# Single rare-earth ions as atomic-scale probes in ultra-scaled transistors

## TL;DR

This paper demonstrates that single erbium ions can serve as highly sensitive, non-destructive probes for 3D mapping of local electric fields and strain in ultra-scaled transistors, surpassing standard techniques in sensitivity.

## Contribution

The study introduces the use of single erbium ions as atomic-scale probes for measuring electric field and strain in transistors, enabling ultra-sensitive, non-destructive 3D characterization.

## Key findings

- Detection of Stark shifts due to electric field and charge environment
- Strain sensitivity exceeding standard techniques by two orders of magnitude
- Potential for non-destructive 3D mapping of transistor channels

## Abstract

Continued dimensional scaling of semiconductor devices has driven information technology into vastly diverse applications. As the size of devices approaches fundamental limits, metrology techniques with nanometre resolution and three-dimensional (3D) capabilities are desired for device optimisation. For example, the performance of an ultra-scaled transistor can be strongly influenced by the local electric field and strain. Here we study the spectral response of single erbium ions to applied electric field and strain in a silicon ultra-scaled transistor. Stark shifts induced by both the overall electric field and the local charge environment are observed. Further, changes in strain smaller than $3\times 10^{-6}$ are detected, which is around two orders of magnitude more sensitive than the standard techniques used in the semiconductor industry. These results open new possibilities for non-destructive 3D mapping of the local strain and electric field in the channel of ultra-scaled transistors, using the single erbium ions as ultra-sensitive atomic probes.

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Source: https://tomesphere.com/paper/1803.01573