ChemFET sensor including floating gate

• US 9,958,415 B2
• Filed: 05/04/2015
• Issued: 05/01/2018
• Est. Priority Date: 09/15/2010
• Status: Active Grant

• Current Assignee: Life Technologies Corporation (Thermo Fisher Scientific Incorporated)
• Original Assignee: Life Technologies Corporation (Thermo Fisher Scientific Incorporated)
• Inventors: Rothberg, Jonathan M., Rearick, Todd
• Primary Examiner(s): GORDON, MATTHEW E
• Application Number:
  US14/703,752
• Publication Number:
  US 20160061772A1
• Time in Patent Office: 1,093 Days
• Field of Search: 257253, 257E2308, 438 10
• CPC Class Codes: C12Q 1/6874 involving nucleic acid arrays, e.g. sequencing by hybridisation
• 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

Abstract

Methods and apparatus relating to FET arrays including large FET arrays for monitoring chemical and/or biological reactions such as nucleic acid sequencing-by-synthesis reactions. Some methods provided herein relate to improving signal (and also signal to noise ratio) from released hydrogen ions during nucleic acid sequencing reactions.

Claims

1. A chemical sensor, comprising:

a chemically-sensitive field effect transistor including a floating gate conductor having an upper surface;

a dielectric material defining an opening extending to the upper surface of the floating gate conductor; and

an electrode capacitively coupled to the floating gate conductor;

wherein an electrically conductive material is disposed on the upper surface of the floating gate conductor and wherein the dielectric material defines a sidewall of the opening, and the electrically conductive material extends incompletely up the sidewall.

2. The chemical sensor of claim 1, wherein the electrode is capacitively coupled to the upper surface of the floating gate conductor.

3. The chemical sensor of claim 2, wherein the electrode is electrically isolated from the floating gate conductor.

4. The chemical sensor of claim 1, wherein the floating gate conductor is coupled to the opening via a passivation layer.

5. The chemical sensor of claim 4, wherein the passivation layer is sensitive to hydrogen ions.

6. The chemical sensor of claim 1, further comprising:

a microfluidic structure in fluid flow communication with the chemically-sensitive field effect transistor, and arranged to deliver analytes for sequencing.

7. The chemical sensor of claim 1, wherein the chemically-sensitive field effect transistor includes a floating gate structure comprising a plurality of conductors electrically coupled to one another and separated by dielectric layers, and the floating gate conductor is an uppermost conductor in the plurality of conductors.

8. The chemical sensor of claim 4, wherein the chemically-sensitive field effect transistor generates a sensor signal in response to a chemical reaction occurring proximate to the passivation layer.

9. The chemical sensor of claim 8, wherein the chemical reaction is a sequencing reaction.

10. The chemical sensor of claim 1, wherein the chemically-sensitive field effect transistor is electrically addressable via the electrode.

11. The chemical sensor of claim 1, wherein the opening defines a reaction chamber, and further comprising:

a reference electrode coupled to the reaction chamber.