During the project's first year, the consortium successfully established its collaborative framework, and a strong, visible spirit of cooperation has emerged among the partners. For example, the teams from TUC and from PlasmaSolve are working on a common modeling concept for plasma etching to generate data for a model-based life cycle and sustainability analysis to be performed by the UG team. We also achieved a lively exchange between the modeling teams and the technology experts from TUC, ENAS, VUB, and the company Lionix.
In the modeling work package, a database of halogen-free etchants was built, and their stability and reactivity were screened using quantum chemical calculations based on density functional theory. Using this approach, we identified a preliminary set of promising candidates for lab-scale evaluation.
Further modeling activities focused on the computational investigation of the sulfur hexafluoride etching processes as well as of a promising new etching chemistry. By process modeling, we investigate their implementation in specific etching equipment. By interfacing these models with the results of computational screening, we will be able to reduce the experimental workload throughout the project significantly. The plasma model for a novel etch chemistry exhibits a significantly lower yield compared to sulfur hexafluoride etching and identifies directions for future improvements of halogen-free etching.
In the first-year lab-scale work, the focus was on exploring the feasibility of etching of silicon using catalysts. Preliminary work was foundational for all future tasks, as more than one task relied on catalysts. The experimental approach involves applying nanoparticles and nanostructures as catalysts on silicon surfaces, which facilitate the dissociative adsorption of potential etchants that spread across the catalyst surface. Additionally, the possibility of metal-assisted plasma etching (MAPE) is being investigated in detail, based on literature suggesting suitable metals for silicon etching.
For a reference process based on halogens, a baseline life-cycle analysis (LCA) has been calculated. Using primary data from real etching equipment and from secondary literature an inventory as basis for the impact assessment was created. Challenges arose regarding data availability and benchmarking. To support the process, a quick-LCA tool was created to help build life cycle inventory directly from etching recipes and subsequently conduct impact assessments. Similar concepts will be used for a prospective LCA of halogen-free etching which is in preparation now.
Finally, the foundations of the project dissemination and communication strategy have been laid within the first year. This includes the launch of HaloFreeEtch website, the development of a visual identity and communication kit, the establishment of a social media presence, the release of a first newsletter, the organization of a first public webinar, along with the active participation in portfolio events. These activities enhanced HaloFreeEtch visibility, strengthened portfolio collaboration, and engaged stakeholders through news, posts, and events, ensuring effective outreach and impact. Further, an exploitation methodology aimed at shaping effective exploitation strategies aligned with the technical progress of HaloFreeEtch innovations has been developed.
