Donor-bound-exciton strain microscopy in silicon devices

2024/08/30 by Pierandrea Conti, Siddharth Dhomkar, Conti, Pierandrea +7
Engineering · Physics and Astronomy · #Advanced MEMS and NEMS Technologies #FOS: Physical sciences #Force Microscopy Techniques and Applications #Mechanical and Optical Resonators #Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

paper · pdf · doi:10.48550/arxiv.2408.17382

openalex publication_date 2024/08/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30

Abstract

We explore the effects of stress on silicon donor bound exciton (D⁰X) transitions in bulk silicon and in microfabricated silicon devices. We first study D⁰X transitions in an isotopically purified silicon-28 bulk doped sample under controlled uniaxial stress, confirming the validity of existing models in the low strain (\lesssim 10^-5) regime. We then demonstrate the localised photoconductive detection of a few thousand donors illuminated by a 1078 nm resonant laser with 4~μm spot focused on a microfabricated device consisting of an implanted phosphorus layer between a pair of metallic contacts. We observe local variations in the strained exciton peak splitting from 10~μeV to 200~μeV, and obtain scanning microscopy stress maps in good agreement with finite-element-model thermal stress simulations. Our results suggest a potential use of donor bound excitons for in-situ stress sensing, and demonstrate pathways for the miniaturisation of D⁰X photoconductive detection.

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