Selective chemical sensitive FET transducers
First Claim
1. A chemical sensitive field-effect transistor transducer unit for detecting chemical properties of substances to which the unit is exposed and including a transducer which comprises:
- a semi-conductor substrate having a doping polarity,a pair of spaced apart diffusion regions located at the surface of said substrate material,an electrical insulator material overlying at least a portion of said diffusion regions and the surface of the substrate material lying between the diffusion regions,a chemical selective system containing a chemical selective membrane overlying said insulator material, anda reference electrode connected in circuit relationship with said spaced apart diffusion regions through a potential source such that a potential is created and added to the potential generated in the chemical selective membrane the combination of which affects the conductivity between said diffusion regions as a measure of the chemical properties of said substances.
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Reexamination
Accused Products
Abstract
A chemical sensitive field-effect transistor transducer capable of selectively detecting and measuring chemical properties of substances to which the transducer is exposed. The transducer includes a semiconductor substrate material having a certain doping polarity, a pair of spaced apart diffusion regions located at the surface of the substrate material and having a doping polarity opposite that of the substrate material, electrical insulator material overlying the diffusion regions and the surface of the substrate material lying between the diffusion regions, and a chemical selective system overlying the insulator material. The chemical selective system is adapted to interact with certain substances and thereby modulate an electric field produced in the substrate material between the diffusion regions. This modulation is dependent upon the chemical properties of the substances and provides a measure of those chemical properties. The chemical selective system may include various structures for measuring ion activity, immunochemical concentrations, reducible gas concentrations and the concentrations of enzymes and substrates.
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Citations
27 Claims
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1. A chemical sensitive field-effect transistor transducer unit for detecting chemical properties of substances to which the unit is exposed and including a transducer which comprises:
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a semi-conductor substrate having a doping polarity, a pair of spaced apart diffusion regions located at the surface of said substrate material, an electrical insulator material overlying at least a portion of said diffusion regions and the surface of the substrate material lying between the diffusion regions, a chemical selective system containing a chemical selective membrane overlying said insulator material, and a reference electrode connected in circuit relationship with said spaced apart diffusion regions through a potential source such that a potential is created and added to the potential generated in the chemical selective membrane the combination of which affects the conductivity between said diffusion regions as a measure of the chemical properties of said substances. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A chemical sensitive field-effect transistor transducer for detecting different chemical properties of a substance comprising:
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a semi-conductor substrate material having a doping polarity, a plurality of pairs of spaced apart diffusion regions located at the surface of said substrate and having a doping polarity opposite that of the substrate material, electrical insulator material overlying at least portions of each diffusion region and the surface of the substrate material lying between each pair of diffusion regions, a plurality of chemical selective systems, each containing a chemical selective membrane overlying the insulator material covering a different pair of diffusion regions and the substrate surface lying therebetween, and a reference electrode connected in circuit relationship with each pair of spaced apart diffusion regions through a potential source such that a potential is created and added to the potential generated in each chemical selective membrane the combination of which affects the conductivity between each pair of diffusion regions as a measure of the chemical property of said substance being detected at each pair of diffusion regions. - View Dependent Claims (22, 23, 24)
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25. A chemical sensitive field-effect transistor transducer unit for detecting chemical properties of substances to which the unit is exposed and including a transducer which comprises:
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a semi-conductor substrate having a doping polarity, a pair of spaced apart diffusion regions located at the surface of said substrate material, an electrical insulator material overlying at least a portion of said diffusion regions and the surface of the substrate material lying between the diffusion regions, a chemical selective system comprising; a pair of electrodes, one of which is positioned in contacting relation to the insulated material, a solid rare earth fluoride electrolyte material disposed between and maintained in contact with the electrodes, a constant current source coupled between said electrodes to polarize the electrodes, a selective first membrane overlying the other electrode not in contacting relation to the insulator material, and adapted to selectively pass certain reducible gases when exposed to a gas containing such reducible gases said constant current source being connected in circuit relationship with said spaced apart diffusion regions such that a potential is created and added to the potential generated between the electrodes by the reducible gases the combination of which affects the conductivity between said diffusion regions as a measure of the concentration of the reducible gases. - View Dependent Claims (26, 27)
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Specification