1. © April 26, 2010 Dr. Lynn Fuller Chemical Sensor Lab Page 1 Rochester Institute of Technology Microelectronic Engineering ROCHESTER INSTITUTE OF TECHNOLOGY MICROELECTRONIC ENGINEERING  Chemical Sensor Lab  Dr. Lynn Fuller  Webpage: http://people.rit.edu/lffeeehttp://people.rit.edu/lffeee  Microelectronic Engineering  Rochester Institute of Technology  82 Lomb Memorial Drive  Rochester, NY 14623-5604  Tel (585) 475-2035  Fax (585) 475-5041  Email: Lynn.Fuller@rit.eduLynn.Fuller@rit.edu  Department webpage: http://www.microe.rit.eduhttp://www.microe.rit.edu 4-26-2010 chemical_sensor_lab.ppt

2. © April 26, 2010 Dr. Lynn Fuller Chemical Sensor Lab Page 2 Rochester Institute of Technology Microelectronic Engineering OUTLINE Lab Proceedure Concentration Calculation ISFET

3. © April 26, 2010 Dr. Lynn Fuller Chemical Sensor Lab Page 3 Rochester Institute of Technology Microelectronic Engineering LAB PROCEEDURE Measure Resistance of Chemical Sensor in air Measure Resistance of Chemical Sensor in 10,000 ppm Acetone Set up HP4145 to obtain resistance vs time Take data for 3 min on 3 min off at 1000ppm, 10,000ppm, 100,000ppm Measure ISFET Id vs Vgs in DI water Measure ISFET Id vs Vgs in different pH liquids

4. © April 26, 2010 Dr. Lynn Fuller Chemical Sensor Lab Page 4 Rochester Institute of Technology Microelectronic Engineering GAS CONCENTRATION CALCULATOR

5. © April 26, 2010 Dr. Lynn Fuller Chemical Sensor Lab Page 5 Rochester Institute of Technology Microelectronic Engineering CHEMICAL SENSOR MEASUREMENTS Computer controlled ohmmeter measures resistance every second for 15 min. Output is plotted versus time. 30s off, 3 min on, 3 min off, 3 min on, 3 min off, etc. Mix a polymer with Carbon Black and apply a thin coat over interdigitated gold fingers

6. © April 26, 2010 Dr. Lynn Fuller Chemical Sensor Lab Page 6 Rochester Institute of Technology Microelectronic Engineering ICS R VS TIME SETUP Turn on HP4145 and PC Open ICS software on desktop Select NI 32 Thunk Select HP 4145 connect --> configure  poll Select Device Icon --> New: give name  Select symbol Assign Source Units: SMU1 and SMU2 Click on Time  Stimulus: Voltage  Measure: Voltage and Current  Mode: Constant  Value (depends on resistance)  Time Measurement Bias: Time Bias  OK

7. © April 26, 2010 Dr. Lynn Fuller Chemical Sensor Lab Page 7 Rochester Institute of Technology Microelectronic Engineering ICS R VS TIME SETUP Set up equation for resistance Select Time Measure Then Single Set up Plot

8. © April 26, 2010 Dr. Lynn Fuller Chemical Sensor Lab Page 8 Rochester Institute of Technology Microelectronic Engineering ION-SENSITIVE FETS ISFETS SiO2/Si3N4 Gate Insulator Drain Source Silicon When immersed in a solution containing ions, the ions at the surface of the gate insulator control the drain current similar to a voltage on the gate of a FET. pH Vds Ids (Amps) RIT’s First ISFETs 2010 Murat Baylav Reference Electrode Vref = -2 volts pH ~ 4 pH ~ 10

9. © April 26, 2010 Dr. Lynn Fuller Chemical Sensor Lab Page 9 Rochester Institute of Technology Microelectronic Engineering MEMS ISFET PH TESTING pH Ids (Amps)

10. © April 26, 2010 Dr. Lynn Fuller Chemical Sensor Lab Page 10 Rochester Institute of Technology Microelectronic Engineering REFERENCES 1.“Recent Advances in the Gas-Phase MicroChem Lab”, Patrick R. Lewis, et.al., IEEE Sensors Journal, Vol 6 No. 3, June 2006 2.“MEMS Chemical Gas Sensor”, Frank Zee and Jack Judy, UCLA, IEEE UGIM Conference 3.http://csrg.ch.pw.edu.pl/tutorials/electronicT_N/ Chemical Sensor Researd Group, Warsaw University of Technology, Warsaw, Poland, Professor Zbigniew Bruzozkahttp://csrg.ch.pw.edu.pl/tutorials/electronicT_N/