Heteroep1Taxial Nucleation and Structural Properties of MBE GaAs on Recessed Si: Etching Implications.

1989 ◽  
Vol 145 ◽  
Author(s):  
Jo De Boeck ◽  
Jiben Liang ◽  
Jan Vanhellemont ◽  
Kristin Deneffe ◽  
Chris Van Hoof ◽  
...  
Keyword(s):  
Growth Front ◽  
Gaas Layer ◽  
Si Substrate ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Device Integration ◽  
Dry Etch ◽  
Induced Defects ◽  
The Impact ◽  
Facet Formation

AbstractGaAs is grown embedded in pre-etched wells in the Si substrate. HNO3:HF, KOH:H2O and a dry etch technique are used as alternatives to form the wells. Cross-sectional SEM views of AlGaAs/GaAs heterostructures reveal the growth front and facet formation for the different sidewall geometries. Transmission electron microscopy is used to study epilayer degradation in relation to the substrate damage and the presence of edge induced defects in the GaAs. Cathodoluminescence reveals the uniformity of strain present in the GaAs layer embedded in the wet etched well. The impact of the different etching techniques on device integration is briefly discussed.

Experimental Investigation of the Impact of Implanted Phosphorus Dose and Anneal on Dopant Diffusion and Activation in Germanium

2008 ◽  
Vol 1070 ◽  
Author(s):  
Vincent Mazzocchi ◽  
Stéphane Koffel ◽  
Cyrille Le Royer ◽  
Pascal Scheiblin ◽  
Jean-Paul Barnes ◽  
...  
Keyword(s):  
Semiconductor Industry ◽  
Doping Profile ◽  
Dopant Diffusion ◽  
Activation Temperature ◽  
Cross Sectional ◽  
Annealing Conditions ◽  
Transmission Electron ◽  
Activation Level ◽  
Induced Defects ◽  
The Impact

ABSTRACTGermanium has regained attention in the semiconductor industry for MOSFET application because of the higher mobility of carriers – two times higher mobility for electrons and four times for holes – as compared to silicon. In the opposite of the Silicon, the major issue with Germanium is to limit the n-dopant diffusion. Usual n-dopants (Phosphorus and Arsenic for example) are not electrically activated at an acceptable level without a large diffusion of the doping profile and a substantial dose loss. In this work, we have studied the influence of low energy and dose implant (15KeV to 40KeV @ 8E13 to 1E15at.cm−2) and low temperature anneal (515°C to 600°C) on diffusion, exodiffusion and activation of the phosphorus dopant into Germanium. The annealing steps were made in RTP furnace, the chemical profile and electrically active profiles were extracted by using Secondary-Ion-Mass Spectroscopy (SIMS) and sheet resistance measurement (Rs). To investigate the implantation-induced defects in depth, cross-sectional micrographs were made by using Transmission Electron Microscopy (TEM). Experimental results show that we achieved an efficient activation level by tuning both dose implant and anneal temperature, limiting the exodiffusion with pratically no diffusion of the dopant. We also show that very abrupt profile can be achieved with appropriate implant and thermal annealing conditions. To limit the leakage current in devices, we suppose we have to limit the defects generated during the implantation. Specially for dopant activation temperature anneal below 550°C, we have shown and observed by cross-sectional micrograph that the defects are totally removed by addition of a pre step of annealing at 400°C.

Temperature Dependent Quasi-Periodic Facetting of AlAs Grown by MBE on (100) GaAs Substrates

1993 ◽  
Vol 312 ◽  
Author(s):  
Richard Mirin ◽  
Mohan Krishnamurthy ◽  
James Ibbetson ◽  
Arthur Gossard ◽  
John English ◽  
...  
Keyword(s):  
Growth Conditions ◽  
High Energy ◽  
High Energy Electron ◽  
Temperature Dependent ◽  
Cross Sectional ◽  
Mbe Growth ◽  
Atomic Force ◽  
Gaas Substrates ◽  
Transmission Electron ◽  
Facet Formation

