Thin film transistor

• US 20080099803A1
• Filed: 10/12/2006
• Published: 05/01/2008
• Est. Priority Date: 10/12/2006
• Status: Active Grant

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Li, Yuning, Ong, Beng S.
• Granted Patent: US 7,511,343 B2
• Time in Patent Office: Days
• US Class Current: 257/291
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: H01L 29/04 characterised by their crystalline structure, e.g. polycrystalline, cubic or particular orientation of crystalline planes characterised by physical imperfections H01L29/30
• CPC Class Codes: H01L 29/045 by their particular orientation of crystalline planes
• CPC Class Codes: H01L 29/0665 the shape of the body defining a nanostructure nanotechnology per se B82B
• CPC Class Codes: H01L 29/0673 oriented parallel to a substrate
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

A thin film transistor is disclosed comprising comprises a substrate, a dielectric layer, and a semiconductor layer. The semiconductor layer, which is crystalline zinc oxide preferentially oriented with the c-axis perpendicular to the plane of the dielectric layer or substrate, is prepared by liquid depositing a zinc oxide nanodisk composition. The thin film transistor has good mobility and on/off ratio.

Claims

1. A thin film transistor, comprising:

a substrate;

a gate electrode, a source electrode, and a drain electrode;

a dielectric layer; and

a semiconductor layer;

wherein the semiconductor layer comprises zinc oxide nanodisks oriented with their c-axis perpendicular to the dielectric layer or the substrate.

2. The thin film transistor of claim 1, wherein the semiconductor layer is deposited upon a surface of the substrate, and the substrate has at least one type of polar functional group on the surface.

3. The thin film transistor of claim 2, wherein the polar functional group is selected from the group consisting of —

OH, —

NH₂, —

COOH, —

SO₃H, and —

P(═

O)(OH)₂.

4. The thin film transistor of claim 1, wherein the semiconductor layer is deposited upon a surface of the dielectric layer, and the dielectric layer has at least one type of polar functional group on the surface.

5. The thin film transistor of claim 4, wherein the polar functional group is selected from the group consisting of —

OH, —

NH₂, —

COOH, —

SO₃H, and —

P(═

O)(OH)₂.

6. The thin film transistor of claim 1, wherein the dielectric layer comprises a material selected from the group consisting of aluminum-titanium oxide, aluminum oxide, silicon oxide, silicon nitride, barium titanate, barium zirconium titanate, polyesters, polycarbonates, poly(vinyl phenol), polyimides, polystyrene, poly(methacrylate)s, poly(acrylate)s, and epoxy resin.

7. The thin film transistor of claim 1, wherein the semiconductor layer has a field effect mobility of at least 1 cm²/V·

sec.

8. The thin film transistor of claim 1, wherein the semiconductor layer has a current on/off ratio greater than about 10³.

9. The thin film transistor of claim 1, wherein the semiconductor layer has a thickness of from about 10 nanometers to about 1 micrometer.

10. The thin film transistor of claim 1, wherein the substrate is a polymer film or sheet comprising a polyester, polycarbonate, or polyimide.

11. The thin film transistor of claim 1, wherein the substrate has a thickness of from about 10 micrometers to about 10 millimeters.

12. The thin film transistor of claim 1, wherein the semiconductor layer further comprises metal nanoparticles or metal oxide nanoparticles.

13. The thin film transistor of claim 1, wherein the semiconductor layer is deposited by liquid deposition of a composition comprising zinc oxide nanodisks.

14. The thin film transistor of claim 13, wherein the method of liquid deposition is selected from the group consisting of spin coating, blade coating, rod coating, dip coating, screen printing, microcontact printing, ink jet printing, and stamping.

15. The thin film transistor of claim 13, wherein the composition further comprises an organoamine complexing agent.

16. A thin film transistor, comprising:

a polymeric substrate;

a gate electrode, a source electrode, and a drain electrode;

a dielectric layer; and

a semiconductor layer, wherein the semiconductor layer comprises zinc oxide nanodisks oriented with their c-axis perpendicular to the substrate.

17. A thin film transistor, comprising:

a polymeric substrate;

a gate electrode, a source electrode, and a drain electrode;

a dielectric layer; and

a semiconductor layer, wherein the semiconductor layer comprises zinc oxide nanodisks oriented with their c-axis perpendicular to the dielectric layer.