A chemical semiconductor sensor for oxygen gas was activated by thermal treatment. The thin Pt layer of the n-Si/SiO2/Si3N4/LaF3/Pt field effect structure was used as the gate electrode for sensitivity measurements, heating resistance and temperature sensor. Taking advantage of using the gate electrode for heating only the sensitive two layer system LaF3/Pt (thickness only 300 nm) has to be at high temperature. The reactivation was shown to be a very fast process. Within a period of 10ms the structure was heated and the activation process was completed. The temperature measurement was done using the voltage drop at the gate and the current of the heating impulse. For the temperature measurement a resolution on the time scale of nanoseconds was achieved. The time dependent temperature distribution in the sensor multi layer structure was simulated using the CFD-ACE+ software of CFDRC. For the ms-impulses the temperature increase of only the thin layers and not the silicon bulk was shown.
Journal: TechConnect Briefs
Volume: Technical Proceedings of the 1999 International Conference on Modeling and Simulation of Microsystems
Published: April 19, 1999
Pages: 655 - 658
Industry sector: Sensors, MEMS, Electronics
Topics: Micro & Bio Fluidics, Lab-on-Chip, Modeling & Simulation of Microsystems