In an endpoint detection method for a process performed in a substrate processing chamber with an energized gas, a process variable of the process is detected. The process variable comprising at least one of (i) a radiation emitted by the energized gas, (ii) a radiation reflected from a substrate in the chamber, (iii) a reflected power level of the energized gas, and (iv) a temperature in the chamber. An endpoint signal is issued when the process variable is indicative of an endpoint of the process. A process parameter of the process is also detected, the process parameter comprising at least one of (i) a source power, (ii) an RF forward power, reflected power, or match components, (iii) an RF peak-to-peak voltage, current or phase, (iv) a DC bias level, (v) a chamber pressure or throttle valve position, (vi) a gas composition or flow rate, (vii) a substrate temperature or composition, (viii) a temperature of a chamber component or wall, and (ix) a magnetic confinement level or magnet position. The endpoint signal is determined to be true or false by evaluating the process parameter.