These sensors are becoming particularly more important in manufacturing
process monitoring and control. It is important to Measure the
identities of gases and liquids, concentrations, and states, chemical
sensors for worker safety (to insure no exposure to hazardous materials
or gases), process control (to monitor, for example, the quality
of fluids or gases used in production; this is specially critical in the
semiconductor industry which relies on complex process “recipes”
for successful production), and process state (presence or absence of
a material, gas or fluid, for example.) Chemical sensors have been
successfully produced as micro-sensors using semiconductor technologies
primarily for the detection of gaseous species. Most of these
devices rely on the interaction of chemical species at semiconductor
surfaces (adsorption onto a layer of material, for example) and then
the change caused by the additional mass affecting the performance