Gassensor und Verfahren zur Detektion von einer oder mehrerer Komponenten eines Gasgemisches und/oder von Gasen in einer Flüssigkeit nach dem Prinzip der Austrittsarbeitsmessung

摘要

The invention relates to a gas sensor and a method for detecting one or more substances in a gas and/or a liquid, according to the work function principle. The invention is first characterised in that the gas sensor has two field effect structures - measurement FET and compensation FET (MessFET and KompFET), each comprising one channel (3,3') between a source and a drain region, in addition to a gate electrode (G) equipped with a sensitive material (8). The drain current (IDS) in the channel (3) of the MessFET can be influenced by a modification of the work function of the sensitive material (8), e.g. by the adsorption of molecules from the substance on the surface of the sensitive material (8). The temperature characteristic of the drain current (IDS) of the MessFET is referenced by a comparison with the drain current (IDS) of a compensation FET (KompFET). The invention is also characterised in that the channel (3) of the MessFET is protected by a guard electrode (10), which surrounds the channel (3), against electrical disturbances that occur more frequently in increased humidity.