Templated solid-state dewetting of single-crystal metal films

초록

Thin solid films are usually thermodynamically metastable or unstable, so that they often dewet to form an array of islands when heated to sufficiently high temperatures. Much attention has been paid to the potential application of this phenomenon to create structures useful in areas such as catalysis and plasmonics. Dewetting of single-crystal solid films is crystallographically confined to result in the formation of regular morphologies that are consistent with the symmetries of the initial film surface. In addition to the intrinsic crystallographic constraint, geometric constraints can also be imposed on the morphological evolution of single-crystal films by lithographically pre-patterning them. Because of these constraints, dewetting of pre-patterned single-crystal films is templated to produce well-ordered regular structures in deterministic ways. In this talk, I will first introduce the mechanisms underlying the regular morphological evolution observed during dewetting of single-crystal films. Then, I will present results showing that ordered arrays of micro- and nanoscale features can be fabricated with control over their shapes and sizes via solid-state dewetting of patches patterned from single-crystal metal films. The mechanisms underlying the pattern formation will also be explained. This understanding of mechanisms of pattern formation will provide a guideline for designing patches to precisely fabricate regular structures with the desired shapes and feature sizes via templated-dewetting.