GATE DIELECTRIC BREAKDOWN PROTECTION DURING ESD EVENTS

摘要

Protection circuits, design structures, and methods for isolating the gate and gate dielectric of a field-effect transistor from electrostatic discharge (ESD). A protection field-effect transistor is located between a protected field-effect transistor and a voltage rail. Under normal operating conditions, the protection field-effect transistor is saturated so that the protected field-effect transistor is coupled to the voltage rail. The protection field-effect transistor may be driven into a cutoff condition in response to an ESD event while the chip is unpowered, which increases the series resistance of an ESD current path between the gate of the protected field-effect transistor and the voltage rail. The voltage drop across the protection field-effect transistor may reduce the ESD stress on the gate dielectric of the protected field-effect transistor. Alternatively, the gate and source of an existing field-effect transistor are selectively coupled provide ESD isolation to the protected field-effect transistor.