Low Cost of Ownership scalable copper Direct Bond Interconnect 3D IC technology for three dimensional integrated circuit applications

Abstract

This paper presents preliminary results of a copper-based direct bond interconnect (DBIreg) 3D integration process that has been developed to leverage foundry standard copper dual damascene and Ziptronix bond technology to achieve scalable, very low Cost-of-Ownership, 3D interconnects with minimum foundry adoption barrier. Results achieved include 100% operable arrays of 72,500 3D copper DBIreg interconnections on a 25 micron pitch with a 125degC thermal budget and 10 micron pitch 3D copper DBIreg interconnections with a 350degC thermal budget. DBIreg contact resistance and resistivity achieved are < 50 mOhm / connection and < 0.45 Ohm-um <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , respectively, using three or four micron diameter Cu DBIreg plugs and a TiW barrier layer. Reliability results include bare die that pass temperature cycling and HAST JEDEC tests.