Metal Thermocompression Wafer Bonding for 3D Integration and MEMS Applications

Autor: Dragoi, Viorel, Mittendorfer, Gerald, Burggraf, Jürgen, Wimplinger, Markus
Zdroj: ECS Transactions; October 2010, Vol. 33 Issue: 4
Abstrakt: Metal bonding layers are used in various wafer bonding applications in MEMS and more recent in wafer-level 3D integration and optoelectronics. The bond process investigated in this paper is thermocompression. The most used metals for such applications are Cu, Au and Al, each of them with specific requirements for the wafer bonding process. While Au use doesn't face the problem of surface oxidation, both Cu and Al surfaces are covered by native oxides when exposed to ambient atmosphere: the oxidized surfaces impact on bonding process results, so their condition is crucial for successful process. The main process conditions for Cu-Cu and Al-Al bonding are reviewed and examples are presented.
Databáze: Supplemental Index