Alexander Ciliox

Reliability aspects of copper metallization and interconnect technology for power devices

Abstract The introduction of thick copper metallization and topside interconnects as well as a superior die attach technology is improving the performance and reliability of IGBT power transistor technologies significantly. The much higher specific heat capacity and higher thermal conductivity increases the short circuit capability of IGBTs, which is especially important for inverters for drives applications. This opens the potential to further optimize the electrical performance of IGBTs for higher energy efficiency. The change in metallization requires the introduction of a reliable barrier against copper diffusion and copper silicide formation. This requires the development of an efficient test method and reliability assessment according to a robustness validation approach. In addition, the new metallization enables interconnects with copper bond wires, which yield, together with an improved die attach technology, a major improvement in the power cycling capability.