scholarly journals Thermophysics Simulation of Laser Recrystallization of High-Ge-Content SiGe on Si Substrate

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Chao Zhang ◽  
Jianjun Song ◽  
Jie Zhang ◽  
Shulin Liu
Keyword(s):  
Epitaxial Layer ◽  
Lattice Mismatch ◽  
Defect Density ◽  
Low Cost ◽  
Threading Dislocation ◽  
Si Substrate ◽  
Si Substrates ◽  
Laser Recrystallization ◽  
Threading Dislocation Density ◽  
Physics Model

The high-Ge-content SiGe material on the Si substrate can be applied not only to electronic devices but also to optical devices and is one of the focuses of research and development in the field. However, due to the 4.2% lattice mismatch between Si and Ge, the epitaxial growth of the high-Ge-content SiGe epitaxial layer directly on the Si substrate has a high defect density, which will seriously affect the subsequent device performance. Laser recrystallization technique is a fast and low-cost method to effectively reduce threading dislocation density (TDD) in epitaxial high-Ge-content SiGe films on Si. In this paper, by means of finite element numerical simulation, a 808 nm laser recrystallization thermal physics model of a high-Ge-content SiGe film (for example, Si0.2Ge0.8) on a Si substrate was established (temperature distribution physical model of Si0.2Ge0.8 epitaxial layer under different laser power, Si0.2Ge0.8 epitaxial layer thickness, and initial temperature). The results of this paper can provide important technical support for the preparation of high-quality high-Ge-content SiGe epilayers on Si substrates by laser recrystallization.

The Heteroepitaxy and Characterization of Inp and GaInP on Silicon for Solar Cell Applications

1990 ◽  
Vol 198 ◽  
Author(s):  
M.M. Al-Jassim ◽  
R.K. Ahrenkiel ◽  
M.W. Wanlass ◽  
J.M. Olson ◽  
S.M. Vernon
Keyword(s):  
Carrier Lifetime ◽  
Minority Carrier ◽  
Defect Density ◽  
Minority Carrier Lifetime ◽  
Buffer Layers ◽  
Threading Dislocation ◽  
Si Substrates ◽  
Threading Dislocation Density ◽  
Direct Growth

ABSTRACTInP and GaInP layers were heteroepitaxially grown on (100) Si substrates by atmospheric pressure MOCVD. TEM and photoluminescence (PL) were used to measure the defect density and the minority carrier lifetime in these structures. The direct growth of InP on Si resulted in either polycrystalline or heavily faulted single-crystal layers. The use of GaAs buffer layers in InP/Si structures gave rise to significantly improved morphology and reduced the threading dislocation density. The best InP/Si layers in this study were obtained by using GaAs-GaInAs graded buffers. Additionally, the growth of high quality GaInP on Si was demonstrated. The minority carrier lifetime of 7 ns in these layers is the highest of any III-V/Si semiconductor measured in our laboratory.

The Reduction of The Defect Density in CdTe Buffer Layers for The Growth of HgCdTe Infrared Photodiodes on Si (211) Substrates

1997 ◽  
Vol 484 ◽  
Author(s):  
H.-Y. Wei ◽  
L. Salamanca-Riba ◽  
N. K. Dhar
Keyword(s):  
Dislocation Density ◽  
Defect Density ◽  
Three Dimensional ◽  
Buffer Layers ◽  
Threading Dislocation ◽  
Si Substrates ◽  
Migration Enhanced Epitaxy ◽  
Threading Dislocation Density ◽  
Order Of Magnitude ◽  
Cdte Buffer

CdTe epilayers were grown by molecular beam epitaxy on As-passivated nominal (211) Si substrates using thin interfacial ZnTe layers. By using thin recrystallized (initially amorphous) ZnTe buffei layers, we utilized migration enhanced epitaxy (MEE) in the ZnTe layer and overcome the tendency toward three dimensional nucleation. The threading dislocation densities in 8–9 tm thick CdTe films deposited on the recrystallized amorphous ZnTe films were in the range of 2 to 5 × 105 cm−2. In addition to the reduction of threading dislocation density, the interface between the ZnTe layers and the Si substrate is much smoother and the microtwin density is an order of magnitude lower than in regular MEE growth. In order to understand the initial nucleation mechanism of the ZnTe on the As precursor Si surface, we also grew ZnTe epilayers on Te precursor treated Si substrates. The growth mode, microtwin density, and threading dislocation density are compared for films grown on Si substrates with different surface precursors and grown by different growth methods.

