Fraunhofer Institute for Photonic Microsystems
Ion-sensitive field-effect transistors (ISFET)
In the field of chemosensor technology, Fraunhofer IPMS develops sensors for the detection of ion concentrations and conductivities in aqueous solutions.
- Design and development of ISFET chips and wafer test structures
- Metrological testing and characterization at wafer level (modeling for sensor operating point prediction, layer characterization and wafer area evaluation)
- Development and design of assembly and connection technologies for use as sensors (module concept) including investigations and developments for polymer insulation of ISFET chips and the evaluation and testing of sensor seals
- Metrological testing and characterization in aqueous solution (pH0-14, 0-95°C) with the development, testing and automation of measurement and characterization sequences
- Development and pilot production of ISFET chips for integrators, system developers and industry. The main areas of application are environmental sensors, indoor farming, agriculture and water management as well as lifestyle and healthcare products.
- Development and pilot production of ISFET arrays based on n-trough technology
- Development and pilot production of ion-selective ISFETs
Sensor chip parameters
- Chip size: 5x5 mm2
- Operating point: e. g. VDS - 0,5 V; IDS = 190...170 µA
- Reference electrode is needed
- Fraunhofer IPMS n-Well ISFET allows multiple separate ISFETS on one chip
| Parameter | Min | Typ | Max | CONdition | Units |
|---|---|---|---|---|---|
| Sensitivity | 56 | 58,2 | 60 | 20 °C | mV/pH |
| Drift | 20 | 40 | ph 7 | µV / h | |
| Response time (accuracy 0,02 pH) | 5 | 8 | pH 4-7 (bei 25 °C) | s | |
| Temperature | 5 | 80 | pH 1-13 | °C | |
| pH range | 1 | 13 | pH | ||
| Pressure | 10 | 100 | kPa |
