Island Coalescence Induced Substructure Within GaP Epitaxial Layers Grown on (001), (111), (110) and (113) Si

2000 ◽  
Vol 618 ◽  
Author(s):  
V. Narayanan ◽  
S. Mahajan ◽  
K. J. Bachmann ◽  
V. Woods ◽  
N. Dietz
Keyword(s):  
Defect Formation ◽  
Chemical Beam Epitaxy ◽  
Inversion Domain ◽  
Transmission Electron ◽  
Domain Boundaries ◽  
Lattice Images ◽  
Tilt Boundaries ◽  
Island Coalescence ◽  
Inversion Domain Boundaries ◽  
Multiple Twinning

ABSTRACTGaP islands grown on selected surfaces of Si and their coalescence behavior have been investigated by transmission electron microscopy. These layers were grown by chemical beam epitaxy. A number of significant observations emerge from this study. First, planar defect formation has been shown to be related to stacking errors on the smaller P-terminated {111} facets of GaP islands. Amongst the four orientations, (111) epilayers have a higher density of stacking faults and first order twins because of more P-terminated {111} facets per island. Second, multiple twinning on exposed {111} facets can produce tilt boundaries and irregular growths when islands coalesce. Third, inversion domain boundaries lying on {110} planes have been shown to form during GaP island coalescence across monatomic steps on (001) Si. Image simulations have been performed to show that these boundaries can be seen in high resolution lattice images and the observed contrast is attributed to the presence of wrong Ga-Ga and P-P bonds at the inversion boundary.

Microstructral Investigations on GaN Films Grown by Laser Induced Molecular Beam Epitaxy

1999 ◽  
Vol 595 ◽  
Author(s):  
H. Zhou ◽  
F. Phillipp ◽  
M. Gross ◽  
H. Schröder
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Threading Dislocations ◽  
Planar Defects ◽  
Sapphire Substrates ◽  
Inversion Domain ◽  
Transmission Electron ◽  
Domain Boundaries ◽  
Line Defects ◽  
Inversion Domain Boundaries

AbstractMicrostructural investigations on GaN films grown on SiC and sapphire substrates by laser induced molecular beam epitaxy have been performed. Threading dislocations with Burgers vectors of 1/3<1120>, 1/3<1123> and [0001] are typical line defects, predominantly the first type of dislocations. Their densities are typically 1.5×1010 cm−2 and 4×109 cm−2 on SiC and sapphire, respectively. Additionally, planar defects characterized as inversion domain boundaries lying on {1100} planes have been observed in GaN/sapphire samples with an inversion domain density of 4×109 cm−2. The inversion domains are of Ga-polarity with respect to the N-polarity of the adjacent matrix. However, GaN layers grown on SiC show Ga-polarity. Possible reasons for the different morphologies and structures of the films grown on different substrates are discussed. Based on an analysis of displacement fringes of inversion domains, an atomic model of the IDB-II with Ga-N bonds across the boundary was deduced. High resolution transmission electron microscopy (HRTEM) observations and the corresponding simulations confirmed the IDB-II structure determined by the analysis of displacement fringes.

Inversion Domain Boundaries in GaN Grown on Sapphire

1996 ◽  
Vol 449 ◽  
Author(s):  
L. T. Romano ◽  
J.E. Northrup
Keyword(s):  
Dark Field ◽  
Hydride Vapor Phase Epitaxy ◽  
Dark Field Imaging ◽  
Inversion Domain ◽  
Transmission Electron ◽  
Domain Boundaries ◽  
Convergent Beam ◽  
Inversion Domain Boundaries ◽  
Field Imaging ◽  
Beam Diffraction

ABSTRACTInversion domain boundaries (IDBs) in GaN grown on sapphire (0001) were studied by a combination of high resolution transmission electron microscopy, multiple dark field imaging, and convergent beam diffraction. Films grown by molecular beam epitaxy (MBE), metalorganic vapor deposition (MOCVD), and hydride vapor phase epitaxy (HVPE) were investigated and all found to contain IDBs. Inversion domains (IDs) that extended from the surface to the interface were found to be columnar with facets on the {10–10} and {11–20} planes. Other domains ended within the film that formed IDBs on the (0001) and {1–102} planes. The domains were found to grow in clusters and connect at points along the boundary.

