Depth profile detection limit of 3×1015 atom cm−3 for As in Si using Cs+ bombardment negative secondary ion mass spectrometry

Depth profiles of As-implanted silicon samples have been determined by secondary ion mass spectrometry in order to establish a practical detection limit for As in Si. By monitoring the AsSi− species, produced in high yield by Cs+ ion bombardment, it is shown that As is detectable down to a background count limit of ∼3×1015 atom cm−3 (50 ppb) during a depth profile of a 250-μm square area.