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Title: The impact of metal line reflections on through-wafer TPA SEE testing

Charge-collection experiments and simulations designed to quantify the effects of reflections from metallization during through-wafer TPA testing are presented. The results reveal a strong dependence on metal line width and metal line position inside the SiO 2 overlayer. The charge-collection enhancement is largest for the widest metal lines and the metal lines closest to the Si/SiO 2 interface. The charge-collection enhancement is also dependent on incident laser pulse energy, an effect that is a consequence of higher-order optical nonlinearities induced by the ultrashort optical pulses. However, for the lines further away from the Si/SiO 2 interface, variations in laser pulse energies affect the charge-collection enhancement to a lesser degree. Z-scan measurements reveal that the peak charge collection occurs when the axial position of the laser focal point is inside the Si substrate. There is a downward trend in peak collected-charge enhancement with the increase in laser pulse energies for the metal lines further away from the Si/SiO 2 interface. Metallization enhances the collected charge by same amount regardless of the applied bias voltage. In conclusion, for thinner metal lines and laser pulse energies lower than 1 nJ, the collected charge enhancement due to metallization is negligible.
 [1] ;  [2] ;  [3] ;  [4] ;  [4] ;  [4] ;  [5]
  1. Sotera Defense Solutions, Herndon, VA (United States)
  2. George Washington Univ., Washington, D.C. (United States)
  3. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
  4. U.S. Naval Research Lab., Washington, D.C. (United States)
  5. Vanderbilt Univ., Nashville, TN (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 0018-9499; 604023
Grant/Contract Number:
Accepted Manuscript
Journal Name:
IEEE Transactions on Nuclear Science
Additional Journal Information:
Journal Volume: 62; Journal Issue: 6; Conference: Proposed for presentation at the Nuclear and Space Radiation Effects Conference, Boston, MA (United States), 13-17 Jul 2015; Journal ID: ISSN 0018-9499
Institute of Electrical and Electronics Engineers (IEEE)
Research Org:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA)
Country of Publication:
United States
36 MATERIALS SCIENCE; two-photon absorption; charge generation; charge-collection enhancement; etalon effect; laser testing; multiple reflections; reflected laser light intensity; TPA; transmitted laser intensity
OSTI Identifier: