Currents of individual avalanches in the space-charge region of a p-n junction

The passage of separate electron-hole avalanches, previously known for microplasma, at the start of breakdown in a large-area, planar-homogeneous p-n junctions has been observed. From the results obtained, it is concluded that the impact-ionization current is localized in front of the onset of a breakdown, and that avalanches appear in the now channel of this current. The dimensions of the avalanches are estimated, and the decrease in the impact-ionization current after the passage of a sufficiently long-lived n avalanche is explained. (C) 1996 American Institute of Physics.