Aligned pipe arrays formation by silicon anodic etching

A simple technique is described here that produces aligned curved or straight arrays of pipes. This opens the way to produce complete systems (electronic, photonic and fiber optic connectors) from silicon with large scale fabrication techniques. Our strategy in creating parallel pipes is to use high current densities (similar to 100 mA/cm(2)) silicon anodization in HF solutions, in a cell where the current direction and the preferential etching directions are not coincident in (111) silicon substrates. The etched structure in a nanoscale range was observed using atomic force microscopy, which shows steps. In a macroscopic scale steps were observed in the walls of arrays of tenths of millimeters diameter pipes. Pores arrays were obtained forming a similar to 90 degrees angle with the current direction. Molecular mechanics simulations of the pipe wall structure show that a preferential etching along the < 100 > direction and passivation of the (111) planes are the mechanisms responsible for the formation of pore arrays structure. (C) 1998 American Vacuum Society.