Interface Formation and the Heteroepitaxy of ZnSe on Si.

1990 ◽  
Vol 198 ◽  
Author(s):  
R. D. Bringans ◽  
D. K. Biegelsen ◽  
F. A. Ponce ◽  
L.-E. Swartz ◽  
J. C. Tramontana
Keyword(s):  
Zinc Selenide ◽  
Room Temperature ◽  
Molecular Beam ◽  
Solid Phase ◽  
Bulk Material ◽  
Znse Crystal ◽  
Si Substrate ◽  
Transmission Electron ◽  
Temperature Deposition ◽  
Substrate Temperatures

ABSTRACTZinc selenide films have been grown heteroepitaxially on Si(100) substrates by molecular beam epitaxy. The growth has been carried out for raised substrate temperatures and also at room temperature followed by solid-phase epitaxial (SPE) regrowth. The ZnSe films have been characterized by a number of surface-sensitive techniques and both the interface and the bulk material have been examined with high resolution transmission electron microscopy (HRTEM). We find that an interlayer, which is most likely SiSex, is present between the ZnSe film and the Si substrate for growths made at 300 °C and causes loss of epitaxy. In the case of room temperature deposition and SPE, it is absent, leading to good epitaxy. In the latter situation, the films are very uniform and there is a 4° rotation of the ZnSe crystal axes relative to those of the Si substrate.

Initial Stages of Growth of ZnSe on Si

1992 ◽  
Vol 242 ◽  
Author(s):  
R. D. Bringans ◽  
D. K. Biegelsen ◽  
L.-E. Swartz ◽  
F. A. Ponce ◽  
J. C. Tramontana
Keyword(s):  
Zinc Selenide ◽  
Room Temperature ◽  
Molecular Beam ◽  
Solid Phase ◽  
Solid Phase Epitaxy ◽  
Compound Formation ◽  
Stages Of Growth ◽  
Gaas Films ◽  
Temperature Deposition ◽  
Growth Methods

ABSTRACTZinc selenide films have been grown heteroepitaxially on Si(100) substrates by molecular beam epitaxy. The initial stages of growth are dominated by the reaction of Se and Si atoms to form the compound SiSe2- The compound formation disrupts epitaxy, and several growth methods which avoid this are described and compared. We find that room temperature deposition plus solid phase epitaxy does not lead to significant SiSex formation and yields uniformly thick films which are misoriented with respect to the substrate and contain large regions of twinned ZnSe. The use of an As monolayer on the Si surface before the start of ZnSe growth allows good ZnSe epitaxy without any Si-Se reaction or any misorientation. ZnSe films have also been used as interlayers for GaAs growth on Si. This has allowed us to obtain uniform GaAs films at thicknesses which typically manifest a coalesced island morphology for GaAs grown directly on Si.

Evolution of Co/Ge Films on Si(100) and Ge(100) Substrates

1995 ◽  
Vol 382 ◽  
Author(s):  
G.R. Carlow ◽  
T.D. Lowes ◽  
M. Grunwell ◽  
M. Zinke-Allmang
Keyword(s):  
Electron Microscopy ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Room Temperature ◽  
Molecular Beam ◽  
Si Substrate ◽  
Si Substrates ◽  
Annealing Temperatures ◽  
Temperature Deposition ◽  
Scanning Electron

ABSTRACTWe present results on the evolution of Co/Ge films on Si(100) substrates. Room temperature deposition of 18 nm thick Ge films followed by 5 nm thick Co films was done by Molecular Beam Epitaxy (MBE) and then post-deposited annealing was done at 700 C. Using combinations of Scanning electron microscopy, Auger electron spectroscopy and Rutherford backscattering spectroscopy, we determine that the Co and Ge are clustering on the Si surface at these annealing temperatures. During the clustering, the Co is diffusing into the Si substrate leaving a Ge-rich clustered morphology. To test the effect of the Si substrate on the evolution of the films, Co films were deposited on Ge(100) substrates and annealed at 700 C. Clustered morphologies are seen on the Ge substrates and Co in-diffusion is also occurring. The morphologies on the Ge substrates are significantly different from those on the Si substrates.

(111) Monocrystalline Nickel Films

1972 ◽  
Vol 30 ◽  
pp. 512-513
Author(s):  
T.E. Pratt ◽  
R.W. Vook
Keyword(s):  
Film Thickness ◽  
Deposition Rate ◽  
Room Temperature ◽  
Narrow Range ◽  
High Vacuum ◽  
Residual Pressure ◽  
Temperature Dependent ◽  
Deposition Parameters ◽  
Transmission Electron ◽  
Substrate Temperatures

(111) oriented thin monocrystalline Ni films have been prepared by vacuum evaporation and examined by transmission electron microscopy and electron diffraction. In high vacuum, at room temperature, a layer of NaCl was first evaporated onto a freshly air-cleaved muscovite substrate clamped to a copper block with attached heater and thermocouple. Then, at various substrate temperatures, with other parameters held within a narrow range, Ni was evaporated from a tungsten filament. It had been shown previously that similar procedures would yield monocrystalline films of CU, Ag, and Au.For the films examined with respect to temperature dependent effects, typical deposition parameters were: Ni film thickness, 500-800 A; Ni deposition rate, 10 A/sec.; residual pressure, 10-6 torr; NaCl film thickness, 250 A; and NaCl deposition rate, 10 A/sec. Some additional evaporations involved higher deposition rates and lower film thicknesses.Monocrystalline films were obtained with substrate temperatures above 500° C. Below 450° C, the films were polycrystalline with a strong (111) preferred orientation.

