Ge δ-Layers on Si(111) and Si(001) Grown by MBE and SPE

1994 ◽  
Vol 375 ◽  
Author(s):  
J. Falta ◽  
T. Gog ◽  
G. Materlik ◽  
B. H. Müjller ◽  
M. Horn-Von Hoegen
Keyword(s):  
Room Temperature ◽  
Molecular Beam ◽  
Solid Phase ◽  
Standing Waves ◽  
Solid Phase Epitaxy ◽  
High Crystalline Quality ◽  
X Ray ◽  
High Annealing

AbstractGe δ-layers on Si(111) and Si(001), grown by molecular beam epitaxy (MBE) and solid phase epitaxy (SPE) were characterized in-situ by high-resolution low-energy electrondiffraction and post-growth by x-ray standing waves. LEED intensity oscillations are used to determine the growth mode of Ge on Si which is found to proceed in a double bilayer fashion for Ge on Si(111). X-ray standing waves are employed to investigate crystal quality of the Ge layer. SPE on Si(111) requires high annealing temperatures (600°C) for sufficient recrystallization of defects in the Ge δ-layer. On Si(001), Ge δ-layers of surprisingly high crystalline quality are grown by solid phase epitaxy at room temperature.

Optimising the Growth of Few-Layer Graphene on Silicon Carbide by Nickel Silicidation

2013 ◽  
Vol 740-742 ◽  
pp. 121-124 ◽  
Author(s):  
Enrique Escobedo-Cousin ◽  
Konstantin Vassilevski ◽  
Toby Hopf ◽  
Nick G. Wright ◽  
Anthony O’Neill ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Solid Phase ◽  
Sample Surface ◽  
Device Fabrication ◽  
Solid Phase Epitaxy ◽  
X Ray ◽  
Graphene Films ◽  
Few Layer Graphene ◽  
The Impact

Few-layers graphene films (FLG) were grown by local solid phase epitaxy on a semi-insulating 6H-SiC substrate by annealing Ni films deposited on the Si and C-terminated faces of the SiC. The impact of the annealing process on the final quality of the FLG films is studied using Raman spectroscopy. X-ray photoelectron spectroscopy was used to verify the presence of graphene on the sample surface. We also demonstrate that further device fabrication steps such as dielectric deposition can be carried out without compromising the FLG films integrity.

The use of NiMnSb Heusler alloy in MBE Grown Tunnel Junction

2001 ◽  
Vol 690 ◽  
Author(s):  
Pascal Turban ◽  
Stéphane Andrieu ◽  
Alberto Tagliaferri ◽  
Céline De Nadai ◽  
Nike Brookes
Keyword(s):  
Electronic Properties ◽  
Growth Process ◽  
Room Temperature ◽  
Molecular Beam ◽  
Magnetic Circular Dichroism ◽  
Growth Conditions ◽  
Photoemission Spectroscopy ◽  
Structural Quality ◽  
X Ray

ABSTRACTIn this paper, the structural, magnetic and electronic properties of single-crystalline NiMnSb thin films grown by molecular beam epitaxy are presented. The growth process and surface morphology were studied by RHEED and STM. The structural quality of the films was investigated by EXAFS and HRTEM. For the optimized growth conditions, the expected NiMnSb C1b structure was obtained. Moreover, the most stable surface was found to be 4x1 reconstructed. The magnetic and electronic properties were studied by X-ray magnetic circular dichroïsm and spin-resolved x-ray photoemission spectroscopy experiments. The magnetization was observed to be essentially due to Mn, in agreement with theory. The surface was not found to be fully polarized but a polarization near 50% at room temperature was observed. Finally, the preparation of fully epitaxial NiMnSb/MgO/NiMnSb(001) trilayers is presented.

Growth of Epitaxial CoSi2/Si Multilayers

1986 ◽  
Vol 77 ◽  
Author(s):  
B. D. Runt ◽  
N. Lewis ◽  
L. J. Schotalter ◽  
E. L. Hall ◽  
L. G. Turner
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Room Temperature ◽  
Solid Phase ◽  
Multilayer Structures ◽  
Solid Phase Epitaxy ◽  
Cross Sectional ◽  
Temperature Growth ◽  
Transmission Electron

ABSTRACTEpitaxial CoSi2/Si multilayers have been grown on Si(111) substrates with up to four bilayers of suicide and Si. To our knowledge, these are the first reported epitaxial metal-semiconductor multilayer structures. The growth of these heterostructures is complicated by pinhole formation in the suicide layers and by nonuniform growth of Si over the suicide films, but these problems can be controlled through nse of proper growth techniques. CoSi2 pinhole formation has been significantly reduced by utilizing a novel solid phase epitaxy technique in which room-temperature-deposited Co/Si bilayers are annealed to 600–650δC to form the suicide layers. Islanding in the Si layers is minimized by depositing a thin (<100Å) Si layer at room temperature with subsequent high temperature growth of the remainder of the Si. Cross-sectional transmission electron microscopy studies demonstrate that these growth procedures dramatically improve the continuity and quality of the CoSi. and Si multilayers.

