Structure Analysis of the Al-Inp (100) Interface

1987 ◽  
Vol 94 ◽  
Author(s):  
C. d'Anterroches ◽  
F. Houzay ◽  
M. Bensoussan
Keyword(s):  
Ultra Violet ◽  
High Resolution Electron Microscopy ◽  
High Energy ◽  
Epitaxial Relationship ◽  
Metallic Behavior ◽  
Covalent Bonds ◽  
Resolution Electron ◽  
Strong Exchange ◽  
Inp Surface

ABSTRACTHigh Resolution Electron Microscopy (HREM) images of the Al/InP interface were obtained from as-deposited films. The high purity Al films were deposited onto a clean (100) InP surface in a Molecular Beam Epitaxy (MBE) chamber. The in situ Reflection High Energy Electron Diffraction (RHEED) and Ultra-Violet Photoemission Spectroscopy (UPS) analyses showed a transformation of the InP surface during the Al deposition. The UPS data are interpreted as a strong exchange reaction between incoming Al and substrate In atoms. The In atoms are released and recover metallic behavior while Al atoms are involved in covalent bonds. At high coverages the RHEED analysis shows an epitaxial relationship in between Al and InP such as (110)Al//(100)InP with the two variants: [001]Al//[011]InP and [001]Al//[0–11]InP. The HREM images show that the interface AI/InP is perturbed and an intermediate layer is found. This layer appears to have the same crystal structure as InP indicated by extension of atomic planes from InP to the layer. However, the observed intensity, which corresponds to the mean potential of the forming atoms, is lighter than that of InP. Hence,out of these HREM and UPS results it is derived that an AlP or AlxIn1−xP compound is located at the Al/InP interface.

Structural Evolution of Ni/Au Contact on GaN(0001)

2000 ◽  
Vol 639 ◽  
Author(s):  
Chong Cook Kim ◽  
Jong Kyu Kim ◽  
Jong-Lam Lee ◽  
Min-Su Yi ◽  
Jin-Woo Kim ◽  
...  
Keyword(s):  
Structural Evolution ◽  
High Resolution Electron Microscopy ◽  
X Ray Diffraction ◽  
Epitaxial Relationship ◽  
X Ray ◽  
Thermally Activated ◽  
X Ray Scattering ◽  
Resolution Electron ◽  
Relationship Of

ABSTRACTWe investigated the structural behavior of the Ni/Au contact on GaN(000l) during annealing in N2, using in-situ x-ray diffraction, anomalous x-ray scattering, and high resolution electron microscopy. Thermally activated atomic mobility caused the two metal atoms, Au and Ni, to interdiffuse during annealing and form solid solutions. At temperature higher than 500°C, GaN decomposition and reactions occurred mostly along GaN dislocations. By decomposed nitrogen reacted with Ni, interestingly, epitaxial Ni4N phase was formed. The epitaxial relationship of the Ni4N, Au, and Ni was identified as M(111)//GaN(0002) and M[0 1 1]//GaN[0211] (M= Ni4N, Au, and Ni).

Structural Transformation of a Germanium Σ=13 (510) [001] Tilt Grain Boundary under the Electron Beam

1990 ◽  
Vol 48 (1) ◽  
pp. 52-53 ◽  
Author(s):  
Jean-Luc Rouvière ◽  
Alain Bourret
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Grain Boundary ◽  
Structural Transformation ◽  
Mirror Symmetry ◽  
High Resolution Electron Microscopy ◽  
Structural Transformations ◽  
Covalent Bonds ◽  
Resolution Electron ◽  
Tilt Grain Boundary

The possible structural transformations during the sample preparations and the sample observations are important issues in electron microscopy. Several publications of High Resolution Electron Microscopy (HREM) have reported that structural transformations and evaporation of the thin parts of a specimen could happen in the microscope. Diffusion and preferential etchings could also occur during the sample preparation.Here we report a structural transformation of a germanium Σ=13 (510) [001] tilt grain boundary that occurred in a medium-voltage electron microscopy (JEOL 400KV).Among the different (001) tilt grain boundaries whose atomic structures were entirely determined by High Resolution Electron Microscopy (Σ = 5(310), Σ = 13 (320), Σ = 13 (510), Σ = 65 (1130), Σ = 25 (710) and Σ = 41 (910), the Σ = 13 (510) interface is the most interesting. It exhibits two kinds of structures. One of them, the M-structure, has tetracoordinated covalent bonds and is periodic (fig. 1). The other, the U-structure, is also tetracoordinated but is not strictly periodic (fig. 2). It is composed of a periodically repeated constant part that separates variable cores where some atoms can have several stable positions. The M-structure has a mirror glide symmetry. At Scherzer defocus, its HREM images have characteristic groups of three big white dots that are distributed on alternatively facing right and left arcs (fig. 1). The (001) projection of the U-structure has an apparent mirror symmetry, the portions of good coincidence zones (“perfect crystal structure”) regularly separate the variable cores regions (fig. 2).

