Improved breakdown-voltage complementary MOSFET in a 0.18µm standard CMOS process for switch mode power supply (SMPS) applications

In this paper, a novel improved breakdown-voltage (BV) complementary MOSFET for SMPS applications is introduced in a standard 0.18µm VLSI (Very Large Scale Integration) process without any extra processes. Proposed NMOS and PMOS breakdown voltages have been improved up to 22.6V (∼3.5-times increase) and 13.2V (∼2-times increase) each. And the merged-charge effect (charge-coupling) through STI (Shallow Trench Isolation) which contributes to the higher breakdown voltage in a standard CMOS process is explained. A novel higher breakdown voltage CMOS shows the lowest FOMs among the same voltage rate devices good enough for high-frequency and low power applications. Finally, novel improved BV devices are integrated as power switches with VLSI low-voltage CMOS for SMPS applications. And ISE-TCAD and Cadence-SPICE simulations show that the designed monolithic buck-converter including parasite components achieves 88% high-efficiency.