INFLUENCE OF THE LAF3 METAL INTERFACE ON THE PROPERTIES OF A LOW-TEMPERATURE OXYGEN SENSOR

The oxygen sensitive field effect structure Si/LaF3/metal was realized . To find correlations to sensor response time and to improve sensor c haracteristics the composition of the LaF3 surface was changed in a de fined manner by means of a pretreatment and a variation of the prepara tion parameters of the LaF3 layer. It could be shown by means of XPS m easurements that there is a correlation between the surface concentrat ion of different oxygen species in LaF3 and the response kinetics of t he sensor structure. To get information concerning the influence of th e catalytic metal the preparation parameters of the platinum layer wer e varied and new gate materials as for instance gold and iridium were used. A model is given to explain these results.