Self-Terminating Growth of Platinum Films by Electrochemical Deposition

Atomic Layers from Solution Growth of flat thin films is often plagued by the formation of mounds and pyramids. To avoid this problem, atomic-layer deposition (ALD) can be used whereby alternating self-termination reactions stop the layer growth. Electrochemical approaches to ALD use surface alloys to slow film growth, but often lead to film contamination. Yihua Liu et al. (p. 1327 ; see the Perspective by Switzer ) show that for platinum films, controlling surface potential can lead to adsorbed hydrogen on the surface, which can terminate film growth at one layer, leaving platinum species in solution available for further reduction. Rapid changes in applied potential can oxidize the hydrogen, which allows efficient contamination-free growth of an additional atomic layer.