Low voltage programmable storage element.

摘要

A programmable storage element for redundancy-programming includes a programmable antifuse circuit which includes a plurality of first resistors (F1a, F1b, F1c) and a switching circuit (QFa, QFb, QFc, QFd) for coupling the first resistors in series in response to a plurality of first control signals (Ta, Tb, Tc, Td) and for coupling the first resistors in parallel in response to a plurality of second control signals to permit programming of the first resistors, and a sensing circuit for determining whether or not the first resistors have been programmed. The state of the first resistors is determined by comparing a first voltage drop across the first resistors with a second voltage drop across a second resistor. Each of the first resistors is an unsilicided polysilicon conductor which has an irreversible resistance decrease when a predetermined threshold current is applied for a minimum period of time.