A scanning probe microscopy approach for identifying defects in aluminum oxide

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Tom, Leah, Krebs, Zachary J., Varley, Joel B., Joseph, E. S., Behn, Wyatt A., Eriksson, M. A., Ray, Keith G., Lordi, Vincenzo, Coppersmith, S. N., Brar, Victor W., Friesen, Mark
Natura: Preprint
Pubblicazione: 2025
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866912791019913216
author Tom, Leah
Krebs, Zachary J.
Varley, Joel B.
Joseph, E. S.
Behn, Wyatt A.
Eriksson, M. A.
Ray, Keith G.
Lordi, Vincenzo
Coppersmith, S. N.
Brar, Victor W.
Friesen, Mark
author_facet Tom, Leah
Krebs, Zachary J.
Varley, Joel B.
Joseph, E. S.
Behn, Wyatt A.
Eriksson, M. A.
Ray, Keith G.
Lordi, Vincenzo
Coppersmith, S. N.
Brar, Victor W.
Friesen, Mark
contents The coherence of quantum dot qubits fabricated in semiconductors is often limited by charge noise from defects in gate dielectrics, which are material- and process-dependent. Characterizing these defects is an important step towards reducing their impact and improving qubit coherence. The identification of individual defects requires atomic-scale spatial resolution, however, and sufficient spectral sensitivity to determine their electronic structure. Electrostatic force microscopy (EFM) provides highly resolved maps of the surface potential of dielectrics, and importantly, is also sensitive to single-electron charging processes that reflect the spectral structure of underlying defects. In this work, we use cryogenic EFM to characterize aluminum oxide grown by atomic layer deposition (ALD) on bulk silicon. These measurements reveal defects close to the surface that exchange electrons with the EFM tip as they transition through different charge states. Detailed electrostatic modeling opens the door to powerful techniques for mapping tip-backgate charging voltages onto defect transition energies, allowing defects such as aluminum vacancies, and carbon, oxygen, or hydrogen impurities to be identified, by comparing to density functional theory (DFT). These results point towards EFM as a powerful tool for exploring defect structures in solid-state qubits.
format Preprint
id arxiv_https___arxiv_org_abs_2512_22369
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle A scanning probe microscopy approach for identifying defects in aluminum oxide
Tom, Leah
Krebs, Zachary J.
Varley, Joel B.
Joseph, E. S.
Behn, Wyatt A.
Eriksson, M. A.
Ray, Keith G.
Lordi, Vincenzo
Coppersmith, S. N.
Brar, Victor W.
Friesen, Mark
Mesoscale and Nanoscale Physics
The coherence of quantum dot qubits fabricated in semiconductors is often limited by charge noise from defects in gate dielectrics, which are material- and process-dependent. Characterizing these defects is an important step towards reducing their impact and improving qubit coherence. The identification of individual defects requires atomic-scale spatial resolution, however, and sufficient spectral sensitivity to determine their electronic structure. Electrostatic force microscopy (EFM) provides highly resolved maps of the surface potential of dielectrics, and importantly, is also sensitive to single-electron charging processes that reflect the spectral structure of underlying defects. In this work, we use cryogenic EFM to characterize aluminum oxide grown by atomic layer deposition (ALD) on bulk silicon. These measurements reveal defects close to the surface that exchange electrons with the EFM tip as they transition through different charge states. Detailed electrostatic modeling opens the door to powerful techniques for mapping tip-backgate charging voltages onto defect transition energies, allowing defects such as aluminum vacancies, and carbon, oxygen, or hydrogen impurities to be identified, by comparing to density functional theory (DFT). These results point towards EFM as a powerful tool for exploring defect structures in solid-state qubits.
title A scanning probe microscopy approach for identifying defects in aluminum oxide
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2512.22369