Publications

Nanotechnology

Basso, Luca B.; Kehayias, Pauli M.; Henshaw, Jacob D.; Ziabari, Maziar S.; Byeon, Heejun B.; Lilly, Michael L.; Bussmann, Ezra B.; Campbell, DeAnna M.; Misra, Shashank M.; Mounce, Andrew M.

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 report, 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 200 μm wide APAM ribbon of ~6 μA. 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.

Physical Review Applied

Kehayias, Pauli M.; Levine, E.V.; Basso, Luca B.; Henshaw, J.; Saleh Ziabari, Maziar S.; Titze, Michael T.; Haltli, Raymond A.; Okoro, J.; Tibbetts, Denise R.; Udoni, D.M.; Bielejec, E.; Lilly, M.P.; Lu, Tzu-Ming L.; Schwindt, Peter S.; Mounce, Andrew M.

Quantum diamond microscope (QDM) magnetic field imaging is an emerging interrogation and diagnostic technique for integrated circuits (ICs). To date, the ICs measured with a QDM have been either too complex for us to predict the expected magnetic fields and benchmark the QDM performance or too simple to be relevant to the IC community. In this paper, we establish a 555 timer IC as a "model system"to optimize QDM measurement implementation, benchmark performance, and assess IC device functionality. To validate the magnetic field images taken with a QDM, we use a spice electronic circuit simulator and finite-element analysis (FEA) to model the magnetic fields from the 555 die for two functional states. We compare the advantages and the results of three IC-diamond measurement methods, confirm that the measured and simulated magnetic images are consistent, identify the magnetic signatures of current paths within the device, and discuss using this model system to advance QDM magnetic imaging as an IC diagnostic tool.

Basso, Luca B.; Kehayias, Pauli M.; Titze, Michael T.; Saleh Ziabari, Maziar S.; Byeon, Heejun B.; Campbell, DeAnna M.; Bussmann, Ezra B.; Lu, Tzu-Ming L.; Bielejec, Edward S.; Misra, Shashank M.; Lilly, Michael L.; Mounce, Andrew M.

Abstract not provided.