A crystallographic analysis of the CoSi/Si(111) interface using Transmission Electron Microscopy

1990 ◽  
Vol 48 (4) ◽  
pp. 574-575
Author(s):  
A.C. Daykin ◽  
C.J. Kiely ◽  
R.C. Pond ◽  
J.L. Batstone
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Defect Structure ◽  
Room Temperature ◽  
Theoretical Method ◽  
Crystallographic Analysis ◽  
Si Substrate ◽  
Transmission Electron ◽  
Theoretical Predictions

When CoSi2 is grown onto a Si(111) surface it can form in two distinct orientations. A-type CoSi2 has the same orientation as the Si substrate and B-type is rotated by 180° degrees about the [111] surface normal.One method of producing epitaxial CoSi2 is to deposit Co at room temperature and anneal to 650°C.If greater than 10Å of Co is deposited then both A and B-type CoSi2 form via a number of intermediate silicides .The literature suggests that the co-existence of A and B-type CoSi2 is in some way linked to these intermediate silicides analogous to the NiSi2/Si(111) system. The phase which forms prior to complete CoSi2 formation is CoSi. This paper is a crystallographic analysis of the CoSi2/Si(l11) bicrystal using a theoretical method developed by Pond. Transmission electron microscopy (TEM) has been used to verify the theoretical predictions and to characterise the defect structure at the interface.

Growth of Epitaxial IrSi3 Layers on Si(111)

1989 ◽  
Vol 160 ◽  
Author(s):  
T. L. Lin ◽  
C. W. Nieh
Keyword(s):  
Surface Morphology ◽  
Molecular Beam ◽  
Solid Phase ◽  
Single Mode ◽  
Growth Conditions ◽  
Tem Analysis ◽  
Mbe Growth ◽  
Good Surface ◽  
Transmission Electron

AbstractEpitaxial IrSi3 films have been grown on Si (111) by molecular beam epitaxy (MBE) at temperatures ranging from 630 to 800 °C and by solid phase epitaxy (SPE) at 500 °C. Good surface morphology was observed for IrSi3 layers grown by MBE at temperatures below 680 °C, and an increasing tendency to form islands is noted in samples grown at higher temperatures. Transmission electron microscopy (TEM) analysis reveals that the IrSi3 layers grow epitaxially on Si(111) with three epitaxial modes depending on the growth conditions. For IrSi3 layers grown by MBE at 630 °C, two epitaxial modes were observed with ~ 50% area coverage for each mode. Single mode epitaxial growth was achieved at a higher MBE growth temperature, but with island formation in the IrSi3 layer. A template technique was used with MBE to improve the IrSi3 surface morphology at higher growth temperatures. Furthermore, single-crystal IrSi3 was grown on Si(111) at 500 °C by SPE, with annealing performed in-situ in a TEM chamber.

scholarly journals Structural and Optical Properties of Self-Catalyzed Axially Heterostructured GaPN/GaP Nanowires Embedded into a Flexible Silicone Membrane

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2110
Author(s):  
Olga Yu. Koval ◽  
Vladimir V. Fedorov ◽  
Alexey D. Bolshakov ◽  
Sergey V. Fedina ◽  
Fedor M. Kochetkov ◽  
...  
Keyword(s):  
Optical Properties ◽  
Room Temperature ◽  
Molecular Beam ◽  
Nanowire Array ◽  
Growth Mechanisms ◽  
Structural And Optical Properties ◽  
Rubber Membrane ◽  
Transmission Electron ◽  
The Difference ◽  
Photoluminescence Studies

Controlled growth of heterostructured nanowires and mechanisms of their formation have been actively studied during the last decades due to perspectives of their implementation. Here, we report on the self-catalyzed growth of axially heterostructured GaPN/GaP nanowires on Si(111) by plasma-assisted molecular beam epitaxy. Nanowire composition and structural properties were examined by means of Raman microspectroscopy and transmission electron microscopy. To study the optical properties of the synthesized nanoheterostructures, the nanowire array was embedded into the silicone rubber membrane and further released from the growth substrate. The reported approach allows us to study the nanowire optical properties avoiding the response from the parasitically grown island layer. Photoluminescence and Raman studies reveal different nitrogen content in nanowires and parasitic island layer. The effect is discussed in terms of the difference in vapor solid and vapor liquid solid growth mechanisms. Photoluminescence studies at low temperature (5K) demonstrate the transition to the quasi-direct gap in the nanowires typical for diluted nitrides with low N-content. The bright room temperature photoluminescent response demonstrates the potential application of nanowire/polymer matrix in flexible optoelectronic devices.

