A new two dimensional analytical breakdown model of SOI RESURF devices

In this paper, a new breakdown model of SOI RESURF devices is proposed based on solving 2-D Poisson equation. The approach explores the physical insights of the lateral and vertical breakdowns for both of the completely and incompletely depleted drift regions. Analytical 2-D electrostatic potential and electric fields distributions are compared with the simulating results by MEDICI, The impacts of the geometry parameters on the breakdown voltage are also investigated by the analytical model and numerical simulation. A well agreement between the analytical and simulating results proofs the availability of the model. Finally, as a further experimental verification, LDMOS with a breakdown voltage of 220 V was fabricated on a bonding SOI wafer with a top silicon thickness of 3.0 mum and a buried oxide thickness of 1.5 mum.