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

This paper presents preliminary results of a copper—based Direct Bond Interconnect (DBI®) 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 DBI® interconnections on a 25 micron pitch with a 125°C thermal budget and 10 micron pitch 3D copper DBI® interconnections with a 350°C thermal budget. DBI® contact resistance and resistivity achieved are ≪ 50 mOhm / connection and ≪ 0.45 Ohm-um 2 , respectively, using three or four micron diameter Cu DBI® plugs and a TiW barrier layer. Reliability results include bare die that pass temperature cycling and HAST JEDEC tests.