Basal Plane Dislocation Analysis of 4H-SiC Using Multi Directional STEM Observation

2015 ◽  
Vol 821-823 ◽  
pp. 303-306 ◽  
Author(s):  
Takahiro Sato ◽  
Yoshihiro Ohtsu ◽  
Yoshihisa Orai ◽  
Toshiyuki Isshiki ◽  
Munetoshi Fukui
Keyword(s):  
Basal Plane ◽  
Scanning Transmission Electron Microscopy ◽  
Surface Defect ◽  
Stacking Fault ◽  
Partial Dislocations ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Basal Plane Dislocation ◽  
Novel Method ◽  
Extended Dislocation

A peculiar surface defect on a silicon carbide (SiC) epitaxial wafer, found to be associated a basal plane dislocation (BPD), was studied using a low energy scanning electron microscope (LESEM), and a novel method we are calling multi directional scanning transmission electron microscopy (MD-STEM). We have confirmed that an etch pit with double cores neighboring a peculiar surface defect is derived from the extended BPD. The BPD consisted of two partial dislocations with a stacking fault width of about 100 nm. Observation of only one viewing direction in a previous study missed the extended dislocation but through the use of the MD-STEM method in the current study, the dislocation has been confirmed to be extended into a stacking fault.

Cross Section and Plan View STEM Analysis on Identical Conversion Point of Basal Plane Dislocation to Threading Edge Dislocation of 4H-SiC

2016 ◽  
Vol 858 ◽  
pp. 397-400
Author(s):  
Takahiro Sato ◽  
Yoshihisa Orai ◽  
Toshiyuki Isshiki ◽  
Munetoshi Fukui ◽  
Kuniyasu Nakamura
Keyword(s):  
Cross Section ◽  
Edge Dislocation ◽  
Basal Plane ◽  
Dislocation Line ◽  
Plan View ◽  
Conversion Point ◽  
Partial Dislocations ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Basal Plane Dislocation

Cross section and plan view dislocation analysis at the conversion point of a basal plane dislocation (BPD) into a threading edge dislocation (TED) in a silicon carbide epitaxial wafer was developed using a newly modified multi directional scanning transmission electron microscopy (STEM) technique. Cross section STEM observation in the [-1100] direction, found a conversion point located 5.5 μm from the surface, where two dislocation lines in the basal plane convert into one dislocation line nearly along the hexagonal c axis was observed. Using plan view STEM observation along the [000-1] direction, it is confirmed that the dislocation lines are two partial dislocations of a BPD and one TED by g·b invisibility analysis. This new technique is a powerful tool to evaluate the fundamental dislocation characteristics of power electronics devices.

Structural variability of edge dislocations in a SrTiO3 low-angle [001] tilt grain boundary

2009 ◽  
Vol 24 (7) ◽  
pp. 2191-2199 ◽  
Author(s):  
James P. Buban ◽  
Miaofang Chi ◽  
Daniel J. Masiel ◽  
John P. Bradley ◽  
Bin Jiang ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Scanning Transmission Electron Microscopy ◽  
Spherical Aberration ◽  
Structural Variations ◽  
Partial Dislocations ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Tilt Grain Boundary ◽  
Edge Dislocations ◽  
Electron Energy Loss

Using a spherical aberration (Cs)-corrected scanning transmission electron microscopy (STEM) and electron energy-loss spectroscopy (EELS), we investigated a 6° low-angle [001] tilt grain boundary in SrTiO3. The enhanced spatial resolution of the aberration corrector leads to the observation of a number of structural variations in the edge dislocations along the grain boundary that neither resemble the standard edge dislocations nor partial dislocations for SrTiO3. Although there appear to be many variants in the structure that can be interpreted as compositional effects, three main classes of core structure are found to be prominent. From EELS analysis, these classifications seem to be related to Sr deficiencies, with the final variety of the cores being consistent with an embedded TiOx rocksalt-like structure.

