A SHORT-TERM HIGH-CURRENT-DENSITY RELIABILITY INVESTIGATION OF ALGAASGAAS HETEROJUNCTION BIPOLAR-TRANSISTORS/

In high current and power density applications of AlGaAs/GaAs heteroju nction bipolar transistors (HBT's), reliability is a critical issue, T herefore, in this letter we show results of a fundamental investigatio n on the temperature and current dependence of the fast initial rise o f the dc-current gain (burn-in), which takes place during stress at cu rrent densities beyond those of today's applications. We find that the burn-in occurs at lower device junction temperatures (135 degrees C) than previously reported in literature, and that it depends linearly o n the current density. An activation energy of 0.4 eV is extracted for the burn-in effect.