Misfit dislocations in epitaxial Ni/Cu bilayer and Cu/Ni/Cu trilayer thin films.

Conference · Mon Jan 01 04:00:00 EST 2001

OSTI ID:975339

Misra, A ^[1]; G, Hoagland R ^[2]; Kung, H ^[3]; Yamamoto, T ^[4]

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1. Amit
2. Richard G.
3. Harriett
4. Tadashi

Misfit dislocations at the interfaces of bilayer (Ni/Cu) and trilayer (Cu/Ni/Cu) thin films are examined by plan-view TEM observation. In the bilayers, the spacing of misfit dislocations is measured as a fiinction of nickel layer thickness. The critical thickness, at which misfit dislocations start to appear with the loss of coherency, was found to be about 2 nm. The spacing of the misfit dislocations decreases with increasing nickel layer thickness and reaches a plateau at the thickness of 30 nm. The minimum spacing is observed to be about 20 nm. g {center_dot} b analysis of the cross-grid of misfit dislocations revealed 90{sup o} Lomer dislocations of <110>{l_brace}001{r_brace} type lying in the (001) interface plane at the relatively large thickness of nickel layer, but 60{sup o} glide dislocations of <110>{l_brace}111{r_brace} type at the relatively small thickness of nickel layer. In the trilayers, misfit dislocations formed at both interfaces. The spacing of the misfit dislocation is in agreement with that of the bilayers with similar nickel layer thickness. The misfit dislocation arrays at the two interfaces, having the same line directions, are 60{sup o} dislocations with edge components with opposite signs but are displaced with respect to each other in the two different interface planes. This suggests that the strain field of the dislocations has a strong influence on the position of the misfit dislocations at the subsequent interface.

• Research Organization: Los Alamos National Laboratory
• Sponsoring Organization: DOE
• OSTI ID: 975339
• Report Number(s): LA-UR-01-2818
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COPPER
DISLOCATIONS
INTERFACES
LAYERS
NICKEL
STRAINS
THIN FILMS