AbstractHigh temperature (≥ 650°C) MBE growth of AlAs and AlAs/GaAs superlattices on (100) GaAs is shown to lead to quasi-periodic facetting. We demonstrate that the facetting is only due to the AlAs layers, and growth of GaAs on top of the facets replanarizes the surface. We show that the roughness between the AlAs and GaAs layers increases with increasing number of periods in the superlattice. The roughness increases to form distinct facets, which rapidly grow at the expense of the (100) surface. Within a few periods of the initial facet formation, the (100) surface has disappeared and only the facet planes are visible in cross-sectional transmission electron micrographs. At this point, the reflection high-energy electron diffraction pattern is spotty, and the specular spot is a distinct chevron. We also show that the facetting becomes more pronounced as the substrate temperature is increased from 620°C to 710°C. Atomic force micrographs show that the valleys enclosed by the facets can be several microns long, but they may also be only several nanometers long, depending on the growth conditions.

Growth and Characterizations of Gaas on Inp with Different Buffer Structures by Molecular Beam Epitaxy

1989 ◽  
Vol 148 ◽  
Author(s):  
Xiaoming Liu ◽  
Henry P. Lee ◽  
Shyh Wang ◽  
Thomas George ◽  
Eicke R. Weber ◽  
...  
Keyword(s):  
Low Temperature ◽  
Buffer Layer ◽  
Gaas Layer ◽  
Optical Quality ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Layer Structures ◽  
Gaas Films ◽  
Initial Deposition ◽  
Strained Layer Superlattices

ABSTRACTWe report the growth and characterizations of 31μm thick GaAs films grown on (100) InP substrates by MBE employing different buffer layer structures during the initial deposition. The buffer layer structures under study are: 1) GaAs layer grown at low temperature; 2) GaAs layer grown at low temperature plus two sets of In0.08Ga0.92As/GaAs strained layer superlattices (SLS) and 3) a transitional compositionally graded InxGal-xAs layer between the InP substrate and the GaAs film. After the buffer layer deposition, the growth was continued by conventionalMBE to a total thickness of 3μm for all samples. From the 77K photoluminescence (PL) measurement, it was found that the sample with SLS layers has the highest PL intensity and the narrowest PL linewidth. Cross-sectional transmission electron microscopy (TEM) studies showed that the SLS is effective in reducing the propagation of threading dislocations and explains the observed superior optical quality from the PL measurement.

Transmission Electron Microscopy Observation of 11MEV B5+ Ion Irradiation in Bi2Sr2CaCu2O7-x Single Crystal

1999 ◽  
Vol 5 (S2) ◽  
pp. 758-759
Author(s):  
W.L. Zhou ◽  
Y. Sasaki ◽  
Y. Ikuhara ◽  
C.J.O’Connor
Keyword(s):  
Single Crystal ◽  
Ion Irradiation ◽  
Target Material ◽  
Heavy Ion ◽  
Zone Melting ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Different Types ◽  
Induced Defects ◽  
Irradiation Induced Defects

Artificial defects generated by ion irradiation have been considered an efficient method to enhance the critical current density in superconducting materials. The mechanism of producing defects as flux pining centers is still an important issue since the efficiency of irradiation-induced defects in flux pinning strongly depends on their microstructures. Different types of defects have been found in heavy ion irradiation. However, there are few results that show light ion irradiation due to the target material selected, the type of light ion and energy, and the incident ion angle. Another factor is the difficulty of cross-sectional sample preparation. In this paper, a single crystal Bi2Sr2CaCu2O7-x with 11 MeV B5+ ion irradiation was observed by transmission electron microscope (TEM) from both plan and cross-sectional view.The Bi2Sr2CaCu2O7-x single crystals used for ion irradiation were prepared using the floating-zone melting method. The crystals were cleaved into thin sheets of about 20 μm thickness along the a-b plane and cut to about 2mmx2mm size.

