Dummy-gate structure to improve ESD robustness in a fully-salicided 130-nm CMOS technology without using extra salicide-bloc king mask

Abstract

NMOS with dummy-gate structure is proposed to significantly improve electrostatic discharge (ESD) robustness in a fully-salicided CMOS technology. By using this structure, ESD current is discharged far away from the salicided surface channel of NMOS, therefore the NMOS can sustain a much higher ESD level. The HBM (MM) ESD robustness of the NMOS with dummy-gate structure (W/L = 480 mu m/0.18 mu m) has been successfully improved from 0.5 kV (125 V) to 1.5 W (325 V) in a 130-nm fully-salicided CMOS process. Under the same layout area of the gate-grounded NMOS (ggNMOS), HBM (MM) ESD level can be improved over 300% (260%) by the proposed dummy-gate structure. The proposed dummy-gate structure is fully process compatible to general salicided CMOS processes without additional mask which is very cost-efficient for application in the IC products.