Formation technique for macroporous morphology superlattice

In this work, the investigators studied etching conditions for generating macro porous silicon with different morphologies in p‐type (111) substrates. Both crystal orientation dependent growth of macropores and electric current direction dependent growth of macropores have been achieved. A superlattice structure, which consists of several layers of macroporous silicon with different morphologies, has been demonstrated by modulating the etch conditions during the anodization process. The morphology superlattice structure is developed for an inlet particle filter of a micro gas chromatograph (µGC). It may offer a number of other new MEMS applications. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)