Ald Conformality and Optimization in Ultrahigh Aspect Ratio Nanopores for Electrical Energy Storage Nanodevices

In exploiting nanostructures for applications such as energy devices, conformal coatings are playing an increasingly crucial role. Atomic layer deposition (ALD) is receiving responsibility for the most demanding deposition in nanotechnology, especially in terms of conformality due to its self-limiting surface reactions. In this work, we investigate the effects of reactant dosage on deposition rates and thickness uniformity across a planar wafer versus conformality down the length of an ultrahigh aspect ratio nanopore as a means to optimize the ALD process in electrostatic nanocapacitor fabrication. Porous anodic alumina (PAA) templates were used as a versatile and facile platform to analyze TiO2 ALD profiles via ex-situ SEM, EDS line scans and TEM. Initial results illustrate how tailoring precursor exposure times display CVD-like deposition mechanisms leading to poor conformality. These results provide insight to deposition mechanisms in ultrahigh aspect ratio nanostructures.