Planar and Curved Defects in Aluminum Nitride: Their Microstructure and Microchemistry

1989 ◽  
Vol 167 ◽  
Author(s):  
Alistair D. Westwood ◽  
Michael R. Notis
Keyword(s):  
Electron Microscopy ◽  
Aluminum Nitride ◽  
Analytical Electron Microscopy ◽  
Microchemical Analysis ◽  
Inversion Domain ◽  
Transmission Electron ◽  
Proposed Model ◽  
Domain Boundaries ◽  
Convergent Beam ◽  
Inversion Domain Boundaries

AbstractThe microstructure and microchemistry of planar and curved defects in Aluminum Nitride (AIN) has been investigated using Conventional Transmission Electron Microscopy (CTEM), Convergent Beam Electron Diffraction (CBED), and Analytical Electron Microscopy (AEM) techniques. Both defect morphologies were identified as Inversion Domain Boundaries (IDB). Microchemical analysis revealed oxygen segregation to the planar faults; when present on the curved defects, oxygen was at a lower concentration than in the planar defect case. Annealing experiments on defect containing AIN support our microchemical analysis of oxygen segregation. A proposed model for the formation of these two types of boundaries is presented.

A TEM Study of Inversion Domain Boundaries Annihilation Mechanism in 3C-SiC during Growth

2009 ◽  
Vol 615-617 ◽  
pp. 331-334 ◽  
Author(s):  
Alkyoni Mantzari ◽  
Christos B. Lioutas ◽  
Efstathios K. Polychroniadis
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Physical Mechanism ◽  
Simulation Analysis ◽  
Inversion Domain ◽  
Transmission Electron ◽  
Domain Boundaries ◽  
Crystallographic Planes ◽  
Inversion Domain Boundaries

The aim of the present work is to study the evolution and the annihilation of inversion domain boundaries in 3C-SiC during growth. For this investigation conventional and high resolution transmission electron microscopy were employed. It is shown that the physical mechanism which results in the annihilation of inversion domain boundaries in 3C-SiC starting from the 3C-SiC/Si interface is the change of the crystallographic planes in which inversion domain boundaries propagate into the {111} ones. In all cases modeling and simulation analysis by EMS software [1] are in agreement with the experimental results.

Inversion Domain Boundary Dislocations in Heteroepitaxial Films

1988 ◽  
Vol 144 ◽  
Author(s):  
T. T. Cheng ◽  
P. Pirouz ◽  
F. Ernst
Keyword(s):  
Electron Microscope ◽  
Domain Boundary ◽  
Relative Displacement ◽  
Boundary Dislocation ◽  
Fringe Contrast ◽  
Burgers Vector ◽  
Inversion Domain ◽  
Transmission Electron ◽  
Domain Boundaries ◽  
Inversion Domain Boundaries

ABSTRACTTransmission electron microscope (TEM) images of inversion domain boundaries (IDB) show fringe contrast, thus indicating a relative displacement between the two adjoining domains. When the IDBs are facetted, different facets may have different displacement fault vectors. This implies that when the facetting changes from one plane to another, there should be a dislocation at the intersection of the planes. This is termed an “inversion domain boundary dislocation” and it will have a Burgers vector b=R1–R2 where R1, and R2 are the fault vectors of the two facets. Experimental results for facetted IDBs and IDB dislocations in SiC grown heteroepitaxially on (001) silicon are presented.

Exit Wave Reconstruction and Elemental Mapping of Twin Boundaries in the System Zno - Ga2O3

2001 ◽  
Vol 7 (S2) ◽  
pp. 290-291
Author(s):  
J. Barf ◽  
T. Walther ◽  
A. Steinecker ◽  
W. Mader
Keyword(s):  
Hexagonal Wurtzite Structure ◽  
Dark Field ◽  
Ion Milling ◽  
Twin Boundaries ◽  
Inversion Domain ◽  
Transmission Electron ◽  
Lattice Images ◽  
Lattice Planes ◽  
Inversion Domain Boundaries ◽  
Argon Ion

