CEA-Leti And Alchimer Bring Us High Aspect Ratio TSVs
But achieving high aspect ratio TSVs remains a major challenge ; current techniques are limited to about 10:1. Now CEA-Leti has validated Alchimer's wet nanometric film deposition processes for 300mm high volume manufacturing.
Together, the firms 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 believes its technology shows the potential to break through existing barriers to achieve high aspect ratio TSVs. The collaboration with Leti will evaluate the potential of its technology and its suitability for high-volume manufacturing.
"Current techniques, such as PECVD isolation and iPVD metallisation, have performance limitations that are limiting achievable TSVs to 10:1 aspect ratios," says 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," adds 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.
Alchimer is a provider of wet deposition technologies for dual damascene, through-silicon vias (TSVs), MEMS and other electronic applications and is aiming to change the way people think about metallisation processes.
Founded in 2001 as a spin-off from the Commissariat à l'Energie Atomique (CEA), the company has assembled a team of scientists and engineers who excel in the fields of surface science, chemistry, electrochemistry, physics, materials science and semiconductors. Alchimer's innovations include Electrografting (eG), a wet, electrochemical-based process that enables the growth of extremely