Observation of open-ended stacking fault tetrahedra in Si0.85Ge0.15grown on V-grooved (001) Si and planar (11¯1) Si substrates

1993 ◽  
Vol 63 (21) ◽  
pp. 2893-2895 ◽  
Author(s):  
David J. Howard ◽  
William E. Bailey ◽  
David C. Paine
Keyword(s):  
Stacking Fault ◽  
Si Substrates ◽  
Stacking Fault Tetrahedra

Observation of Open-Ended Stacking Fault Tetrahedra in Si0.85Ge0.15 Grown on V-Grooved (001) Si and Planar (111) Si Substrates

1993 ◽  
Vol 319 ◽  
Author(s):  
David J. Howard ◽  
David C. Paine
Keyword(s):  
Chemical Vapor ◽  
Stacking Fault ◽  
Line Pattern ◽  
Plan View ◽  
Thermal Chemical Vapor Deposition ◽  
Si Substrates ◽  
Transmission Electron ◽  
Stacking Fault Tetrahedra ◽  
Planar Substrates ◽  
Tem Transmission Electron Microscopy

AbstractA new strain relief mechanism was observed in thin films of Si0.85Ge0.15 grown by RTCVD (rapid thermal chemical vapor deposition) on patterned (001) and planar (111) Si substrates. The (001) Si substrates were lithographically patterned and anisotropically etched to produce a line pattern of V-shaped grooves running in the [110] direction where the walls of the grooves were the {111} crystal planes lying in the [110] zone. Cross-section and plan-view TEM (transmission electron microscopy) studies revealed the presence of open ended stacking fault tetrahedra in strained-layer Si0.85Ge0.15 grown both on (111) Si wafers and the {111} sidewalls of the patterned (001) Si wafers. No defects were observed in the (001) portions of the films grown on non-planar substrates.

Stacking Fault Tetrahedra Formation During Growth of Si1-xGex Strained Layers on 〈111〉 Oriented Si Substrates: Tem Observations and Defect Modeling

1994 ◽  
Vol 356 ◽  
Author(s):  
David J. Howard ◽  
Allan F. Bower ◽  
David C. Paine
Keyword(s):  
Strain Energy ◽  
Stacking Fault ◽  
Dislocation Network ◽  
Dislocation Loops ◽  
Strained Layers ◽  
Plan View ◽  
Strained Layer ◽  
Si Substrates ◽  
Stacking Fault Tetrahedra ◽  
Stable Growth

AbstractWe report the observation of stacking fault tetrahedra (SFT) in strained Si1-xGex layers grown via rapid thermal CVD on (111) Si substrates. It is shown that these defects provide a mechanism for strain relief in films strained in compression due the presence of bounding edge-type stair rod partials whose Burgers vectors lie parallel to the strained layer interface. Cross section and plan view TEM were used to characterize this defect structure in epilayers (30 to 650nm thick) of Si1-xGex (0 < xGe < 0.27) grown on 〈111〉 oriented Si wafers. Stacking fault tetrahedra were observed only in alloys in the compositional range xGe ≥ 0.13 and only when growth proceeded on the 〈111〉 surface. A critical strain energy model that identifies conditions for the stable growth of stacking fault tetrahedra in a strained layer is presented. The model was based on conventional strain energy considerations where the energy of the stacking fault area plus the bounding dislocation network (including dislocation interactions but neglecting the free surface) was balanced against the strain energy released by the introduction of the defect. In addition, a formation mechanism consistent with these observations is described that involves the dissociation of Frank partial dislocation loops bounding stacking faults lying in the growth plane.

Formation Of Stacking Fault Tetrahedra During Epitaxial Growth of Silicon and Germanium-Silicon Layers on {111} Silicon Substrates

1985 ◽  
Vol 54 ◽  
Author(s):  
D. Brasen ◽  
S. Nakahara ◽  
J. C. Bean
Keyword(s):  
Molecular Beam ◽  
Stacking Fault ◽  
Silicon Substrates ◽  
Si Substrate ◽  
Si Substrates ◽  
Transmission Electron ◽  
Stacking Fault Tetrahedra ◽  
Local Stresses ◽  
Silicon And Germanium ◽  
Germanium Silicon

