Chemical sensor with air via

Patent metadata

Field	Value
Publication number	US-10386328-B2
Application number	US-201715700630-A
Country	US
Kind code	B2
Filing date	Sep 11, 2017
Priority date	Sep 9, 2016
Publication date	Aug 20, 2019
Grant date	Aug 20, 2019

Abstract

In one embodiment, a chemical sensor is described. The chemical sensor includes a chemically-sensitive field effect transistor including a floating gate conductor having an upper surface, a first opening extending through a first material and through a portion of a second material located on the first material and a second opening extending from the bottom of the first opening to the top of a liner layer located on the upper surface of the floating gate conductor.

First claim

What is claimed is:

1. A method for manufacturing a chemical sensor, the method comprising:
forming a chemically-sensitive field effect transistor including a floating gate conductor having an upper surface;
forming a metal layer on the upper surface;
forming a first material over the floating gate conductor and the metal layer, the first material comprising an insulator;
forming a first opening in the first material extending from the upper surface of the first material to the metal layer by anisotropically etching a portion of the first material to the metal layer;
filling the first opening with a filler material including tungsten, titanium, or tantalum, the filler in direct contact with the first material;
depositing a second material on the surface of the first material and the filler material;
forming a second opening extending through the second material and a portion of the first material by etching the second material and a portion of the first material below a top surface of the filler material to expose the filler material in a void left by the etched portion of the first material; and
removing the filler material from the first opening.

2. The method of claim 1 , further comprising:
forming a liner layer on the metal layer prior to forming an opening in the first material.

3. The method of claim 2 , wherein the liner layer includes titanium nitride.

4. The method of claim 1 , wherein the insulator includes an oxide.

5. The method of claim 1 , wherein the second material includes a dielectric material.

6. The method of claim 5 , wherein the dielectric material includes a nitride or oxide of silicon.

7. The method of claim 1 , wherein the forming the second opening includes etching the first material and the second material during the same etch step.

8. The method of claim 1 , wherein the second opening is a well.

9. The method of claim 1 , wherein forming the second opening includes forming an opening having a larger area than the area of the first opening.

Assignees

• Life Technologies Corp

Inventors

• Li James
• Owens Jordan
• Bustillo James

Classifications

• G01N27/128

  Microapparatus · CPC title

• G01N27/4148 Primary

  Integrated circuits therefor, e.g. fabricated by CMOS processing · CPC title

• G01N27/4143

  Air gap between gate and channel, i.e. suspended gate [SG] FETs (work function measurement per se G01N27/002) · CPC title

• B01L2300/0636

  Integrated biosensor, microarrays · CPC title

• G01N27/125

  Composition of the body, e.g. the composition of its sensitive layer · CPC title