WeC-2-1 Transmission electron microscopy study on origin of threading dislocations in GaN layer grown on patterned sapphire substrate

2015 ◽  
Vol 2015 (0) ◽  
pp. _WeC-2-1-1-_WeC-2-1-3
Author(s):  
Tohoru Matsubara ◽  
Kohei Sugimoto ◽  
Narihito Okada ◽  
Kazuyuki Tadatomo
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Sapphire Substrate ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Threading Dislocations ◽  
Transmission Electron Microscopy Study ◽  
Patterned Sapphire Substrate ◽  
Transmission Electron

A Transmission Electron Microscopy Study of Dislocation Substructures in PLD-grown Epitaxial Films of (Ba,Sr)TiO3 on (001) LaAlO3

2003 ◽  
Vol 784 ◽  
Author(s):  
I. B. Misirlioglu ◽  
A. L. Vasiliev ◽  
M. Aindow ◽  
R. Ramesh ◽  
S. P. Alpay
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Threading Dislocations ◽  
Misfit Dislocations ◽  
Transmission Electron Microscopy Study ◽  
Transmission Electron ◽  
Half Loop ◽  
Island Coalescence

ABSTRACTEpitaxial Ba0.6Sr0.4TiO3 films were grown onto (001) LaAlO3 by pulsed-laser deposition, and the dislocation structures of the films were investigated using transmission electron microscopy. Misfit dislocations with a periodicity of about 7 nm and Burgers vectors b = a<100> were observed at the interface. High densities of threading dislocations was present in the films with Burgers vector b = a<100>. The observations reveal that threading dislocations are not generated as the result of half-loop climb from the deposit surface as proposed previously, but are instead formed when misfit dislocations are forced away from the interface during island coalescence.

Transmission electron microscopy study of epitaxial InN thin films grown on c-plane sapphire

2006 ◽  
Vol 21 (7) ◽  
pp. 1693-1699 ◽  
Author(s):  
C.J. Lu ◽  
X.F. Duan ◽  
Hai Lu ◽  
William J. Schaff
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Film Growth ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Threading Dislocations ◽  
Transmission Electron Microscopy Study ◽  
Transmission Electron ◽  
Gan Buffer Layer

High-quality epitaxial InN thin films grown on (0001) sapphire with GaN buffer were characterized using transmission electron microscopy. It was found that the GaN buffer layer exhibits the (0001) Ga polarity and the InN film has In-terminated polarity. At the InN/GaN interface, there exists a high density of misfit dislocation (MD) array. Perfect edge threading dislocations (TDs) with (1/3)〈1120〉 Burgers vectors are predominant defects that penetrate the GaN and InN layers. Pure screw and mixed TDs were also observed. Overall, the TD density decreases during film growth due to annihilation and fusion. The TD density in GaN is as high as ∼1.5 × 1011 cm−2, and it drops rapidly to ∼2.2 × 1010 cm−2 in InN films. Most half-loops in GaN are connected with MD segments at the InN/GaN interface to form loops, while some TD segments threaded the interface. Half-loops were also generated during the initial stages of InN growth.

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