Improved UHV IGBT−Cell for ESD Protection with High Holding Voltage via a 0.5µm BCD Process

CMOS technology can be applied to POWER MOSFET integrated Circuits(ICs) for vehicle power management system. However, the Electronic Discharged (ESD) reliability of the device is essential issue for Power MOSFETs. Because ESD failure is one of the most serious problem in the reliability of ICs and other electronic systems. In order to enhance the ESD capability of ultra-high voltage (UHV) lateral diffused MOS (LDMOS) devices, we designed an IGBT−like cell for a 0.5µm 300V BCD process. This paper proposed to improve the problem of low holding-voltage caused by IGBT−like cells. First, the drain side radius is decreased from 32.5µm to 19.5µm. Meanwhile, the drain side is divided into three partitions of circles. Then, the device drain side p ⁺ outer circle was floating. Finally, the holding voltage(V h ) of the reference device is improved 41% from 66.88V to 94.85V. Compared with the Reference UHV LDMOS, the second breakdown current(I t2 ) of the IGBT_PPN4 is increased from1.72A to 4.17A.