Accuracy of calibrated depth by delta-doped reference materials in shallow depth profiling

The influence of the initial surface roughness and the structure (crystalline/amorphous) of delta-doped reference materials (fabricated with molecular beam epitaxy (MBE) and magnetron sputtering) for depth-scale calibration of secondary ion mass spectrometry (SIMS) depth profiles on the sputtering rate and shift length under low-energy ion bombardment was investigated. The influence of the properties of the reference materials on the sputtering rate under normal oxygen ion bombardment is negligible, and the depth scale can be calibrated accurately using the sputtering rate. However, the shift length under normal oxygen ion bombardment and the sputtering rate under oblique cesium ion bombardment depend on the properties of the reference materials. (C) 2008 Elsevier B. V. All rights reserved.