Evolution of Epitaxial SixGei1-x Alloys on Si(100) During Thermal Annealing a-Ge/Au Bilayers Deposited on Si Substrate

1992 ◽  
Vol 280 ◽  
Author(s):  
Z. Ma ◽  
L. H. Allen
Keyword(s):  
Single Crystal ◽  
Thermal Annealing ◽  
Rutherford Backscattering Spectrometry ◽  
Solid Phase ◽  
Growth Dynamics ◽  
X Ray Diffraction ◽  
Si Substrate ◽  
Cross Sectional ◽  
X Ray ◽  
Transmission Electron

ABSTRACTSolid phase epitaxial (SPE) growth of SixGei1-x alloys on Si (100) was achieved by thermal annealing a-Ge/Au bilayers deposited on single crystal Si substrate in the temperature range of 280°C to 310°C. Growth dynamics was investigated using X-ray diffraction, Rutherford backscattering spectrometry, and cross-sectional transmission electron microscopy. Upon annealing, Ge atoms migrate along the grain boundaries of polycrystalline Au and the epitaxial growth initiates at localized triple points between two Au grains and Si substrate, simultaneously incorporating a small amount of Si dissolved in Au. The Au is gradually displaced into the top Ge layer. Individual single crystal SixGei1-x islands then grow laterally as well as vertically. Finally, the islands coalesce to form a uniform layer of epitaxial SixGe1-x alloy on the Si substrate. The amount of Si incorporated in the final epitaxial film was found to be dependent upon the annealing temperature.

An Influence of the Si(111)3-4o Vicinal Surface on the Solid Phase Epitaxy of α-FeSi2 Nanorods and their Crystal Parameters

2019 ◽  
Vol 806 ◽  
pp. 30-35
Author(s):  
Nikolay Gennadievich Galkin ◽  
Konstantin N. Galkin ◽  
Sergei Andreevich Dotsenko ◽  
Dmitrii L'vovich Goroshko ◽  
Evgeniy Anatolievich Chusovitin ◽  
...  
Keyword(s):  
Direct Evidence ◽  
Solid Phase ◽  
Iron Silicide ◽  
Solid Phase Epitaxy ◽  
Vicinal Surface ◽  
Si Substrate ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Spe Method ◽  
First Time

The morphology and structure of iron silicide nanorods formed on Si (111) vicinal surface by the SPE method at T = 630 °C were studied. Optimal Fe coverage and Fe deposition rate for the formation of a dense array of the nanorods (54-65% of the substrate area) on Si (111) surface with 3-4o miscut angles were established. The aspect ratio of the nanorods is 1.9 – 3.3. Cross-sectional images of a high-resolution transmission electron microscopy (HRTEM) have shown that the nanorods have α-FeSi2 crystal structure. They are strained along the “a” axis and stretched along the “c” axis, which increased the unit cell volume by 10.3%. According to HRTEM image analysis, the nanorods have the following epitaxial relationships: α-FeSi2[01]//Si [10] and α-FeSi2(112)//Si (111). All the data obtained have provided, for the first time, a direct evidence of α-FeSi2 nanorods formation on Si (111) vicinal surface without noticeable penetration of Fe atoms into the Si substrate.

Effects of Growth Parameters on the Epitaxy of CoSi2/Si(100) Formed by Reactive Deposition Epitaxy

1995 ◽  
Vol 402 ◽  
Author(s):  
André Vantommela ◽  
Stefan Degroote ◽  
Johan Dekoster ◽  
Hugo Bender ◽  
Guido Langouche
Keyword(s):  
Growth Parameters ◽  
Si Substrate ◽  
Cross Sectional ◽  
Plan View ◽  
X Ray ◽  
Reactive Deposition ◽  
Transmission Electron ◽  
Highly Strained ◽  
Substrate Temperatures ◽  
Minimum Yield

AbstractEpitaxial CoSi2(100) layers in the thickness range of 20 to 50 nm have been formed by reactive deposition epitaxy (i.e. Co deposition onto a hot Si substrate) without the use of either a template or an intermediate Ti layer. It is explained how growth parameters such as the deposition rate and substrate temperature are crucial in determining the epitaxial nature of the silicide. According to this model, good CoSi2/Si(100) alignment is only achieved when very low deposition rates are used (0.1 Å/s or less), combined with relatively high substrate temperatures during deposition (∼ 600°C or higher). Using these conditions, highly strained, continuous CoSi2 layers with a channeling minimum yield of χmin = 9% could be formed. Using higher rates and/or lower deposition temperatures, an increasing fraction of misoriented CoSi2 grains is presumed from backscattering/channeling and x-ray experiments, the nature of which is under investigation with plan view and cross sectional transmission electron microscopy.

