An in situ and ex situ TEM study of the formation of thin cobalt silicide films by molecular beam epitaxy on the silicon (100) surface

1988 ◽  
Vol 46 ◽  
pp. 884-885
Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove ◽  
R. T. Tung
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Defect Density ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Metal Base ◽  
In Situ Experiments ◽  
Potential Applications

The cobalt disilicide/silicon system has potential applications as a metal-base and as a permeable-base transistor. Although thin, low defect density, films of CoSi2 on Si(111) have been successfully grown, there are reasons to believe that Si(100)/CoSi2 may be better suited to the transmission of electrons at the silicon/silicide interface than Si(111)/CoSi2. A TEM study of the formation of CoSi2 on Si(100) is therefore being conducted. We have previously reported TEM observations on Si(111)/CoSi2 grown both in situ, in an ultra high vacuum (UHV) TEM and ex situ, in a conventional Molecular Beam Epitaxy system.The procedures used for the MBE growth have been described elsewhere. In situ experiments were performed in a JEOL 200CX electron microscope, extensively modified to give a vacuum of better than 10-9 T in the specimen region and the capacity to do in situ sample heating and deposition. Cobalt was deposited onto clean Si(100) samples by thermal evaporation from cobalt-coated Ta filaments.

In-Situ Rapid Thermal Annealing of Heterostructures Grown by Molecular Beam Epitaxy

1987 ◽  
Vol 102 ◽  
Author(s):  
M. Cerullo ◽  
Julia M. Phillips ◽  
M. Anzlowar ◽  
L. Pfeiffer ◽  
J. L. Batstone ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Molecular Beam ◽  
High Vacuum ◽  
Processing Technique ◽  
Ultra High Vacuum ◽  
On Line ◽  
High Vacuum Environment

ABSTRACTA new in-situ rapid thermal annealing (RTA) apparatus which can be used to anneal entire wafers in an ultra high vacuum environment has been designed to be used in conjunction with the epitaxial growth of heterostructures. Drastic improvement in the crystallinity of CaF2/Si(100) can be achieved with RTA, and our results suggest that RTA can be used as an on-line processing technique for novel epitaxial structures.

Silicon Homoepitaxy at 300°C Using ArF Excimer Laser Photolysis of Disilane

1990 ◽  
Vol 201 ◽  
Author(s):  
B. Fowler ◽  
T. Lian ◽  
D. Bullock ◽  
S. Banerjee
Keyword(s):  
Electron Diffraction ◽  
Excimer Laser ◽  
Growth Rates ◽  
Defect Density ◽  
High Vacuum ◽  
High Energy ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Arf Excimer Laser

AbstractPhotolysis of Si2H6 by an ArF excimer laser has been used to deposit Si homoepitaxial layers at temperatures as low as 300°C. The chemical vapor deposition process at growth rates from 0.5-4 Å/minute is performed in an ultra-high vacuum chamber which, along with an ex situ HF dip and a novel in situ hydrogen clean using laser excitation, results in minimization of oxygen and carbon contamination which inhibits Si epitaxy. The growth involves photolytic decomposition of Si2H6 and the generation and adsorption of SiH2 precursors on the hydrogenated Si surface, which is the rate limiting step. Growth rates are observed to vary proportionally with laser power. Very low defect density films in terms of stacking faults and dislocation loops (less than 105 cm−2), and excellent crystallinity have been deposited as confirmed by Schimmel etching and Nomarski microscopy, transmission electron microscopy, electron diffraction and in situ reflection high energy electron diffraction.

In-Situ Rapid Thermal Annealing of Heterostructures Grown by Molecular Beam Epitaxy

1987 ◽  
Vol 107 ◽  
Author(s):  
M. Cerullo ◽  
Julia M. Phillips ◽  
M. Anzlowar ◽  
L. Pfeiffer ◽  
J. L. Batstone ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Molecular Beam ◽  
High Vacuum ◽  
Processing Technique ◽  
Ultra High Vacuum ◽  
On Line ◽  
High Vacuum Environment

AbstractA new in-situ rapid thermal annealing (RTA) apparatus which can be used to anneal entire wafers in an ultra high vacuum environment has been designed to be used in conjunction with the epitaxial growth of heterostructures. Drastic improvement in the crystallinity of CaF2/Si(100) can be achieved with RTA, and our results suggest that RTA can be used as an on-line processing technique for novel epitaxial structures.

Transmission Electron Microscopy of Epitaxial silicides grown by ultra high vacuum deposition

1989 ◽  
Vol 47 ◽  
pp. 462-463
Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
High Vacuum ◽  
High Energy ◽  
Energy Electron ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Transmission Electron

The silicides CoSi2 and NiSi2 are both metallic with the fee flourite structure and lattice constants which are close to silicon (1.2% and 0.6% smaller at room temperature respectively) Consequently epitaxial cobalt and nickel disilicide can be grown on silicon. If these layers are formed by ultra high vacuum (UHV) deposition (also known as molecular beam epitaxy or MBE) their thickness can be controlled to within a few monolayers. Such ultrathin metal/silicon systems have many potential applications: for example electronic devices based on ballistic transport. They also provide a model system to study the properties of heterointerfaces. In this work we will discuss results obtained using in situ and ex situ transmission electron microscopy (TEM).In situ TEM is suited to the study of MBE growth for several reasons. It offers high spatial resolution and the ability to penetrate many monolayers of material. This is in contrast to the techniques which are usually employed for in situ measurements in MBE, for example low energy electron diffraction (LEED) and reflection high energy electron diffraction (RHEED), which are both sensitive to only a few monolayers at the surface.

