Vertical oxide nanotubes connected by subsurface microchannels
We describe the fabrication of arrays of oxide nanotubes using a combination of bottom up and top down nanofabrication. The nanotubes are made from epitaxially grown semiconductor nanowires that are covered with an oxide layer using atomic layer deposition. The tips of the oxide-covered nanowires are removed by argon sputtering and the exposed semiconductor core is then selectively etched, leaving