Invited by the Department of Optical Science and Engineering, Professor Min-Feng Yu in the School of Aerospace Engineering at Georgia Institute of Technology is paying a visit to the School of Information Science and Technology, Fudan University from June 13 to July 5, and provided a lecture titled “Direct Writing of Wire Bonds with Sub-Micron Dimensions” on June 15.

The increasing device density in IC has led to exponential growth in the density of interconnects and the complexity of their design.  With the introduction of three-dimensional (3D) chip architecture, interchip vias constitute one method to integrate devices in 3D stacks, but alternative interconnect technologies that can provide flexible means to electrically wire microscale device components in three dimensions are still required. In this talk, we introduce a “direct-write” method for metal wires to demonstrate an automated wire-bonding process that enabled Cu and Pt wire diameters of less than 1 micrometer and bond sizes of less than 3 micrometers, with a breakdown current density of more than 1011 amperes per square meter for the wire bonds.  This new technology thus provides a brand new route to downscale interconnects to very fine pitches on the order of a few micrometers.  In addition, the technology makes possible many new strategies for fabricating ultra-high-density and high-quality 3D microscale and nanoscale structures with designed structural and device functionalities, Professor Yu introduced in his lecture.