Buried air gap structure for improving the breakdown voltage of SOI power MOSFET's

A novel SOI power MOSFET employing a buried air gap structure (BAGS) is proposed and verified by numerical simulation. Higher breakdown voltage is achieved in proposed structure than conventional ones, because the buried air gap reduces the vertical electric field near the drain junction efficiently. It is shown that the drain-substrate capacitance is reduced due to the low dielectric constant of the buried air gap.