High Temperature Reliability of the SiC-MOSFET with Copper Metallization

We investigated the SiC-MOSFET with Cu metallization instead of conventional Al metallization to apply to high reliability power modules. As Cu has higher electrical and thermal conductivity, yield strength, and tolerance of its migration than those of Al, applying Cu to metallization and wire bonds will lead to longer lifetime for power modules. One of the major difficulties with Cu metallization is its high diffusivity into SiO2 and poly-Si which are used as gate oxide, interlayer oxide, and gate electrodes in SiC-MOSFETs, resulting in degradation of devices. We fabricated the SiC-MOSFET with Cu metallization and a diffusion barrier. We have successfully obtained good characteristics same as conventional Al metallization and demonstrated its high temperature reliability.