Fabrication process and Performance analysis of Ion Sensitive Field Effect transistor Sensor (ISFET)

Abstract

Life science, healthcare and in the field of chemical science, detection and quantification of different chemical and biological species is a matter of central interests from the last many decades. It is required for the diagnosis of the disease, detection of dangerous and lethal epidemics, and detection of toxic gases in mines and in many other applications. However the direct and real time detection was the need in those areas. Solid state device sensors that basically comprise of semiconductor materials comes with a revolution in the field of biosensors. With lot of collective research work of physical science researchers and biomedical community these semiconductors sensors passed a lot many milestones in the way of selectively sensing the molecules and other chemical ions. The use of Nanowire in these semiconductor sensors has made them capable of ultrasensitive direct electrical detection, So these device became capable of detecting a very smaller concentration of target molecules in Femtomolar range. However they are still lagging in the sensitivity issues from the conventional label based detection with the sensitivity in Attomolar range. So here in this work we are going to present the two fabrication approaches of the Nanowire sensor i.e. top down and bottom up, with the detailed silicon nanowire growth method and use of that nanowire in the overall device fabrication. Then the sensitivity issues related with the geometries of the different sensors is analyzed with main focus on the nanowire cylindrical sensors, with this analysis we have tried to find the limitation of these nanowire sensors