intensity spike which remains substantially unchanged while the intensity spike characteristic of gold has increased indicating that gold is present in the plasma 15 due to sputtering referring now to fig5 c an actual spectral waveform is shown after portions of the gold layer has been completely sputtered away exposing the copper to the argon plasma as a result copper sputtering has started to occur and is detectable by traces of copper in the plasma relying on the auto identification technique described above the processor detects the presence of an intensity spike characteristic of copper the comparator compares the actual spectrum of fig5 c with the fingerprint spectrum of fig5 b and determines that the presence of cu is outside the target range of values relying on the third type of empirical data for sputtering procedures the processor acknowledges that the detection of copper is due to the fact that portions of the gold layer have been completely removed from the copper mass 50 exposing copper to the argon ion bombardment thereafter the processor instructs the controller to generate control signals to automatically stop the sputtering procedure based on the auto identification of copper in the plasma 15 the control signals direct the reduction of the plasma ion intensity level and depressurize the chamber by opening pressure regulator 20 to permit the argon gas to escape the auto identification technique of the present invention can also be used for end point detection of an etching process such end point detection requires that a specific emitting species be identified and that its spectral features change intensity in a detectable fashion when the interface between the film and the substrate is reached it will be obvious to those skilled in the.