Thin film transistor comprising novel conductor and dielectric compositions

• US 20080012006A1
• Filed: 07/17/2006
• Published: 01/17/2008
• Est. Priority Date: 07/17/2006
• Status: Active Grant

• Current Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Malajovich, Irina, O'Neil, Gerard, Johnson, Lynda Kaye, Tassi, Nancy G., Goldfinger, Marc B., Nunes, Geoffrey, Keusseyan, Roupen Leon, Bailey, Richard Kevin, Meth, Jeffrey Scott, Blanchet, Graciela Beatriz, Chesterfield, Reid John, Meng, Hong, Gao, Feng, Glicksman, Howard David, Sharp, Kenneth George, Jaycox, Gary Delmar, Catron, John W.
• Granted Patent: US 7,528,448 B2
• Time in Patent Office: Days
• US Class Current: 257/40
• CPC Class Codes: H10K 10/464 Lateral top-gate IGFETs comprising only a single gate
• CPC Class Codes: H10K 10/466 Lateral bottom-gate IGFETs comprising only a single gate
• CPC Class Codes: H10K 10/471 the gate dielectric comprising only organic materials
• CPC Class Codes: H10K 10/481 characterised by the gate conductors
• CPC Class Codes: H10K 10/82 Electrodes
• CPC Class Codes: H10K 71/18 using non-liquid printing techniques, e.g. thermal transfer printing from a donor sheet
• CPC Class Codes: H10K 85/111 comprising aromatic, heteroaromatic, or aryl chains, e.g. polyaniline, polyphenylene or polyphenylene vinylene
• CPC Class Codes: H10K 85/615 Polycyclic condensed aromatic hydrocarbons, e.g. anthracene
• CPC Class Codes: H10K 85/655 comprising only sulfur as heteroatom

Abstract

The invention relates to thin film transistors comprising novel dielectric layers and novel electrodes comprising metal compositions that can be provided by a dry thermal transfer process.

Claims

1. A thin film transistor comprising:

a) a substrate;

b) a gate electrode;

c) a dielectric layer;

d) a source electrode;

e) a drain electrode; and

f) a semiconductor layer;

wherein at least one of the gate, source and drain electrodes comprises a metal composition (A) comprising;

(1) about 65 to about 95 wt %, based on the total weight of the metal composition, of a metal powder selected from the group consisting of;

Ag, Cu and alloys thereof;

having a plurality of metal particles having an average longest dimension of about 5 nm to about 1500 nm; and

(2) about 5 to about 35 wt % of a dispersant comprising one or more resins selected from the group consisting of;

conducting polymers selected from the group consisting of;

polyaniline, polythiophene, polypyrrole, polyheteroaromatic vinylenes, and their derivatives;

nonconducting polymers selected from the group consisting of;

acrylic and styrenic-acrylic latexes, and solution-based acrylics and styrenic-acrylic (co)polymers, and combinations thereof;

copolymers of ethylene with one or more monomers selected from the group consisting of;

(meth)acrylate(s), vinyl acetate, carbon monoxide and (meth)acrylic acid; and

polyvinylacetate and its copolymers.

2. The thin film transistor of claim 1, wherein the gate electrode comprises the metal composition (A).

3. The thin film transistor of claim 1, wherein both the source and drain electrodes comprise the metal composition (A).

4. The thin film transistor of claim 1, wherein said gate, source and drain electrodes each comprise the metal composition (A).

5. The thin film transistor of claim 1, wherein the dielectric layer is interposed between the gate electrode and the semiconductor layer, the source electrode and the drain electrode both contact the semiconductor layer and the electrodes do not contact each other.

6. The thin film transistor of claim 1, wherein the dielectric layer has a resistivity of about 10¹⁴ ohm-cm or greater and comprises at least one Layer A, comprising:

(1) one or more dielectric polymer(s) selected from the group consisting of;

acrylic and styrenic polymers selected from the group consisting of;

acrylic, styrenic and styrenic-acrylic latexes, solution-based acrylic, styrenic and styrenic-acrylic polymers, and combinations thereof;

heteroatom-substituted styrenic polymers selected from the group consisting of;

partially hydrogenated poly(4-hydroxystyrene), poly(4-hydroxystyrene), and copolymers of poly(4-hydroxystyrene) with hydroxyethyl (meth)acrylate, alkyl (meth)acrylate, styrene, and alkyl-substituted styrene wherein the alkyl group is a C1 to C18 straight or branched chain alkyl group;

phenol-aldehyde (co)polymers and (co)oligomers and combinations thereof; and

poly(vinyl acetate); and

(2) about 0.5 wt % to about 10 wt %, based on a dry weight of Layer A, of one or more near-IR dye(s) characterized by an absorption maximum in the range of about 600 to about 1200 nm within Layer A.

