Thermal Behavior of SiC Power Diodes

Abstract

The electro-thermal characteristics of 1.2 kV SiC diodes are investigated in this paper. SBD and JBS diodes with different P+/N area ratio have been fabricated with Ti/Ni and Tungsten anode contact metals, which are able to work at high temperature (300ºC). Novel solutions are proposed for improving the thermal behavior of SiC JBS turn-off process, surge current and power cycling. Forward, reverse and switching characteristics are analyzed in the 25ºC-300ºC temperature range. Furthermore, to get SiC diodes able to operate up to 300ºC, different technological approaches have been considered, mainly concerning interconnection techniques and metallization layers to reduce the package thermal resistance. This work makes also a comparison of various interconnection techniques: Al wedge bonding on Al metallization, Au ball bonding on Au metallization and the press-pack encapsulations. The press-packaged SiC diodes are highly stable, showing no degradation after 650,000 power cycles.