Comparison of high voltage devices for power integrated circuits

A variety of lateral high voltage devices has been investigated for applications in power ICs, including RESURFed LDMOS transistors, merged bipolar-MOS transistors (LBMOS) and insulated gate rectifiers (LIGR). The devices are described and compared on the basis of current handling capability and switching speed. It is shown that for low load currents, the LDMOS exhibits superior performance, while for high load currents, the LIGR is advantageous, and the LBMOS shows only marginal improvement over the LDMOS at current gain of 5. In terms of switching, the LBMOS switches in 1-3 µsec, the LIGR in 3-10 µsec, and the LDMOS in tens of nsec. depending on the bias condition. The role of the substrate in lateral devices is also discussed.