Modifications of a JEOL 2000EX TEM for insSitu surface studies

1993 ◽  
Vol 51 ◽  
pp. 640-641
Author(s):  
Michael T. Marshall ◽  
Xianghong Tong ◽  
J. Murray Gibson
Keyword(s):  
Electron Diffraction ◽  
Surface Science ◽  
Film Growth ◽  
High Vacuum ◽  
High Energy ◽  
Energy Electron ◽  
Ultra High Vacuum ◽  
Transmission Electron ◽  
Fundamental Insight

We have modified a JEOL 2000EX Transmission Electron Microscope (TEM) to allow in-situ ultra-high vacuum (UHV) surface science experiments as well as transmission electron diffraction and imaging. Our goal is to support research in the areas of in-situ film growth, oxidation, and etching on semiconducter surfaces and, hence, gain fundamental insight of the structural components involved with these processes. The large volume chamber needed for such experiments limits the resolution to about 30 Å, primarily due to electron optics. Figure 1 shows the standard JEOL 2000EX TEM. The UHV chamber in figure 2 replaces the specimen area of the TEM, as shown in figure 3. The chamber is outfitted with Low Energy Electron Diffraction (LEED), Auger Electron Spectroscopy (AES), Residual Gas Analyzer (RGA), gas dosing, and evaporation sources. Reflection Electron Microscopy (REM) is also possible. This instrument is referred to as SHEBA (Surface High-energy Electron Beam Apparatus).The UHV chamber measures 800 mm in diameter and 400 mm in height. JEOL provided adapter flanges for the column.

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.

In Situ Uhv-Tem Oxidation And Reduction Of Metals

1999 ◽  
Vol 5 (S2) ◽  
pp. 132-133
Author(s):  
J. C. Yang ◽  
M Yeadon ◽  
B. Kolasa ◽  
J. M. Gibson
Keyword(s):  
Surface Science ◽  
Materials Science ◽  
Film Growth ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Science Methods ◽  
Copper Oxidation ◽  
Transmission Electron ◽  
Partial Pressures

In this proceedings, we present a review of our experimental results of our investigations of the mechanisms of the initial stages of copper oxidation. We examined the initial stages of Cu(001) oxidation and reduction by in situ ultra-high vacuum (UHV) transmission, electron microscopy (TEM). We observed surface reconstruction and nucleation and growth of copper oxide islands. We have examined the oxidation processes from oxygen partial pressures of 10-5 torr to atmospheric pressures and temperatures from 25°C to 600°C, in order to gain fundamental insights into this important gas-metal reaction.Fundamental knowledge of gas-metal reactions, in particular oxidation, is important for a wide variety of materials science fields, such as dry corrosion, catalysis, as well as some thin film growth, such as ferroelectrics. However, there is a wide gap between information provided by surface science methods and that provided by bulk oxidation studies. The former have mostly examined the adsorption of up to ˜1ML of oxygen on the metal surface.

In situ quantitative analysis of GeXSi1-X alloys during growth by reflection EELS

1991 ◽  
Vol 49 ◽  
pp. 878-879
Author(s):  
Shouleh Nikzad ◽  
Channing C. Ahn ◽  
Harry A. Atwater
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Film Growth ◽  
High Vacuum ◽  
High Energy ◽  
Ultra High Vacuum ◽  
Mbe Growth ◽  
Electron Microscopes ◽  
Electron Energy Loss

The universality of reflection high energy electron diffraction (RHEED) as a structural tool during film growth by molecular beam epitaxy (MBE) brings with it the possibility for in situ surface chemical analysis via spectroscopy of the accompanying inelastically scattered electrons. We have modified a serial electron energy loss spectrometer typically used on an electron microscope to work with a 30 keV RHEED-equipped MBE growth chamber in order to determine the composition of GexSi1-x alloys by reflection electron energy loss (REELS) experiments. Similar work done in transmission electron microscopes has emphasized the surface sensitivity of this technique even though these experiments have never been done under ultra-high vacuum conditions. In this work, we are primarily concerned with the accuracy with which core losses can be used to determine composition during MBE growth.

In situ reflection high-energy electron diffraction (RHEED) observation of Bi2Te3/Sb2Te3 multilayer film growth

1999 ◽  
Vol 203 (1-2) ◽  
pp. 125-130 ◽  
Author(s):  
Y Iwata ◽  
H Kobayashi ◽  
S Kikuchi ◽  
E Hatta ◽  
K Mukasa
Keyword(s):  
Electron Diffraction ◽  
Multilayer Film ◽  
Film Growth ◽  
High Energy ◽  
Energy Electron ◽  
High Energy Electron

scholarly journals Stm at High Temperature: What you see is what you see … usually

1993 ◽  
Vol 1 (5) ◽  
pp. 4-4
Author(s):  
Michael M. Kersker
Keyword(s):  
Electron Diffraction ◽  
Surface Structure ◽  
High Vacuum ◽  
High Energy ◽  
Atomic Level ◽  
Energy Electron ◽  
Ultra High Vacuum ◽  
Scanning Probe ◽  
Sem Images ◽  
Optical Discs

There remains two basic axioms of all microscopists: the first….if you look, you're bound to see something, and the second….not everything you will see is artifact. These axioms apply particularly well to scanning probe microscopy at the molecular and atomic level. Fortunately, coarser resolution images share comforting similarities with images from other established scanning methods. Holes in optical discs look like holes when probed with AFM tips, and these holes look very much like SEM images, a subject with which we have some familiarity. At the molecular and atomic level, however, the scanning probe instruments may or may not be “seeing” the sample, though they are clearly seeing something.Comparison of surface structure observed with indirect surface structural measurements, for example by LEED (Low Energy Electron Diffraction) or RHEED (Reflection High Energy Electron Diffraction) usually under ultra-high vacuum conditions can lead, by inference, to an understanding of the real bulk or average surface structure.

Growth and Structure of Al/MgO Interfaces

1994 ◽  
Vol 357 ◽  
Author(s):  
T. Wagner ◽  
M. Ruhle
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
High Vacuum ◽  
High Energy ◽  
Ultra High Vacuum ◽  
Structural Defects ◽  
Cross Sectional ◽  
Aluminum Films ◽  
Transmission Electron

AbstractThe A1/MgO system has been used as a model system to study growth processes and structure at metal/ceramic interfaces. Aluminum films were grown on air-cleaved MgO (100) substrates in ultra high vacuum (UHV) by molecular beam epitaxy (MBE). The substrates and films were characterized by reflection high energy electron diffraction (RHEED), x-ray diffraction (XRD), conventional transmission electron microscopy (CTEM), and high resolution transmission electron microscopy (HREM). XRD measurements exhibited a pronounced {100} texture. Employing electron diffraction in the TEM on cross sectional samples, we observed the following orientation relationship between Al and MgO: (100)A1 II (100)MgO; [010]A1 II [010]MgO. The atomistic structure of the interface was investigated by HREM. Regions of structural defects can be identified clearly at the interface.

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