# Enhanced Secondary-Electron Detection of Single-Ion Implants in Silicon through Thin SiO2 Layers

## TL;DR

The paper introduces a method to detect single-ion implants in silicon with high efficiency using secondary electrons and SiO2 layers.

## Contribution

A new method for high-efficiency single-ion detection using SiO2 layers in a focused-ion-beam system is introduced.

## Key findings

- Using low-energy Sb ions, up to 98 ± 1% single-ion detection efficiency is achieved.
- Thin SiO2 layers enhance secondary electron yield while maintaining successful ion deposition.
- The method enables precise donor placement for scalable quantum devices.

## Abstract

Deterministic placement of single dopants is essential
for scalable
quantum devices based on Group V donors in silicon. We demonstrate
a nondestructive, high-efficiency method for detecting individual
ion implantation events using secondary electrons (SEs) in a focused-ion-beam
system. Using low-energy Sb ions implanted into undoped silicon, we
achieve up to 98 ± 1% single-ion detection efficiency (DE). We
find that introducing thin, controlled SiO2 capping layers
enhances the SE yield, consistent with the increased electron mean-free
path in the oxide, while maintaining successful ion deposition in
the underlying silicon substrate. Our approach provides a robust and
scalable route to precise donor placement and extends deterministic
implantation strategies to a broad range of material systems and quantum
device architectures.