Electropolishing of Copper in H[sub 3]PO[sub 4]

Abstract

Electropolishing copper in 14M normalH3PnormalO4 was studied using both ex situ and in situ optical techniques. First, an ex situ study revealed the influence of the electropolishing potential on the visual appearance and the surface topography. Gloss together with total integrated scattering reflected the changes in surface roughness as evidenced from optical profilometry images. Second, an in situ optical study using ellipsometry revealed the changes in the thickness of the surface film, as well as roughness modifications. Altogether, this provided the characterization of the whole electropolishing process in terms of roughness and film formation. From the polarization curve combined with the complementary analysis techniques it was observed in situ that an initial regime showed increased roughness of the copper surface, followed by a current limiting plateau exhibiting the best conditions of electropolishing: anodic brightening. For higher applied potentials, a region with pitting and deterioration of the appearance followed.

Electrochemical Approach to and the Physical Consequences of Preparing Nanostructures from Gold Nanorods with Smooth Ends

“…The lack of this capability is surprising considering hundreds of papers are published each year on such structures. Electropolishing, mechanical polishing, 23 and bulk high pressure methods, 24 which work well for micro and macroscale objects, 25 cannot be used effectively to control surface roughness with nanostructured rods.…”

Establishing the patterns in anode behavior of copper in phosphoric acid solutions when adding alcohols

“…The dissolution of copper proceeds through the stage of film formation, which consists of a mixture of oxides of one-and bivalent copper [23][24][25][26]. It is not excluded that the film at the surface of the anode can contain oxides with a non-stoichiometric composition or consist of a mixture of copper oxides and phosphates [27][28][29][30][31].…”

Electrochemical Equilibria of Copper in Aqueous Phosphoric Acid Solutions

“…While there is an agreement in the literature that Cu ECP should be conducted under masstransfer-controlled conditions, there is no unequivocal explanation for the mass-transfer limitation. 44 Several researchers explained the limiting-current plateau in terms of the formation of a viscous liquidlike salt film, in which the surface concentration of the metal ions produced from the dissolution reaction exceeds a solubility limit, resulting in the precipitation of a salt film. [45][46][47][48] Finding alternatives to these mechanisms, other researchers proposed that mass-transfer limitation is due to the diffusion-limited transport of an acceptor species to the anode.…”