Effects of the Nitridation Process of (0001) Sapphire on Crystalline Quality of InN Grown by RF-MBE

2004 ◽  
Vol 831 ◽  
Author(s):  
Daisuke Muto ◽  
Ryotaro Yoneda ◽  
Hiroyuki Naoi ◽  
Masahito Kurouchi ◽  
Tsutomu Araki ◽  
...  
Keyword(s):  
Low Temperature ◽  
Buffer Layer ◽  
Buffer Layers ◽  
Crystalline Quality ◽  
Constant Independent ◽  
Nitrogen Flux ◽  
Sapphire Substrates ◽  
Nitridation Process ◽  
Flux Modulation

ABSTRACTThe effects of the nitridation process of (0001) sapphire on crystalline quality of InN were clearly demonstrated. The InN films were grown on NFM (nitrogen flux modulation) HT-InN or LT-InN buffer layers, which had been deposited on nitridated sapphire substrates. We found that low-temperature nitridation of sapphire is effective in improving the tilt distribution of InN films. Whereas the twist distribution remained narrow and almost constant, independent of nitridation conditions, when LT-InN buffer layers were used. The XRC-FWHM value of 54 arcsec for (0002) InN, the lowest reported to date, was achieved by using the LT-InN buffer layer and sapphire nitridation at 300°C for 3 hours.

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

2008 ◽  
Vol 1068 ◽  
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.

Improvement of the crystalline quality of the ZnO epitaxial layer on a low-temperature grown ZnO buffer layer

2004 ◽  
Vol 266 (4) ◽  
pp. 505-510 ◽  
Author(s):  
J.F. Yan ◽  
Y.M. Lu ◽  
Y.C. Liu ◽  
H.W. Liang ◽  
B.H. Li ◽  
...  
Keyword(s):  
Low Temperature ◽  
Buffer Layer ◽  
Epitaxial Layer ◽  
Crystalline Quality ◽  
Zno Buffer Layer

Low-temperature buffer layer effects on the quality of ZnTe epilayers grown on sapphire substrates

2010 ◽  
Vol 107 (12) ◽  
pp. 123525 ◽  
Author(s):  
Qixin Guo ◽  
Masaki Nada ◽  
Yaliu Ding ◽  
Tooru Tanaka ◽  
Mitsuhiro Nishio
Keyword(s):  
Low Temperature ◽  
Buffer Layer ◽  
Sapphire Substrates

Improvements in crystalline quality of thick GaN layers on GaAs (111)A by periodic insertion of low-temperature GaN buffer layers

2003 ◽  
Vol 0 (7) ◽  
pp. 2141-2144
Author(s):  
H. Murakami ◽  
N. Kawaguchi ◽  
Y. Kangawa ◽  
Y. Kumagai ◽  
A. Koukitu
Keyword(s):  
Low Temperature ◽  
Buffer Layers ◽  
Crystalline Quality

Initial Stages of MOCVD Growth of Gallium Nitride Using a Multi-Step Growth Approach

1997 ◽  
Vol 468 ◽  
Author(s):  
J. T. Kobayashi ◽  
N. P. Kobayashi ◽  
P. D. Dapkus ◽  
X. Zhang ◽  
D. H. Rich
Keyword(s):  
Low Temperature ◽  
Buffer Layer ◽  
Chemical Vapor ◽  
Buffer Layers ◽  
Mocvd Growth ◽  
Initial Stage ◽  
Step Growth ◽  
Van Der Pauw ◽  
Growth Approach

ABSTRACTA multilayer buffer layer approach to GaN growth has been developed in which the thermal desorption and mass transport of low temperature buffer layer are minimized by deposition of successive layers at increased temperatures. High quality GaN with featureless surface morphology has been grown on (0001) sapphire substrate by metalorganic chemical vapor deposition using this multilayer buffer layer approach. The lateral growth and coalescence of truncated 3D islands (TTIs) nucleated on low temperature buffer layers at the initial stage of overlayer growth is affected by the thickness of the final buffer layer on which nucleation of TTIs takes place. The effect of the thickness of this buffer layer on the quality of GaN is studied by using scanning electron microscopy, van der Pauw geometry Hall measurements and cathodoluminescence and an optimum value of 400Å is obtained.

scholarly journals Investigation of the Heteroepitaxial Process Optimization of Ge Layers on Si (001) by RPCVD

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 928
Author(s):  
Yong Du ◽  
Zhenzhen Kong ◽  
Muhammet Toprak ◽  
Guilei Wang ◽  
Yuanhao Miao ◽  
...  
Keyword(s):  
High Temperature ◽  
Buffer Layer ◽  
Layer Thickness ◽  
Growth Temperature ◽  
Crystalline Quality ◽  
Initial Growth ◽  
Two Dimensional ◽  
High Quality ◽  
Reduced Pressure

