A Novel Fabrication Technique for MEMS Based on Agglomeration of Powder by ALD

This paper describes a novel fabrication technique for microelectromechanical systems (MEMS) based on the agglomeration of micron-sized powder into rigid 3-D porous structures by means of atomic layer deposition (ALD). Since ALD is performed at low temperatures, such structures can be created from a broad variety of materials. It is shown that the compatibility of substrates with embedded porous structures to common back-end-of-line environment can be regained, and post-processed by applying standard processes of MEMS and integrated circuit technology is possible. In such a way, for the first time, nearly any material can be integrated onto silicon substrates in a simple and generic way. Moreover, not only a particular porosity or internal surface can be targeted. The bulk properties of the structure can be tailored as well, which opens up unique prospects for the future of MEMS.