Frontside and backside pressure monitoring for substrate movement prevention

Abstract

A pressure control system includes a first sensor, a second sensor, an evacuation valve and a controller. The first sensor is configured to detect a frontside pressure within a processing chamber. The frontside pressure is indicative of a downforce on a substrate isposed on a substrate support within the processing chamber. The second sensor is configured to detect a backside pressure on a ackside of the substrate. The controller is configured to: control the evacuation valve to remove gas from and reduce the frontside pressure of the processing chamber; and during the removal of gas from a reduction in the frontside pressure of the processing chamber and based on the frontside pressure and the backside pressure, regulate an opening of the evacuation valve such that the frontside pressure does not drop below the backside pressure.

Dependencies are inferred from the claim text.