Self-assembling of metal nanoparticles on patterned semiconductor surfaces (Au/GaAs)

The fabrication of selectively deposited arrays of metal nanoparticles on textured semiconductor surfaces is reported. Gold nanoparticles were grown on previously textured surfaces using photostimulated chemical deposition from an aqueous solution of AuCl3 salt. Surfaces with random and periodic microreliefs were used as templates of sites for nanoparticle deposition. Dendrite-like and quasi-grating-like microreliefs were produced by anisotropic etching of GaAs (100) substrates. Periodic reliefs (diffraction gratings and bi-gratings) were fabricated by the holographic photochemical etching of the same substrates. Our results from AFM, SEM and EDX show that gold predominantly locates on the tops of the microreliefs. Since the surface relief strongly affects the topology of metal deposition, the use of microprofiling of semiconductor surfaces allows designing nanostructure deposition.