Nanoscale Imaging of Buried Structures via Scanning Near-Field Ultrasound Holography
Gajendra S. Shekhawat1,2 and
Vinayak P. Dravid1,2,3*
A nondestructive imaging method, scanning near-field ultrasound
holography (SNFUH), has been developed that provides depth information
as well as spatial resolution at the 10- to 100-nanometer scale.
In SNFUH, the phase and amplitude of the scattered specimen
ultrasound wave, reflected in perturbation to the surface acoustic
standing wave, are mapped with a scanning probe microscopy platform
to provide nanoscale-resolution images of the internal substructure
of diverse materials. We have used SNFUH to image buried nanostructures,
to perform subsurface metrology in microelectronic structures,
and to image malaria parasites in red blood cells.
2 NUANCE Center,
3 Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, USA.
* To whom correspondence should be addressed. E-mail: v-dravid{at}northwestern.edu
