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.

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.