The chart shows the time cycle of the primary ion pulsing and secondary ion extraction, and the specimen sputtering in between. As the sample is sputtered the bottom of the crater is analyzed by the Ga beam. The schematics of the sample shows the sputtered crater of 200 x 200 µm2. The analysis is taken from a small zone in the center of the crater.
Due to this dual beam approach, both sputter and analysis beam can be optimized independently. Moreover, as during the sputtering the extraction field is switched off, the handling of the sputter beam is easy even for very low beam energies. This yields a good depth resolution.
Less than 1 nm resolution can be achieved.