Negative capacitance semiconductor sensor

Patent metadata

Field	Value
Publication number	US-11289601-B2
Application number	US-201916717991-A
Country	US
Kind code	B2
Filing date	Dec 17, 2019
Priority date	Dec 18, 2018
Publication date	Mar 29, 2022
Grant date	Mar 29, 2022

Abstract

A semiconductor sensor includes a source element; a drain element; and a semiconductor channel element between the source element and the drain element, forming an electrically conductive channel. An insulator is positioned between the semiconductor channel element and a solution to be sensed. A reference contacts the solution and sets an electric potential of the solution. A bias voltage source generates an external sensor bias voltage for electrically biasing the reference electrode. A sensing surface interacts with the solution comprising analytes for generating a surface potential change at the sensing surface dependent on the concentration of analytes. The sensor further includes a ferroelectric capacitance element between the insulator and the bias voltage source for generating a negative capacitance for a differential gain between the external sensor bias voltage and an internal sensor bias voltage sensed at a surface of the channel element facing the insulator or ferroelectric capacitance element.

First claim

The invention claimed is:

1. A semiconductor sensor comprising:
a source element;
a drain element;
a semiconductor channel element between the source element and the drain element for forming an electrically conductive channel;
a first insulator between the semiconductor channel element and a solution to be sensed;
a reference electrode configured to be in contact with the solution, the reference electrode being configured to set an electric potential of the solution;
a bias voltage source for generating an external sensor bias voltage for electrically biasing the reference electrode; and
a sensing surface for interacting with the solution comprising analytes for generating a surface potential change at the sensing surface dependent upon the concentration of the analytes in the solution,
wherein the semiconductor sensor comprises a ferroelectric capacitance element for generating a negative capacitance for providing a differential gain between the external sensor bias voltage and an internal sensor bias voltage sensed at a surface of the channel element facing the first insulator, and wherein the ferroelectric capacitance element is placed between the bias voltage source and the reference electrode such that the bias voltage is connected through the ferroelectric capacitance element to the reference electrode, and such that the bias voltage source, the ferroelectric capacitance element, and the reference electrode are in a series configuration.

2. The sensor according to claim 1 , wherein the negative capacitance is matched with a stabilising capacitance of the sensor such that an overall capacitance of the sensor consisting of the negative capacitance and the stabilising capacitance is positive.

3. The sensor according to claim 1 , wherein the external sensor bias voltage is a periodic signal.

4. The sensor according to claim 3 , wherein the periodic signal has one of the following waveform shapes: sawtooth, sine and triangle.

5. The sensor according to claim 3 , wherein the sensor further comprises a measurement unit arranged to measure electric current in the channel element at given periodic time intervals such that the value of the external sensor bias voltage is substantially constant for different current measurements.

6. The sensor according to claim 1 , wherein the sensor further comprises a measurement unit arranged to measure a peak shift of the differential gain along an axis representing the external sensor bias voltage for measuring an analyte concentration in the solution.

7. The sensor according to claim 1 , wherein the sensor is one of the following: an ion-sensitive field-effect transistor, a chemical field-effect transistor, field-effect transistor-based biosensor and a tunnel field-effect transistor.

8. The sensor according to claim 1 , wherein the sensor comprises an electrically conductive layer between the ferroelectric capacitance element and the first insulator.

9. The sensor according to claim 1 , wherein the sensor comprises an extended gate configuration such that an electrically conductive layer is provided on the outside of the sensor and faces the solution, the electrically conductive layer being conductively connected to the first insulator.

10. The sensor according to claim 1 , wherein the thickness of the channel element is less than 100 nm and/or the channel element is fully depleted.

11. The sensor according to claim 1 , wherein the sensor further comprises a base substrate and a buried oxide layer, which is between the base substrate and the channel element.

12. A method of sensing a given property of a solution by using the semiconductor sensor according to claim 1 , the method comprising:
applying a periodic external sensor bias voltage to the reference electrode for electrically biasing the reference electrode; and measuring electric current in the channel element at given periodic time intervals such that the value of the external sensor bias voltage is substantially constant for different measurements; and/or
measuring a peak shift of the differential gain along an axis representing the external sensor bias voltage for measuring an analyte concentration in the solution.

13. A wearable device comprising the sensor according to claim 1 .

14. A wearable device comprising the sensor according to claim 2 .

15. A wearable device comprising the sensor according to claim 3 .

16. A wearable device comprising the sensor according to claim 4 .

17. A wearable device comprising the sensor according to claim 5 .

18. A wearable device comprising the sensor according to claim 6 .

19. A wearable device comprising the sensor according to claim 7 .

20. A wearable device comprising the sensor according to claim 8 .

Assignees

• Ecole Polytechnique Fed Lausanne Epfl
• Ecole Poly Technique Fed De Lausanne Epfl

Inventors

• Ionescu Mihai Adrian
• Bellando Francesco
• Saeidi Ali

Classifications

• H10D30/701 Primary

  IGFETs having ferroelectric gate insulators, e.g. ferroelectric FETs · CPC title

• H10D30/0415

  of FETs having ferroelectric gate insulators · CPC title

• H10D64/685

  being perpendicular to the channel plane · CPC title

• H10D30/027

  of lateral single-gate IGFETs · CPC title

• G01N27/4145 Primary

  specially adapted for biomolecules, e.g. gate electrode with immobilised receptors · CPC title