Effects of Pretreatment on the Etch Pit Formation during the Electrochemical Etching of Aluminum
The effect of chemical pretreatments on the electrochemical etching behavior of aluminum was investigated with the topographic studies of surface and the analysis of initial potential transients. Two-step pretreatments with H3PO4 and H2SiF6 result in a high density of pre-etch pits on aluminum surface by the incorporation of phosphate ion inside the oxide film and the removal of surface layer by aggressive fluorosilicic acid solution. It generates a high density of etch pits during electrochemical etching and results in the capacitance increase of etched Al electrode by expanding the surface area, up to 61.3 μF/cm2 with the pretreatment solution of 0.5M H3PO4 at 65°C and 10 mM H2SiF6 at 45°C.
Byung Tae Ahn, Hyeongtag Jeon, Bo Young Hur, Kibae Kim and Jong Wan Park
J. K. Lee et al., "Effects of Pretreatment on the Etch Pit Formation during the Electrochemical Etching of Aluminum", Solid State Phenomena, Vols. 124-126, pp. 1561-1564, 2007