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.

Platelets, dislocation loops and voidites in diamond

1986 ◽  
Vol 407 (1833) ◽  
pp. 239-258 ◽  
Keyword(s):  
Room Temperature ◽  
Solid Phase ◽  
Prismatic Slip ◽  
Dislocation Loops ◽  
High Pressure And Temperature ◽  
Burgers Vector ◽  
Transmission Electron ◽  
Microscope Images ◽  
Diffraction Patterns ◽  
Small Clusters

A type IaB diamond specimen containing partially decomposed platelets, dislocation loops and voidites has been investigated by transmission electron microscopy. The dislocation loops were found to be prismatic and interstitial in nature, some with Burgers vector ½ a <110> previously reported, but most with Burgers vector a <001>. Burgers vector analysis of the bounding dislocation of partially decomposed platelets shows that the a <001> loops are formed by transformation of the platelets, by nucleation and climb of a <00(1— f )> dislocation, combining with the a <00 f > dislocation bounding the platelet. The climb mechanism is driven by the need to generate vacancies for the decomposition of the platelets and to accommodate the nitrogen either in small clusters in solution in the lattice or in voidites. Glide dislocations interacting with the platelets are likely to act as nucleating centres for the climb process. The ½ a <110> dislocation loops are considered to be formed by dissociation of the a <001> loops, promoted by interaction with glide dislocations and involving prismatic slip and conservative climb. Voidites are assumed to originate as bubbles of fluid nitrogen formed at high pressure and temperature as a result of decomposition of the platelets; at room temperature they may be liquid or solid depending on the pressure, which cannot be estimated accurately. Electron diffraction patterns and microscope images of voidites prove that many consist of a solid phase at 300 K. It is suggested that the diamond has been subjected to a drop in pressure at high temperature, causing platelet decomposition and the generation of voidites, that may occur during ejection of the diamond to the earth’s surface.

scholarly journals Magnetic and Structural Studies of CoFe2O4Nanoparticles Suspended in an Organic Liquid

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Branka Babić-Stojić ◽  
Vukoman Jokanović ◽  
Dušan Milivojević ◽  
Zvonko Jagličić ◽  
Darko Makovec ◽  
...  
Keyword(s):  
Room Temperature ◽  
Bulk Material ◽  
Organic Liquid ◽  
Average Particle Size ◽  
Hydrodynamic Diameter ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Ferrite Nanoparticle ◽  
Nanoparticle System

We present a study of magnetic and structural properties of CoFe2O4nanoparticles suspended in an organic liquid. Transmission electron microscopy shows that the nanoparticles have a narrow size distribution of average particle size 5.9 ± 1.0 nm. X-ray diffraction shows that the particles are of cubic spinel crystal structure. Dynamic light scattering measurements reveal the existence of an organic shell around the CoFe2O4nanoparticles with an average hydrodynamic diameter of 14.4 nm. Coercive magnetic field atT=5 K is found to be 11.8 kOe. Disappearance of the coercive field and remanent magnetization at about 170 K suggests that the CoFe2O4nanoparticles are superparamagnetic at higher temperatures which is confirmed by the room temperature Mössbauer spectrum analysis. Saturation magnetization of the nanoparticles of 80.8 emu/g(CoFe2O4) at 5 K reaches the value detected in the bulk material and remains very high also at room temperature. The cobalt ferrite nanoparticle system synthesized in this work exhibits magnetic properties which are very suitable for various biomedical applications.

Molecular Beam Epitaxial Growth of Cdl-xznxTe Matched to HgCdTe Alloys

1986 ◽  
Vol 90 ◽  
Author(s):  
N. Magnea ◽  
F. Dal'bo ◽  
J. L. Pautrat ◽  
A. Million ◽  
L. Di Cioccio ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Molecular Beam ◽  
Bulk Material ◽  
Strained Layers ◽  
Molecular Beam Epitaxial ◽  
Transmission Electron ◽  
Molecular Beam Epitaxial Growth ◽  
Thick Layers

ABSTRACTCD1−xZnxTe alloys of various composition have been grown by the Molecular Beam Epitaxy Technique and characterized by Transmission Electron Microscopy. C(V) measurements and photoluminescence spectroscopy techniques. The quality of the thick layers is comparable to that of bulk material. Thin strained layers have also been grown whose interfaces are structurally good. The recombination within a CdTe well confined between Cd1−xZnxTe barriers is dominated by intrinsic processes.

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