Scanning Transmission Imaging of Elastomer Blends Using an Unmodified Conventional Scanning Electron Microscope

1995 ◽  
Vol 68 (2) ◽  
pp. 342-350 ◽  
Author(s):  
Paul E. F. Cudby ◽  
Barry A. Gilbey
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Scanning Transmission Electron Microscopy ◽  
Transmission Imaging ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Novel Method ◽  
Conventional Microscopy ◽  
Microscopy Techniques ◽  
Scanning Electron

Abstract A novel method for carrying out scanning transmission electron microscopy on a standard scanning electron microscope is described. This method involves the addition of a specially fabricated mount and is accomplished without carrying out any form of modification on the microscope. The method is compared to more conventional microscopy techniques and examples are given showing the advantages of this system.

High-Voltage Scanning Electron Microscopy

1970 ◽  
Vol 28 ◽  
pp. 6-7
Author(s):  
J. M. Cowley
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Scanning Transmission Electron Microscopy ◽  
Wave Optics ◽  
Contrast Effects ◽  
Transmission Electron ◽  
Mode Of Operation ◽  
Scanning Transmission ◽  
Types Of Information ◽  
Voltage Scanning

The comparison of scanning transmission electron microscopy (STEM) with conventional transmission electron microscopy (CTEM) can best be made by means of the Reciprocity Theorem of wave optics. In Fig. 1 the intensity measured at a point A’ in the CTEM image due to emission from a point B’ in the electron source is equated to the intensity at a point of the detector, B, due to emission from a point A In the source In the STEM. On this basis it can be demonstrated that contrast effects In the two types of instrument will be similar. The reciprocity relationship can be carried further to include the Instrument design and experimental procedures required to obtain particular types of information. For any. mode of operation providing particular information with one type of microscope, the analagous type of operation giving the same information can be postulated for the other type of microscope. Then the choice between the two types of instrument depends on the practical convenience for obtaining the required Information.

Imaging and diffraction modes in Scanning Transmission Electron Microscopy

1986 ◽  
Vol 44 ◽  
pp. 684-687
Author(s):  
J. M. Cowley ◽  
R. Glaisher ◽  
J. A. Lin ◽  
H.-J. Ou
Keyword(s):  
Scanning Transmission Electron Microscopy ◽  
High Efficiency ◽  
Fiber Optic ◽  
Image Intensifier ◽  
Detector System ◽  
Detector Plane ◽  
Secondary Electrons ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Special Detector

Some of the most important applications of STEM depend on the variety of imaging and diffraction made possible by the versatility of the detector system and the serial nature, of the image acquisition. A special detector system, previously described, has been added to our STEM instrument to allow us to take full advantage of this versatility. In this, the diffraction pattern in the detector plane may be formed on either of two phosphor screens, one with P47 (very fast) phosphor and the other with P20 (high efficiency) phosphor. The light from the phosphor is conveyed through a fiber-optic rod to an image intensifier and TV system and may be photographed, recorded on videotape, or stored digitally on a frame store. The P47 screen has a hole through it to allow electrons to enter a Gatan EELS spectrometer. Recently a modified SEM detector has been added so that high resolution (10Å) imaging with secondary electrons may be used in conjunction with other modes.

Scanning Transmission Electron Microscopy of Polyethylene Crystals

1980 ◽  
Vol 38 ◽  
pp. 242-245
Author(s):  
F. Khoury ◽  
L. H. Bolz
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Crystallization Temperature ◽  
Scanning Transmission Electron Microscopy ◽  
Growth Habit ◽  
Lateral Growth ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Growth Habits

The lateral growth habits and non-planar conformations of polyethylene crystals grown from dilute solutions (<0.1% wt./vol.) are known to vary depending on the crystallization temperature.1-3 With the notable exception of a study by Keith2, most previous studies have been limited to crystals grown at <95°C. The trend in the change of the lateral growth habit of the crystals with increasing crystallization temperature (other factors remaining equal, i.e. polymer mol. wt. and concentration, solvent) is illustrated in Fig.l. The lateral growth faces in the lozenge shaped type of crystal (Fig.la) which is formed at lower temperatures are {110}. Crystals formed at higher temperatures exhibit 'truncated' profiles (Figs. lb,c) and are bound laterally by (110) and (200} growth faces. In addition, the shape of the latter crystals is all the more truncated (Fig.lc), and hence all the more elongated parallel to the b-axis, the higher the crystallization temperature.

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