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Template-assisted nanostructure fabrication by glancing angle deposition: a molecular dynamics study.

Zhang J, Cao Y, Gao Q, Wu C, Yu F, Liang Y - Nanoscale Res Lett (2013)

Bottom Line: In the present work, we investigate the pre-existing template-assisted glancing angle deposition of Al columnar structures on Cu substrate by means of molecular dynamics simulations, with a focus on examining the effect of deposition-induced template deformation on the morphologies of the fabricated structures.Our simulations demonstrate that the pre-existing templates significantly intensify the shadowing effect, which thus facilitates the formation of columnar structures under small deposition flux.It is found that the template height-dependent deformation behavior of the templates strongly influences the morphologies of the fabricated columnar structures.

View Article: PubMed Central - HTML - PubMed

Affiliation: Center for Precision Engineering, Harbin Institute of Technology, Harbin 150001, People's Republic of China. cflying@hit.edu.cn.

ABSTRACT
In the present work, we investigate the pre-existing template-assisted glancing angle deposition of Al columnar structures on Cu substrate by means of molecular dynamics simulations, with a focus on examining the effect of deposition-induced template deformation on the morphologies of the fabricated structures. Our simulations demonstrate that the pre-existing templates significantly intensify the shadowing effect, which thus facilitates the formation of columnar structures under small deposition flux. The underlying deformation modes of the templates under different deposition configurations are analyzed and are correlated to the geometrical characteristics of the columnar structures. It is found that the template height-dependent deformation behavior of the templates strongly influences the morphologies of the fabricated columnar structures. Our findings provide design and fabrication guidelines for the fabrication of one-dimensional nanostructures by the template-assisted deposition technique.

No MeSH data available.


Coalescence of columnar structures in template-assisted static GLAD. (a) Enlarged view of the coalescence. Atoms are colored according to their types: red, blue, and yellow stand for boundary, thermostat, and mobile atoms, respectively; (b) defect configuration of the substrate shown in (a). Atoms are colored according to their CNA values.
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Figure 3: Coalescence of columnar structures in template-assisted static GLAD. (a) Enlarged view of the coalescence. Atoms are colored according to their types: red, blue, and yellow stand for boundary, thermostat, and mobile atoms, respectively; (b) defect configuration of the substrate shown in (a). Atoms are colored according to their CNA values.

Mentions: Figure 3a shows the enlarged view of the coalescence of the two columnar structures on the left side and in the middle obtained by the template-assisted static GLAD, which results from their inclination toward each other. The coalescence of columnar structures has also been reported by previous atomistic simulations [9,10]. In contrast, the columnar structure on the right side remains straight. To reveal the discrepancy between the morphologies of the columnar structures, defect analysis of the substrate including the templates is conducted. Figure 3b presents the defect configuration of the substrate shown in Figure 3a. The other atoms are eliminated to show defects clearly. In addition to the impact load applied by the impinging Al atoms, the local high temperature accompanied with the energy dissipation may also contribute to the formation of defects in the templates [22]. It is clearly seen from Figure 3b that there are two mechanical TBs inclining to each other formed in the template on the left side. The formation of mechanical TBs, i.e., deformation twinning, is an important deformation mode of 1D nanostructures with large surface-to-volume ratio under external load [23-25]. TB is a special kind of planar defects whose lattice structures exhibit mirror symmetries across the boundary. Therefore, the formation of TBs is accompanied with the change of the crystallographic orientation of the twin matrix. Consequently, the twinned part changes its shape with respect to the initial un-twinned one. The two inclined TBs in the template on the left side leads to more pronounced shape change than the template in the middle, in which there is only one TB formed. However, there is rather limited defect formed in the template on the right side.


Template-assisted nanostructure fabrication by glancing angle deposition: a molecular dynamics study.

Zhang J, Cao Y, Gao Q, Wu C, Yu F, Liang Y - Nanoscale Res Lett (2013)

Coalescence of columnar structures in template-assisted static GLAD. (a) Enlarged view of the coalescence. Atoms are colored according to their types: red, blue, and yellow stand for boundary, thermostat, and mobile atoms, respectively; (b) defect configuration of the substrate shown in (a). Atoms are colored according to their CNA values.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3733689&req=5

Figure 3: Coalescence of columnar structures in template-assisted static GLAD. (a) Enlarged view of the coalescence. Atoms are colored according to their types: red, blue, and yellow stand for boundary, thermostat, and mobile atoms, respectively; (b) defect configuration of the substrate shown in (a). Atoms are colored according to their CNA values.
Mentions: Figure 3a shows the enlarged view of the coalescence of the two columnar structures on the left side and in the middle obtained by the template-assisted static GLAD, which results from their inclination toward each other. The coalescence of columnar structures has also been reported by previous atomistic simulations [9,10]. In contrast, the columnar structure on the right side remains straight. To reveal the discrepancy between the morphologies of the columnar structures, defect analysis of the substrate including the templates is conducted. Figure 3b presents the defect configuration of the substrate shown in Figure 3a. The other atoms are eliminated to show defects clearly. In addition to the impact load applied by the impinging Al atoms, the local high temperature accompanied with the energy dissipation may also contribute to the formation of defects in the templates [22]. It is clearly seen from Figure 3b that there are two mechanical TBs inclining to each other formed in the template on the left side. The formation of mechanical TBs, i.e., deformation twinning, is an important deformation mode of 1D nanostructures with large surface-to-volume ratio under external load [23-25]. TB is a special kind of planar defects whose lattice structures exhibit mirror symmetries across the boundary. Therefore, the formation of TBs is accompanied with the change of the crystallographic orientation of the twin matrix. Consequently, the twinned part changes its shape with respect to the initial un-twinned one. The two inclined TBs in the template on the left side leads to more pronounced shape change than the template in the middle, in which there is only one TB formed. However, there is rather limited defect formed in the template on the right side.

Bottom Line: In the present work, we investigate the pre-existing template-assisted glancing angle deposition of Al columnar structures on Cu substrate by means of molecular dynamics simulations, with a focus on examining the effect of deposition-induced template deformation on the morphologies of the fabricated structures.Our simulations demonstrate that the pre-existing templates significantly intensify the shadowing effect, which thus facilitates the formation of columnar structures under small deposition flux.It is found that the template height-dependent deformation behavior of the templates strongly influences the morphologies of the fabricated columnar structures.

View Article: PubMed Central - HTML - PubMed

Affiliation: Center for Precision Engineering, Harbin Institute of Technology, Harbin 150001, People's Republic of China. cflying@hit.edu.cn.

ABSTRACT
In the present work, we investigate the pre-existing template-assisted glancing angle deposition of Al columnar structures on Cu substrate by means of molecular dynamics simulations, with a focus on examining the effect of deposition-induced template deformation on the morphologies of the fabricated structures. Our simulations demonstrate that the pre-existing templates significantly intensify the shadowing effect, which thus facilitates the formation of columnar structures under small deposition flux. The underlying deformation modes of the templates under different deposition configurations are analyzed and are correlated to the geometrical characteristics of the columnar structures. It is found that the template height-dependent deformation behavior of the templates strongly influences the morphologies of the fabricated columnar structures. Our findings provide design and fabrication guidelines for the fabrication of one-dimensional nanostructures by the template-assisted deposition technique.

No MeSH data available.