Experimental Observations of Orderly Structures in Copper Films Deposited on Liquid Substrates

Abstract

In this paper, an optical microscopy study of orderly structures, namely bands, which are observed in a nearly free sustained copper (Cu) film system, is presented. The band is composed of a large number of parallel key-formed domains with different width w but nearly uniform length L. This study shows that the morphologies of the Cu films are very susceptible to the deposition rate, i.e. with the increase in the deposition rate f , the bands with rectangular domains first become irregular gradually and then disappear completely. The experiment indicates that the growth mechanism of the orderly patterns can be explained in terms of the relaxation of the internal stress in the films, which is related to the characteristic boundary condition of the films on the liquid substrates and the nearly zero adhesion of the solid-liquid interface.

Facile production of monodisperse nanoparticles on a liquid surface

“…Silicone oil, being nonreactive and extremely stable under vacuum conditions (vapor pressure = 3 × 10 −10 mmHg), is appropriate for copper vapor deposition and growth. 36 The property of the sticking coefficient, which experimentally translates to the condensate-substrate energy was calculated via Density Functional Theory (DFT), it was found that copper atoms are weakly bound to the oxygen functional group (−0.55 eV), resulting in the low probability of oxidation from silicone oil. The binding energy with other functional groups was also found be relatively low (methyl −0.15 eV; silicon −1.09; hydrogen −0.55 eV), indicating minimal interaction between the condensing species and substrate.…”