Simple approach for improving gold deposition inside nanoporous alumina template on Si substrate

We report on a simple approach for enhancing gold plating deposition inside the nanochannels of anodic Al oxide (AAO) on a Si substrate. The key to the approach is to insert an Al thin film deposited at a low deposition rate before further thickening the film by sputtering deposition. The deposition of only a 10 nm-thick Al film at a low deposition rate was found to be sufficient to improve the gold deposition with a given gold-plating solution. This was evidenced by the increase in the plating current during gold plating as well as the increase in the surface coverage of deposited gold to as high as 80%. The resultant AAO with plated gold segments is expected to be useful for vapor-liquid-solid techniques of fabricating nanowires guided by pores.