Direct current dechucking system

摘要

An electrostatic chuck, disposed within a processing chamber, receives a substrate and signals to selectively grip and release the substrate. A radio frequency power supply creates and passes a first signal to a first path that passes it to a high pass filter. The high pass filter inhibits signals lower than a first frequency from passing to the radio frequency power supply through the first path, and passes the first signal to a second path. The second path passes the first signal to a first electrode in the processing chamber, which emits the first signal within the processing chamber. A second electrode is also disposed within the processing chamber. The second electrode receives a second signal, and emits the second signal within the processing chamber. The emission of the first and second signals creates a plasma from the environment within the processing chamber. The processing of the substrate tends to create a residual charge in the substrate, and tends to inhibit the selective release of the substrate from the electrostatic chuck. A direct current power supply, connected to a ground, creates and passes an absolute signal to a third path. The third path passes the absolute signal to a low pass filter. The low pass filter passes the absolute signal to a fourth path, and inhibits signals higher than a second frequency from passing to the direct current power supply through the third path. The fourth path passes the absolute signal to the first electrode. The first electrode receives an absolute potential reference from the absolute signal. A controller selectively enables application of the first and second signals to the first and second electrodes, respectively. The controller also enables application of the grip and release signals to the electrostatic chuck. The controller further selectively energizes the direct current power supply to apply the absolute signal to the first electrode to reduce the residual charge in the substrate, enabling an easier release of the substrate from the electrostatic chuck.