A bending N-Well ballast layout to improve ESD robustness in fully-silicided CMOS technology

Ballast technique has been reported as a cost effective method to improve ESD robustness of fully-silicided devices without using silicide block. In this work, a new ballast technique, the bending N-Well (BNW) ballast structure, is proposed to enhance ESD robustness of fully-silicided NMOS. With a deep N-Well to cover the fully-silicided NMOS with BNW ballast structure, ESD robustness of the NMOS can be further improved by enhancing the turn-on uniformity among the multi-fingers of the NMOS.