CAPACITIVELY CONTROLLED FIELD EFFECT TRANSISTOR GAS SENSOR COMPRISING A HYDROPHOBIC LAYER

摘要

The invention relates to a gas sensor (1) comprising a substrate (2) of a first charge carrier type whereon a drain (3) and a source (4) of a second charge carrier type are arranged. A channel area (8) is formed between the drain (3) and the source (4). The gas sensor (1) also comprises a gas sensitive layer (10) comprising poles (11, 12) between which a gas induced voltage is produced according to the concentration of a gas which is in contact with the layer (10). In order to measure said voltage, a pole (12) of the gas sensitive layer (10) is capacitatively coupled to the channel area (8) by means of an air gap (14) and the other pole (11) is connected to a counter-electrode (13) having a reference potential. A hydrophobic layer (19) is arranged on the surface of the gas sensor (1) between the gas sensitive layer (10) and the channel area (8) and/or on a sensor electrode which is connected to a gate electrode arranged on the channel area (8).