1.
Opt Express
; 16(13): 9501-6, 2008 Jun 23.
Article
in English
| MEDLINE
| ID: mdl-18575515
ABSTRACT
We apply the numerical aperture increasing lens technique to widefield subsurface imaging of silicon integrated circuits. We demonstrate lateral and longitudinal resolutions well beyond the limits of conventional backside imaging. With a simple infrared widefield microscope (lambda(0) = 1.2 microm), we demonstrate a lateral spatial resolution of 0.26 microm (0.22 lambda(0)) and a longitudinal resolution of 1.24 microm (1.03 lambda(0)) for backside imaging through the silicon substrate of an integrated circuit. We present a spatial resolution comparison between widefield and confocal microscopy, which are essential in integrated circuit analysis for emission and excitation microscopy, respectively.