Wet etch methods for InAs nanowire patterning and self-aligned electrical contacts

TL;DR

This paper introduces three wet chemical etch techniques for precise post-growth modification of InAs nanowires, enabling self-aligned electrical contacts and quantum device components with stable transport properties.

Contribution

It presents novel wet etch methods for InAs nanowires that allow for detailed morphological control and integration into quantum electronic devices.

Findings

Self-aligned electrical contacts can be formed on etched NWs.

Etched NW segments exhibit stable transport characteristics.

A quantum dot was successfully created between etched NW segments.

Abstract

Advanced synthesis of semiconductor nanowires (NWs) enables their application in diverse fields, notably in chemical and electrical sensing, photovoltaics, or quantum electronic devices. In particular, Indium Arsenide (InAs) NWs are an ideal platform for quantum devices, e.g. they may host topological Majorana states. While the synthesis has been continously perfected, only few techniques were developed to tailor individual NWs after growth. Here we present three wet chemical etch methods for the post-growth morphological engineering of InAs NWs on the sub-100 nm scale. The first two methods allow the formation of self-aligned electrical contacts to etched NWs, while the third method results in conical shaped NW profiles ideal for creating smooth electrical potential gradients and shallow barriers. Low temperature experiments show that NWs with etched segments have stable transport characteristics and can serve as building blocks of quantum electronic devices. As an example we report the formation of a single electrically stable quantum dot between two etched NW segments.