Tem and Hrem Study Of mGH-Temperature Aluminum Ion Implantation to 6H-SiC

1998 ◽  
Vol 512 ◽  
Author(s):  
A. A. Suvorova ◽  
I. O. Usov ◽  
O. I. Lebedev ◽  
G. Van Tendeloo ◽  
A. V. Suvorov
Keyword(s):  
Electron Microscopy ◽  
Low Dose ◽  
High Resolution Electron Microscopy ◽  
Implantation Dose ◽  
Structural Defects ◽  
High Dose ◽  
Dislocation Loops ◽  
Aluminum Ions ◽  
Transmission Electron ◽  
Resolution Electron

ABSTRACT6H silicon carbide wafers were implanted with 40–50 keV aluminum ions to a dose of 1.5 × 1014 – 1.5 × 1016 cm−2 at high temperatures (1100°C–1700°C). The substrate temperature and the implantation dose were varied to investigate the influence of the implantation parameters on the formation of structural defects. Conventional transmission electron microscopy (TEM) and high resolution electron microscopy (HREM) techniques were applied to study the defects. We found that for low dose implants {0001} interstitial dislocation loops are formed but for high dose implants aluminum precipitates associated with {0001} half-loops are formed.

Defect Structures in Al-Ni-Rh Crystalline Approximants Studied by HREM and HAADF Techniques

2007 ◽  
Vol 561-565 ◽  
pp. 1353-1356 ◽  
Author(s):  
Wei Sun ◽  
Y.H. Chen ◽  
J.P. Wang ◽  
Z. Zhang
Keyword(s):  
Electron Microscopy ◽  
Structural Characteristics ◽  
Symmetry Plane ◽  
High Resolution Electron Microscopy ◽  
Dark Field ◽  
Structural Defects ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Scanning Transmission ◽  
Annular Dark Field

By means of a combination of high-resolution electron microscopy (HREM) and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) techniques, we have directly revealed that periodic arrangements in different manners for flattened hexagons constructed with atom columnar clusters can form two Al-Ni-Rh crystalline approximant phases. In contrast to periodic arrangements of flattened hexagons, configurations and distributions of various defects in these structurally-complicated alloy phases have been examined and their structural characteristics discussed. HREM observations clearly show that structural defects in Al-Ni-Rh crystalline approximants are of phason type and they are correlated with incorrect arrangements of atom columnar clusters. The distribution of high density planar defects can destroy the long-range periodicity in at least one direction in the pseudo decagonal symmetry plane. By means of the HAADF-STEM imaging technique, the existence of ill-formed atom columnar clusters in the core area of a linear defect, which is usually not visible in HREM observations, has been clearly revealed.

Investigation of the microstructure of hetero-epitaxial Si/CoSi2/Si (001) and (111) structures by TEM

1990 ◽  
Vol 48 (4) ◽  
pp. 386-387
Author(s):  
C.W.T. Bulle-Lieuwma ◽  
A.H. van Ommen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
High Resolution Electron Microscopy ◽  
High Dose ◽  
Metal Base ◽  
Si Substrates ◽  
Transmission Electron ◽  
Resolution Electron ◽  
High Dose Implantation

Hetero-epitaxial Si/CoSi2/Si structures have been formed by high dose implantation of Co+ ions into (001) and (111) Si substrates and subsequent annealing of the substrates. Such structures are of interest due to their application as metal base base and permeable base transistors. We have studied the microstructure of both as-implanted and annealed structures by transmission electron microscopy (TEM), including high-resolution electron microscopy (HREM). HREM was performed using a Philips 300 kV electron microscope with a point resolution of approximately 0.19 nm. CoSi2 layers have been formed by implantation of 170 keV Co+ ions at a temperature of 450°C and to doses of 1× 1017 and 2× 1017 Co+ / cm2. The wafers were annealed for 30 minutes in a N2/H2 ambient at a temperature of 1000°C. In the as implanted structures, the Co is present in the form of epitaxial CoSi2 precipitates. Precipitates occur both in an aligned (A-type) and twinned (B-type) orientation. Annealing of the implanted structures results in the formation of a buried CoSi2 layer of aligned orientation. A striking observation is that the CoSi2 layer has an aligned orientation with respect to the Si matrix, whereas CoSi2 grown on top of (111) Si has a twinned orientation. The mechanism behind this phenomenon is not fully understood. We think that geometrical aspects play a crucial role. Therefore we have studied in detail the geometry of the coordination of coherent CoSi2 precipitates.

