Alchimer, S.A. today announced a collaboration with the French research institute CEA-Leti to evaluate and implement Alchimer’s wet deposition processes for 300mm high-volume manufacturing. The project will evaluate Alchimer’s Electrografting (eG) and Chemicalgrafting (cG) processes for isolation, barrier and seed layers. When combined, Alchimer’s wet deposition processes have been demonstrated to achieve 20:1 aspect ratio through silicon vias (TSVs) due to their ability to coat conformally regardless of via topography, diameter or depth.

3D integration is moving towards a "via middle" approach where TSVs are formed after front-end processes, but prior to stacking.  Several applications are in the development phase, leading to constraints and different specifications for TSVs. Alchimer’s technology shows the potential to break through existing barriers to achieve high aspect ratio TSVs. This collaboration will evaluate the potential of its technology and its suitability for high-volume manufacturing.

"Current techniques, such as PECVD isolation and iPVD metallization, have performance limitations that are limiting achievable TSVs to 10:1 aspect ratios," said Bruno Morel, CEO of Alchimer. "Our 3D TSV products have unequivocally demonstrated their ability to deliver 20:1 aspect ratios at a significantly reduced cost as compared to current approaches. Now it is critical to validate the products’ full potential for 300mm high-volume manufacturing as well as to study their compatibility with the overall 3D integration process. Leti’s leading 3D expertise and world-class infrastructure will allow us to do that.

"Collaborating with Alchimer fits perfectly our strategy of delivering innovative solutions to industry," added Fabrice Geiger, head of Leti’s Silicon Technology Division. "Alchimer’s eG technology is a promising, cost-effective and breakthrough solution to address the challenges of future 3D TSV integration. Through this collaboration, Alchimer will have access to Leti’s expertise in the domain of 3D TSV integration and its world-class 300mm 3D platform capabilities."

eG is based on surface chemistry formulations and processes. It is applied to conductive and semiconductive surfaces and enables self-oriented growth of thin coatings of various materials, initiated by in-situ chemical reactions between specific precursor molecules and the surface. This process achieves a combination of conformality, step coverage and purity that cannot be matched by dry processes.