Thin partial SOI power devices for high voltage integrated circuits

The forward blocking characteristics of lateral SOI power devices on a very thin (less than or equal to 0.5 mum) silicon layer are analysed. It is known that SOI power devices suffer from reduced breakdown voltage due to the less efficient RESURF effect. Partial SOI technology results in a higher breakdown capability. In addition, partial SOI devices do not require the drift region to be linearly graded. Moreover, the self-heating effect in partial SOI devices is drastically reduced since the patterned oxide layer is very thin and heat can dissipate via the silicon window to the substrate, which also helps to distribute the temperature more evenly in the drift region. It is concluded that thin partial SOI power devices could be strong candidates for high voltage ICs (HVICs).