DC Biased Field Plate RESURF for Further R-DSON Reduction of LDMOS Transistors

A new RESURF variant concept termed DC Biased Field Plate RESURF (BFP-RESURF) is proposed and studied through TCAD simulation in this work. The new LDMOS device structure features multiple field plates over the drift region that are biased at constant voltages. Significant reduction of R-DSON can be achieved by a more ideal electric field profile and an accumulation channel induced by the BFPs. Simulation study indicates that the new BFP-LDMOS offers a specific R-DSON of 58 m Omega center dot mm(2) comparing to 91 m Omega center dot mm(2) of the conventional LDMOS, a 1.6X reduction at a BV of 100V. The concept could be further extended to a wider range of BV ratings, the Rdson benefit becomes more pronounced as BV goes higher. The switching performance shows no obvious difference between the BFP and standard LDMOS. The BFP-RESURF concept is completely compatible with conventional BCDMOS processes and scalable over a wide range of voltage ratings.