Anodic imprint lithography patterns the GaAs substrate electrochemically by applying a voltage through a predefined anodic stamp. This newly devised technique performs anodic etching in a stamping manner. Stamps that serve as anodic electrodes are fabricated precisely, and the patterns can be imprinted continuously on GaAs substrates. The anodic current locally oxidizes the GaAs through the metal attached to the stamp, and the GaAs oxides are subsequently removed by an acid in the solution. The process is simplified because the metal catalyst is not left on the substrate and the use of an oxidizing agent is not required. Anodic imprint lithography integrates the lithography and etching steps without the use of a polymer resist. Predefined anodic stamps with fin, pillar, and mesh arrays clearly imprinted trenches, holes, and embossed disk arrays on the GaAs substrates, respectively. Anodic imprints replace photons and electrons in conventional lithography with electrochemical stamping, which can simplify existing techniques that are highly complex for extreme nanopatterning.
Keywords: GaAs; anodic etching; chemical imprinting; nanoimprint lithography; three-dimensional structures.