Power cycling capability of silicon low-voltage MOSFETs under different operation conditions

Silicon low-voltage MOSFETs with a breakdown voltage lower than 80 V were tested for lifetime estimation under different operation conditions. The on-state resistance for these devices is very low; therefore, a special power cycling method with switching and conduction losses is used to be able to reach high temperature swings. These results are compared with the power cycling capability of inverse diodes and MOSFETs with reduced gate voltage under standard test conditions. The results with switching losses indicate a significantly higher lifetime compared to the other operation conditions. A simulation was performed to investigate the behavior. The temperature and current density distribution differ extremely due to different temperature coefficients. This leads to lower thermal-mechanical stress for the devices in switched mode and therefore to a higher lifetime as well.