Subsurface microscopy of integrated circuits with angular spectrum and polarization control

We investigate the effect of an annular pupil-plane aperture in confocal imaging while using an NA increasing lens. We show that focal spot shape is highly sensitive to both polarization and angular spectrum of the incoming light. We demonstrate a lateral spatial resolution of 145 nm (λ0/9) in the direction perpendicular to the polarization direction. © 2009 Optical Society of America.