Degradation Processes in the Aluminum-Silicon System Induced by Pulsed Electric Signals

Thermal conditions in a metallization layer deposited onto a single crystal silicon substrate were studied during the passage of single electric pulses with a current density of j=(1–8)×10¹⁰ A/m² and a duration of τ=50–800 μs. Mechanisms of the irreversible degradation in the aluminum-silicon contact under the pulsed current action are established. The degradation is manifested by the contact melting and the metallization layer fusion. Methods for the identification of these phenomena and determination of the critical current densities j_k are proposed. The critical current density depends on the current pulse duration as described by the relationship $$j_k \sim 1/\sqrt[4]{\tau }$$ . It is established that the passage of single current pulses with j≥5×10¹⁰ A/m² and τ≥200 μs leads to the formation of linear defects in the region of maximum temperature gradient in the test structure.