We present a silicon isotope superlattice structure that we believe to be the most ideal secondary ion mass spectrometry standard sample for the dopant concentration depth profiling required for characterization of the shallow junction formed by ion implantation. The precisely stacked alternating layers of silicon isotopes function as a depth ruler. Therefore, it enables us to calibrate the depth scale of dopant based on the positions of silicon isotopes. We show the depth profiles of silicon isotopes and arsenic in the arsenic ion-implanted silicon isotope superlattice as a representing example. (C) 2008 Elsevier B.V. All rights reserved.