COMPLEX DYNAMICS OF CURRENT FILAMENTS IN THE LOW-TEMPERATURE IMPURITYBREAKDOWN REGIME OF SEMICONDUCTORS

The formation of spatial and spatiotemporal patterns (current filament s) in semiconductors in the regime of low-temperature impurity impact ionization is investigated theoretically. Our model yields stable fila ments, breathing filaments, and traveling filaments which show an inte rmittent spatiotemporal instability, resulting in chaotic oscillations of the average carrier density and of the current. The crucial role o f the dielectric relaxation of the transverse electric field is single d out. Different strategies for the numerical treatment are discussed.