Reliability study of power RF LDMOS device under thermal stress

This paper presents the results of comparative reliability study of two accelerated ageing tests for thermal stress applied on power RF LDMOS: Thermal Shock Tests (TST, air-air test) and Thermal Cycling Tests (TCT, airair test) under various conditions (with and without DC bias, TST cold and hot, different extremes temperatures ∆T). The performances shift for some critical electrical parameters such as on-state resistance (Rds_on) and feedback capacitance (Crs) have been demonstrated under various tests. To better understand the parameter shift that appear after thermal stress, we used a physical simulation software (Silvaco-Atlas, 2D) to confirm qualitatively degradation phenomena.