Chemical sensor with sidewall spacer sensor surface

• US 8,963,216 B2
• Filed: 03/13/2013
• Issued: 02/24/2015
• Est. Priority Date: 03/13/2013
• Status: Active Grant

• Current Assignee: Life Technologies Corporation (Thermo Fisher Scientific Incorporated)
• Original Assignee: Life Technologies Corporation (Thermo Fisher Scientific Incorporated)
• Inventors: Fife, Keith, Bustillo, James, Owens, Jordan
• Primary Examiner(s): ARMAND, MARC ANTHONY
• Application Number:
  US13/801,002
• Publication Number:
  US 20140264464A1
• Time in Patent Office: 713 Days
• Field of Search: 257/253, 438/49
• US Class Current: 257/253
• CPC Class Codes: G01N 27/414 Ion-sensitive or chemical field-effect transistors, i.e. ISFETS or CHEMFETS
• CPC Class Codes: G01N 27/4145 specially adapted for biomolecules, e.g. gate electrode with immobilised receptors

Abstract

In one implementation, a chemical sensor is described. The chemical sensor includes chemically-sensitive field effect transistor including a floating gate conductor having an upper surface. A dielectric material defines an opening extending to the upper surface of the floating gate conductor. A conductive sidewall spacer is on a sidewall of the opening and contacts the upper surface of the floating gate conductor.

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

a conductive sidewall spacer on a sidewall of the opening and contacting the upper surface of the floating gate conductor;

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.

2. The chemical sensor of claim 1, wherein the conductive sidewall spacer includes an inner surface surrounding a reaction region for the chemical sensor.

3. The chemical sensor of claim 1, wherein the conductive sidewall spacer comprises an electrically conductive material, and an inner surface of the conductive sidewall spacer includes an oxide of the electrically conductive material.

4. The chemical sensor of claim 1, wherein a sensing surface for the chemical sensor includes an inner surface of the conductive sidewall spacer and the upper surface of the floating gate conductor.

5. The chemical sensor of claim 1, wherein the conductive sidewall spacer comprises material different from material at the upper surface of the floating gate conductor.

6. The chemical sensor of claim 1, wherein the chemically-sensitive field effect transistor generates a sensor signal in response to a chemical reaction occurring proximate to the conductive sidewall spacer.

7. 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.

8. The chemical sensor of claim 2, wherein the inner surface of the conductive sidewall spacer is an outer surface of the reaction region, and the upper surface of the floating gate conductor is a bottom surface of the reaction region.

9. The chemical sensor of claim 4, wherein the sensing surface is sensitive to hydrogen ions.

10. The chemical sensor of claim 6, wherein the chemical reaction is a sequencing reaction.