Comparative Study of E-beam and Optical Probing Approaches in Attacking the ICs

Abstract

Optical probing methods through the chip backside have been demonstrated to be powerful attack techniques in the field of electronic security. However, these attacks typically require specific circuit conditions, such as enforcing gate or register switching at certain frequencies or repeating measurements over multiple executions to achieve an acceptable signal-to-noise ratio (SNR). Meeting these requirements can pose challenges, such as low-frequency switching or inaccessibility of the control signals. This study evaluates these requirements for contactless electron- and photon-based probing attacks by performing extensive experiments and discussing the advantages and drawbacks of each approach. Our findings demonstrate that E-beam probing has the potential to outperform optical methods in scenarios involving static or low-frequency circuit activities. Nevertheless, E-beam probing requires the assistance of optical techniques for area localization and requires aggressive thinning and trenching to the STI level.