The Effect of Xe Ion Beam Treatment on the Interaction Between Gold and GaAs

1992 ◽  
Vol 260 ◽  
Author(s):  
B. Pécz ◽  
G. Radnóczi ◽  
Zs. J. Horváth ◽  
P. B. Barna ◽  
Erika Jároli ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Ion Beam ◽  
High Resolution Electron Microscopy ◽  
Gaas Layer ◽  
High Dose ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Ion Beam Treatment ◽  
Defective Area

ABSTRACTThe effect of the defective nature of the substrate on the alloying behaviour of Xe implanted Au(55 ran)/n-GaAs system was studied using cross sectional transmission electron microscopy.Low dose Xe implantation (700 keV, 1*1014 ions/cm2) caused the formation of about SO nm thick polycrystalline region of GaAs beneath the gold layer. Annealing the implanted sample at 450°C gold diffused through the polycrystalline GaAs region and formed large pits of Au(Ga) solid solution in the defective area of GaAs having stacking faults and twins. The formation of a regrown GaAs covering layer was observed on the top of the reacted metallization simultaneously.High dose implantation of Xe++ ions resulted in the formation of amorphous GaAs layer with a thickness of about 750 nm. Twinned regions of GaAs were observed at the amorphous - crystalline GaAs interface by high resolution electron microscopy. Ion beam caused phase transition was observed in this sample. The amorphous GaAs region recrystallized to single crystalline GaAs due to annealing at 400°C.

Microstructural characteristics of conductive SrRuO3 thin films formed by pulsed-laser deposition

1998 ◽  
Vol 13 (8) ◽  
pp. 2302-2307 ◽  
Author(s):  
P. Lu ◽  
F. Chu ◽  
Q. X. Jia ◽  
T. E. Mitchell
Keyword(s):  
Electron Microscopy ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
High Resolution Electron Microscopy ◽  
Laser Deposition ◽  
Structural Defects ◽  
Orientation Relationships ◽  
Coherent Interface ◽  
Transmission Electron ◽  
Resolution Electron

Transmission electron microscopy and high-resolution electron microscopy have been used to study microstructural properties of conductive SrRuO3 films grown by pulsed laser deposition on (001) LaAlO3 and (001) SrTiO3 substrates. It was found that the SrRuO3 films deposited on both substrates consist of mixed domains of [001] and [110] orientations, with orientation relationships that can be described as (i) (001)f ‖ (001)s and [110]f ‖ [100]s and (ii) (110)f ‖ (001)s and [001]f ‖ [100]s, respectively. The SrRuO3 films deposited on SrTiO3, in particular, were found to have a layered domain structure, with the [110] domain grown initially on the substate, followed by growth of the [001] oriented domain with increasing thickness. The films on SrTiO3 are strained and have a coherent interface with the substrate. The SrRuO3 films deposited on LaAlO3, on the other hand, contain a high density of structural defects such as stacking faults and microtwins on the (022) planes. Microtwins as large as 50 nm in thickness are observed in the films deposited on LaAlO3. Possible causes for the observed structural defects in the films are discussed.

scholarly journals Structural Properties of Free-Standing 50 mm Diameter GaN Wafers with (1010) Orientation Grown on LiAlO2

2003 ◽  
Vol 764 ◽  
Author(s):  
Jacek Jasinski ◽  
Zuzanna Liliental-Weber ◽  
Herbert-Paul Maruska ◽  
Bruce H. Chai ◽  
David W. Hill ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Basal Plane ◽  
Stacking Faults ◽  
High Resolution Electron Microscopy ◽  
Structural Defects ◽  
Free Standing ◽  
Lattice Matching ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Good Lattice

Abstract(1010) GaN wafers grown on (100) face of γ-LiAlO2 were studied using transmission electron microscopy. Despite good lattice matching in this heteroepitaxial system, high densities of planar structural defects in the form of stacking faults on the basal plane and networks of boundaries located on prism planes inclined to the layer/substrate interface were present in these GaN layers. In addition, significant numbers of threading dislocations were observed. High-resolution electron microscopy indicates that stacking faults present on the basal plane in these layers are of low-energy intrinsic I1 type. This is consistent with diffraction contrast experiments.

