Spatial temperature profiles due to nonuniform self-heating in LDMOS's in thin SOI

Temperature profiles resulting from self-heating in SOI-LDMOS devices with uniformly doped and linearly graded drift regions were measured using a resistance thermometry technique. Two-dimensional electrothermal device simulations were performed and the results agreed with the experiments. Because of the different power dissipation profiles, RESURF devices with a uniformly doped drift region assume a fairly uniform temperature distribution while devices with a linearly graded drift region have a much higher temperature rise near the source than the drain. This local hot spot near the source raises reliability issues in device design.