ELECTROSTATIC DISCHARGE PROTECTION APPARATUS

摘要

PROBLEM TO BE SOLVED: To reduce the latch up incidence of an ESD structure by suppressing the injection of minority carriers in one or both parasitic bipolar transistors, components unique to the ESD structure. SOLUTION: An ESD structure 300 has some semiconductor diffused regions substituted by contacts 316, 320, 328 which form Schottky barrier diodes with underlying semiconductor diffused regions. The Schottky barrier diode is a majority carrier device with a few of minority carriers when being forward biased. This suppresses the possible bipolar operation from bringing up the latch up in the ESD structure. Since the SDB is a majority carrier device, a very few of minority carrier will be injected when the SBD is forward biased, thus preventing the latch up.