Insights on molecular P implantation for scalable spin-qubit arrays

TL;DR

This paper explores using molecular PF2 ions for phosphorus implantation in silicon to improve the precision and scalability of spin-qubit arrays, addressing key challenges in quantum computer development.

Contribution

It introduces a molecular dynamics approach to analyze PF2 ion implantation, highlighting potential advantages over traditional methods for scalable qubit fabrication.

Findings

Molecular PF2 ions can potentially reduce placement uncertainty.

The presence of an a-SiO2 layer affects molecule breakup during implantation.

Electronic signal intensity does not directly correlate with phosphorus penetration depth.

Abstract

Quantum information technologies hold immense promise, with quantum computers poised to revolutionize problem-solving capabilities. Among the leading contenders are solid-state spin-qubits, particularly those utilizing the spin of phosphorous donors (31 P ). While significant progress has been made in enhancing quantum coherence and qubit control, challenges persist, notably in achieving precise and scalable P placement in Si substrate. This paper investigates by means of molecular dynamics the use of molecular PF2 ions for implantation, aiming to reduce placement uncertainty while maintaining detection efficiency. We examine energy transfer, molecule integrity, implantation profiles, electronic signal components, and stable damage. Among other things we find that the assumption that the molecule only breaks apart immediately due to the presence of an a-SiO2 layer on the surface of the crystal and that the intensity of the electronic signal from ion-solid interactions does not correlate necessarily with the penetration depth of P.