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Effect of gate dielectric on the performance of ISFET with SU-8 encapsulation

  • S. Dawnee
  • Navakanta Bhat
Original Paper
  • 25 Downloads

Abstract

The design and fabrication of open gated ISFETs with different gate dielectric is reported. A comparative analysis of three different sensing layers SiO2, SiO2/Si3N4 stack and SiO2/Al2O3 stack is presented. The focus is on the simple fabrication technique, SU-8 encapsulation and its application as a pH sensor. The SU-8 encapsulation process is developed for the creation of liquid well to enable efficient interaction with biological fluid. For pH analysis the ISFET was tested in buffer solutions with different pH values. A platinum wire was used as the reference electrode for liquid gating. The pH response is evaluated from the IV characteristics and ISFETs with SiO2/Si3N4 stack and SiO2/Al2O3 stack showed better pH response with sensitivity of 59.33 mV/pH and 55.68 mV/pH, respectively as against sensitivity of 48.9 mV/pH in ISFETs with SiO2.

Keywords

Ion sensitive field effective transistors (ISFET) SU-8 encapsulation pH Sensor 

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Copyright information

© Institute of Smart Structures & Systems, Department of Aerospace Engineering, Indian Institute of Science, Bangalore, India 2018

Authors and Affiliations

  1. 1.Department of Electrical Communication EngineeringIndian Institute of ScienceBangaloreIndia
  2. 2.Centre for Nano Science and EngineeringIndian Institute of ScienceBangaloreIndia
  3. 3.Department of Electrical and Electronics EngineeringRamaiah Institute of TechnologyBangaloreIndia

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