Analytical model for an extended field plate effect on trench LDMOS with high-k permittivity

An analytical model for the extended field plate effect on trench LDMOS with high-k permittivity is presented in this paper. The RESURF criterion for the trench LDMOS with extended field plate is derived, both analytical and numerical results show the drift doping is increased with high-k dielectric layer. The analysis of the breakdown mechanism is researched, and an optimal design is achieved that the voltage supported by dielectric layer is equal to the voltage supported by the drift region. The relative dielectric coefficient of high-k materials are in the range of 4~12 when the thickness of the dielectric layer is below 600nm. The breakdown voltage is decreased for a too high permittivity of the high-k material.