| AVS 55th International Symposium & Exhibition | |
| Advanced Surface Engineering | Thursday Sessions |
| Session SE+TF+NC-ThM |
| Session: | Glancing Angle Deposition (GLAD) I |
| Presenter: | A. Dolatshahi-Pirouz, University of Aarhus, Denmark |
| Authors: | A. Dolatshahi-Pirouz, University of Aarhus, Denmark M. Foss, University of Aarhus, Denmark D. Sutherland, University of Aarhus, Denmark J. Chevallier, University of Aarhus, Denmark F. Besenbacher, University of Aarhus, Denmark |
| Correspondent: | Click to Email |
Recently there has been an increasing focus on methods to produce surfaces with a varying topography on the nanometer length scale for applications in e.g. biotechnology, photonics, and catalysis, since the nanoscale surface topography is known to influence the performance in these areas. Here, colloidal lithography is combined with glancing angle deposition (GLAD) to generate well-separated platinum nano-rough columns with a brush like appearance. The columns were fabricated by physical vapor deposition (PVD) with an e-gun evaporator onto surfaces pre-coated with polystyrene particles with a diameter at 137 nm by colloidal lithography at different deposition angles between the substrate and incoming flux (θ = 35, 10 and 5) as well as different depositions times. The effect of θ and deposition time t on the morphological characteristics of the nano-columns was investigated by utilizing scanning electron microscopy (SEM) and subsequently analyzing the images in order to determine the height, width and inclination angle of the nano-rough columns. From the SEM images we observe that the morphology of the nano-rough columns depend on the angle of incidence and as the deposition angle approaches grazing incidence sharp brush like columnar protrusions are grown on the colloidal particles, while more smoothly shaped surface features are grown at higher deposition angles. Moreover, by changing the incidence angle of the incoming flux, well-separated nano-rough columns can be synthesized with an angle of inclination ranging from 26 to 90 degrees. As the deposition time increases the height and width of the nano-rough columns follows a power law and increases accordingly. The power law exponents for the height and width increment as function of the deposition time both depends on the angle of incidence decreasing from 1.06 ± 0.04 to 0.81 ± 0.16 and 0.71 ± 0.07 to 0.19 ± 0.01, respectively, as the deposition angle decreases from 35 to 5 degrees. The change in the power law exponents indicates that the kinetics of the growth of the nano-rough columns is influenced by surface diffusion and shadowing effects. Moreover, from the power law exponents we were able to tailor inclined nano-rough columns with the same height and an inclination angle ranging from 90 to 26 degrees. The nano-rough surfaces are currently being used in cell experiments which indicate that inclined nano-rough columns can be used to guide the cellular behavior on a surface.