As disclosed herein, an electrostatic discharge (ESD) protection circuit is provided
for an integrated circuit including a semiconductor substrate. The ESD protection
circuit includes a plurality of active devices formed in the semiconductor substrate,
the active devices being formed by a process including a plurality of steps carried
out to form, at the same time, a plurality of active devices having a function
other than ESD protection. For example, the ESD circuit may include an array of
vertical transistors formed according to a process including many of the steps
used to form, at the same time, vertical transistors of a DRAM array. Also disclosed
is the formation of an ESD circuit in an "unusable" area of a semiconductor chip,
such as under a bond pad, land or under bump metallization of the chip.