Thin films with nanometer-scale pillar microstructure

Thin films possessing microstructure composed of isolated vertical pillars were deposited by glancing angle deposition (GLAD) without the need for sub sequent etch processing. The GLAD technique uses substrate rotation and obl ique angle flux incidence to deposit a porous columnar thin film with engin eered microstructures, Thin films with a pillar microstructure were fabrica ted from a variety of metals, metal oxides and fluorides, and semiconductor s. The rate and incident angle of vapor flux, as well as the substrate rota tion speed during deposition, were found to critically affect pillar micros tructure. Thin films with pillar diameters and densities as low as 30 nm an d 3 pillars per mu m(2), respectively, were deposited. The low stress, high surface area, and porous nature of these films suggests use of pillar micr ostructure films in optical, chemical, biological, mechanical, magnetic, an d electrical applications.