The Reduction of The Defect Density in CdTe Buffer Layers for The Growth of HgCdTe Infrared Photodiodes on Si (211) Substrates

1997 ◽  
Vol 487 ◽  
Author(s):  
H.-Y. Wei ◽  
L. Salamanca-Riba ◽  
N. K. Dhar
Keyword(s):  
Dislocation Density ◽  
Defect Density ◽  
Three Dimensional ◽  
Buffer Layers ◽  
Threading Dislocation ◽  
Si Substrates ◽  
Migration Enhanced Epitaxy ◽  
Threading Dislocation Density ◽  
Order Of Magnitude ◽  
Cdte Buffer

CdTe epilayers were grown by molecular beam epitaxy on As-passivated nominal (211) Si substrates using thin interfacial ZnTe layers. By using thin recrystallized (initially amorphous) ZnTe buffer layers, we utilized migration enhanced epitaxy (MEE) in the ZnTe layer and overcome the tendency toward three dimensional nucleation. The threading dislocation densities in 8–9 μm thick CdTe films deposited on the recrystallized amorphous ZnTe films were in the range of 2 to 5 × 105 cm−2. In addition to the reduction of threading dislocation density, the interface between the ZnTe layers and the Si substrate is much smoother and the microtwin density is an order of magnitude lower than in regular MEE growth. In order to understand the initial nucleation mechanism of the ZnTe on the As precursor Si surface, we also grew ZnTe epilayers on Te precursor treated Si substrates. The growth mode, microtwin density, and threading dislocation density are compared for films grown on Si substrates with different surface precursors and grown by different growth methods.

Structural and Optical Characteristics of Laterally Overgrown GaN Pyramids on (111) Si Substrate

2001 ◽  
Vol 693 ◽  
Author(s):  
Yong-Hoon Cho ◽  
H. M. Kim ◽  
T. W. Kang ◽  
J. J. Song ◽  
W. Yang
Keyword(s):  
Electron Microscopy ◽  
Defect Density ◽  
Optical Characteristics ◽  
Structural Defects ◽  
Band Edge Emission ◽  
Threading Dislocation ◽  
Si Substrate ◽  
Cross Sectional ◽  
Band Emission ◽  
Threading Dislocation Density

AbstractStructural and optical characteristics of laterally overgrown GaN pyramids on a (111) Si substrate were investigated by scanning electron microscopy, transmission electron microscopy (TEM), and cathodoluminescence (CL) microscopy and spectroscopy. Cross-sectional TEM images revealed that the threading dislocation density over the window openings is very high, but gradually decreases with increasing GaN thickness, and that dislocations observed over the mask are parallel to the mask interface. Cross-sectional-view CL images taken at different emission wavelengths clearly showed significant differences between the overgrown areas on top of the mask and the coherently grown regions over the windows. A clear reverse contrast in the cross-sectional CL images of bandedge (identical contrast in case of yellow-band) emission was observed by comparing the defect density observed in cross-sectional TEM images. The CL peak intensity ratio of band-edge-emission to yellow luminescence was also investigated as a function of position in the GaN pyramid cross section. It was demonstrated that there exists a strong correlation between structural defects and optical properties in laterally overgrown GaN pyramids on (111) Si substrate.

Horizontal Defects Parallel to the Interface in GaN Pyramids

1999 ◽  
Vol 5 (S2) ◽  
pp. 734-735
Author(s):  
Zhigang Mao ◽  
Stuart McKernan ◽  
C. Barry Carte ◽  
Wei Yang ◽  
Scott A. McPherson
Keyword(s):  
Defect Density ◽  
Low Cost ◽  
Substrate Surface ◽  
Optoelectronic Devices ◽  
Limited Information ◽  
Si Substrate ◽  
Si Substrates ◽  
Lateral Overgrowth ◽  
Large Size ◽  
Window Area

The performance of III-V nitride-based microelectronic and optoelectronic devices relates directly to the micro structure of these materials. Selective lateral overgrowth has been exploited to produce GaN heteroepitaxial films with low defect density [1]. Si is a promising substrate due to its low cost, large size, and the potential for the intergration of GaN-based optoelectronic devices with Si-based electronics. It is also possible to produce high-quality GaN material for devices using lateral overgrowth on a Si substrate [2]. At present, only limited information on the defect structure in GaN heteroepitaxial films grown by selective lateral growth is available, especially those grown on Si substrate. Recent work [3] on GaN pyramids grown on (111) Si substrates by this method has shown that in the center, or core, of the GaN pyramid (at and above the window area) dislocations thread through the pyramid nearly perpendicular to the substrate surface and the dislocation density is quite high.

