focused ion beam - atom probe

**FIB-APT** (Focused Ion Beam - Atom Probe Tomography) refers to the **site-specific specimen preparation workflow for APT using focused ion beam milling** — enabling atom probe analysis of precisely targeted regions within semiconductor devices. **How Does FIB-APT Work?** - **Identify**: Locate the region of interest (e.g., a specific transistor) using SEM imaging. - **Lift-Out**: Use FIB to cut and extract a small wedge containing the target feature. - **Annular Mill**: Shape the wedge into a sharp needle (tip radius < 50 nm) using progressively lower beam currents. - **Low-kV Cleaning**: Final milling at 2-5 kV to minimize FIB damage to the specimen. - **APT Analysis**: Load the needle into the atom probe for 3D atomic analysis. **Why It Matters** - **Site-Specific**: FIB enables targeting specific device features (a single transistor, a specific interface). - **Routine Workflow**: FIB lift-out + annular milling is now a routine, reproducible specimen preparation method. - **Artifact Minimization**: Low-kV cleaning reduces Ga contamination and amorphous damage from FIB. **FIB-APT** is **surgical specimen preparation for atom-by-atom analysis** — using ion beam sculpting to target and prepare specific device features for 3D atomic characterization.