ABSTRACTTransmission electron microscopy was used to characterize defects formed in silicon (Si) and germanium-silicon (Ge-Si) alloy layers grown sequentially by molecular-beam epitaxy (MBE) on {111} Si substrates. Stacking fault tetrahedra (SFT) were found to form in these epitaxial layers. In addition, the apex of the SFT are seen to be pointing down toward the Si substrate, with most of the SFT tips converging exactly at the Si/Si and the Ge-Si/Si interfaces. Diffraction contrast experiments using various two-beam conditions have shown that the stacking faults bounding the SFT are of intrinsic (vacancy) type. In the case of a Si layer on the Si substrate, it is reasoned that the SFT are caused by impurities on the surface of the Si substrate prior to deposition. However, in the Ge-Si layer, it is believed that the formation of the S FT is due to local stresses caused by the structural ordering/phase separation of the Ge atoms.

Contrast From Point Defects in The Infinitesimal Approximation

1980 ◽  
Vol 38 ◽  
pp. 350-351
Author(s):  
L. J. Sykes ◽  
J. J. Hren
Keyword(s):  
Electron Microscope ◽  
Point Defects ◽  
Broad Class ◽  
Stacking Fault ◽  
Crystalline Solids ◽  
Dislocation Loops ◽  
Analytical Expression ◽  
Stacking Fault Tetrahedra

In electron microscope studies of crystalline solids there is a broad class of very small objects which are imaged primarily by strain contrast. Typical examples include: dislocation loops, precipitates, stacking fault tetrahedra and voids. Such objects are very difficult to identify and measure because of the sensitivity of their image to a host of variables and a similarity in their images. A number of attempts have been made to publish contrast rules to help the microscopist sort out certain subclasses of such defects. For example, Ashby and Brown (1963) described semi-quantitative rules to understand small precipitates. Eyre et al. (1979) published a catalog of images for BCC dislocation loops. Katerbau (1976) described an analytical expression to help understand contrast from small defects. There are other publications as well.

Dislocation-Stacking Fault Tetrahedron Interactions in Cu

2002 ◽  
Vol 124 (3) ◽  
pp. 329-334 ◽  
Author(s):  
B. D. Wirth ◽  
V. V. Bulatov ◽  
T. Diaz de la Rubia
Keyword(s):  
Edge Dislocation ◽  
Interatomic Potential ◽  
High Energy ◽  
Dislocation Motion ◽  
Shear Localization ◽  
Stacking Fault ◽  
Dynamics Simulation ◽  
High Energy Particle ◽  
Face Centered Cubic ◽  
Stacking Fault Tetrahedra

In copper and other face centered cubic metals, high-energy particle irradiation produces hardening and shear localization. Post-irradiation microstructural examination in Cu reveals that irradiation has produced a high number density of nanometer sized stacking fault tetrahedra. The resultant irradiation hardening and shear localization is commonly attributed to the interaction between stacking fault tetrahedra and mobile dislocations, although the mechanism of this interaction is unknown. In this work, we present results from a molecular dynamics simulation study to characterize the motion and velocity of edge dislocations at high strain rate and the interaction and fate of the moving edge dislocation with stacking fault tetrahedra in Cu using an EAM interatomic potential. The results show that a perfect SFT acts as a hard obstacle for dislocation motion and, although the SFT is sheared by the dislocation passage, it remains largely intact. However, our simulations show that an overlapping, truncated SFT is absorbed by the passage of an edge dislocation, resulting in dislocation climb and the formation of a pair of less mobile super-jogs on the dislocation.

Direct Transformation of Vacancy Voids to Stacking Fault Tetrahedra

2007 ◽  
Vol 99 (13) ◽  
Author(s):  
B. P. Uberuaga ◽  
R. G. Hoagland ◽  
A. F. Voter ◽  
S. M. Valone
Keyword(s):  
Stacking Fault ◽  
Direct Transformation ◽  
Stacking Fault Tetrahedra

Atomistic simulation of stacking fault tetrahedra formation in Cu

2000 ◽  
Vol 283-287 ◽  
pp. 773-777 ◽  
Author(s):  
B.D Wirth ◽  
V Bulatov ◽  
T Diaz de la Rubia
Keyword(s):  
Atomistic Simulation ◽  
Stacking Fault ◽  
Stacking Fault Tetrahedra
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