Electrical activation and electron spin coherence of ultra low dose antimony implants in silicon

TL;DR

This study demonstrates high electrical activation and long electron spin coherence times in ultra low dose antimony-implanted silicon, providing valuable data for quantum device development.

Contribution

It reports the first detailed measurement of electron spin coherence times in ultra low dose Sb-implanted silicon, highlighting the effects of dopant depth and surface passivation.

Findings

Achieved high electrical activation with minimal dopant diffusion.

Measured spin coherence times up to 0.75 ms with surface passivation.

Provided benchmark data for quantum information device development.

Abstract

We implanted ultra low doses (2x10^11 cm-2) of 121Sb ions into isotopically enriched 28Si and find high degrees of electrical activation and low levels of dopant diffusion after rapid thermal annealing. Pulsed Electron Spin Resonance shows that spin echo decay is sensitive to the dopant depths, and the interface quality. At 5.2 K, a spin decoherence time, T2, of 0.3 ms is found for profiles peaking 50 nm below a Si/SiO2 interface, increasing to 0.75 ms when the surface is passivated with hydrogen. These measurements provide benchmark data for the development of devices in which quantum information is encoded in donor electron spins.