Electrochemical synthesis of highly ordered nanowires with a rectangular cross-section using an in-plane nanochannel array

TL;DR

This paper introduces a method for fabricating highly ordered, rectangular nanowires within nanochannel templates using electrochemical deposition, enabling large-scale, aligned nanowire arrays with integrated electrical contact for device applications.

Contribution

The study presents a novel fabrication process combining laser interference lithography, reactive ion etching, and atomic layer deposition to create nanochannels for in situ growth and measurement of nanowires, with minimal processing.

Findings

Successfully fabricated cm-long nanochannels with 40 nm dimensions.

Electrodeposited iron nanowires are aligned and rectangular within the channels.

Integrated multi-probe measurement platform enables direct electrical characterization.

Abstract

Rapid and reproducible assembly of aligned nanostructures on a wafer-scale is a crucial, yet one of the most challenging tasks in the incorporation of nanowires into integrated circuits. We present the synthesis of a periodic nanochannel template designed for electrochemical growth of perfectly aligned, rectangular nanowires over large areas. The nanowires can be electrically contacted and characterized in situ using a pre-patterned multi-point measurement platform. During the measurement the wires remain within a thick oxide matrix providing protection against breaking and oxidation. We use laser interference lithography, reactive ion etching and atomic layer deposition to create cm-long parallel nanochannels with characteristic dimensions as small as 40 nm. In a showcase study pulsed electrodeposition of iron is carried out creating rectangular shaped iron nanowires within the nanochannels. By design of the device, the grown wires are in contact with an integrated electrode system on both ends directly after the deposition. No further processing steps are required for electrical characterization, minimizing the risk of damage and oxidation. The developed nanowire measurement device allows for multi-probe resistance measurements and can easily be adopted for transistor applications. The guided, in-plane growth of electrodeposited nanowire arrays which are tunable in size and density paves the way for the incorporation of nanowires into a large variety of multifunctional devices.