Structural Studies of Metal-Semiconductor Interfaces with High-Resolution Electron Microscopy

1982 ◽  
Vol 14 ◽  
Author(s):  
J. M. Gibson ◽  
R. T. Tung ◽  
J. M. Poate
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Dislocation Core ◽  
High Resolution Electron Microscopy ◽  
Nucleation And Growth ◽  
Interfacial Structure ◽  
Preparation Conditions ◽  
Semiconductor Interfaces ◽  
Resolution Electron ◽  
Crystal Films

ABSTRACTWe have studied interface atomic structure in epitaxial cobalt and nickel disilicides on silicon using high-resolution transmission electron microscopy. By employing UHV techniques during deposition and reaction we have grown truly single-crystalline NiSi2 and CoSi2 films on (111) Si and in the former case on (100) Si. These films are shown to be continuous to below 10Å thickness. By close control over preparation conditions, afforded by UHV, we can greatly influence the nucleation and growth of these films to the extent, for example with NiSi2 on (111)Si, of yielding continuous single-crystal films with either of two orientations as desired. Whilst in the (111) NiSi2 on Si system the interfacial structure invariably appears to well-fit a model in which metal atoms nearest to the interface are 7-fold co-ordinated, for (111) CoSi2 on Si agreement is generally better with a model involving 5-fold co-ordination of these atoms. A misfit dislocation core is also imaged. Results are discussed in the light of silicide nucleation and growth. The structure and stability of the (100) NiSi2 on Si interface is also considered.

HRTEM simulation of interfacial structure in amorphous multilayers

1989 ◽  
Vol 47 ◽  
pp. 466-467
Author(s):  
Margaret L. Sattler ◽  
Michael A. O'Keefe
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Cross Section ◽  
High Resolution Electron Microscopy ◽  
Interfacial Structure ◽  
Multilayer Sample ◽  
Resolution Electron ◽  
Multilayered Materials ◽  
Simulated Images

Multilayered materials have been fabricated with such high perfection that individual layers having two atoms deep are possible. Characterization of the interfaces between these multilayers is achieved by high resolution electron microscopy and Figure 1a shows the cross-section of one type of multilayer. The production of such an image with atomically smooth interfaces depends upon certain factors which are not always reliable. For example, diffusion at the interface may produce complex interlayers which are important to the properties of the multilayers but which are difficult to observe. Similarly, anomalous conditions of imaging or of fabrication may occur which produce images having similar traits as the diffusion case above, e.g., imaging on a tilted/bent multilayer sample (Figure 1b) or deposition upon an unaligned substrate (Figure 1c). It is the purpose of this study to simulate the image of the perfect multilayer interface and to compare with simulated images having these anomalies.

A study of Al2Ti precipitation in a Cu-modified Al3Ti alloy

1992 ◽  
Vol 7 (4) ◽  
pp. 876-882 ◽  
Author(s):  
L. Potez ◽  
A. Loiseau ◽  
S. Naka ◽  
G. Lapasset
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Mechanical Behavior ◽  
Vickers Microhardness ◽  
High Resolution Electron Microscopy ◽  
Nucleation And Growth ◽  
Ti Alloy ◽  
Hardening Effect ◽  
Resolution Electron

An equilibrium precipitation of Al2Ti is shown to occur within a Cu-modified Al2Ti alloy having the L12 structure. This precipitation is analyzed by conventional and high resolution electron microscopy and some insights are given concerning the mechanisms of nucleation and growth of Al2Ti within the L12 matrix. In the meantime, Vickers microhardness tests have been performed as a first approach to the mechanical behavior of this alloy and the results are compared to measurements obtained in an actual single-phased L12 compound. The Al2Ti precipitation seems to have an important hardening effect.

Atomic Structure of Interfaces: Link of Atomistic Calculations with High Resolution Electron Microscopy

1998 ◽  
Vol 4 (S2) ◽  
pp. 762-763
Author(s):  
V. Vitek
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Computer Modeling ◽  
Atomic Structure ◽  
High Resolution Electron Microscopy ◽  
Interfacial Structure ◽  
Embedded Atom ◽  
Resolution Electron ◽  
Atomic Interactions ◽  
Atomistic Calculations

Since interfaces and grain boundaries affect critically many properties of materials, their atomic structure has been investigated very extensively using computer modeling. Most of these calculations have been made using semi-empirical central-force descriptions of atomic interactions, recently primarily the embedded-atom type many-body potentials. Owing to the approximate nature of such schemes, a connection with experimental observations that can validate the calculations is essential. The high resolution electron microscopy (HREM) is such experimental technique and it has, indeed, been frequently combined with calculations of interfacial structure and chemistry. In fact such a link is not only important for verification of the results of computer modeling but also crucial for meaningful interpretation of HREM observations. Hence, coupling the atomistic modeling with HREM is a synergistic procedure. It not only leads to better understanding of interfacial structures but may contribute significantly to the validation and assessment of limits of the schemes used for the description of atomic interactions.

Mixed partial dislocation core structure in GaN by high resolution electron microscopy

2006 ◽  
Vol 203 (9) ◽  
pp. 2156-2160 ◽  
Author(s):  
J. Kioseoglou ◽  
G. P. Dimitrakopulos ◽  
Ph. Komninou ◽  
Th. Kehagias ◽  
Th. Karakostas
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Partial Dislocation ◽  
Dislocation Core ◽  
High Resolution Electron Microscopy ◽  
Core Structure ◽  
Resolution Electron ◽  
Dislocation Core Structure

Nanoscale Measurement of Stress and Strain by Quantitative High-Resolution Electron Microscopy

2005 ◽  
Vol 482 ◽  
pp. 39-44 ◽  
Author(s):  
Martin J. Hÿtch ◽  
Jean-Luc Putaux ◽  
Jean-Michel Pénisson
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Spatial Resolution ◽  
Strain Tensor ◽  
Dislocation Core ◽  
High Resolution Electron Microscopy ◽  
Stress And Strain ◽  
Fourier Space ◽  
Resolution Electron ◽  
Anisotropic Elastic

The geometric phase technique (GPA) for measuring the distortion of crystalline lattices from high-resolution electron microscopy (HRTEM) images will be described. The method is based on the calculation of the “local” Fourier components of the HRTEM image by filtering in Fourier space. The method will be illustrated with a study of an edge dislocation in silicon where displacements have been measured to an accuracy of 3 pm at nanometre resolution as compared with anisotropic elastic theory calculations. The different components of the strain tensor will be mapped out in the vicinity of the dislocation core and compared with theory. The accuracy is of the order of 0.5% for strain and 0.1° for rigid-body rotations. Using bulk elastic constants for silicon, the stress field is determined to 0.5 GPa at nanometre spatial resolution. Accuracy and the spatial resolution of the technique will be discussed.

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