High-Voltage 3-D Partial SOI Technology Platform for Power Integrated Circuits

A partial silicon on insulator (PSOI) is a widely recognized technology suitable for high-voltage (HV) architectures for power integrated circuits (PICs). Despite the added process complexity compared with SOI reduced surface field (RESURF), this technology offers a wider range of voltage ratings due to the action of the depletion layer in the handle wafer (HW), reduced parasitic capacitances
due to the extra volume of the depletion region in the HW, and better heat conduction due to thinner buried oxide layer. The newly developed platform technology, featuring 3-D designs to fully utilize the PSOI potential, is particularly relevant to the manufacturing of HV integrated circuits (HVICs) where low ON-state resistance and reduced self-heating are essential requirements. This work presents
a PSOI technology platformwith the voltage ratings ranging from 45 to 400 V while providing low ON-state resistance, good hot carrier injection stability, as well as electrostatic discharge (ESD) capability of the HV devices. For example, for a 375-V rated laterally diffused MOSFET (LDMOSFET), this technology achieves an ON-state resistance of 1435mmm2, an over 50% improvement comparedwith the
state-of-the-artSOI technologies whilemaintaining competitive reliability.