Galvanic deposition of gold on GaAs: A tip-induced lithography approach

A lithography technique based on reduction of metal ions on localized regions of GaAs surfaces is demonstrated. In this technique, an atomic force microscopy (AFM) tip was used to create localized defect patterns on a GaAs surface while operated in air. Subsequent exposure of the semiconductor surface to an Au(III) solution results in the deposition of gold by galvanic displacement reaction on pre-patterned defect areas. Random formation of gold islands outside of the pattern is eliminated by restricting the contact time between the Au(III) solution and GaAs semiconductor to approximately 5 minutes.