To improve the conformality of Cu seed layer prepared by ELD, we have also developed a novel activation technique by combining a self assembled monolayer (SAM) and Au catalyst. A coupling agent to anchor Au complex ions instead of metallic catalysts on the substrate was used, which enabled a defect free Cu filling of trenches by minimizing the electrical repulsion among the Au catalysts in the solution. The Cu seed layer formed by this method showed a highly conformal and continuous structure. Cu electrodeposition on the 32-nm trench was demonstrated using an acid cupric sulfate electrolyte containing chloride, polyethylene glycol 4000 and bis(3-sulfopropyl)disulfide. The resulting electroplated Cu showed excellent filling capability and no voids or other defects were observed in a 32-nm trench pattern. Therefore, this proposed method has the potential solution to replace the Cu seed layer formation method for future Cu metalizing technology for sub-32nm features. .
Journal: TechConnect Briefs
Volume: 2, Nanotechnology 2011: Electronics, Devices, Fabrication, MEMS, Fluidics and Computational
Published: June 13, 2011
Pages: 88 - 91
Industry sector: Sensors, MEMS, Electronics
Topics: Nanoelectronics, Photonic Materials & Devices