GAS-SENSITIVE SENSOR BASED ON FIELD-EFFECT TRANSISTOR AND PROCESS OF DETERMINATION OF CONCENTRATION OF GASES Russian patent published in 2001 - IPC

FIELD: primary converters of concentration of gases to electric signals. SUBSTANCE: multilayer dielectric film having windows for gate, in regions of source, drain and contacts of polysilicon heater is deposited on surface of silicon substrate on which gas-sensitive field-effect transistor with polysilicon heater is formed. On reverse side substrate under field-effect transistor is etched to thickness limited by depth of source and drain and their regions of spatial discharge. Substrate around transistor is etched to multilayer dielectric film. Dissociation and adsorption of large spectrum of hydrogen-carrying gases in catalytic electrode of gate are achieved by heating of active part of sensor to temperature of 800 C and fast cooling of active part thanks to small time constant to low working temperature of 100-150 C " freezes " hydrogen in electrode and makes it feasible to measure concentration of various gases. EFFECT: reduced energy consumption, expanded range of diagnosed gases by gas-sensitive sensor based on field-effect transistor. 2 cl, 2 dwg