Study of As and P Incorporation Behavior in GaAsP by Gas-Source Molecular-Beam Epitaxy

1991 ◽  
Vol 222 ◽  
Author(s):  
B. W. Liang ◽  
H. Q. Hou ◽  
C. W. Tu
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
High Energy ◽  
Ex Situ ◽  
Limited Growth ◽  
Group V ◽  
Group Iii ◽  
Gas Source ◽  
Simple Kinetic Model

ABSTRACTA simple kinetic model has been developed to explain the agreement between in situ and ex situ determination of phosphorus composition in GaAs1−xPx (x < 0.4) epilayers grown on GaAs (001) by gas-source molecular-beam epitaxy (GSMBE). The in situ determination is by monitoring the intensity oscillations of reflection high-energy-electron diffraction during group-V-limited growth, and the ex situ determination is by x-ray rocking curve measurement of GaAs1−xPx/GaAs strained-layer superlattices grown under group-III-limited growth condition.

Ultra-high-vacuum epitaxial growth of MgB2(0001) thin films on Mg(0001) via molecular beam epitaxy

2004 ◽  
Vol 16 (33) ◽  
pp. S3451-S3458 ◽  
Author(s):  
R Macovez ◽  
C Cepek ◽  
M Sancrotti ◽  
A Goldoni ◽  
L Petaccia ◽  
...  
Keyword(s):  
Thin Films ◽  
Molecular Beam Epitaxy ◽  
Epitaxial Growth ◽  
Molecular Beam ◽  
High Vacuum ◽  
Ultra High Vacuum

Amorphous Silicon Films and Superlattices Grown by Molecular Beam Epitaxy: An Optical Analysis

2002 ◽  
Vol 715 ◽  
Author(s):  
D. J. Lockwood ◽  
J.-M. Baribeau ◽  
M. Noël ◽  
J. C. Zwinkels ◽  
B. J. Fogal ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Amorphous Silicon ◽  
Molecular Beam ◽  
Crystalline Silicon ◽  
Quartz Substrate ◽  
High Vacuum ◽  
Impurity Content ◽  
Thin Layers ◽  
Silicon Films ◽  
Ultra High Vacuum

AbstractWe produce a novel form of amorphous silicon through ultra-high-vacuum molecular beam epitaxy. By depositing silicon atoms onto a fused quartz substrate at temperatures between 98 and 335°C, we obtain a silicon-based material that lacks the characteristic periodicity of crystalline silicon but nevertheless has 98% of its density. The impurity content of this material is studied through infrared and secondary ion mass spectroscopies. The primary impurity found is oxygen, with hydrogen and carbon atoms also being found at trace levels. The Raman spectra of the amorphous silicon films are measured and the results, as they relate to the presence of disorder, are interpreted. We also use this molecular beam epitaxy method to fabricate a number of amorphous silicon superlattices, comprised of thin layers of amorphous silicon separated with even thinner layers of SiO2. The optical properties of the films and superlattices are contrasted.

Ge Nanocrystals Grown on Si(111) by Molecular Beam Epitaxy with and without CaF2 Buffer Layers

1994 ◽  
Vol 358 ◽  
Author(s):  
Peter W. Deelman ◽  
Thomas Thundat ◽  
Leo J. Schowalter
Keyword(s):  
Molecular Beam Epitaxy ◽  
Substrate Temperature ◽  
Molecular Beam ◽  
Buffer Layers ◽  
Ex Situ ◽  
Rheed Pattern ◽  
Island Growth ◽  
Clustering Behavior ◽  
Ge Nanocrystals

ABSTRACTThe Stranski-Krastanov growth mode of Ge thin films on Si and the clustering behavior of Ge on calcium fluoride have been exploited to grow self-assembled nanocrystals by molecular beam epitaxy. The growth of the samples was monitored in situ with RHEED, and they were analyzed ex situ with AFM and RBS. For each system (Ge/Si and Ge/CaF2/Si), the dependence of Ge islanding on substrate temperature and on substrate misorientation was studied. When grown on Si(111) at temperatures between 500°C and 700°C, Ge clusters nucleated at step edges on vicinal wafers and nucleated homogeneously on on-axis wafers. Above 600°C, no transition to a spotty RHEED pattern, which would be expected for island growth, was observed for the vicinal samples. Ge grown at 500°C on on-axis Si(111) formed islands with a relatively narrow size distribution, typically 160nm in diameter and 10nm to 20nm in height. When grown on a CaF2 buffer layer, Ge islands nucleated homogeneously at a substrate temperature of 750°C, resulting in randomly distributed, oblate crystallites approximately 100nm to 200nm in diameter. At 650°C and 700°C, although we still observed many randomly distributed, small crystallites, most islands nucleated at step bunches and had a length scale of over 500nm.

Properties of Metal / Polyphenylquinoxaline Interfaces

1994 ◽  
Vol 337 ◽  
Author(s):  
L. Bellard ◽  
J.M. Themlin ◽  
F. Palmino ◽  
A. Cros
Keyword(s):  
Metal Layer ◽  
High Vacuum ◽  
Polymer Surface ◽  
Pure Metal ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Layer By Layer ◽  
Force Microscopy ◽  
Atomic Force

ABSTRACTWe have investigated the microscopic properties of copper and chromium layers deposited on polyphenylquinoxaline (PPQ). PPQ is a thermostable polymer used for multichip module applications. The metal is deposited under ultra-high vacuum conditions and analysed in-situ by X-ray photoemission (XPS) and atomic force microscopy (ex situ). Copper does not react significantly with the PPQ and tends to diffuse into the polymer matrix upon annealing. On the contrary, chromium strongly reacts with the polymer surface at room temperature. With increasing metal coverage, chromium grows in a layer-by-layer mode and the reacted interface is progressively burried under the pure metal layer.

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