Quantitative Analysis and Modeling of Templated Solid-State Dewetting of Thin Single-Crystal Ni Films

icon Quantitative Analysis and Modeling of Templated Solid-State Dewetting of Thin Single-Crystal Ni Films

Y. A. Shin, K. Keane, G. H. Kim, W. C. Carter, C. V. Thompson
Sponsorship: National Science Foundation

It has been shown that templated solid-state dewetting of single crystal films (120 nm thick) can be used to make periodic complex structures with dimensions smaller than the templating patterns, making it a potential self-assembly method (Figure 1). A quantitative understanding of dewetting mechanisms is critical for design of self-assembled structures made through dewetting. In the past we have studied corner, pinch-off, and Rayleigh instabilities. We are currently studying the fingering instability using single-crystal Ni films that have been patterned with edges lying along different in-plane crystallographic orientations. These edges were also patterned with periodic perturbations having various wavelengths. We found that some edges with specific in-plane crystallographic alignments were resistant to development of fingering instabilities, even with templating, and became straight as they retracted during dewetting. In the case of edges with other crystallographic alignments, we have shown that templating with patterned edge perturbations can be used to

 

 

control the period of the fingering instability that develops the edges retract during dewetting (Figure 2). We are developing a kinetic Monte Carlo model to better understand mechanisms of the fingering instability.
In parallel with studies of templated fingering instabilities, we aim to generate smaller-scale dewetting structures using templated solid-state dewetting. Finer dewetting structures require thinner films. However, natural hole formation becomes easier as the film thickness is decreased, and uncontrolled formation of natural holes limits our ability to decrease the length-scale of dewetting structures, as naturally forming holes interrupt processes controlled through templating. We are developing methods to identify the cause of natural hole formation and to control it. After achieving control of natural hole formation, we will study dewetting phenomenologies in ultra-thin single crystal films and test the potential of templated solid-state dewetting as a self-assembly method for fabrication of nanostructures.

dewetted patches

patterened edge
FURTHER READING
  • C. V. Thompson, “Solid-state dewetting of thin films,” Annual Review of Materials Research, vol. 42, pp. 399-434, 2012.
  • R. V. Zucker, G. H. Kim, J. Ye, W. C. Carter, and C. V. Thompson, “The mechanism of corner instabilities in single-crystal thin films during dewetting,” J. Appl. Phys., vol. 119, p. 125306, 2016.
  • G. H. Kim and C. V. Thompson, “Effect of surface energy anisotropy on Rayleigh-like solid-state dewetting and nanowire stability,” Acta Materialia, vol. 84, p. 190, 2015.
Last Updated on Thursday, 21 July 2016 20:23