Abstract: A method for increasing a rate of processing a substrate to achieve an etch profile of the substrate is described. The method includes receiving a parameter signal from a first sensor when a first radio frequency (RF) signal is provided to a substrate support and a second RF signal is provided to an upper electrode. The method further includes determining, based on the parameter signal, a first time at which a value of a parameter is maximum. The method also includes receiving a variable signal from a second sensor. The method includes determining, based on the variable signal, a second time at which a first amount of flux of secondary electrons from the upper electrode to the substrate support is maximum. The method includes determining a phase difference to be a difference between the first time and the second time and achieving the phase difference.