MEMS pH sensor based on custom ISFET

LioniX International develops the MEMS chips that sit at the heart of sophisticated sensing technology. We have developed a highly sensitive MEMS pH sensor based on custom designed ISFETs (ion sensitive field effect transistors). This sensor chip forms the basis of systems built by our customers and enables the realization of extremely small devices that can be implanted in living tissue or for real time sensing in catheter probes.

Component layout on MEMS pH meter based on custom ISFET made by LioniX International

ISFET specifications for pH sensor

  • Custom design
  • High sensitivity (58 mV/pH)
  • pH 1-14, linear
  • Low drift
  • Integration of ESD electrode and T-diode

ISFET production and performance

Our standard production process is based on ion implantation and a tantalum oxide ( Ta2O5) gate dielectric. This configuration offers superb performance compared to ISFETs with aluminum oxide (Al2O3) or silicon nitride (Si3N4) gates. This MEMS pH sensor with a very high, almost Nernstian response and very low drift. Sensors can be equipped with a protection electrode for electro static discharge (ESD) and a temperature diode.