METHODS FOR MANUFACTURING MICROWELL STRUCTURES OF CHEMICALLY-SENSITIVE SENSOR ARRAYS

• US 20120329192A1
• Filed: 08/30/2012
• Published: 12/27/2012
• Est. Priority Date: 05/29/2009
• Status: Abandoned Application

• Current Assignee: Life Technologies Corporation (Thermo Fisher Scientific Incorporated)
• Original Assignee: Life Technologies Corporation (Thermo Fisher Scientific Incorporated)
• Inventors: BUSTILLO, James, Milgrew, Mark
• Application Number:
  US13/599,886
• Publication Number:
  US 20120329192A1
• Time in Patent Office: Days
• US Class Current: 438/49
• CPC Class Codes: C12Q 1/6869 Methods for sequencing
• CPC Class Codes: C12Q 1/6874 involving nucleic acid arrays, e.g. sequencing by hybridisation
• CPC Class Codes: G01N 27/27 Association of two or more measuring systems or cells, each measuring a different parameter, where the measurement results may be either used independently, the systems or cells being physically associated, or combined to produce a value for a further parameter
• 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
• CPC Class Codes: G01N 27/4148 Integrated circuits therefor, e.g. fabricated by CMOS processing CMOS processing per se H01L21/82
• CPC Class Codes: G01N 33/54373 involving physiochemical end-point determination, e.g. wave-guides, FETS, gratings
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

Methods and apparatus relating to 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 method for manufacturing a sensor, comprising:

forming an array of chemically-sensitive field effect transistors (chemFETs), each chemFET in the array having a floating gate structure including a sensing surface;

depositing a dielectric layer over the sensing surfaces of the floating gate structures of the chemFETs in the array;

etching the dielectric layer to define cavities exposing the sensing surfaces of the floating gate structures; and

depositing a layer of sensing material within the cavities and lining sidewalls of the cavities to define microwells having sensing layers contacting the sensing surfaces of the floating gate structures.

2. The method of claim 1, wherein the dielectric layer comprises at least one of silicon oxide, silicon nitride and silicon oynitride.

3. The method of claim 1, wherein the sensing material comprises tantalum oxide.

4. The method of claim 1, wherein the sensing material is a metal oxide or metal nitride selected from one or more of the group of Al₂O₃, Ta₂O₅, HfO₃, WO₃ or mixtures thereof.

5. The method of claim 1, wherein the sensing material includes Al₂O₃, and Ta₂O₅ over the Al₂O₃.

6. The method of claim 1, wherein the chemFETs in the array provide signals indicating an ion-concentration in an analyte solution coupled to the floating gate via the microwells.

7. The method of claim 1, wherein the microwells have non-circular cross-sections.

8. A method of manufacturing a sequencing device, comprising:

forming an array of chemically-sensitive field effect transistors (chemFETs), each chemFET in the array having a floating gate structure;

depositing a dielectric layer over the floating gate structures of the chemFETs in the array;

etching the dielectric layer to define cavities to expose upper surfaces of the floating gate structures;

depositing a layer of sensing material within the cavities, thereby forming microwells having sensing layers contacting the upper surfaces of the floating gate structures; and

forming a microfluidic structure in fluid flow communication with the array of microwells, and arranged to deliver analytes for sequencing.

9. The method of claim 8, wherein the dielectric layer comprises at least one of silicon oxide, silicon nitride and silicon oxynitride.

10. The method of claim 8, wherein the sensing material comprises tantalum oxide.

11. The method of claim 8, wherein the sensing material is a metal oxide or metal nitride selected from one or more of the group of Al₂O₃, Ta₂O₅, HfO₃, WO₃, or mixtures thereof.

12. The method of claim 8, wherein the sensing material includes Al₂O₃, and Ta₂O₅ over the Al₂O₃.

13. The method of claim 8, wherein the microwells have non-circular cross-sections.