Fabrication of ultrahigh-density nanowires by electrochemical nanolithography

Feng Chen,Amy E Wendt,Anna M Clausen,Bingjun Ding,Hongquan Jiang,Yuk-Hong Ting,Arnold M Kiefer,Max G Lagally

doi:10.1186/1556-276x-6-444

Abstract

An approach has been developed to produce silver nanoparticles (AgNPs) rapidly on semiconductor wafers using electrochemical deposition. The closely packed AgNPs have a density of up to 1.4 × 1011 cm-2 with good size uniformity. AgNPs retain their shape and position on the substrate when used as nanomasks for producing ultrahigh-density vertical nanowire arrays with controllable size, making it a one-step nanolithography technique. We demonstrate this method on Si/SiGe multilayer superlattices using electrochemical nanopatterning and plasma etching to obtain high-density Si/SiGe multilayer superlattice nanowires.

Highlights

Low-dimensional systems are of high interest because their unique properties can improve device performance in a range of applications, including optics [1,2], mechanics [3], microelectronics [4], and magnetics [5]
Superlattice nanowires have the potential to improve the performance of thermoelectronics [6,7,8,9], small sizes have lower thermal conductivity [8,9], and they can be made at a high density, providing improved performance
The pulse length τ is first fixed to 0.5 s in order to study the result for different immersion time t

Summary

Introduction

Low-dimensional systems are of high interest because their unique properties can improve device performance in a range of applications, including optics [1,2], mechanics [3], microelectronics [4], and magnetics [5]. By using this mask in combination with chemical vapor deposition (CVD) growth and plasma etching, we are able to fabricate ultrahigh-density (6.2 × 1010 cm-2) Si/ SiGe superlattice nanowire arrays over a large area, with individual wires < 30 nm in diameter and approximately 200 nm in length. Various immersion times (t) and pulse lengths (τ = 1 ms to 0.5 s) were tried in the experiment in order to obtain AgNPs with uniform small size and high density.

Results

Conclusion