Relaxation Of High-energy Heavy-ion Induced Bipolar Plasmas In Si Epilayer Devices As A Function Of Temperature

摘要

The electronic energy loss of high-energy heavy ions striking a reverse biased junction in an electronic component designed for space induces an electron-hole pair (or bipolar) plasma with ultrahigh injection levels contained within an ionization column of submicron radial dimensions. The relaxation of this highly nonequilibrium plasma induces a large transient current on nodes coupled to the field which propagate down through external circuits, the ramification of which in some devices depends on the transient pulse shape. Pulse shape depends on the bipolar plasma decay under space-charge screening conditions, which is itself a complex function of various parameters including the junction structure, injection level, and ambipolar diffusivity. In this paper we consider the Edmonds model for describing carrier collection in a Si p~+-n-n~+ epilayer structure as a function of temperature. Experimental data collected from 90 to 300 K are used to examine bipolar plasma dispersion with temperature and confirm the Edmonds model.