Comparative analysis of accelerated ageing effects on power RF LDMOS reliability

We present in this paper results of comparative reliability study of three accelerated ageing tests applied on power RF LDMOS: Thermal Shock Tests (TST, air-air test), Thermal Cycling Tests (TCT, air-air test) and High Temperature Storage Life (HTSL). The two first tests are carried out with a drain current flowing through the device during stress. The results obtained show the variation and the Device's performance quantitative shifts for some macroscopic electric parameters such as threshold voltage (Vth), transconductance (Gm), drain-source current (Ids), on-state resistance (Rds_on) and feedback capacitance (Crs) under various ageing tests. To understand the degradation phenomena that appear after ageing, we used a new electro-thermal model implemented in Agilent's ADS as a reliability tool.