Silicon-controlled rectifier

PURPOSE: To provide field-implantation process used to regulate the operating characteristic of a silicon-controlled rectifier(SCR). CONSTITUTION: An integrated circuit formed on a semiconductor substrate has a contact pad 20 for communicating a signal between an external device and an internal signal line 22. This pad 20 is protected by a silicon-controlled rectifier 28 for conducting a static discharge pulse from the pad directly to a current sink. This silicon-controlled rectifier includes a small region, into which a high concentration dopant is implanted under a field oxide. A device 23 having this field implanted layer lowers the trigger voltage of the silicon- controlled rectifier, and as a result, the silicon-controlled rectifier triggers before the static pulse discharge gives rise to latch up or damage in the other device within the integrated circuit. COPYRIGHT: (C)1995,JPO