Microrod and Microtube Formation by Electrodeposition of Metal into Ordered Macropores Prepared in p-Type Silicon

Abstract

Copper and nickel electrodeposition into ordered macropores prepared in p-type silicon has been studied in aqueous solutions containing cupric and nickel ions, respectively. When a macroporous silicon template was cathodically polarized in 0.1 M cupric sulfate solution, copper was deposited preferentially at the pore bottom in the dark, whereas the deposition was found to proceed not only at the pore bottom but also partially on the pore wall under the back side illumination. In contrast, the deposition of nickel in 0.1 M nickel sulfate solution was not possible in the dark, while deposition occurred uniformly on the entire surface of the pore wall under the back side illumination. Dissolution of silicon templates by the alkaline etching process led to the formation of copper microrods and nickel microtubes. The deposition behavior of both metals was compared and this discrepancy was discussed.

Large photocurrent-response observed at Pt/InP Schottky interface formed on anodic porous structure

“…A platinum film with an average thickness of about 280 nm was formed on the wall surface inside the pores, indicating that cathodic currents were supplied from the InP wall inside the pores. Similar structure has been reported in the case using a conductive porous template such as a Si porous structure [16]. Average thickness of the platinum film is plotted against processing time of the cathodic formation in Fig.…”

Filling of mesoporous silicon with copper by electrodeposition from an aqueous solution

“…A limited number of studies on the filling of porous silicon with metals by electrodeposition were reported [7][8][9][10][11][12][13][14][15][16] compared with the other non-conducting template such as porous alumina and porous silica. This is because electrodeposition reactions proceed not only at the pore bottom but also on the wall, leading to the complex distribution of electric field and concentration profiles in the pore.…”

“…From a different point of view, there are possibilities to form various morphologies of deposits by controlling the electrodeposition reaction on the pore wall. We reported that shapes of deposits could be controlled as rods or tubes in ordered macroporous p-type silicon [13][14][15][16]. The mechanism of the macropore filling depends on various factors, for instance, the equilibrium potential of metal, the depth of the macropore, the supporting electrolyte for electrodeposition and the displacement deposition.…”

Metal nanorod production in silicon matrix by electroless process

“…In this study, we combine these methods to produce metal filled Si nanopores, that is, metal nanorods in an Si matrix by an electroless process. This simple and low cost process is not only interesting for making such a structure [19,20], but is also favorable to apply ultrahigh-density perpendicular magnetic recording media [21].…”