As the Si-based semiconductor industry goes into the sub-10 nm scale of its physical limit, conventional patterning processes, based on photolithography and etching, are facing fundamental limits for device downscaling. Accordingly, directing matter to create structures with atomic-scale control of physical and chemical properties is a technical breakthrough in next-generation nanotechnology. The deposition of atoms at specific locations on a desired surface can boost advances in catalysis, energy harvesting as well as semiconductor device fabrication. Significant efforts are currently underway in both industry and academia to develop highly reliable and robust direct pattern transfer from the bottom-up approach.<br/>Of several paths being explored for novel nanopatterning, Area-selective atomic layer deposition (AS-ALD) is attracting increasing interest because of its ability to enable both continued dimensional scaling and accurate pattern placement for next-generation nanoelectronics. Here we report a strategy for depositing material onto three-dimensional (3D) nanostructures with topographic selectivity using an ALD process with the aid of an ultrathin hydrophobic surface layer. Using ion implantation of fluorocarbons (CF<sub>x</sub>), a hydrophobic interfacial layer is formed, which in turn causes significant retardation of nucleation during ALD. We demonstrate the process for Pt ALD on both blanket and 2D patterned substrates. We extend the process to 3D structures, demonstrating that this method can achieve selective anisotropic deposition, selectively inhibiting Pt deposition on deactivated horizontal regions while ensuring that only vertical surfaces are decorated during ALD. The efficacy of the approach for metal oxide ALD also shows promise, though further optimization of the implantation conditions is required. The present work advances practical applications that require area-selective coating of surfaces in a variety of 3D nanostructures according to their topographical orientation.

Topographically selective atomic layer deposition on 3D nanostructures for novel nanopatterning processes

255th National Meeting (2018)

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