Heating mechanisms of LDMOS and LIGBT in ultrathin SOI

Temperature rises due to self-heating in silicon-on-insulator (SOI) power devices may lead to performance degradation and reliability problems. This letter investigates the mechanisms and spatial distribution of heat generation in linearly graded SOI LDMOS and LIGBT devices. While Joule heating dominates in LDMOS devices, hole collection at the p-well-drift region junction contributes strongly to the heating of LIGBT's. Also, the presence of both Joule and recombination heating makes the heating profile more uniform in LIGBT's. These effects combine to yield a temperature rise in LIGBT's that is more uniform and lower on average than that in LDMOS devices.