Room Temperature KlettWelding Interconnect Technology for High Performance CMOS Logic

Abstract

In this work we report a novel room temperature bonding technology based on metallic NanoWires, so-called KlettWelding. This technology can be used for bonding Flip-Chips with down to $5\ \mu\mathrm{m}$ edge length bumps and fine pitches less than $8 \mu\mathrm{m}$. The process is expected to work for die to wafer (d2w) or wafer to wafer (w2w) bonding. The required bonding pressures range from 1 to 15 MPa for flip chips, Diodes, IGBT, MOSFETS, $\mu \mathrm{C}$, Video chips, LEDs and sensors. The measured shear strength of these connections yields 15 to 60 MPa. Such contacts have shown in the first results a high thermal conductance in the range of 350 W/mK. Also, the connections can tolerate temperatures higher than 500 °C.