Compound semiconductor activation energy in humidity

Product reliability investigations typically include accelerated humidity testing. Originally, the “standard” test was a biased 85 °C/85% relative humidity (RH) lifetest for 1000 h. Recently, a substitute accelerated version of this test has been used. The accelerated version is called highly accelerated stress test (HAST). The HAST conditions are also biased, at 130 °C, 85%RH, and approximately 18 PSI overpressure. The duration of the HAST test is normally 96–100 h – to be equivalent to the 85/85 test. This study is intended to investigate thermal acceleration and show that equivalent HAST tests on compound semiconductors are more highly accelerated and could be conducted with much shorter durations.