Wire Bonding Interconnects for High Temperature Silicon Carbide Electronics

We propose to investigate the use of new three-layer metallization schemes for wire bond pads to improve the reliability of wire bonding interconnects used in high temperature silicon carbide electronics. Current wire bonding technology does not have the ability to survive elevated temperatures (500" C) for extensive periods of time without failure by several mechanisms which include corrosion, oxidation, intermetallic formation, and metal creep. Metalization schemes for bond pads have three requirements which, if met, will result in an effective and reliable wire bond: (1) good adherence to the semiconductor including good electrical as well as mechanical contact; (2) the ability to block the diffusion of impurities both into and out of the semiconductor; and (3) the ability to provide a metallurgical compatability and a good bond to the wire material, in this case, gold wire. Our metallurgical schemes will meet all three of these criteria as well as the criteria of long term survivability at elevated temperatures. If time permits, we will also investigate the availability of high temperature wire materials other than gold, as well as the possibility of using photonics as an interconnect technology with a view to eliminating wire bonding issues altogether.