Stage 3 – 14AMI

During the final implementation stage (Stage III – 2026), POLITEHNICA Bucharest (UPB) successfully completed all activities set out in the work plan, fully achieving the project’s objectives.

Activity 2.1:

The complete SEM-FIB lamella extraction procedure for co-localised SEM-TEM-ZC-EDX analysis was finalised, tested and validated using a diverse range of samples (metals, semiconductors and multilayer heterostructures). The protective-layer deposition steps, cutting geometry, manipulation with the extraction needle and final thinning using Ga and Ar ions (to thicknesses below 30 nm) were optimised. The resulting lamellae were characterised morphologically and compositionally using TEM-SEM-ZC-EDX, enabling the measurement of layer thicknesses, critical dimensions (CD) and elemental distributions (including Ge) through line profiles and EDX maps.

Activity 2.2:

UPB defined and implemented an innovative hybrid metrology methodology at laboratory scale, combining scanning probe microscopy (SPM) and electron-beam methods to locate and investigate nanoscale defects in 14 Å technology with a reduced cycle time. High-purity TEM lamellae, placed on Si substrates, were located by correlating optical microscopy integrated into the AFM system with SEM images. Their layered structure was validated by line scanning and EDX mapping, followed by investigation of the region of interest using AFM-IR.

Activity 2.3:

A working procedure for the systematic characterisation of polymers similar to EUV resists using the AFM-IR system was established and applied to samples from UPB’s own laboratory. This demonstrated the system’s capability for complex chemical and structural analysis, illustrated by mapping the characteristic bands of PS and PMMA.

Activity 2.4:

During this final stage, the optimised workflow for analytical measurements of thickness and sidewall angle was finalised and fully validated. Optimal final-thinning parameters were established for each material type, the mechanical stability of the lamellae on TEM grids was confirmed, and a standardised measurement procedure (TEM, ZC, EDX) was implemented. The procedure was successfully applied to priority experimental samples to ensure a high level of accuracy and reproducibility.

Activity 2.5:

UPB completed deliverable “D3.3.3.2 Technical Report on the First Set of Samples Investigated Using the New Hybrid Metrology Methodology”, using coupons supplied by Thermo Fisher from wafers provided by imec. A sequential, non-destructive workflow was established, combining high-resolution STEM/EDX and AFM-IR on the same FIB-prepared CFET lamella. This enabled the detection of corner residues and internal defects (AFM-IR resolution below 10 nm on samples thinner than 100 nm) and contributed to achieving a precision-to-tolerance ratio between 0.1 and 0.3 for the 14 Å technology node. Furthermore, a stepwise scanning strategy (from the support pillar towards the region of interest) demonstrated the feasibility of AFM/AFM-IR characterisation of electron-transparent TEM lamellae.

Activity 2.6:

Research results were disseminated through participation in international scientific conferences, including the oral presentation “Multifunctional Collagen-based Nanocomposites Reinforced with Essential Oil-Loaded MWCNTs for Biomedical Applications” (Mariana Prodana, Daniela Ioniță, Cristina Badea, Geanina Mihai, Teodor Jianu, Marius Enăchescu), delivered at the 24th Romanian International Conference on Chemistry and Chemical Engineering, Poiana Brașov, Romania (1–4 September 2026).

In conclusion, POLITEHNICA Bucharest fully achieved the objectives set for all activities planned under Stage III, validating the hybrid metrology protocols and methodologies developed during the project.