Methods and apparatus for measuring analytes
AssigneeIon Torrent Systems Incorporated
InventorsJonathan M. Rothberg, James M. Bustillo, Mark J. Milgrew, Jonathan C. Schultz, David Marran, Todd M. Rearick, Kim L. Johnson
Life of this patent
Estimating the term…
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.
Claims27
An apparatus, comprising:
- an array of sensors, each sensor comprising one chemically-sensitive field effect transistor (chemFET), said chemFET having a floating gate structure;
- a layer of first material disposed over the sensor array and having formed therein a plurality of microwells, each microwell forming a cavity disposed over at least one of the chemFETS for receiving fluid analyte therein;
- and
- a layer of protection material on said floating gate structure to separate the material of the floating gate from the analyte,
- wherein the layer of protection material has a thickness over the floating gate structure of up to about 600 Angstroms.
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A method of forming an array of chemically-sensitive field effect transistors (chemFETs), each said chemFET having a floating gate structure, with a corresponding array of microwells disposed over the floating gate structures, each microwell forming a cavity disposed over the floating gate structure of at least one of the chemFETs for receiving fluid analyte therein, said method comprising:
- a. providing an array of chemFETs in a semiconductor substrate, the floating gate structures of the chemFETs being covered by a layer of protection material;
- b. depositing a layer of material over the protection material and removing portions of said material over the floating gate structures to form said microwells therein;
- and
- c. removing, if necessary, a portion of said layer of protection material so that a thickness of protection material of no more than about 600 Angstroms remains.
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A method of forming an array of chemically-sensitive field effect transistors (chemFETs), each said chemFET having a floating gate structure, with a corresponding array of microwells disposed over the floating gate structures, each microwell forming a cavity disposed over the floating gate structure of at least one of the chemFETs for receiving fluid analyte therein, said method comprising:
- a. providing an array of chemFETs in a semiconductor substrate, the floating gate structures of the chemFETs being covered by a layer of protection material;
- b. substantially completely removing the protection material over the floating gate structures to form cavities in the protection material over the floating gate structures;
- and
- c. depositing on the floating gate structures and sidewalls of said cavities a thin layer of a relatively high dielectric constant material and to a thickness of no more than about 600 Angstroms.
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Dependencies are inferred from the claim text.