Interaction Between Basal Stacking Faults and Prismatic Inversion Domain Boundaries in GaN

2000 ◽  
Vol 639 ◽  
Author(s):  
Philomela Komninou ◽  
Joseph Kioseoglou ◽  
Eirini Sarigiannidou ◽  
George P. Dimitrakopulos ◽  
Thomas Kehagias ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Stacking Faults ◽  
High Resolution Electron Microscopy ◽  
High Energy ◽  
Low Energy ◽  
Inversion Domain ◽  
Resolution Electron ◽  
Domain Boundaries ◽  
Inversion Domain Boundaries

ABSTRACTThe interaction of growth intrinsic stacking faults with inversion domain boundaries in GaN epitaxial layers is studied by high resolution electron microscopy. It is observed that stacking faults may mediate a structural transformation of inversion domain boundaries, from the low energy types, known as IDB boundaries, to the high energy ones, known as Holt-type boundaries. Such interactions may be attributed to the different growth rates of adjacent domains of inverse polarity.

In-Situ Studies of Epitaxial Thin-Film Growth

1964 ◽  
Vol 19 (7-8) ◽  
pp. 835-843 ◽  
Author(s):  
H. Poppa
Keyword(s):  
Film Growth ◽  
High Resolution Electron Microscopy ◽  
Thin Film Growth ◽  
Continuous Observation ◽  
Epitaxial Thin Film ◽  
Epitaxial Thin Film Growth ◽  
Resolution Electron ◽  
Substrate Surfaces ◽  
Kinetics Of

Early stages of oriented overgrowth of Ag, Au, and Pd on thin, single-crystal substrates of mica, molybdenite, Au and Pd were studied by high-resolution electron microscopy and diffraction. Cleaning of substrate surfaces and deposition of evaporated materials were conducted inside an electron microscope. High-magnification, continuous observation during growth permitted investigation of the kinetics of growth. A number of probably elementary epitaxial processes were studied in detail. Nucleation and growth behavior was examined for different supersaturations and free surface energies of substrate and overgrowth materials. The influence of alloying on growth and the spacing of parallel moiré structures was investigated.

In Situ HREm of Reactions at Interfaces

1997 ◽  
Vol 3 (S2) ◽  
pp. 621-622 ◽  
Author(s):  
R. Sinclair ◽  
T. Itoh ◽  
H. J. Lee ◽  
K. W. Kwon
Keyword(s):  
Chemical Interaction ◽  
High Resolution Electron Microscopy ◽  
Point Of View ◽  
Interface Chemistry ◽  
Amorphous Phases ◽  
Resolution Electron ◽  
Analogous Manner ◽  
The Stability ◽  
Basic Studies

Reactions at solid-solid interfaces are important both scientifically and technologically. Firstly, there is quite a wide variety of possibilities. Materials can react with one another, forming equilibrium, meta-stable or even amorphous phases. The interface can provide a means to promote phase reactions kinetically, in an analogous manner to catalysis. Even when the materials are mutually compatible chemically, the interface topography and atomic structure can evolve over the course of time. From the practical point-of-view, changes in the interface chemistry and structure can profoundly alter the physical properties. This is especially notable in thin film technology, whereby the interfaces constitute a signigicant proportion of the whole device. In this article, contributions to understanding this field are illustrated through application of in situ and high-resolution electron microscopy (HREM).Basic studies of metal-semicoductor interfacial reactions have been successfully carried out for a number of years. of increasing importance in microelectronics is the stability of layers which prevent chemical interaction, namely the diffusion barriers.

Precipitation behavior in the early stage of aging in an Al–Li°Cu–Mg–Zr–Ag (Weldalite 049) alloy

1999 ◽  
Vol 14 (2) ◽  
pp. 384-389 ◽  
Author(s):  
Kap Ho Lee ◽  
Yeung Jo Lee ◽  
Kenji Hiraga
Keyword(s):  
Aging Process ◽  
Early Stage ◽  
High Resolution Electron Microscopy ◽  
S Phase ◽  
Precipitation Behavior ◽  
Ordered Structures ◽  
Resolution Electron ◽  
The Matrix ◽  
Habit Planes

The precipitation behavior of various phases during the aging process of an Ag–Li°Cu–Mg–Zr–Ag (Weldalite 049) alloy was investigated by high-resolution electron microscopy and in situ hot-stage microscopy. Two kinds of domains with L12-type ordered structures, which are considered to be δ′ and β′ phases, are observed with different domain sizes in the alloy quenched from 530 °C. In the early stage of aging at 190 °C, the δ′ phase is precipitated as surrounding the β' phase, and the δ′ domains appear with in-phase and antiphase relationships to the β′ lattices. In situ observations at 190 °C clearly show that the T1 phase precipitates predominantly on dislocations at subgrain boundaries and then is homogeneously formed in the matrix with increasing aging time. The nucleation of the S′ phase is associated with clustering of Cu and Mg in the matrix, and the S0 domains are grown with {210} habit planes.

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