800-V Wiring for HVIC Application using Biased Polysilicon Field Plates

Biased polysilicon field plates [1] are used to achieve 800-V wiring in a typical junction isolated, high voltage integrated circuit. The field plates are biased by phosphorous doped polysilicon resistors, connected in a voltage division scheme to the high voltage wire. The effect of using doped (as opposed to undoped), polysilicon resistors on field plate potential distribution is investigated. It is found that a 1.5 ¿m TEOS film is an adequate inter-layer dielectric for 800-V operation.