Substrate biasing circuit that utilizes a gated diode to set the bias on the substrate

摘要

A substrate biasing circuit utilizes a gated diode and a detection transistor to set the potential on a substrate to a desired substrate bias level. The potential on the substrate is set to the desired substrate bias level by applying a series of pulses to the gated diode. Each of the pulses applied to the gated diode causes a fixed amount of charge to be injected into the substrate. When the potential on the substrate has reached the desired substrate bias level, the pulses are insufficient to cause any further charge to be injected into the substrate. The detection transistor is used to determine when the potential is at the desired substrate bias level by biasing the transistor to output a current that corresponds to the potential on the substrate.