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

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.

Head-to-head domain walls in one-dimensional nanostructures

“…Thus, there has not been global thinking about the names of DWs in these systems. Making this connexion is not a purely theoretical consideration, as processes are emerging for producing wires with a well-defined rectangular or square cross-section (Sergelius et al, 2014). Also, the latter should not be confused with the vortex wall in strips (McMichael and Donahue, 1997;Nakatani et al, 2005), which has a different shape and even topology, as we will detail later.…”

Stepwise magnetization reversal of geometrically tuned in diameter Ni and FeCo bi-segmented nanowire arrays

“…Nowadays, the modulation in diameter imprinted along the length of magnetic nanowires has become as a promising route to tailor their magnetic properties, allowing for a controlled motion of magnetic domain walls (DWs) and the possibility to manipulate the DW displacement by applying magnetic fields for their implementation in new-generation devices for information storage, logic system and sensors [1][2][3][4][5][6][7][8]. Cylindrical nanowires with modulated diameter and specific compositions are fabricated by different techniques such as the combination of mild and hard anodization processes [9][10][11] or by anodization together with atomic layer deposition (ALD) technique [12][13][14][15][16][17].…”

Vertical shift register using dipolar interaction in magnetic multilayers

“…In this paper, we propose a design for a multilayered soliton shift register which only uses dipolar interaction and in-plane shape anisotropy. Such a device can be realized due to the recent progress in nanowires fabrication techniques [18][19][20][21][22][23] . This device also has the added advantage that it can be fabricated using more commercially competitive methods such as electro-deposition 21 and atomic layer deposition 19,20,22 , which are unlikely to produce interfaces of sufficient quality to support strong RKKY interactions.…”

“…Such a device can be realized due to the recent progress in nanowires fabrication techniques [18][19][20][21][22][23] . This device also has the added advantage that it can be fabricated using more commercially competitive methods such as electro-deposition 21 and atomic layer deposition 19,20,22 , which are unlikely to produce interfaces of sufficient quality to support strong RKKY interactions. Sergelius et al have shown that by using laser interference lithography to create nanochannel arrays, rectangular bars with high aspect ratios and with lateral dimensions similar to the ones described in this manuscript can be fabricated experimentally 22 .…”