Abstract: Broadly speaking, an invention is provided for monitoring a plasma optical emission. More specifically, the present invention provides a method for monitoring the plasma optical emission through a variable aperture to detect an endpoint of a plasma etching process without interferences that could lead to false endpoint calls. The method includes collecting optical emission data from a plasma through an aperture defined by moveable members. The moveable members are capable of varying a configuration of the aperture. The method also includes holding the moveable members at a particular time to cause the aperture to maintain a fixed configuration. The method further includes detecting a specific perturbation in the plasma optical emission while holding the moveable members.

Abstract: A plasma processing control system including a V-I probe for effectively monitoring a plasma processing chamber, where the probe can provide electrical parameters in response to a radio frequency (RF) supply (e.g., about 2 MHz, about 27 MHz, or about 60 MHz), a processor coupled to and/or included with a commercially available probe product that can provide harmonics for each of the electrical parameters, and a controller coupled to the processor that can select one of the electrical parameters and one of the associated harmonics for endpoint detection for a plasma processing step is disclosed. The electrical parameters can include voltage, phase, and current and the plasma processing application can be dielectric etching. A system according to embodiments of the invention may be particularly suited for dielectric etching in a production environment.