Porous silicon formation by mechanical means

Abstract

In this chapter a mechanical method of porous silicon formation is described. By applying high-energy ball milling to polycrystalline silicon powder or single crystalline silicon wafers, highly dispersed and nanocrystalline silicon powders are produced. Pressing and sintering then lead to a porous matrix. The macroporous structures made in this way can then be permeated by meso- and micropores. The sinters have isotropic character of the pore distribution and morphology; this method is not limited by the wafer dimensions, and it is possible to make largescale porous bodies, which is an advantage in comparison to lithographic methods.