Correcting topographic artifacts in three-dimensional ToF-SIMS: A practical guide from data-only reconstruction to correlative AFM

Abstract

Three-dimensional time-of-flight secondary ion mass spectrometry (3D ToF-SIMS) builds chemical volumes by stacking images acquired between sputter cycles. Standard reconstruction assumes a flat starting surface and a single sputter rate, so samples with topography, or with layers that sputter at different rates, yield distorted interface positions and depth scales. This article is a practical guide to correcting these artifacts. We group the available corrections by the information they need: the SIMS data alone, atomic force microscopy (AFM) topography before and after the profile, or AFM topography also at intermediate stages. All three are applied to a model Pt/TaOx/Ta/Pt/Ti crossbar memristor device measured with in situ SIMS/AFM at ten stages, together with the data preparation they share. Each correction method is evaluated using the known device geometry and the measured surface evolution. The data-only correction requires no additional instrumentation and restores relative topography, but its depth scale depends on nominal layer thicknesses and remains unconstrained below the last calibrated interface. AFM before and after the profile fixes the start and end surfaces but assumes uniform sputtering in between, which fails next to the device, where the surroundings change material during the profile. Multi-stage AFM correction follows these changes and reproduces the structure of the device, at the cost of instrument time and repeated imaging of a partially sputtered surface. A decision flowchart and a checklist help readers choose, validate and report a correction.