Electrical Characteristics of Solder-Free SiC Die/Metal Foil/AlN Plate Junctions Fabricated Using Surface Activated Bonding

Abstract

SiC die/Al foil/AlN junctions are successfully fabricated by using surface activated bonding, i.e., without using solders. No structural defects are observed in Al/AlN interfaces. We measure current-voltage characteristics of Schottky diodes, which are fabricated on the SiC die before bonding, by applying bias voltages between Schottky contacts and the surface of Al foil that is connected to ohmic contacts. Schottky diodes normally operate at junction temperatures up to 300 °C. No change is observed in appearance of the SiC die/Al foil/AlN junction even after the measurement at 300 °C. Parasitic resistances get larger after the measurement at 300 °C, which is assumed to be due to the possible oxidation of surfaces of Al foil.

Low-loss characteristics of coplanar waveguides fabricated by directly bonding metal foils to high-resistivity Si substrates

“…The direct bonding of metals based on the surface activated bonding (SAB) technologies 14,15) were applied for realizing three-dimensional integration of semiconductor chips 16) and packaging advanced micro electron mechanical systems. 17) We previously bonded metal foils to Si 18) and SiC 19) substrates as well as AlN plates 20) using SAB to investigate the possibility of foils as low-resistance contacts and interconnect layers. We also bonded Al foils with t of 17 μm to sapphire substrates and fabricated CPWs and inductors.…”