Transmissive high-resolution small-angle neutron and x-ray scattering, and grazing-incidence small-angle x-ray scattering are used to characterize the structure of designed surface patterns created by advanced nanofabrication methods. With these methods, many feature dimensions important for electronic and other applications can be quantitatively determined. The potential for this approach has been demonstrated on arrays of lines as well as rectangular holes etched into oxide layers to measure their pitch or the repeat distance, line profile, and line edge roughness. A silicon wafer with a nominal thickness of approximately 1 mm is sufficiently transparent to allow a simple transmission scattering measurement. Many orders of diffraction peaks have been obtained from patterns with a total average pitch ranging from 200 nm to several micrometers. An important advantage of a scattering based metrology is its excellent extensibility. In contrast to existing metrologies, these measurements become easier as the feature size continues to decrease into the sub-100 nm regime. Research projects include the analysis of scattering from nanoscale structures consisting of disparate materials, determination of the fundamental properties of fabricated nanostructures, and the investigation of patterned, nanostructured materials.

 

key words

Nanofabrication; Nanoscale patterns; Neutron scattering; Photolithography; Polymer nanostructures; X-ray scattering;

Citizenship:  Open to U.S. citizens

Level:  Open to Postdoctoral applicants