Next generation pressure sensors in surface micromachining technology

One of the first MEMS products - the pressure sensor - has still room for innovation. We report a completely new pressure sensor generation based on a novel surface micromachining technology. Using porous silicon the membrane fabrication can be monolithically integrated with high synergy in an analog/digital semiconductor process suited for high volume production in an IC-fabrication facility. Only two mask layers and one electrochemical etching step are inserted at the beginning of a standard IC-process to transform the epitaxial silicon layer from the electronic process into a monocrystalline membrane with a vacuum cavity under it.