Electric Field Induced Phenomena Mass Flow and Chemical Reaction based Patterning

Abstract

Numerous electric field induced phenomena have been studied, for long, at various length scales. In particular, a concentrated electric field applied across a conductor, or equivalently an electric current of very high density passing through a conductor, can manifest in form of both destructive and constructive processes, depending on the requirements of an application. For example, electromigration, which is a diffusion-controlled electric field directed mass transport phenomenon, often leads to the formation of voids and hillocks near the cathode and the anode, respectively, metal interconnects in microelectronic devices. This results in failure of the device and hence this destructive manifestation of the electric field is considered as a villain in microelectronic interconnects. On the other hand, recently discovered electromigration in liquid metals may pave the path for various useful applications, such as maskless conformal coating, pattern formation, surface modification, etc. Besides the exploitation of the capability of the electric field for transporting matter (e.g., in liquid metals) in controlled and directed fashion in various applications, harnessing the unique potential of the electric field in inducing a chemical reaction in a controlled fashion in a confined region also provides new avenues for constructive usage. In particular, the electric field induced chemical reaction has been exploited for patterning at extremely small length scale, using scanning probe microscopes, such as atomic force microscope (AFM) and scanning tunneling microscope (STM). It is imperative to unambiguously understand the fundamentals of the concerned phenomenon before the aforementioned electric current induced phenomenon can be exploited to bear numerous technologies and applications. Here, we have studied two different electric field induced phenomena, namely electromigration in liquid metals and electric field-induced chemical reaction in solid thin metals1. The presentation of the study in form of this the...