This work presents the growth of high-quality Ge epilayers on Si (001) substrates using a reduced pressure chemical vapor deposition (RPCVD) chamber. Based on the initial nucleation, a low temperature high temperature (LT-HT) two-step approach, we systematically investigate the nucleation time and surface topography, influence of a LT-Ge buffer layer thickness, a HT-Ge growth temperature, layer thickness, and high temperature thermal treatment on the morphological and crystalline quality of the Ge epilayers. It is also a unique study in the initial growth of Ge epitaxy; the start point of the experiments includes Stranski–Krastanov mode in which the Ge wet layer is initially formed and later the growth is developed to form nuclides. Afterwards, a two-dimensional Ge layer is formed from the coalescing of the nuclides. The evolution of the strain from the beginning stage of the growth up to the full Ge layer has been investigated. Material characterization results show that Ge epilayer with 400 nm LT-Ge buffer layer features at least the root mean square (RMS) value and it’s threading dislocation density (TDD) decreases by a factor of 2. In view of the 400 nm LT-Ge buffer layer, the 1000 nm Ge epilayer with HT-Ge growth temperature of 650 °C showed the best material quality, which is conducive to the merging of the crystals into a connected structure eventually forming a continuous and two-dimensional film. After increasing the thickness of Ge layer from 900 nm to 2000 nm, Ge surface roughness decreased first and then increased slowly (the RMS value for 1400 nm Ge layer was 0.81 nm). Finally, a high-temperature annealing process was carried out and high-quality Ge layer was obtained (TDD=2.78 × 107 cm−2). In addition, room temperature strong photoluminescence (PL) peak intensity and narrow full width at half maximum (11 meV) spectra further confirm the high crystalline quality of the Ge layer manufactured by this optimized process. This work highlights the inducing, increasing, and relaxing of the strain in the Ge buffer and the signature of the defect formation.

Influences of two-step growth and off-angle Ge substrate on crystalline quality of GaAs buffer layers grown by MOVPE

2015 ◽  
Vol 414 ◽  
pp. 15-20 ◽  
Author(s):  
Pornsiri Wanarattikan ◽  
Sakuntam Sanorpim ◽  
Somyod Denchitcharoen ◽  
Kenjiro Uesugi ◽  
Shigeyuki Kuboya ◽  
...  
Keyword(s):  
Buffer Layers ◽  
Crystalline Quality ◽  
Step Growth

Epitaxial GaN Layer Growth Using Nitrogen Enriched TiN Buffer Layers

2006 ◽  
Vol 916 ◽  
Author(s):  
Kazuhiro Ito ◽  
Yu Uchida ◽  
Sang-jin Lee ◽  
Susumu Tsukimoto ◽  
Yuhei Ikemoto ◽  
...  
Keyword(s):  
Buffer Layer ◽  
Light Emission ◽  
Chemical Vapor ◽  
Nucleation Site ◽  
Layer Growth ◽  
Buffer Layers ◽  
Organic Chemical ◽  
Nitrogen Enrichment ◽  
Threading Dislocation ◽  
Sapphire Substrates

AbstractAbout 20 years ago, the discovery of an AlN buffer layer lead to the breakthrough in epitaxial growth of GaN layers with mirror-like surface, using a metal organic chemical vapor deposition (MOCVD) technique on sapphire substrates. Since then, extensive efforts have been continued to develop a conductive buffer layer/substrate for MOCVD-grown GaN layers to improve light emission of GaN light-emitting diodes. In the present study, we produced MOCVD-grown, continuous, flat epitaxial GaN layers on nitrogen enriched TiN buffer layers with the upper limit of the nitrogen content of TiN deposited at room temperature (RT) on sapphire substrates. It was concluded that the nitrogen enrichment would reduce significantly the TiN/GaN interfacial energy. The RT deposition of the TiN buffer layers suppresses their grain growth during the nitrogen enrichment and the grain size refining must increase nucleation site of GaN. In addition, threading dislocation density in the GaN layers grown on TiN was much lower than that in the GaN layers grown on AlN.

Effect of low temperature Ge seed layer and post thermal annealing on quality of Ge1− x Si x (0.05 ≤ x ≤ 0.1) graded buffer layers by UHV-CVD

2014 ◽  
Vol 10 (4) ◽  
pp. 759-762
Author(s):  
Chi-Lang Nguyen ◽  
Nguyen Hong Quan ◽  
Binh-Tinh Tran ◽  
Yung-Hsuan Su ◽  
Shih-Hsuan Tang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Thermal Annealing ◽  
Seed Layer ◽  
Buffer Layers
Sign in / Sign up

Export Citation Format

Share Document