with symmetry of c(2×2) and approximate “4×5” are found under N- and Ga-rich conditions, respectively. We propose a model for Ga-rich conditions with the “4×5” structure consisting of ≥ 2 monolayers of Ga terminating the GaN surface.

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