CVD-Al2O3-Layers: Applicability in Sensor Devices

A convenient method for measuring the ionic concentration in aqueous solutions is the use of ion sensitive field effect transistors (ISFET). The performance of these sensors and especially sensitivity and long- time- stability are mainly influenced by the membrane layer situated above the transistor gate. The aim of our investigations was to test the aluminum oxide layers deposited by CVD technique with regard to their applicability as membrane layers. This paper contains a brief description of the deposition technique and statements about the performance of so manufactured sensors.