Thermal Accumulation Effects on the Transient Temperature Responses in LDMOSFETs Under the Impact of a Periodic Electromagnetic Pulse

Thermal accumulation effects in an LDMOSFET under the impact of a periodic electromagnetic pulse (EMP) are investigated using time-domain finite-element method combined with the preconditioned conjugated gradient technique. The transient thermal response in the LDMOSFET and its peak temperature are captured and compared, with different waveforms of the injected EMP chosen for computation. It is shown that, as the ratio of the pulsewidth and its periodicity increases, thermal accumulation effects on the transient thermal response as well as the peak temperature in LDMOSFETs are observable, which should be treated appropriately in the prediction of its electrothermal breakdown and reliability.