7. The thin film transistor of claim 1, wherein the dielectric layer has a resistivity of about 10¹⁴ ohm-cm or greater and comprises at least one Layer C, comprising:

one or more dielectric polymer(s) selected from the group consisting of;

acrylic, styrenic and styrenic-acrylic latexes;

comprising at least about 85 wt % of monomers selected from the group consisting of;

alkyl (meth)acrylate, styrene, and alkyl-substituted styrene wherein the alkyl group is a C1 to C18 straight or branched chain alkyl group.

8. The thin film transistor of claim 1, wherein the semiconductor layer is pentacene.

9. The thin film transistor of claim 1, wherein the semiconductor layer comprises a compound of Formula (III):

10. The thin film transistor of claim 9, wherein r≠

0, and s≠

1.

11. The thin film transistor of claim 9, wherein Ar is selected from the group consisting of:

12. The thin film transistor of claim 9, wherein Ar is

13. The transistor of claim 9 wherein the semiconductor compound is selected from compound 3 and 77:

14. The thin film transistor of claim 9 wherein Ar is

15. The thin film transistor of claim 1, wherein the substrate is selected from the group consisting of:

polyethylene terephthalate, polyethylene naphthalate, triacetyl cellulose, glass and polyimide.

41. The thin film transistor of claim 1 characterized by Ion/off of about 1E+05 or greater.

42. A thin film transistor array comprising a plurality of transistors of claim 1 having a yield of functional transistors of about 98% or greater.

16. A thin film transistor comprising:

a) a substrate;

b) a gate electrode;

c) a dielectric layer;

d) a source electrode;

e) a drain electrode; and

f) a semiconductor layer;

wherein the dielectric layer has a resistivity of about 10¹⁴ ohm-cm or greater, and comprises at least one Layer A, comprising;

(1) one or more dielectric polymer(s) selected from the group consisting of;

acrylic and styrenic polymers selected from the group consisting of;

acrylic, styrenic and styrenic-acrylic latexes, solution-based acrylic, styrenic and styrenic-acrylic polymers, and combinations thereof;

heteroatom-substituted styrenic polymers selected from the group consisting of;

partially hydrogenated poly(4-hydroxystyrene), poly(4-hydroxystyrene), and copolymers of poly(4-hydroxystyrene) with hydroxyethyl (meth)acrylate, alkyl (meth)acrylate, styrene, and alkyl-substituted styrene wherein the alkyl group is a C₁ to C₁₈ straight or branched chain alkyl group;

phenol-aldehyde (co)polymers and (co)oligomers and combinations thereof; and

poly(vinyl acetate); and

(2) about 0.5 wt % to about 10 wt %, based on a dry weight of Layer A, of one or more near-IR dye(s) having an absorption maximum in the range of about 600 to about 1200 nm within Layer A.

17. The thin film transistor of claim 16 wherein the gate dielectric layer is interposed between the gate electrode and the semiconductor layer, the source electrode and the drain electrode both contact the semiconductor layer and the electrodes do not contact each other.

18. The thin film transistor of claim 16, wherein, within Layer A said one or more dielectric polymer(s) is selected from acrylic and styrenic polymers selected from the group consisting of:

acrylic, styrenic and styrenic-acrylic latexes, solution-based acrylic, styrenic and styrenic-acrylic polymers, and combinations thereof; and

comprises one or more latex(es) comprising at least about 85 wt % of monomers selected from the group consisting of;

alkyl (meth)acrylate, styrene, and alkyl-substituted styrene wherein the alkyl group is a C1 to C18 straight or branched chain alkyl group.

19. The thin film transistor of claim 16 wherein, within Layer A, the one or more near-IR dye(s) comprises an indocyanine dye.

20. The thin film transistor of claim 16, wherein the dielectric layer comprises two or more Layers A that are gradient dye layers, each gradient dye layer having by a dry wt % of near-IR dye of about 0.5 to about 10 wt %;

wherein at least one gradient dye layer has a lower wt % of near-IR dye, at least one gradient dye layer has a higher wt % of near-IR dye, and said higher wt % of near-IR dye is a value at least 20% higher than that of the lower wt % of near-IR dye.

