Generic nano-imprint process for fabrication of nanowire arrays

TL;DR

This paper presents a universal nanoimprint process for fabricating high-quality, uniform nanowire arrays of InP and GaP, utilizing a cleaning step that enhances growth quality and reduces defects.

Contribution

The authors introduce a novel cleaning protocol that improves nanowire array uniformity and defect reduction, applicable across various lithography methods.

Findings

Achieved nanowire length variation of only 1%.

Removed undesired nanowires through optimized cleaning.

Demonstrated process applicability to different lithography techniques.

Abstract

A generic process has been developed to grow nearly defect free arrays of (heterostructured) InP and GaP nanowires. Soft nanoimprint lithography has been used to pattern gold particle arrays on full 2 inch substrates. After lift-off organic residues remain on the surface, which induce the growth of additional undesired nanowires. We show that cleaning of the samples before growth with piranha solution in combination with a thermal anneal at 550 C for InP and 700 C for GaP results in uniform nanowire arrays with 1% variation in nanowire length, and without undesired extra nanowires. Our chemical cleaning procedure is applicable to other lithographic techniques such as e-beam lithography, and therefore represents a generic process.