Comparison of Two and One-Photon Optical Beam-Induced Current Imaging Through the Backside of Integrated Circuits

Optical beam induced current (OBIC) imaging through the back sides of integrated circuits is investigated in the wavelength (lambda) region from 1.15 to 1.26 microns. With a sub-picosecond excitation source and approximately 1 mW at the sample, the two-photon contribution to the generated photocurrent dominates at lambda=1.25 microns and becomes negligible for lambda