Organic semiconductor sensor device

• US 8,569,809 B2
• Filed: 10/13/2006
• Issued: 10/29/2013
• Est. Priority Date: 09/25/2002
• Status: Active Grant

• Current Assignee: STMicroelectronics Incorporated (STMicroelectronics NV)
• Original Assignee: STMicroelectronics Incorporated (STMicroelectronics NV)
• Inventors: Thomas, Danielle A., Debeurre, Bruno J., Thoma, Peter J.
• Primary Examiner(s): HUBER, ROBERT T
• Application Number:
  US11/580,582
• Publication Number:
  US 20070029583A1
• Time in Patent Office: 2,573 Days
• Field of Search: 257/252, 257/253, 257/414, 257/E51.006, 257/E29.255
• US Class Current: 257/253
• CPC Class Codes: G01L 1/146 for measuring force distributions, e.g. using force arrays G01L1/148 takes precedence
• CPC Class Codes: G01L 1/148 using semiconductive material, e.g. silicon
• CPC Class Codes: G01N 27/4145 specially adapted for biomolecules, e.g. gate electrode with immobilised receptors
• CPC Class Codes: G01N 27/4148 Integrated circuits therefor, e.g. fabricated by CMOS processing CMOS processing per se H01L21/82
• CPC Class Codes: G06V 40/1306 non-optical, e.g. ultrasonic or capacitive sensing
• CPC Class Codes: H10K 10/46 Field-effect transistors, e.g. organic thin-film transistors [OTFT] H10K10/43 takes precedence
• CPC Class Codes: H10K 39/32 Organic image sensors

Abstract

Sensor cells are arranged in an array in an organic semiconductor layer. Row and column select circuitry addresses the cells of the array one cell at a time to determine the presence of an object, such as a fingerprint ridge or valley, contacting or proximate to a sensing surface above each cell. Control circuitry can be provided in a companion silicon chip or in a second layer of organic semiconductor material to communicate with the array and an associated system processor. The array of sensor cells can be fabricated using a flexible polymer substrate that is peeled off and disposed of after contacts have been patterned on the organic semiconductor layer. The organic semiconductor layer can be used with a superimposed reactive interface layer to detect specific chemical substances in a test medium.

Claims

1. A sensor device, comprising:

a substrate having an upper surface with contacts thereon;

a first organic semiconductor layer supported above the substrate, the first organic semiconductor layer including a plurality of sensor cells therein and comprising a grounded surface grid, the grounded surface grid comprising a plurality of doped p-type lines arranged in a grid and adjacent to a top surface of the first organic semiconductor layer;

a second organic semiconductor layer positioned between the first organic semiconductor layer and the substrate, the second organic semiconductor layer comprising a control unit for the sensor device and a plurality of conductors on a bottom surface of the second organic semiconductor layer, the conductors configured to communicate with the contacts, the control unit configured to selectively access each of the plurality of sensor cells;

a reactive interface layer disposed on the first organic semiconductor layer and having an exposed upper surface, the reactive interface layer comprising a polymer containing a chemical that is selectively reactive to a specific substance in contact with the exposed upper surface; and

a frame extending outward from the substrate and adjacent to an edge of the reactive interface layer, the second organic semiconductor layer, and the first organic semiconductor layer, the frame comprising a frame portion that extends over and contacts a portion of a top surface of the reactive interface layer, the frame configured to secure the layers to the substrate;

wherein a depletion region in each sensor cell is configured to vary in at least one dimension in response to a reaction in the reactive interface layer of the chemical therein with the specific substance, the variation in the at least one dimension of the depletion region configured to cause a variation in a capacitance in the sensor cell.

2. The sensor device of claim 1 wherein the chemical is an enzyme.

3. The sensor device of claim 2 wherein the enzyme is glucose oxidase and the specific substance is glucose.

4. The sensor device of claim 1, wherein the capacitance in each sensor cell is a capacitance of a junction field-effect transistor (JFET) channel formed between the depletion region and the reactive interface layer.

5. The sensor device of claim 1, wherein the plurality of conductors are coupled to the contacts.

6. The sensor device of claim 1, wherein the dimension of the depletion region is reduced and the capacitance in each sensor cell is increased in response to the reaction in the reactive interface layer.

