Self-aligned fabrication process for silicon quantum computer devices

TL;DR

This paper presents a self-aligned fabrication process for silicon quantum devices with few qubits, enabling precise placement and control of 31P donors for quantum computing demonstrations.

Contribution

It introduces a novel self-aligned fabrication method combining electron beam patterning, ion implantation, and shadow-mask evaporation for silicon quantum devices.

Findings

Successful registration of 31P donors with control gates and SETs

Fabrication of devices suitable for proof-of-principle quantum computing experiments

Enhanced precision in donor placement and device alignment

Abstract

We describe a fabrication process for devices with few quantum bits (qubits), which are suitable for proof-of-principle demonstrations of silicon-based quantum computation. The devices follow the Kane proposal to use the nuclear spins of 31P donors in 28Si as qubits, controlled by metal surface gates and measured using single electron transistors (SETs). The accurate registration of 31P donors to control gates and read-out SETs is achieved through the use of a self-aligned process which incorporates electron beam patterning, ion implantation and triple-angle shadow-mask metal evaporation.