Field effect transistor for detecting ionic material and method of detecting ionic material using the same

• US 8,035,175 B2
• Filed: 12/20/2006
• Issued: 10/11/2011
• Est. Priority Date: 04/26/2006
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Yoo, Kyu-tae, Lee, Kyu-sang, Shim, Jeo-young, Chung, Won-seok
• Primary Examiner(s): Pert; Evan
• Assistant Examiner(s): Rodela; Eduardo A
• Application Number:
  US11/613,258
• Publication Number:
  US 20070252176A1
• Time in Patent Office: 1,756 Days
• Field of Search: 257/213, 257/E51.045, 257/249, 257/318, 257/326, 257/448, 435/4, 435/287.1, 435/287.2
• US Class Current: 257/414
• CPC Class Codes: G01N 27/4145 specially adapted for biomolecules, e.g. gate electrode with immobilised receptors

Abstract

A field effect transistor for detecting ionic material and a method of detecting ionic material using the field effect transistor. The field effect transistor for detecting ionic material includes a substrate formed of a semiconductor material, a source region and a drain region spaced apart from each other in the substrate and doped with an opposite conductivity type to that of the substrate, a channel region interposed between the source region and the drain region, an insulating layer disposed on the channel region and formed of an electrically insulating material, a first reference electrode disposed at an edge of the upper portion of the insulating layer and a second reference electrode disposed to be spaced apart from the insulating layer.

Claims

1. A field effect transistor for detecting ionic material, the field effect transistor comprising:

a substrate formed of a semiconductor material;

a source region and a drain region spaced apart from each other in the substrate and doped with an opposite conductivity type to that of the substrate;

a channel region interposed between the source region and the drain region;

an insulating layer disposed on the channel region and formed of an electrically insulating material;

a first reference electrode disposed at an edge of the upper portion of the insulating layer;

wherein the first reference electrode has an opening in the center thereof, exposing the insulating layer, and

a second reference electrode disposed upon an upper surface of a separation layer and in intimate contact with the separation layer;

the separation layer being disposed upon the source region, the drain region and the first reference electrode such that a lowest surface of the second electrode lies above a highest surface of the first electrode;

wherein the separation layer comprises an electrically insulating material.

2. The field effect transistor of claim 1, further comprising a separation layer disposed on the source region, the drain region and the first reference electrode and formed of an electrically insulating material.

3. The field effect transistor of claim 2, wherein the second reference electrode is disposed on the separation layer.

4. The field effect transistor of claim 1, wherein the insulating layer is disposed on portions of the source region and the drain region.

5. The field effect transistor of claim 1, wherein the electrically insulating material is silicon dioxide, silicon nitride, or metal oxide.

6. The field effect transistor of claim 1, wherein the source region and the drain region are doped with a p-type material when the substrate is doped with n-type material.

7. The field effect transistor of claim 1, wherein the source region and the drain region are doped with an n-type material when the substrate is doped with a p-type material.

8. The field effect transistor of claim 1, wherein the second reference electrode is formed of one of platinum and Ag/AgCl.

9. The field effect transistor of claim 1, wherein the ionic material is a biomolecule.

10. The field effect transistor of claim 9, wherein the biomolecule is one of nucleic acid and protein.

11. The field effect transistor of claim 10, wherein the nucleic acid is selected from the group consisting of DNA, RNA, PNA, LNA and a hybrid thereof.

12. The field effect transistor of claim 10, wherein the protein is selected from the group consisting of an enzyme, a substrate, an antigen, an antibody, a ligand, an aptamer, and a receptor.

13. A microflow apparatus comprising the field effect transistor for detecting ionic material of claim 1.

14. The microflow apparatus of claim 13, wherein the field effect transistor is formed in a micro channel of the microflow apparatus.

15. The microflow apparatus of claim 13, wherein the substrate of the field effect transistor is an inner surface of a micro channel of the microflow apparatus.