Gate-grounded NMOS (ggNMOS) transistors have widely served as electro-static discharge (ESD) protection devices for integrated circuits. The layout strategy of ggNMOS greatly influences its ESD protection characteristics. Layout strategies forvariation of the number of substrate-pickup stripes are investigated in this paper. Direct current and transmission-line pulsing test results are presented to verify that adjustable holding voltages are accessed by variation of the number of substrate-pickup stripes. The design with two evenly distributed substrate-pickup stripes among different fingers is found to exhibit the highest second break current and optimal width-scaling characteristics.
['Guangyi Lu', 'Yuan Wang', 'Lizhong Zhang', 'Jian Cao', 'Song Jia', 'Xing Zhang']
Investigation on the layout strategy of ggNMOS ESD protection devices for uniform conduction behavior and optimal width scaling