Abstract: An Electro-Static-Discharge (ESD) protection device has a Fin Field-Effect Transistor (FinFET) with a silicon fin with a step separating a top fin and a bottom fin. The gate wraps around the top fin but not the bottom fin. Normal gate-controlled channel conduction occurs in the top fin between a source and a drain in the top fin. Underneath the conducting channel is a buried conducting region in the bottom fin that conducts after a breakdown voltage is reached during ESD. A ledge, abrupt slope change in the sidewalls of the fin, or a doping increase occurs at the step between the top fin and bottom fin. The bottom fin is 2-3 times wider than the top fin, causing the resistance of the buried conducting region to be 2-3 times less than the resistance of the conducting channel, steering breakdown current away from the channel, reducing failures during breakdown.

Abstract: An Electro-Static-Discharge (ESD) protection device has a Fin Field-Effect Transistor (FinFET) with a silicon fin with a step separating a top fin and a bottom fin. The gate wraps around the top fin but not the bottom fin. Normal gate-controlled channel conduction occurs in the top fin between a source and a drain in the top fin. Underneath the conducting channel is a buried conducting region in the bottom fin that conducts after a breakdown voltage is reached during ESD. A ledge, abrupt slope change in the sidewalls of the fin, or a doping increase occurs at the step between the top fin and bottom fin. The bottom fin is 2-3 times wider than the top fin, causing the resistance of the buried conducting region to be 2-3 times less than the resistance of the conducting channel, steering breakdown current away from the channel, reducing failures during breakdown.

Abstract: A power-to-ground clamp transistor provides electrostatic discharge (ESD) protection. A filter capacitor and resistor generate a filter voltage that is buffered by three stages to drive the gate of the clamp transistor. The filter capacitor is about twenty times smaller than in a conventional clamp circuit. Feedback in the circuit keeps the clamp transistor turned on after the R-C time constant of the capacitor and resistor in the filer has elapsed, allowing for a smaller capacitor to turn on the clamp transistor longer. A sub-threshold-conducting transistor in the first stage conducts only a small sub-threshold current, which extends the discharge time of the first stage. The gate of the sub-threshold-conducting transistor is driven by feedback from the second stage. A feed-forward resistor has a high resistance value to slowly raise the voltage of the second stage from the filter voltage, and thus slowly raise the gate of the sub-threshold-conducting transistor.

Abstract: A power-to-ground clamp transistor provides electrostatic discharge (ESD) protection. A filter capacitor and resistor generate a filter voltage that is buffered by three stages to drive the gate of the clamp transistor. The filter capacitor is about twenty times smaller than in a conventional clamp circuit. Feedback in the circuit keeps the clamp transistor turned on after the R-C time constant of the capacitor and resistor in the filer has elapsed, allowing for a smaller capacitor to turn on the clamp transistor longer. A sub-threshold-conducting transistor in the first stage conducts only a small sub-threshold current, which extends the discharge time of the first stage. The gate of the sub-threshold-conducting transistor is driven by feedback from the second stage. A feed-forward resistor has a high resistance value to slowly raise the voltage of the second stage from the filter voltage, and thus slowly raise the gate of the sub-threshold-conducting transistor.