Study of Structural Defects in CdZnTe Crystals by High Resolution Electron Microscopy

2011 ◽  
Vol 1341 ◽  
Author(s):  
A. Hossain ◽  
A. E. Bolotnikov ◽  
G. S. Camarda ◽  
Y. Cui ◽  
R. Gul ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
Scanning Transmission Electron Microscope ◽  
Structural Defects ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Scanning Transmission ◽  
Infrared Microscope

ABSTRACTWe investigated defects in CdZnTe crystals produced from various conditions and their impact on fabricated devices. In this study, we employed transmission and scanning transmission electron microscope (TEM and STEM), because defects at the nano-scale are not observed readily under an optical or infrared microscope, or by most other techniques. Our approach revealed several types of defects in the crystals, such as low-angle boundaries, dislocations and precipitates, which likely are major causes in degrading the electrical properties of CdZnTe devices, and eventually limiting their performance.

Structural analysis of the surface-layer protein of spirillum serpens by high-resolution electron microscopy

1983 ◽  
Vol 41 ◽  
pp. 738-739
Author(s):  
W. H. Wu ◽  
R. M. Glaeser
Keyword(s):  
Electron Microscopy ◽  
Surface Layer ◽  
Structural Analysis ◽  
High Resolution ◽  
Low Dose ◽  
High Resolution Electron Microscopy ◽  
Optical Diffraction ◽  
Surface Layer Protein ◽  
Morphological Unit ◽  
Resolution Electron

Spirillum serpens possesses a surface layer protein which exhibits a regular hexagonal packing of the morphological subunits. A morphological model of the structure of the protein has been proposed at a resolution of about 25 Å, in which the morphological unit might be described as having the appearance of a flared-out, hollow cylinder with six ÅspokesÅ at the flared end. In order to understand the detailed association of the macromolecules, it is necessary to do a high resolution structural analysis. Large, single layered arrays of the surface layer protein have been obtained for this purpose by means of extensive heating in high CaCl2, a procedure derived from that of Buckmire and Murray. Low dose, low temperature electron microscopy has been applied to the large arrays.As a first step, the samples were negatively stained with neutralized phosphotungstic acid, and the specimens were imaged at 40,000 magnification by use of a high resolution cold stage on a JE0L 100B. Low dose images were recorded with exposures of 7-9 electrons/Å2. The micrographs obtained (Fig. 1) were examined by use of optical diffraction (Fig. 2) to tell what areas were especially well ordered.

Interface structures in polycrystalline ceramic materials

1986 ◽  
Vol 44 ◽  
pp. 468-471
Author(s):  
K. J. Morrissey
Keyword(s):  
Electron Microscopy ◽  
Analytical Electron Microscopy ◽  
Physical And Mechanical Properties ◽  
High Resolution Electron Microscopy ◽  
Ceramic Materials ◽  
Polycrystalline Materials ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Interface Structures

Grain boundaries and interfaces play an important role in determining both physical and mechanical properties of polycrystalline materials. To understand how the structure of interfaces can be controlled to optimize properties, it is necessary to understand and be able to predict their crystal chemistry. Transmission electron microscopy (TEM), analytical electron microscopy (AEM,), and high resolution electron microscopy (HREM) are essential tools for the characterization of the different types of interfaces which exist in ceramic systems. The purpose of this paper is to illustrate some specific areas in which understanding interface structure is important. Interfaces in sintered bodies, materials produced through phase transformation and electronic packaging are discussed.

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