A Capacitive Humidity/Ammonia Sensor Based on a Porous Silicon Carbide Dielectric


The aim of this project is the development of capacitive humidity sensors based on porous silicon (PS). The use of porous silicon carbide offers the possibility of fabricating a true smart silicon humidity/ammonia sensor, in which the sensor and the associated readout electronics are co-integrated. Furthermore, the Silicon carbide gives chemical robustness for harsh environments. The basic structures have been fabricated and tested. These tests have shown that porous silicon carbide is a highly suitable material for humidity/ammonia sensors.

A number of important issues will be addressed in two MSc project. The first will focus on materials and processing, and will address the following topics:

  • Simplification of the fabrication process
  • Top electrode design
  • Improved contact to the top electrode
  • Chemical cross-sensitivity test

In the second project, the sensor’s readout electronics will be developed, with a focus on the following topics:

  • Energy-efficient readout of the sensor and digitization of its output
  • Compensation for temperature cross-sensitivity
  • Inclusion of self-test features

Together, the MSc candidates will make important steps towards realizing truly smart silicon humidity/ammonia sensors.



Paddy French