Structure and Electronic Properties of Misfit Dislocations in ZnSe/GaAs(001) Heterojunctions

1994 ◽  
Vol 340 ◽  
Author(s):  
Y. Chen ◽  
X. Liu ◽  
E. Weber ◽  
E. D. Bourret ◽  
D. J. Olego ◽  
...  

ABSTRACTStudies of the structure and electrical properties of regular and irregular misfit dislocations in undoped and N-doped ZnSe epilayers grown on GaAs(001) substrates by transmission electron microscopy (TEM), cathodoluminescence (CL) are reported. In undoped ZnSe epilayers, two sets of misfit dislocation arrays were observed: a straight orthogonal array along [110] and, and an irregular array roughly along [100] and [010] directions. The CL observations suggest that the irregular dislocations trap carriers more efficiently than the dislocations along <110>, possibly due to the high density of kinks existing along the zig-zag irregular dislocations. These irregular dislocations can be eliminated by doping nitrogen in the ZnSe epilayer with [N]≥l×1018 cm−3.

1990 ◽  
Vol 216 ◽  
Author(s):  
S.G. Lawson-Jack ◽  
I.P. Jones ◽  
D.J. Williams ◽  
M.G. Astles

ABSTRACTTransmission electron microscopy has been used to assess the defect contents of the various layers and interfaces in (CdHg) Te heterostructures. Examination of cross sectional specimens of these materials suggests that the density of misfit dislocations at the interfaces is related to the layer thicknesses, and that the high density of dislocations which are generated at the GaAs/CdTe interface are effectively prevented from penetrating into the CdHgTe epilayer by a 3um thick buffer layer. The majority of the dislocations in the layers were found to have a Burgers vector b = a/2<110> and either lie approximately parallel or inclined at an angle of ∼ 60° to the interfacial plane.


2011 ◽  
Vol 1324 ◽  
Author(s):  
Y. Wang ◽  
P. Ruterana ◽  
L. Desplanque ◽  
S. El Kazzi ◽  
X. Wallart

ABSTRACTHigh resolution transmission electron microscopy in combination with geometric phase analysis is used to investigate the interface misfit dislocations, strain relaxation, and dislocation core behavior versus the surface treatment of the GaAs for the heteroepitaxial growth of GaSb. It is pointed out that Sb-rich growth initiation promotes the formation of a high quality network of Lomer misfit dislocations that are more efficient for strain relaxation.


1991 ◽  
Vol 238 ◽  
Author(s):  
M. Albrecht ◽  
H. P. Strunk ◽  
P. O. Hansson ◽  
E. Bauser

ABSTRACTThe initial stages of heteroepitaxial growth of Ge0.85 Si0.15 on Si(001) grown from Bi solution (liquid phase epitaxy) are studid by transmission electron microscopy. Stranski-Krastanov growth is observed to take place. After growth of a pseudomorphic Ge0.85 Si0.15 layer of 4 monolayer thickness, islands form and grow pseudomorphically up to a thickness of 30 nm. Then first misfit dislocations form. The formation process of these dislocations is analyzed and discussed in terms of half loop nucleation at the surface and dislocation glide. Evidence for glide on (110) planes is put forward.


2003 ◽  
Vol 779 ◽  
Author(s):  
Hyung Seok Kim ◽  
Sang Ho Oh ◽  
Ju Hyung Suh ◽  
Chan Gyung Park

AbstractMechanisms of misfit strain relaxation in epitaxially grown Bi4-xLaxTi3O12 (BLT) thin films deposited on SrTiO3 (STO) and LaAlO3 (LAO) substrates have been investigated by means of transmission electron microscopy (TEM). The misfit strain of 20 nm thick BLT films grown on STO substrate was relaxed by forming misfit dislocations at the interface. However, cracks were observed in 100 nm thick BLT films grown on the same STO. It was confirmed that cracks were formed because of high misfit strain accumulated with increasing the thickness of BLT, that was not sufficiently relaxed by misfit dislocations. In the case of the BLT film grown on LAO substrate, the magnitude of lattice misfit between BLT and LAO was very small (~1/10) in comparison with the case of the BLT grown on STO. The relatively small misfit strain formed in layered structure of the BLT films on LAO, therefore, was easily relaxed by distorting the film, rather than forming misfit dislocations or cracks, resulting in misorientation regions in the BLT film.


2005 ◽  
Vol 864 ◽  
Author(s):  
Qianghua Xie ◽  
Peter Fejes ◽  
Mike Kottke ◽  
Xiangdong Wang ◽  
Mike Canonico ◽  
...  

AbstractIn this paper, various types of defects (both threading dislocation and misfit dislocations) in strained Si (sSi) have been analyzed by transmission electron microscopy (TEM). Germanium upper-diffusion has been studied by scanning transmission electron microscopy (STEM) for strained Si on SiGe/SOI. SGOI-devices processed using an optimized thermal budget show minimal Ge diffusion and minimal process related defects. Correlation between the device performance (such as leakage current and reliability) and structural information found in TEM has been established.


2011 ◽  
Vol 675-677 ◽  
pp. 247-250 ◽  
Author(s):  
Yoshio Tanita ◽  
Daiji Matsui ◽  
Hiroshi Fukushima

Micro- and nano-structures of the Cr-Mo electroplated layers were studied mainly by Transmission Electron Microscopy (TEM), High Resolution TEM (HRTEM) and Positron Annihilation Lifetime Spectroscopy (PALS). These electroplated layers which were deposited in Cr-Mo electrolyte containing an organic sulfonic acid, showed surface structures having severe ups and downs of small crystal grains. Both selected area diffraction and dark-field image of TEM confirmed the presence of very small crystal grains of less than 50 nm. These small crystal grains exhibited textured structure when the electrolyte contained an organic sulfonic catalyst. PALS results indicated the presence of high density nano-size voids, and HRTEM analysis confirmed the presence of high density voids of 1 nm to 2 nm in diameter. Size and density of these nano-voids increased with the amount of catalyst in the electrolyte.


1992 ◽  
Vol 263 ◽  
Author(s):  
A.E.M. de Veirman ◽  
F. Hakkens ◽  
W. Coene ◽  
F.J.A. Den Broeder

ABSTRACTThe results of a transmission electron microscopy study of Co/Au and Co/Pd multilayers are reported. Special emphasis is put on the epitaxial growth and the relaxation of the misfit strain of these high misfit systems. In bright-field cross-sectional images, periodic contrast fringes are observed at the interfaces, which are the result of Moiré interference and which allow determination of the degree of misfit relaxation at the interface. It was established that 80-85% of the misfit is relaxed. From high resolution electron microscopy images the Burgers vector of the misfit dislocations was derived, being a/2<110> lying in the (111) interface plane. The results obtained for the Co/Au and Co/Pd multilayers will be discussed in comparison with those obtained for a bilayer of Co and Au.


Sign in / Sign up

Export Citation Format

Share Document