New ESD protection circuits based on PNP triggering SCR for advanced CMOS device applications

New silicon controlled rectifier (SCR) structures for ESD protection circuits, with low parasitic capacitance, are proposed. These new SCR structures are triggered by parasitic PNP (not NPN) transistor, with which the anode-cathode spacing (L
SCR
), the triggering voltage (V
TRIG
), the holding voltage (V
HOLD
), and the on-resistance (R
ON
) were reduced successfully, and excellent ESD performance was achieved