Polycrystalline ZnO was sintered with 5 mol.% Ga2O3 at 1350°C for lhour in air. Samples for transmission electron microscopy (TEM) were prepared by cold pressing, grinding, dimpling and Argon ion-milling.ZnO crystallizes in the hexagonal wurtzite structure. Bright field and dark field images reveal lamellar defect structures which are not observed in undoped ZnO. Electron diffraction shows that the lamellar regions consist of heavily twinned ZnO. The twin boundaries (TB) of both twin variants are parallel to lattice planes of type { }. Lattice images along reveal narrow planar twin boundaries as well as a diffuse image contrast within the twin lamellae (Fig. la). to characterize the nature of the boundaries we recorded dark field images of the twinned regions using reflections of type ±{0002}. in combination with microdiffraction it can be shown that the diffuse boundaries are inversion domain boundaries (IDB) which alternate with the sharp TB. This microstructure is related to the polarity of ZnO.

Application of AEM to chemical and structural characterization of the AlN-Al2O3 and AlN-Al2O3-SiO2 Systems

1995 ◽  
Vol 53 ◽  
pp. 318-319
Author(s):  
A. D. Westwood
Keyword(s):  
Thermal Conductivity ◽  
Defect Formation ◽  
Prototype System ◽  
Extended Defects ◽  
Inversion Domain ◽  
Domain Boundaries ◽  
Properties Of Materials ◽  
Inversion Domain Boundaries

The thermal, electronic and mechanical properties of aluminum nitride (A1N) make it an attractive material to a number of technologically important areas; microelectronic packaging, high temperature semiconductors, opto-electronic and piezoelectric devices and structural ceramics. It is well established that the concentration and distribution of impurities can control the macroscopic properties of materials. A1N is a classic example, with oxygen (O) being the dominant controlling impurity. The role of O in point defect formation and its detrimental effect on thermal conductivity was first documented by Slack. Oxygen has subsequently been shown to cause the formation of two-dimensional extended defects of which two variants exist, planar and curved. Both defects have been identified as O-rich inversion domain boundaries (IDB´s) (Fig.l). Because of the controlling influence that O has on thermal conductivity, it is important to fully understand the defect structures and chemistries that exist as a result of O incorporation. A1N-A12O3 is a prototype system for understanding the role that non-stoichiometry (impurities) plays in IDB formation.

Oxygen incorporation in aluminum nitride via extended defects: Part III. Reevaluation of the polytypoid structure in the aluminum nitride-aluminum oxide binary system

1995 ◽  
Vol 10 (10) ◽  
pp. 2573-2585 ◽  
Author(s):  
Alistair D. Westwoord ◽  
Robert A. Youngman ◽  
Martha R. McCartney ◽  
Alasiair N. Cormack ◽  
Michael R. Notis
Keyword(s):  
Aluminum Nitride ◽  
Stacking Faults ◽  
Structural Rearrangement ◽  
Extended Defects ◽  
Structural Elements ◽  
Inversion Domain ◽  
Transmission Electron ◽  
New Variant ◽  
Domain Boundaries ◽  
Inversion Domain Boundaries

This paper extends the concepts that were developed to explain the structural rearrangement of the wurtzite AlN lattice due to incorporation of small amounts of oxygen, and to directly use them to assist in understanding the polytypoid structures. Conventional and high-resolution transmission electron microscopy, specific electron diffraction experiments, and atomistic computer simulations have been used to investigate the structural nature of the polytypoids. The experimental observations provide compelling evidence that polytypoid structures are not arrays of stacking faults, but are rather arrays of inversion domain boundaries (IDB's). A new model for the polytypoid structure is proposed with the basic repeat structural unit consisting of a planar IDB-P and a corrugated IDB. This model shares common structural elements with the model proposed by Thompson, even though in his model the polytypoids were described as consisting of stacking faults. Small additions (≃ 1000 ppm) of silicon were observed to have a dramatic effect on the polytypoid structure. First, it appears that the addition of Si causes the creation of a new variant of the planar IDB (termed IDB-P'), different from the IDB-P defect observed in the AlN-Al2O3 polytypoids; second, the addition of Si influences the structure of the corrugated IDB, such that it appears to become planar.

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