B. Nagabhirava

University at Albany, The State University of New York, New York City, NY, United States

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Publications (4)8.1 Total impact

  • Tianhua Yu, Eun-Kyu Lee, B. Briggs, B. Nagabhirava, Bin Yu
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    ABSTRACT: In this paper, we investigate key reliability limiting factors of bilayer graphene (BLG)/copper hybrid interconnect system by examining its current-induced breakdown behavior and BLG/Cu contact. The results show that BLG displays an impressive current-carrying capacity (~100 times that of Cu), and dc current-induced thermal annealing helps to significantly reduce the BLG/Cu contact resistance. Breakdown occurs with two different failure modes depending on stressing current density in each material subsystem, while contact damage dominates in scaled structure. The observed linear dependence of breakdown current on graphene geometry aspect ratio suggests Joule heating as the primary breakdown mechanism in graphene.
    IEEE Transactions on Nanotechnology 08/2011; · 1.80 Impact Factor
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    ABSTRACT: We report on the electromechanical robustness of graphene in an extreme condition of deformation: uniaxial bending. A large-angle-bent graphene monolayer was obtained with a predefined template. Structural/mechanical analysis is conducted, followed by electronic transport measurement. Raman spectroscopy analysis suggests negligible strain in the significantly bent graphene, showing mechanical robustness of the two-dimensional carbon nanostructure. The impact on band structure with respect to key deformation parameters (bending angle and curvature radius) were investigated using sp3 tight-binding simulation. Results show insignificant local band modification at bending locations. Even with extreme deformation, excellent carrier mobility in monolayer graphene is preserved.
    Applied Physics Letters 11/2010; 97(22):223102-223102-3. · 3.52 Impact Factor
  • Tianhua Yu, Eun-Kyu Lee, B. Briggs, B. Nagabhirava, Bin Yu
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    ABSTRACT: We investigate the key reliability limiting factors of bilayer graphene (BLG) under current stressing by examining the breakdown characteristics of BLG with chemical-mechanical planarization copper contacts. It is observed that dc current-induced thermal annealing helps to reduce the BLG-to-Cu contact resistance. Breakdown occurs with two noticeably different failure modes depending on local stressing current level, while copper contact damage dominates in scaled structure. The measured linear dependence of breakdown current on graphene width/length aspect ratio suggests Joule heating as the primary breakdown mechanism.
    IEEE Electron Device Letters 11/2010; · 2.79 Impact Factor
  • Tianhua Yu, Eun-Kyu Lee, B. Briggs, B. Nagabhirava, Bin Yu
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    ABSTRACT: Graphene is considered to be promising candidate for future transistor and interconnects material in integrated circuits because of its high intrinsic mobility and current-carrying capacity outperforming Cu. Particularly, bilayer graphene (BLG) systems offer controllable and wide band gap tunability without the need for nontrivial atomically precise nanoribbon patterning, which is indispensable to band gap engineering of monolayer graphene. Hence, novel devices consisting of BLG as both transistors and interconnects in combination with well-established Cu interconnects is conceivable. In this frame, this study has aimed to address reliability limiting factors of BLG/Cu contacts and current-carrying capacity.
    Reliability Physics Symposium (IRPS), 2010 IEEE International; 06/2010