1.1 This International Standard specifies a procedure for calibrating the depth scale in a shallow region, less than 50 nm deep, in SIMS depth profiling of silicon, using multiple delta-layer reference materials. 1.2 This International Standard is not applicable to the surface-transient region where the sputtering rate is not in the steady state. 1.3 This International Standard is applicable to single-crystalline silicon, polycrystalline silicon and amorphous silicon.