We present a single-exposure fabrication technique for a very large array of microscopic air-bridges using a tri-layer resist process with electron-beam lithography. The technique is capable of forming air-bridges with strong metal-metal or metal-substrate connections. This was demonstrated by its application in an electron tunnelling device consisting of 400 identical surface gates for defining quantum wires, where the air-bridges are used as suspended connections for the surface gates. This technique enables us to create a large array of uniform one-dimensional channels that are open at both ends. In this article, we outline the details of the fabrication process, together with a study and the solution of the challenges present in the development of the technique, which includes the use of water-IPA (isopropyl alcohol) developer, calibration of resist thickness and numerical simulation of the development.
@article{arxiv.2102.06123,
title = {Microscopic metallic air-bridge arrays for connecting quantum devices},
author = {Y. Jin and M. Moreno and P. M. T. Vianez and W. K. Tan and J. P. Griffiths and I. Farrer and D. A. Ritchie and C. J. B. Ford},
journal= {arXiv preprint arXiv:2102.06123},
year = {2021}
}
Comments
6 pages, 5 figures; This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing