title: Impact of the atomic layer deposition precursors diffusion on solid-state carbon nanotube based supercapacitors performances.
abstract: A study on the impact of atomic layer deposition (ALD) precursors diffusion on the performance of solid-state miniaturized nanostructure capacitor array is presented. Three-dimensional nanostructured capacitor array based on double conformal coating of multiwalled carbon nanotubes (MWCNTs) bundles is realized using ALD to deposit Al2O3 as dielectric layer and TiN as high aspect-ratio conformal counter-electrode on 2 μm long MWCNT bundles. The devices have a small footprint (from 100 μm(2) to 2500 μm(2)) and are realized using an IC wafer-scale manufacturing process with high reproducibility (≤0.3E-12F deviation). To evaluate the enhancement of the electrode surface, the measured capacitance values are compared to a lumped circuital model. The observed discrepancies are explained with a partial coating of the CNT, that determine a limited use of the available electrode surface area. To analyze the CNT coating effectiveness, the ALD precursors diffusions inside the CNT bundle is studied using a Knudsen diffusion mechanism.
authors.affiliation: Delft University of Technology, Delft Institute of Microsystems and Nanotechnology, Faculty of Electrical Engineering, Mathematics and Computers Science, Laboratory of Electronic Components, Technology and Materials, Feldmannweg 17, 2628 CT Delft, The Netherlands.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Fiorentino
authors.forename: Sten
authors.initials: S
authors.lastname: Vollebregt
authors.forename: F D
authors.initials: FD
authors.lastname: Tichelaar
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Ishihara
authors.forename: Pasqualina M
authors.initials: PM
authors.lastname: Sarro