Semiconductor field effect devices

Abstract

Abstract The research and development of biosensors is at present in a rapidly growing phase due to the demands from a number of different areas such as clinical chemistry, process industry, agriculture and environmental control. Many different types of biosensor have been developed, and the majority of the biosensor concepts are based on the combination of immobilized enzymes with classical sensors such as photometers, amperometric or potentiometric electrodes, gas electrodes or thermistors. The performance of a biosensor is to a large extent dependent on the sensor elements. One class of sensors that has been developed during the last decade is the solid state chemical sensors; these have properties that make them especially valuable for biosensing purposes. Based on semiconductor technology, they are characterized by their ruggedness, ability to be directly integrated with microelectronics and hence the possibility to be mass fabricated at low cost. One type of such sensor is based on field effect devices, made by the MOS (Metal Oxide Semiconductor) technology. They can be designed either as capacitors or field effect transistors.