Self-heating effect in lateral DMOS on SOI

The self-heating effect in an SOI LDMOS device, originating from the low thermal conductance of the buried silicon dioxide, was investigated under steady-state conditions. It is found that the temperature increase inside a device built in a 1 μm silicon over 2 μm buried oxide can be as high as 40°C at a power level of 3 W/mm ². The effective thermal resistances of the devices are found to increase with buried oxide thickness and decrease with silicon thickness. Two-dimensional thermal simulations with device simulator MEDICI are performed and the results are consistent with the experiments