Porous silicon membranes

Abstract

Porosified silicon membranes of defined thicknesses were first studied in the 1990s and have now been realized by electrochemical anodization, micromachining techniques, and the annealing of ultrathin deposited films. The three fabrication routes produce very different morphologies and levels of porosity. A variety of applications have been explored for both macroporous and mesoporous membranes and these are also surveyed. Wholly microporous membranes in silicon, where all pores have diameters less than 2 nm, have not been achieved to date.