Angular spectrum tailoring in solid immersion microscopy for circuit analysis

Abstract

We present a technique that involves tailoring the angular spectrum in optical microscopy of silicon integrated circuits, with a solid immersion lens. Spatial light modulation to select only supercritical light at the substrate/dielectric interface yields only evanescent and scattered light in the interconnect layers. We demonstrated the technique in optical excitation microscopy of 65 nm silicon-on-insulator circuits, which enabled localization of a fault during microprocessor development. Acquiring images with and without angular spectrum tailoring allowed longitudinal localization of the electrical response to optical excitation. Lateral registration of electrical response and confocal reflection images to the circuit layout was also significantly improved. © 2008 American Institute of Physics.