Influence of Joule heating on current filaments induced by avalanche injection.

The influence of Joule heating on current filaments evolving during the reverse recovery phase in high-power diodes is analysed by electro-thermal simulations. Depending on the turn-off conditions, transitions of the uniform current-density distribution into a quasi-static filament, a travelling filament, or a periodic current-density distribution may occur. Simulations show under which conditions a pure electronic mechanism or Joule heating may cause the evolution of travelling current filaments. In general, strong local heating favours the transition of static into travelling structures. Under certain conditions, the simultaneous activation of the electronic and the thermal mechanism may lead to the coexistence of filaments travelling with different velocities. [ABSTRACT FROM AUTHOR]