Phase separation-suppressed and strain-modulated improvement of crystalline quality of AlGaN epitaxial layer grown by MOCVD

2018 ◽  
Vol 83 ◽  
pp. 286-292 ◽  
Author(s):  
Tien Tung Luong ◽  
Yen-Teng Ho ◽  
Yuen-Yee Wong ◽  
Shane Chang ◽  
Edward-Yi Chang
Keyword(s):  
Phase Separation ◽  
Epitaxial Layer ◽  
Crystalline Quality

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

Crystalline Quality Evaluation of SiC p/n Column Layers Formed by Trench-Filling-Epitaxial Growth

2020 ◽  
Vol 1004 ◽  
pp. 445-450
Author(s):  
Kohei Adachi ◽  
Ryoji Kosugi ◽  
Shi Yang Ji ◽  
Yasuyuki Kawada ◽  
Hiroyuki Fujisawa ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Epitaxial Growth ◽  
Epitaxial Layer ◽  
Quality Evaluation ◽  
Crystalline Quality ◽  
Threading Dislocation ◽  
Threading Dislocations ◽  
Threading Dislocation Density

We evaluated crystalline quality of SiC p/n column layers over 20 μm thickness formed by trench-filling-epitaxial growth. Although threading dislocation density of trench-filling-epitaxial layer is almost same as flat n-type epitaxial layer, threading dislocations are localized in only trench-filled p-columns. We consider that threading dislocations migrated toward p-columns around trench bottom during trench-filling-epitaxial growth.

Phase Separation on GaInAsSb Films for Thermophotovoltaic Devices

2006 ◽  
Vol 514-516 ◽  
pp. 447-451 ◽  
Author(s):  
Victoria Corregidor ◽  
Nuno Franco ◽  
Eduardo Alves ◽  
Nuno P. Barradas
Keyword(s):  
Phase Separation ◽  
Vapour Deposition ◽  
Lattice Structure ◽  
Reciprocal Space ◽  
Crystalline Quality ◽  
Substrate Orientation ◽  
X Ray ◽  
Super Lattice

Ga0.81In0.19As0.14Sb0.86 layers were grown on (100)-Te doped GaSb substrates 2º missoriented towards (110), (111)A and (111)B directions by metalorganic vapour deposition (MOVPE) at 540 °C. X-ray reciprocal space maps done in symmetric (224) and asymmetric (115) directions show a super-lattice structure due to the phase separation with a 5 nm period and independent of substrate orientation. The x-ray maps show different stage of relaxation of the films and in same cases an interdiffusion region near the substrate. Despite of the phase separation, channelling experiments with H ions as projectiles showed a good quality of the films. Channelling experiments show that the crystalline quality gets worse with increasing the In and As concentration.

Improved crystalline quality of AlN epitaxial layer on sapphire by introducing TMGa pulse flow into the nucleation stage

2018 ◽  
Vol 490 ◽  
pp. 56-60 ◽  
Author(s):  
Hualong Wu ◽  
Hailong Wang ◽  
Yingda Chen ◽  
Lingxia Zhang ◽  
Zimin Chen ◽  
...  
Keyword(s):  
Epitaxial Layer ◽  
Crystalline Quality ◽  
Pulse Flow ◽  
Nucleation Stage

Evaluation of Crystalline Quality of Zirconium Dioxide Films on Silicon by Means of Ion Beam Channeling

1988 ◽  
Vol 116 ◽  
Author(s):  
Yoshiki Nishibayashi ◽  
Takeshi Imura ◽  
Yukio Osaka ◽  
Hirofumi Fukumoto
Keyword(s):  
Angular Dependence ◽  
Energy Dependence ◽  
Epitaxial Layer ◽  
Zirconium Dioxide ◽  
Ion Beam ◽  
Rutherford Backscattering ◽  
Vacuum Evaporation ◽  
Crystalline Quality ◽  
Crystallite Orientation

AbstractZirconium dioxide (ZrO2) films are deposited on Si(100) and Si(lll) substrates at 800ºC by vacuum evaporation. Channeling spectrum of the Rutherford backscattering shows that ZrO2 films (tetragonal(200)) are epitaxially grown on the Si(100) substrate. The fluctuation of crystallite orientation in the epitaxial layer is estimated to be 0.32º, by analyzing the angular dependence of the aligned and random backscattering spectra. Energy dependence of dechanneling factors in 0.3—2.0 MeV 4He+ indicates that the dominant defect arises from the stackingfaults.

Structure and Orientation of As Precipitates in LT-MBE Grown GaAs

1991 ◽  
Vol 49 ◽  
pp. 900-901 ◽  
Author(s):  
Alain Claverie ◽  
Zuzanna Liliental-Weber
Keyword(s):  
Transport Properties ◽  
Layer Thickness ◽  
Growth Temperature ◽  
Low Temperatures ◽  
Lattice Parameter ◽  
Crystalline Quality ◽  
Insulating Properties ◽  
Lt Gaas

GaAs layers grown by MBE at low temperatures (in the 200°C range, LT-GaAs) have been reported to have very interesting electronic and transport properties. Previous studies have shown that, before annealing, the crystalline quality of the layers is related to the growth temperature. Lowering the temperature or increasing the layer thickness generally results in some columnar polycrystalline growth. For the best “temperature-thickness” combinations, the layers may be very As rich (up to 1.25%) resulting in an up to 0.15% increase of the lattice parameter, consistent with the excess As. Only after annealing are the technologically important semi-insulating properties of these layers observed. When annealed in As atmosphere at about 600°C a decrease of the lattice parameter to the substrate value is observed. TEM studies show formation of precipitates which are supposed to be As related since the average As concentration remains almost unchanged upon annealing.

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

Improved Crystalline Quality of GaN by Substrate Ion Beam Pretreatment

2002 ◽  
Vol 41 (Part 1, No. 6B) ◽  
pp. 4299-4303 ◽  
Author(s):  
Yong Suk Cho ◽  
Junggeun Jhin ◽  
Eui Kwan Koh ◽  
Young Ju Park ◽  
Eun Kyu Kim ◽  
...  
Keyword(s):  
Ion Beam ◽  
Crystalline Quality
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