Photoluminescence Study of Oxidation-Induced Stacking Faults in 4H-SiC Epilayers

2015 ◽  
Vol 821-823 ◽  
pp. 327-330 ◽  
Author(s):  
Yutaro Miyano ◽  
Shuhei Yagi ◽  
Yasuto Hijikata ◽  
Hiroyuki Yaguchi

We have investigated the effect of thermal oxidation on stacking faults (SFs) in 4H-SiC epilayers using photoluminescence imaging. We found that a comb-shaped dislocation array was deformed by thermal oxidation and that SFs were formed on both sides of the comb-shaped dislocation array by a laser irradiation. Transmission electron microscopy has been performed in the comb-shaped dislocation array to observe the stacking pattern of SF near the dislocation. As a result, the SF turned out to be a single Shockley SF (1SSF). We also found that line-shaped faults perpendicular to the off-cut direction were formed during oxidation and were stretched with oxidation time. Moreover, triangle-shaped SFs were formed/expanded from the line-shaped faults by a laser irradiation. The characteristics of these line-shaped faults were discussed.

1983 ◽  
Vol 29 ◽  
Author(s):  
M. I. Birjega ◽  
C. A. Constantin ◽  
M. Dinescu ◽  
I. Th. Florescu ◽  
I. N. Mihailescu ◽  
...  

ABSTRACTThe crystallization and oxidation processes of thin, free-standing (FS), sputtered Cr films under the action of cw CO2 laser irradiation were studied by transmission electron microscopy (TEM) and transmission electron diffraction (TED). The crystallization is induced at power densities above 28.65 W cm−2, dwell time of 1 s, and the oxidation at power densities of 48.1 W cm−2 and longer dwell times.


Further experiments by transmission electron microscopy on thin sections of stainless steel deformed by small amounts have enabled extended dislocations to be observed directly. The arrangement and motion of whole and partial dislocations have been followed in detail. Many of the dislocations are found to have piled up against grain boundaries. Other observations include the formation of wide stacking faults, the interaction of dislocations with twin boundaries, and the formation of dislocations at thin edges of the foils. An estimate is made of the stacking-fault energy from a consideration of the stresses present, and the properties of the dislocations are found to be in agreement with those expected from a metal of low stacking-fault energy.


2008 ◽  
Vol 600-603 ◽  
pp. 67-70 ◽  
Author(s):  
Alkyoni Mantzari ◽  
Frédéric Mercier ◽  
Maher Soueidan ◽  
Didier Chaussende ◽  
Gabriel Ferro ◽  
...  

The aim of the present work is to study the structural properties of 3C-SiC which is grown on (0001) 6H-SiC and on (100) 3C-SiC (Hoya) seeds using the Continuous Feed Physical Vapor Transport (CF-PVT) method. Transmission Electron Microscopy (TEM) observations confirm that the overgrown layer is of the 3C-SiC polytype. In the case of the 6H-SiC substrate, microtwins (MTs), stacking faults (SFs) and dislocations (D) are observed at the substrate-overgrown interface with most of the dislocations annihilating within the first few µm from the interface. In the case of 3C-SiC crystals grown on 3C seeds, repeated SFs are formed locally and also coherent (111) twins of 3C-SiC are frequently observed near the surface. The SF density is reduced at the uppermost part of the grown material.


Microscopy ◽  
2018 ◽  
Vol 67 (1) ◽  
pp. 30-36
Author(s):  
Hiroyuki Iwata ◽  
Daisuke Kawaguchi ◽  
Hiroyasu Saka

Abstract Internal modification induced in Si by a permeable pulse laser was investigated by transmission electron microscopy. A laser induced modified volume (LIMV) was a cylindrical rod along the track of a laser beam with the head at the focus of the laser beam. In the LIMV, beside voids, dislocations, micro-cracks and what had been supposed to be an unidentified high-pressure phase (hpp) of Si were observed in LIMV. The so-called ‘hpp’ was identified mostly as diamond Si.


2008 ◽  
Vol 41-42 ◽  
pp. 15-19 ◽  
Author(s):  
Y.Q. Wu ◽  
Han Huang ◽  
Jin Zou

In this work, deformation of monocrystalline silicon (Si) under nanoscratching was investigated using transmission electron microscopy (TEM). The results indicated that no fracture occurred during nanoscratching with loads ranging from 1 to 6 mN. The damaged regions induced by nanoscratching included an amorphous Si region and a damaged crystalline Si region. Detailed TEM analyses revealed that at the lowest load of 1 mN no dislocation was observed in the damaged crystalline region, and only stacking faults were observed at the boundary between the damaged crystalline Si and amorphous Si. Dislocations started to nucleate along (111) planes and penetrated into the bulk Si when the normal load was increased to 2 mN and above. Defects perpendicular to the scratched surface were initiated when the load was greater than 4 mN. The density of dislocations also increased rapidly with the increase of the applied load.


1999 ◽  
Vol 572 ◽  
Author(s):  
Z. Liliental-Weber ◽  
M. Benamara ◽  
S. Ruvimov ◽  
J. H. Mazur ◽  
J. Washburn ◽  
...  

ABSTRACTTransmission electron microscopy was applied to cross-sectioned samples to study surface morphology, sample polarity and defect distribution in bulk GaN samples doped with Mg. These crystals were grown from a Ga melt under high hydrostatic pressure of Nitrogen. It was shown that the types of defects and their distribution along the c-axis depends strongly on sample polarity. Based on this finding the growth rate along the c-axis for the two polar directions was compared and shown to be approximately ten times larger for Ga polarity than for N-polarity. In the part of the crystals with Ga polarity pyramidal defects with a base consisting of high energy stacking faults were found. The parts of the crystals grown with Npolarity were either defect free or contained regularly spaced stacking faults. Growth of these regularly spaced cubic monolayers is polarity dependent; this structure was formed only for the growth with N polarity and only for the crystals doped with Mg. Formation of this superstructure is similar to the polytypoid structure formed in AlN crystals rich in oxygen. It is also likely that oxygen can decorate the cubic monolayers and compensate Mg. This newly observed structure may shed light on the difficulties of p-doping in GaN:Mg.


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