Epitaxial Al/GaAs/Al tri-layers fabricated using a novel wafer-bonding technique

TL;DR

This paper presents a novel wafer-bonding technique to fabricate high-quality epitaxial Al/GaAs/Al tri-layers with pristine interfaces, enabling advanced quantum information processing applications.

Contribution

A new wafer-bonding method for creating epitaxial Al/GaAs/Al tri-layers with controlled thickness and high interface quality on silicon and sapphire substrates.

Findings

Successful fabrication of epitaxial Al/GaAs/Al tri-layers

High-quality interfaces confirmed by multiple characterization techniques

Potential applications in quantum information processing

Abstract

Epitaxial Al/GaAs/Al structures having controlled thickness of high-quality GaAs and pristine interfaces have been fabricated using a wafer-bonding technique. III-V semiconductor/Al structures are grown by molecular beam epitaxy on III-V semiconductor substrates and bonded to silicon and sapphire. Selective etching is used to remove the III-V substrate followed by surface cleaning and superconductor regrowth, resulting in epitaxial Al/GaAs/Al tri-layers on sapphire or silicon substrates. Structures are characterized with reflection high energy electron diffraction, atomic force microscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, and X-ray diffraction. Applications of these structures to the field of quantum information processing is discussed.