Self－deformation of Coated Al Nanowires Induced by Residual Stress in Coating Film

Abstract

Micro/nano coils have been expected to be utilized in various applications as small inductors. Various methods have been proposed for fabricating them. Most of these methods were based on self-assembly technique such as thermal sublimation and chemical vapor deposition. In our previous study, we proposed an alternative method based on a mechanical process, where a straight nanowire is bent by depositing a thin film with a circumferentially nonuniform thickness on the nanowire. The bending is due to the misfit strain of the coated film. In order to enhance the bending, we also adopted a heat treatment that induces a creep flow only in the nanowire and thereby released the constraint of the nanowire on elastic bending due to film strain. However, the shape control of micro/nano coils such as coil pitch and direction of helical deformation was still not succeeded. In present study, we investigated the effects of film thickness and nanowire position on the coil formation during coil formation in the sputtering chamber. We achieved the shape control of micro/nano coils by varying the film thickness and nanowire position.