Channel- Drift Region's STI-Lengths Impacts of ESD Immunity in HV 60 V nLDMOS Devices

摘要

In this paper, the channel length and drift region's STI length modulations have been realized by a TSMC 0.25- μm 60-V high voltage n-LDMOS process to evaluate its ability of ESD improvement. It can found that both the modulations of channel length and drain-side STI length can improve the ESD capability of nLDMOSs. With the channel-length extension, the secondary breakdown current (It2) can be increased from 1.89A to 2.23A (improved 17.99%) compared with the reference device; and with the STI-length extension of the drift region can upgrade the value of It2 from 1.89A in the reference group to 2.13A (improved 12.7%). As the lengths of channel and drain-side STI increasing, the higher series resistance of this device can effectively suppress the ESD transient current. It is also resulting in source and drain electrodes not easy to fail for a contact spiking, which makes the secondary breakdown current (It2) improved.