US4960722A
Expired / Lapsed
US
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Sensor using a field effect transistor and method of fabricating the same
Assignee: Panasonic Holdings Corp
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Filing: 1989-05-15
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Granted: 1990-10-02
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Expires: 2009-05-15
Abstract
Abstract Disclosed is a sensor using a field effect transistor. The sensor includes a field effect transistor having a gate electrode, a reactive monomolecular film formed on the surface of the gate electrode, and a sensing material fixed on the gate electrode through a reactive monomolecular film by the chemical bond. A sensing material is strongly bonded to the reactive monomolecular film in such manner that the sensing material is kept alive. Thereby, sensitivity of the sensor is improved.
Inventors
- 👤 Kazufumi Ogawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:56
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/403; G01N27/414; G01N27/4145; B; B82; B82Y; B82Y10/00; B82Y15/00; B82Y30/00; B82Y40/00; Y; Y10; Y10S; Y10S438/00; Y10S438/939
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
111 words
A method for making a sensor comprising the steps of: forming a field effect transistor on a semiconductor substrate, said field effect transistor having a gate electrode; forming a photoresist layer on said semiconductor substrate except the portion of said gate electrode; forming a reactive monomolecular film on the surface of said gate electrode, said reactive monomolecular film being formed by means of silane surface active agent having a reactive group; transforming the reactive group of said silane surface active agent into a hydroxyl group; transforming said hydroxyl group into an aldehyde group; fixing a sensing material made of proteins or enzymes to said aldehyde group; and removing said photoresist layer.
Claim 2
Independent Claim
111 words
A method for making a sensor comprising the steps of: forming a field effect transistor on a semiconductor substrate, said field effect transistor having a gate electrode; forming a photoresist layer on said semiconductor substrate except the portion of said gate electrode; forming a reactive monomolecular film on the surface of said gate electrode, said reactive monomolecular film being formed by means of silane surface active agent having a reactive group; transforming the reactive group of said silane surface active agent into a hydroxyl group; transforming said hydroxyl group into an aldehyde group; fixing a sensing material made of proteins or enzymes to said aldehyde group; and removing said photoresist layer.
Claim 3
Dependent Claim
23 words
The method of claim 1, wherein said reactive monomolecular film is fixed to the surface of said gate electrode by chemical adsorption process.
Claim 4
Dependent Claim
22 words
The method of claim 1, wherein said reactive monomolecular film is fixed to the surface of said gate electrode by Langmuir-Blodgett process.
Claim 5
Independent Claim
104 words
A method for making a sensor comprising the steps of: forming a field effect transistor on a semiconductor substrate, said field effect transistor having a gate electrode; forming a hydrophilic polymer photosensitive thin film having a sensing group on said semiconductor substrate; removing said hydrophilic polymer photosensitivie thin film from said semiconductor substrate except the portion on said gate electrode by use of a mask having an opening which corresponds to said gate electrode; transforming the sensing group of said hydrophilic high polymer photosensitive thin film into an aldehyde group; and fixing a sensing material composed of protein or enzyme to said aldehyde group.
Claim 6
Independent Claim
104 words
A method for making a sensor comprising the steps of: forming a field effect transistor on a semiconductor substrate, said field effect transistor having a gate electrode; forming a hydrophilic polymer photosensitive thin film having a sensing group on said semiconductor substrate; removing said hydrophilic polymer photosensitivie thin film from said semiconductor substrate except the portion on said gate electrode by use of a mask having an opening which corresponds to said gate electrode; transforming the sensing group of said hydrophilic high polymer photosensitive thin film into an aldehyde group; and fixing a sensing material composed of protein or enzyme to said aldehyde group.
Claim 7
Independent Claim
114 words
A method for making a sensor comprising the steps of: forming a field effect transistor on a semiconductor substrate, said field effect transistor having a gate electrode; forming a reactive monomolecular film on a surface of said semiconductor substrate, said reactive monomolecular film being formed by means of silane surface active agent having a reactive group; exposing said reactive monomolecular film with energy beam leaving only a portion on said gate electrode to deactivate said reactive monomolecular film; transforming the reactive group of said silane surface active agent into a hydroxyl group; transforming said hydroxyl group into an aldehyde group; and fixing a sensing material made of proteins or enzymes to said aldehyde group.
Claim 8
Independent Claim
114 words
A method for making a sensor comprising the steps of: forming a field effect transistor on a semiconductor substrate, said field effect transistor having a gate electrode; forming a reactive monomolecular film on a surface of said semiconductor substrate, said reactive monomolecular film being formed by means of silane surface active agent having a reactive group; exposing said reactive monomolecular film with energy beam leaving only a portion on said gate electrode to deactivate said reactive monomolecular film; transforming the reactive group of said silane surface active agent into a hydroxyl group; transforming said hydroxyl group into an aldehyde group; and fixing a sensing material made of proteins or enzymes to said aldehyde group.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-10-01 | 1994-04-02 | 1994-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-10-01 | 1998-04-02 | 1998-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-10-01 | 2002-04-02 | 2002-10-02 | $7700.00 | Window Closed / Lapsed |