ELECTROSTATIC DISCHARGE DEVICES AND METHOD OF MAKING THE SAME

In one embodiment, electrostatic discharge (ESD) devices are disclosed. The ESD devices may include, among other things, a semiconductor substrate (25) of a first conductivity type and having a first doping concentration, the semiconductor substrate (25) having first and second surfaces; a first semiconductor layer (33) of a second conductivity type on the first surface of the semiconductor substrate (25), wherein the first semiconductor layer (33) has a first surface that is disposed between the first surface of the semiconductor substrate (25) and a second surface of the semiconductor layer, and wherein the first semiconductor layer (33) has a second doping concentration; a first semiconductor region (29) of the second conductivity type positioned between a first portion of the first semiconductor layer (33) and the first surface of the semiconductor substrate (25), the first semiconductor region (29) forming a zener diode (I 8) with dopants of the semiconductor substrate (25); and a first P-N diode formed ( 42) in the first semiconductor layer (33) and overlying a first portion of the first semiconductor region (29), wherein the first P-N diode is internal to a first isolation trench (35).