Porous silicon as multifunctional material in MEMS

Porous Si with pore size in the range of a few nanometers can be used as multifunctional material in different MEMS applications. In this paper, we first discuss the fabrication and characterization of porous Si. Porous Si has been used as sacrificial layer for the realization of micro-heaters, micro-hotplates and microphones. A new type of surface micromachining process for the fabrication of sub-/spl mu/m freestanding crystalline structures is presented. The use of porous Si as functional layer for different types of microsystems is discussed.