Microstructures in the Pendeo Epitaxial Layer of 3C-SiC on Si Substrate

2005 ◽  
Vol 483-485 ◽  
pp. 221-224 ◽  
Author(s):  
A. Shoji ◽  
Mitsutaka Nakamura ◽  
K. Mitikami ◽  
Toshiyuki Isshiki ◽  
Satoru Ohshima ◽  
...  
Keyword(s):  
High Resolution ◽  
Epitaxial Layer ◽  
Defect Density ◽  
Si Substrate ◽  
Electron Microscopic ◽  
Grown Layer ◽  
Si Substrates ◽  
High Defect Density ◽  
Transmission Electron ◽  
Transmission Electron Microscopic

The pendeo epitaxial growth has been applied for the growth of 3C-SiC on (001) Si substrates. This growth was performed by VPE using hexamethyldisilane (HMDS) as a source gas. To characterize the crystallinity of the seed 3C-SiC and the pendeo epitaxial layer, the high resolution transmission electron microscopic (HRTEM) analysis was carried out. In the vertically grown layer on the seed 3C-SiC, the high-defect-density regions were observed. On the contrary, the low-defect-density regions were observed in the laterally grown layer. It was revealed from the TEM observations that lattice information can be transferred through the seed 3C-SiC while defects can be prevented from propagating into the epitaxial layer due to the presence of the air gap.

Correlation Between Defect Density and Process Variables In Step-Graded, Relaxed Si0.7Ge0.3 Grown on Si by Rtcvd

1993 ◽  
Vol 303 ◽  
Author(s):  
G. Patrick Watson ◽  
Eugene A. Fitzgerald ◽  
Bahram Jalali ◽  
Ya-Hong Xie ◽  
Bonnie Weir ◽  
...  
Keyword(s):  
Defect Density ◽  
Chemical Vapor ◽  
Dark Spot ◽  
Threading Dislocation ◽  
Dark Line ◽  
Si Substrates ◽  
Transmission Electron ◽  
Threading Dislocation Density ◽  
Line Defects ◽  
Threading Defects

ABSTRACTThe effect of the average grading rate and of the number of incremental Ge alloy steps on the threading dislocation density has been studied in 30% Ge relaxed films formed by rapid thermal chemical vapor deposition (RTCVD) on Si substrates. Electron beam induced current (EBIC) images and transmission electron microscopy (TEM) show that threading defects fall in two categories: individual threading dislocations (dark spot defects), and organized clusters of these threads (pile-ups, or dark line defects). The overall surface defect density must include both categories to properly characterize the material. The lowest defect density, 4 × 105cm−2, was found in specimens grown at an average grading rate of 10% Ge per pm thickness.

Influence of MBE Growth Conditions on Dislocation Densities of GaAs/Ge Epilayers Grown on Silicon Substrates

1985 ◽  
Vol 43 ◽  
pp. 364-365
Author(s):  
K.M. Hones ◽  
P. Sheldon ◽  
B.G. Yacobi ◽  
A. Mason
Keyword(s):  
High Efficiency ◽  
Lattice Mismatch ◽  
Low Cost ◽  
Growth Conditions ◽  
Nonradiative Recombination ◽  
Device Structure ◽  
Si Substrates ◽  
Transmission Electron ◽  
Dislocation Densities ◽  
Dislocation Type

There is increasing interest in growing epitaxial GaAs on Si substrates. Such a device structure would allow low-cost substrates to be used for high-efficiency cascade- junction solar cells. However, high-defect densities may result from the large lattice mismatch (∼4%) between the GaAs epilayer and the silicon substrate. These defects can act as nonradiative recombination centers that can degrade the optical and electrical properties of the epitaxially grown GaAs. For this reason, it is important to optimize epilayer growth conditions in order to minimize resulting dislocation densities. The purpose of this paper is to provide an indication of the quality of the epitaxially grown GaAs layers by using transmission electron microscopy (TEM) to examine dislocation type and density as a function of various growth conditions. In this study an intermediate Ge layer was used to avoid nucleation difficulties observed for GaAs growth directly on Si substrates. GaAs/Ge epilayers were grown by molecular beam epitaxy (MBE) on Si substrates in a manner similar to that described previously.

Evaluation of threading dislocation density of strained Ge epitaxial layer by high resolution x-ray diffraction

2017 ◽  
Vol 26 (12) ◽  
pp. 127309 ◽  
Author(s):  
Yuan-Hao Miao ◽  
Hui-Yong Hu ◽  
Xin Li ◽  
Jian-Jun Song ◽  
Rong-Xi Xuan ◽  
...  
Keyword(s):  
High Resolution ◽  
Dislocation Density ◽  
Epitaxial Layer ◽  
Threading Dislocation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Threading Dislocation Density
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