Fabrication of Fractal Surfaces by Electron Beam Lithography

We describe a method based on electron beam lithography to fabricate patterns of fractal islands on a surface. The island morphology resembles that of a random deposition of particles in a diffusion-limited aggregation regime in 2-D, which is often encountered in the growth of atoms and molecules upon ultrahigh vacuum sublimation. With our fabrication protocol, the morphological parameters of the fractal islands (correlation length, fractal dimension, coverage, and roughness) can be controlled. The fabricated structures can be used as templates for investigating the interplay of self-affinity on thin film nucleation and growth, the adsorption of functional molecules, and the anchoring of living cells. Also they can be exploited as masters for nanoimprinting lithography and replica molding.