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Title: Nanoscale x-ray imaging of circuit features without wafer etching

Modern integrated circuits (ICs) employ a myriad of materials organized at nanoscale dimensions, and certain critical tolerances must be met for them to function. To understand departures from intended functionality, it is essential to examine ICs as manufactured so as to adjust design rules ideally in a nondestructive way so that imaged structures can be correlated with electrical performance. Electron microscopes can do this on thin regions or on exposed surfaces, but the required processing alters or even destroys functionality. Microscopy with multi-keV x-rays provides an alternative approach with greater penetration, but the spatial resolution of x-ray imaging lenses has not allowed one to see the required detail in the latest generation of ICs. X-ray ptychography provides a way to obtain images of ICs without lens-imposed resolution limits with past work delivering 20–40-nm resolution on thinned ICs. We describe a simple model for estimating the required exposure and use it to estimate the future potential for this technique. Here we show that this approach can be used to image circuit detail through an unprocessed 300-μm-thick silicon wafer with sub-20-nm detail clearly resolved after mechanical polishing to 240-μm thickness was used to eliminate image contrast caused by Si wafer surface scratches.more » Here, by using continuous x-ray scanning, massively parallel computation, and a new generation of synchrotron light sources, this should enable entire nonetched ICs to be imaged to 10-nm resolution or better while maintaining their ability to function in electrical tests.« less
 [1] ;  [2] ;  [3] ;  [3] ;  [3] ;  [4] ;  [4] ;  [5] ;  [6] ;  [7]
  1. Northwestern Univ., Evanston, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States)
  2. Northwestern Univ., Evanston, IL (United States)
  3. Argonne National Lab. (ANL), Argonne, IL (United States)
  4. Univ. of Southern California, Los Angeles, CA (United States)
  5. Intel Corp., Hillsboro, OR (United States)
  6. Intel Corp., Hillsboro, OR (United States); Micro Encoder, Inc., Kirkland, WA (United States)
  7. Argonne National Lab. (ANL), Argonne, IL (United States); Northwestern Univ., Evanston, IL (United States)
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 95; Journal Issue: 10; Journal ID: ISSN 2469-9950
American Physical Society (APS)
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); National Institutes of Health (NIH)
Country of Publication:
United States
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1348283