# US 10,481,124 B2 · Chemical device with thin conductive element

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- Number: US 10,481,124 B2
- Document ID: US10481124B2
- Status: Granted
- Kind: B2
- Application number: 15/818,718
- Filed: 2017-11-20
- Published: 2018-06-28
- Granted: 2019-11-19
- Earliest claimed: 2013-03-15
- Assignees: Life Technologies Corporation
- Applicants: Life Technologies Corporation
- Inventors: Keith G. Fife; Jordan Owens; Shifeng Li; James Bustillo
- Web page: https://patentgrep.com/patent/US10481124B2

## CPC

- G01N 27/414: Ion-sensitive or chemical field-effect transistors, i.e. ISFETS or CHEMFETS
- B01L 3/502761: {specially adapted for handling suspended solids or molecules independently from the bulk fluid flow, e.g. for trapping or sorting beads or physically stretching molecules}
- G01N 27/4148: {Integrated circuits therefor, e.g. fabricated by CMOS processing}
- B01L 2200/0668: Trapping microscopic beads
- B01L 2300/0636: Integrated biosensor, microarrays
- B01L 2300/0877: Flow chambers
- G01N 27/4145: {specially adapted for biomolecules, e.g. gate electrode with immobilised receptors}
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)
- B01L: CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE

## Abstract

In one implementation, a chemical device is described. The sensor includes a chemically-sensitive field effect transistor including a floating gate structure having a plurality of floating gate conductors electrically coupled to one another. A conductive element overlies and is in communication with an uppermost floating gate conductor in the plurality of floating gate conductors. The conductive element is wider and thinner than the uppermost floating gate conductor. A dielectric material defines an opening extending to an upper surface of the conductive element.

## Claims

### Claim 1

A chemical device, comprising:
a chemically-sensitive field effect transistor including a floating gate structure comprising a plurality of floating gate conductors electrically coupled to one another;
a conductive element overlying and in communication with an uppermost floating gate conductor in the plurality of floating gate conductors, the conductive element wider and thinner than the uppermost floating gate conductor, the conductive element comprising titanium nitride; and
a dielectric material defining an opening extending to an upper surface of the conductive element.

### Claim 2 (depends on 1)

The chemical device of claim 1, further comprising an adjacent conductive element, wherein a distance between the conductive element and the adjacent conductive element in the chemical device is about 0.18 microns.

### Claim 3 (depends on 1)

The chemical device of claim 1, wherein the thickness of the conductive element is about 0.1-0.2 microns.

### Claim 4 (depends on 1)

The chemical device of claim 1, wherein the uppermost floating gate conductor in the plurality of floating gate conductors has a thickness greater than a thickness of other floating gate conductors in the plurality of floating gate conductors.

### Claim 5 (depends on 1)

The chemical device of claim 1, wherein the conductive element comprises a material different from a material comprising the uppermost floating gate conductor.

### Claim 6 (depends on 1)

The chemical device of claim 1, wherein an inner surface of the dielectric material and the upper surface of the conductive element define an outer surface of a reaction region for the chemical device.

### Claim 7 (depends on 1)

The chemical device of claim 1, wherein the plurality of floating gate conductors is within a layer that includes array lines and bus lines.

### Claim 8 (depends on 1)

The chemical device of claim 1, including a sensor region containing the chemically-sensitive field effect transistor and a peripheral region containing peripheral circuitry to obtain a signal from the chemically-sensitive field effect transistor.

### Claim 9 (depends on 8)

The chemical device of claim 8, wherein the conductive element is within a conductive layer that is only within the sensor region.

### Claim 10 (depends on 8)

The chemical device of claim 8, wherein the conductive element comprises a material not within the peripheral region.

### Claim 11 (depends on 1)

The chemical device of claim 1, wherein the plurality of floating gate conductors are electrically coupled to one another and separated by dielectric layers.

### Claim 12 (depends on 1)

The chemical device of claim 1, wherein a first layer of the dielectric material is silicon nitride and a second layer is at least one of silicon dioxide and tetraethyl orthosilicate, and the second layer defines sidewalls of the opening.

### Claim 13 (depends on 1)

The chemical device 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.

### Claim 14

A method for manufacturing a chemical device, the method comprising:
forming a chemically-sensitive field effect transistor including a floating gate structure comprising a plurality of floating gate conductors electrically coupled to one another;
forming a conductive element overlying and in communication with an uppermost floating gate conductor in the plurality of floating gate conductors, the conductive element wider and thinner than the uppermost floating gate conductor, the conductive element comprising titanium nitride; and
forming a dielectric material defining an opening extending to an upper surface of the conductive element.

### Claim 15 (depends on 14)

The method for manufacturing a chemical device of claim 14, wherein the upper surface of the conductive element defines a bottom surface of a reaction region for the chemical device.

### Claim 16 (depends on 14)

The method for manufacturing a chemical device of claim 14, wherein an inner surface of the dielectric material and the upper surface of the conductive element define an outer boundary of a reaction region for the chemical device.

### Claim 17 (depends on 14)

The method for manufacturing a chemical device of claim 14, wherein the conductive element is formed within a conductive layer that is only within a sensor region of the chemical device.