7. The sensor device of claim 1, wherein at least one of the contacts is coupled to a power source via a switch.

8. A sensor device, comprising:

a substrate having an upper surface with contacts thereon;

a first organic semiconductor layer supported above the substrate, the first organic semiconductor layer including a plurality of sensor cells and comprising a grounded surface grid, the grounded surface grid comprising a plurality of doped p-type lines arranged in a grid and adjacent to a top surface of the first organic semiconductor layer;

a second organic semiconductor layer positioned between the first organic semiconductor layer and the substrate, the second organic semiconductor layer comprising a control unit for the sensor device and a plurality of conductors on a bottom surface of the second organic semiconductor layer, the conductors configured to communicate with the contacts, the control unit configured to selectively access each of the plurality of sensor cells;

a reactive interface layer disposed on the first organic semiconductor layer and having an exposed upper surface, the reactive interface layer comprising a plurality of regions, each region comprising a chemical that is selectively reactive to a specific substance in contact with the exposed upper surface, wherein at least two of the regions comprise different chemicals; and

a frame extending outward from the substrate and adjacent to an edge of the reactive interface layer, the second organic semiconductor layer, and the first organic semiconductor layer, the frame comprising a frame portion that extends over and contacts a portion of a top surface of the reactive interface layer, the frame configured to secure the layers to the substrate;

wherein a depletion region in at least one of the sensor cells is configured to vary in at least one dimension in response to a reaction in the reactive interface layer of at least one of the chemicals therein with the specific substance, the variation in the at least one dimension of the depletion region configured to cause a variation in a capacitance in the at least one sensor cell.

9. The sensor device of claim 8 wherein each chemical is an enzyme.

10. The sensor device of claim 9 wherein one of the enzymes is glucose oxidase and the specific substance is glucose.

11. The sensor device of claim 8, wherein the control unit comprises a plurality of column select transistors and row select transistors.

12. The sensor device of claim 8, wherein the conductors are coupled to the contacts.

13. The sensor device of claim 8, wherein at least one of the contacts is coupled to a power source via a switch.

20. The sensor device of claim 8, wherein the capacitance in each sensor cell is a capacitance of a junction field-effect transistor (JFET) channel formed between the depletion region and the reactive interface layer.

14. A sensor device, comprising:

a substrate having an upper surface with contacts thereon;

a first organic semiconductor layer supported above the substrate, the first organic semiconductor layer including an array of sensor cells and comprising a grounded surface grid, the grounded surface grid comprising a plurality of doped p-type lines arranged in a grid and adjacent to a top surface of the first organic semiconductor layer;

a second organic semiconductor layer positioned between the first organic semiconductor layer and the substrate, the second organic semiconductor layer comprising a control unit for the sensor device and a plurality of conductors on a bottom surface of the second organic semiconductor layer, the conductors configured to communicate with the contacts, the control unit configured to selectively access each of the array of sensor cells;

a reactive interface layer disposed on the first organic semiconductor layer and having an exposed upper surface, the reactive interface layer comprising a plurality of regions, each region located above a corresponding sensor cell in the array in the first organic semiconductor layer, each region comprising a chemical in a polymer, the chemical selectively reactive to a specific substance in contact with the exposed upper surface; and

a frame extending outward from the substrate and adjacent to an edge of the reactive interface layer, the second organic semiconductor layer, and the first organic semiconductor layer, the frame comprising a frame portion that extends over and contacts a portion of a top surface of the reactive interface layer, the frame configured to secure the layers to the substrate;

wherein a depletion region in at least one of the array of sensor cells is configured to vary in at least one dimension in response to a reaction in at least one region of the reactive interface layer of the chemical therein with the specific substance, the variation in the at least one dimension of the depletion region configured to cause a variation in a capacitance in the at least one sensor cell.

15. The sensor device of claim 14 wherein each chemical is an enzyme.

16. The sensor device of claim 15 wherein one of the enzymes is glucose oxidase and the specific substance is glucose.

17. The sensor device of claim 14, wherein the control unit comprises a plurality of column select transistors and row select transistors.

18. The sensor device of claim 14, wherein the conductors are coupled to the contacts.

19. The sensor device of claim 14, wherein at least one of the contacts is coupled to a power source via a switch.