Editing Sputtering (section)

===For analysis===
Another application of sputtering is to etch away the target material. One such example occurs in [[secondary ion mass spectrometry]] (SIMS), where the target sample is sputtered at a constant rate. As the target is sputtered, the concentration and identity of sputtered atoms are measured using [[mass spectrometry]]. In this way the composition of the target material can be determined and even extremely low concentrations (20&nbsp;μg/kg) of impurities detected. Furthermore, because the sputtering continually etches deeper into the sample, concentration profiles as a function of depth can be measured.