ION-SELECTIVE FIELD-EFFECT TRANSISTOR Russian patent published in 1997 - IPC

FIELD: semiconductor transducers for determination of various chemical substances in solutions by potentiometric methods of analysis in medicine, biology, agriculture, and in environment monitoring systems. SUBSTANCE: ion-selective field-effect transistor, including a single-crystal substrate carrying a gate containing successively applied layers of silicon dioxide and tantalum pentoxide, and an ion-sensitive membrane plasticized in a polyvinyl-chloride matrix additionally uses an intermediate layer of polymeric compound, 1 to 3 mcm thick, selected from the class of comb-shaped polymers based on polyalkylmethacrylates or polyalkylacrylates, with the length of the alkyl chain within C₁₀-C₂₂; the intermediate layer is positioned between the layer of tantalum pentoxide of the gate and ion-selective membrane. EFFECT: improved design. 1 dwg, 1 tbl