Electric current paths in a Si:P delta-doped device imaged by nitrogen-vacancy diamond magnetic microscopy

Luca Basso; Pauli Kehayias; Jacob Henshaw; Maziar Saleh Ziabari; Heejun Byeon; Michael P Lilly; Ezra Bussmann; Deanna M Campbell; Shashank Misra; Andrew M Mounce

doi:10.1088/1361-6528/ac95a0

Electric current paths in a Si:P delta-doped device imaged by nitrogen-vacancy diamond magnetic microscopy

Nanotechnology. 2022 Oct 20;34(1). doi: 10.1088/1361-6528/ac95a0.

Authors

Luca Basso^{1

2}, Pauli Kehayias¹, Jacob Henshaw^{1

2}, Maziar Saleh Ziabari^{1

2

3}, Heejun Byeon^{1

2}, Michael P Lilly^{1

2}, Ezra Bussmann^{1

2}, Deanna M Campbell¹, Shashank Misra¹, Andrew M Mounce^{1

2}

Affiliations

¹ Sandia National Laboratories, Albuquerque, New Mexico NM-87185, United States of America.
² Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico NM-87123, United States of America.
³ Center for High Technology Materials and Department of Physics and Astronomy, University of New Mexico, Albuquerque, New Mexico NM-87131, United States of America.

PMID: 36170794
DOI: 10.1088/1361-6528/ac95a0

Abstract

The recently-developed ability to control phosphorous-doping of silicon at an atomic level using scanning tunneling microscopy, a technique known as atomic precision advanced manufacturing (APAM), has allowed us to tailor electronic devices with atomic precision, and thus has emerged as a way to explore new possibilities in Si electronics. In these applications, critical questions include where current flow is actually occurring in or near APAM structures as well as whether leakage currents are present. In general, detection and mapping of current flow in APAM structures are valuable diagnostic tools to obtain reliable devices in digital-enhanced applications. In this paper, we used nitrogen-vacancy (NV) centers in diamond for wide-field magnetic imaging (with a few-mm field of view and micron-scale resolution) of magnetic fields from surface currents flowing in an APAM test device made of a P delta-doped layer on a Si substrate, a standard APAM witness material. We integrated a diamond having a surface NV ensemble with the device (patterned in two parallel mm-sized ribbons), then mapped the magnetic field from the DC current injected in the APAM device in a home-built NV wide-field microscope. The 2D magnetic field maps were used to reconstruct the surface current densities, allowing us to obtain information on current paths, device failures such as choke points where current flow is impeded, and current leakages outside the APAM-defined P-doped regions. Analysis on the current density reconstructed map showed a projected sensitivity of ∼0.03 A m^-1, corresponding to a smallest-detectable current in the 200μm wide APAM ribbon of ∼6μA. These results demonstrate the failure analysis capability of NV wide-field magnetometry for APAM materials, opening the possibility to investigate other cutting-edge microelectronic devices.

Keywords: atomic precision advanced manufacturing; magnetic imaging; nitrogen-vacancy centers; quantum sensing.