Microfabrication techniques for chemical/biosensors

Microfabrication processes for chemical and biochemical sensors are reviewed. Standard processing steps originating from semiconductor technology are detailed, and specific micromachining steps to fabricate three-dimensional mechanical structures are described. Fundamental chemical sensor principles are briefly abstracted and corresponding state-of-the-art examples of microfabricated chemical sensors and biosensors are given. The advantages and disadvantages of either fabricating devices in IC fabrication technology with additional microfabrication steps, or of using custom-designed nonstandard microfabrication process flows are debated. Finally, monolithic integrated chemical and biological microsensor systems are presented, which include transducer structures and operation circuitry on a single chip.