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edfas.org 29 ELECTRONIC DEV ICE FA I LURE ANALYSIS | VOLUME 24 NO . 1 SCANNING NITROGEN VACANCY MAGNETOMETRY: A QUANTUM TECHNOLOGY FOR DEVICE FAILURE ANALYSIS Peter Rickhaus 1 and Patrick Maletinsky 2 1 Qnami AG, Basel, Switzerland 2 University of Basel, Switzerland peter.rickhaus@qnami.ch EDFAAO (2022) 4:29-32 1537-0755/$19.00 ©ASM International ® INTRODUCTION Thedevelopment of sensing techniques formagnetism have led to a series of revolutions, from the first compass to the MRI scanner. With classical technologies reaching their limits, it is nitrogen vacancy (NV) centers in diamond that leverage the extreme sensitivity of quantum systems to their environment and offer radically newperformance for magnetic sensing. Their ability to detect weak signals down to the molecular level unlocks new perspectives, for example to characterizemagnetic nanostructures [1] as used in magnetic random access memory (MRAM) tech- nologies. But scanningNVmicroscopy is not only suited to measure tinymagnetic fields, it can also resolve electrical currents (via their magnetic fields) with unprecedented spatial resolution. This presents an opportunity for inte- grated circuit failure analysis. The sensor used in scanning NV microscopy (SNVM) consists of a sharp diamond pillar with the NV center im- planted at a depth of ~10 nm from the tip apex. Figure 1a shows a scanning electron microscopy image of the QuantileverMX, the SNVM sensor pioneered and patented by Qnami AG. The magnetic field signal is read out opti- cally, using fluorescent light emitted by the NV center while driving the spin by microwave fields. Figure 1b gives an impression on how these components are Fig. 1 (a) Image of the QuantileverMX, the scanning NV microscopy sensor. (b) A sample under Qnami ProteusQ, the scanning NV microscope. The main componentsaretheopticalsystem, theQuantileverMX and the microwave antenna. The sample is mounted to an atomic force microscopy stage. Fig. 2 (a) The scanning NV tip is read out optically (fluorescence) while a microwave frequency is applied. (b) The ODMR (optically detected magnetic resonance) spectrum, showing fluorescence versus microwave frequency for different magnetic fields.