METHOD FOR THE FABRICATION OF SUSPENDED POROUS SILICON MICROSTRUCTURES AND APPLICATION IN GAS SENSORS

摘要

his invention provides a front-side silicon micromachining process for the fabrication of suspended Porous Silicon membranes in the form of bridges or cantilevers and of thermal sensor devices employing these membranes. The fabrication of the suspended Porous Silicon membranes comprises the following steps: (a) formation of a Porous Silicon layer (2) in, at least one, predefined area of a Silicon substrate (1), (b) definition of etch windows (5) around or inside said Porous Silicon layer (2) using standard photolithography and (c) selective etching of the Silicon substate (1), underneath the Porous Silicon layer (2), by using dry etching techniques to provide release of the Porous Silicon membrane and to form a cavity (6) under the said Porous Silicon layer.