Uniformity of Arsenic Dimer and Tetramer Fluxes from a Valved Arsenic Cracking Source in MBE

1995 ◽  
Vol 378 ◽  
Author(s):  
George A. Patterson ◽  
James S.C. Chang ◽  
Forrest G. Kellert
Keyword(s):  
Standard Deviation ◽  
Room Temperature ◽  
Flux Distribution ◽  
High Crystalline Quality ◽  
Lattice Match ◽  
X Ray ◽  
Sapphire Substrates ◽  
Case Characteristics ◽  
Substrate Temperatures

AbstractWe have studied the uniformity of the arsenic flux from a commercially available valved arsenic cracker source for MBE. There are many epitaxial structures that require a uniform arsenic flux distribution for rotated epitaxial growth and, in the non-rotated case, for RHEED. For non-stoichiometric GaAs growth at low substrate temperatures, which results in arsenic precipitates being formed during the in-situ anneal process, a specific As/Ga ratio must be used to maintain high crystalline quality and to achieve the desired electrical properties. Also, in the growth of InGaAsP the As/P ratio is equally important for lattice match and quality device results. We report on the uniformity of amorphous arsenic (a-As) films condensed on the surface of 3" diameter sapphire wafers slightly below room temperature. Sapphire substrates were used in place of GaAs wafers to facilitate the use of x-ray fluorescence for the measurement of the arsenic film uniformity. Uniformity maps will be presented for rotated and non-rotated a-As depositions of As2 and As4. Results indicate the uniformity of a-As, As4, films to have a standard deviation of < 2.5% across a 3" diameter substrate for the rotated case. Characteristics of the non-rotated case will be presented.

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.

Solid Phase Epitaxy of Implanted Silicon by Electron Irradiation at Room Temperature

1988 ◽  
Vol 100 ◽  
Author(s):  
G. Lulli ◽  
P. G. Merli ◽  
M. Vittori Antisari
Keyword(s):  
Electron Irradiation ◽  
Cross Sections ◽  
Room Temperature ◽  
Diffusion Length ◽  
Solid Phase ◽  
Basic Mechanism ◽  
Radiation Defects ◽  
Solid Phase Epitaxy ◽  
Transmission Electron

ABSTRACTSolid-phase epitaxy of implanted Si is observed at room temperature during in situ electron irradiation in a Transmission Electron Microscope. Results obtained from irradiation of cross sections of samples containing different doping species show that: i) the basic mechanism of the process is the migration and recombination at the amorphous-crystalline interface of radiation defects coming both from the amorphous and crystalline side; ii) the diffusion length of such defects is of the order of 40 nm; iii) the regrowth rate is impurity dependent: a factor two exists between the faste

In-Situ Investigation of Surface Stoichiometry During InGaN and GaN Growth by Plasma-Assisted Molecular Beam Epitaxy Using RHEED-TRAXS

2005 ◽  
Vol 892 ◽  
Author(s):  
Randy Preston Tompkins ◽  
Brenda L. VanMil ◽  
Kyoungnae Lee ◽  
Eric D. Schires ◽  
Yewhee Chye ◽  
...  
Keyword(s):  
Room Temperature ◽  
Molecular Beam ◽  
Surface Coverage ◽  
High Energy ◽  
X Rays ◽  
X Ray ◽  
Reflection Angle ◽  
High Energy Electrons ◽  
In Situ Investigation

AbstractReflection high-energy electron diffraction total-reflection-angle x-ray spectroscopy (RHEED-TRAXS) uses high-energy electrons from RHEED to excite x-ray fluorescence. Monitoring characteristic x-rays of selected elements thus allows study of surface coverage of materials. In this study, surface coverage of Ga and In during growth of GaN and InGaN was probed using this technique. Evolution of the surface layer of Ga on GaN during growth and deposition of Ga on static GaN at room temperature were studied. RHEED-TRAXS measurements were performed during growth of InGaN by measuring the ratio of the In Lα to Ga Kα intensity. A significant surface coverage of In was observed at all temperatures investigated regardless of actual In incorporation.

Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Crystal Growth ◽  
Single Crystal ◽  
Room Temperature ◽  
Growth Technique ◽  
Salt Hydrate ◽  
X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

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.

Photoluminescence Enhancement of CdS Nanocrystals Fabricated on Dithiocarbamate Functionalized PET Substrates

2012 ◽  
Vol 512-515 ◽  
pp. 1511-1515
Author(s):  
Chun Lin Zhao ◽  
Li Xing ◽  
Xiao Hong Liang ◽  
Jun Hui Xiang ◽  
Fu Shi Zhang ◽  
...  
Keyword(s):  
Room Temperature ◽  
Hexagonal Structure ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
X Ray ◽  
Cds Nanocrystals ◽  
Morphological Studies ◽  
Transmission Electron

Cadmium sulfide (CdS) nanocrystals (NCs) were self-assembled and in-situ immobilized on the dithiocarbamate (DTCs)-functionalized polyethylene glycol terephthalate (PET) substrates between the organic (carbon disulfide diffused in n-hexane) –aqueous (ethylenediamine and Cd2+ dissolved in water) interface at room temperature. Powder X-ray diffraction measurement revealed the hexagonal structure of CdS nanocrystals. Morphological studies performed by scanning electron microscopy (SEM) and high-resolution transmission electron microscope (HRTEM) showed the island-like structure of CdS nanocrystals on PET substrates, as well as energy-dispersive X-ray spectroscopy (EDS) confirmed the stoichiometries of CdS nanocrystals. The optical properties of DTCs modified CdS nanocrystals were thoroughly investigated by ultraviolet-visible absorption spectroscopy (UV-vis) and fluorescence spectroscopy. The as-prepared DTCs present intrinsic hydrophobicity and strong affinity for CdS nanocrystals.

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