Domain and Interface Structures of Epitaxial PtSi

1983 ◽  
Vol 25 ◽  
Author(s):  
H. Kawarada ◽  
I. Ohdomari ◽  
S. Horiuchi
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Domain Boundary ◽  
Intermediate Region ◽  
Si Substrate ◽  
Crystalline Perfection ◽  
Lattice Image ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Interface Structures

ABSTRACTThe crystalline perfection of epitaxial PtSi thin films and the microstructure of the PtSi/Si interface have been examined using transmission electron microscopy (TEM), including lattice image techniques. Epitaxial PtSi layers grow with domains which have three different positions on a (111) Si substrate. Inside a domain the crystalline perfection is high, and at the domain boundary no intermediate region has been observed. The undulation of the PtSi/Si interface is larger than that of other epitaxial silicide/Si interfaces. Despite the large undulation, a cross-sectional lattice image shows the epitaxial layer extends to the interface. The interface is abrupt in the epitaxial PtSi/Si system.

Dry-Etch-induced damage in GaAs investigated via TEM

1993 ◽  
Vol 51 ◽  
pp. 1114-1115
Author(s):  
M.W. Cole ◽  
G.F. McLane
Keyword(s):  
Attractive Alternative ◽  
Device Performance ◽  
Cross Sectional ◽  
Ion Etching ◽  
Near Surface ◽  
Transmission Electron ◽  
Residual Damage ◽  
Moderate Energy ◽  
Wafer Processing ◽  
Dry Etch

Plasma-assisted etching is an important III-V semiconductor fabrication technique for patterning device structures on the nanometer scale with high accuracy. The quality of the processed surface is of primary importance for most electronic applications. It is well documented that reactive ion etching (RIE), with its high self-biases, usually incurs material damage via ion bombardment which ultimately limits device performance. Magnetron ion etching (MIE) is an attractive alternative to RIE. Specifically, MIE has a lower sheath voltage than RIE and the discharge contains low to moderate energy ions, both of which allow wafer processing with less ion-induced damage. This study investigated the nature and extent of near surface disorder resultant from MIE with freon-12 (CCl2F2) via cross-sectional transmission electron microscopy (TEM). The effect of residual damage on device performance was evaluated via Schottky diode measurements. The GaAs wafers were etched under the following conditions:

Growth and Characterization of Si-GaP and Si-GaP-Si Heterostructures

1993 ◽  
Vol 334 ◽  
Author(s):  
N. Dietz ◽  
S. Habermehl ◽  
J. T. Kelliher ◽  
G. Lucovsky ◽  
K. J. Bachmann
Keyword(s):  
Epitaxial Growth ◽  
Chemical Beam Epitaxy ◽  
Si Substrate ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Amorphous Sic ◽  
Secondary Ion ◽  
Source Materials

AbstractThe low temperature epitaxial growth of Si / GaP / Si heterostructures is investigated with the aim using GaP as a dielectric isolation layer for Si circuits. GaP layers have been deposited on Si(100) surfaces by chemical beam epitaxy (CBE) using tertiarybutyl phosphine (TBP) and triethylgallium (TEG) as source materials. The influence of the cleaning and passivation of the GaP surface has been studied in-situ by AES and LEED, with high quality epitaxial growth proceeding on vicinal GaP(100) substrates. Si / GaP / Si heterostructures have been investigated by cross sectional high resolution transmission electron microscope (HRTEM) and secondary ion mass spectroscope (SIMS). These methods reveal the formation of an amorphous SiC interlayer between the Si substrate and GaP film due to diffusion of carbon generated in the decomposition of the metalorganic precursors at the surface to the GaP/Si interface upon prolonged growth (layer thickness > 300Å). The formation of twins parallel to {111} variants in the GaP epilayer are extended into the subsequently grown Si film with minor generation of new twins.

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