21. The thin film transistor of claim 16, wherein Layer A further comprises a high κ

nanoparticle fraction of up to about 90 wt % of Layer A, with the nanoparticle fraction having a dielectric constant greater than about 20 and an average particle size of about 5 nm to about 500 nm;

with the proviso that if the nanoparticle fraction is greater than 80 wt %, the near-IR dye is less than 6 wt % of the layer of material.

22. The thin film transistor of claim 21, wherein the dielectric layer comprises two or more Layers A that are gradient nanoparticle layers, each gradient nanoparticle layer independently having a dry wt % of high κ

nanoparticle fraction of up to about 90 wt %;

wherein at least one gradient nanoparticle layer has a lower wt % of high κ

nanoparticle fraction, at least one gradient nanoparticle layer has a higher wt % of high κ

nanoparticle fraction, and said higher wt % is a value at least 20% higher than that of the lower wt %.

23. The thin film transistor of claim 16, wherein the dielectric layer further comprises a Layer B, comprising one or more dielectric polymers, having a resistivity of about 10¹⁴ ohm-cm or greater.

24. The thin film transistor of claim 16, wherein the semiconductor layer is selected from pentacene, compound 3 and compound 77:

25. The thin film transistor of claim 16, wherein the semiconductor layer comprises a compound of Formula (III):

26. The thin film transistor of claim 25, wherein r≠

0, and s≠

1.

27. The thin film transistor of claim 25, wherein Ar is selected from the group consisting of:

28. The thin film transistor of claim 25, wherein Ar is

29. The thin film transistor of claim 16, wherein the substrate is selected from the group:

polyethylene terephthalate, polyethylene naphthalate, triacetyl cellulose, glass and polyimide.

30. The thin film transistor of claim 16, wherein at least one of the gate electrode, source electrode or drain electrode, comprises a conducting polymer selected from the group:

polyaniline, polythiophene, polypyrrole, polyheteroaromatic vinylene and their derivatives;

being characterized by the presence of nitrogen or sulfur atoms in a polymer backbone; and

further comprises 0.1 to 12 wt % single wall carbon nanotubes and an organic protic acid having 1 to 30 carbons, said acid at a molar equivalent amount of about 25% to about 100% of the nitrogen or sulfur atoms in the polymer backbone.

43. The thin film transistor of claim 16 having an Ion/off of about 1E+05 or greater.

44. A thin film transistor array comprising a plurality of transistors of claim 16 having a yield of functional transistors of about 98% or greater.

45. The thin film transistor of claim 16 having a mobility of about 0.5 cm²V⁻

1s<sup>−

1</sup> or greater.

31. A thin film transistor comprising:

a) a substrate;

b) a gate electrode;

c) a dielectric layer;

d) a source electrode;

e) a drain electrode; and

f) a semiconductor layer;

wherein the dielectric layer has a resistivity of about 10¹⁴ ohm-cm or greater, and comprises at least one Layer C, comprising one or more dielectric polymer(s) selected from the group consisting of;

acrylic, styrenic and styrenic-acrylic latexes;

comprising at least about 85 wt % of monomers selected from the group consisting of;

alkyl (meth)acrylate, styrene, and alkyl-substituted styrene wherein the alkyl group is a C1 to C18 straight or branched chain alkyl group.

32. The thin film transistor of claim 31 wherein the gate electrode and the semiconductor layer both contact the dielectric layer, the source electrode and the drain electrode both contact the semiconductor layer and the electrodes are not in contact with each other.

33. The thin film transistor of claim 31, wherein Layer C further comprises a high κ

nanoparticle fraction of up to about 90 wt % of Layer C, with the nanoparticle fraction having a dielectric constant greater than about 20 and an average particle size of about 5 nm to about 500 nm.

34. The thin film transistor of claim 31, wherein the semiconductor layer is selected from the group consisting of:

pentacene, Compound 3 and Compound 77;

35. The thin film transistor of claim 31, wherein the semiconductor layer comprises a compound of Formula (III):

36. The thin film transistor of claim 35, wherein r≠

0, and s≠

1.

37. The thin film transistor of claim 35, wherein Ar is selected from the group consisting of:

38. The thin film transistor of claim 35, wherein Ar is

39. The thin film transistor of claim 31, wherein the substrate is selected from the group:

polyethylene terephthalate, polyethylene naphthalate, triacetyl cellulose, glass and polyimide.

40. The thin film transistor of claim 31, wherein at least one of the gate electrode, source electrode or drain electrode comprises a conducting polymer selected from the group:

polyaniline, polythiophene, polypyrrole, polyheteroaromatic vinylenes and their derivatives;

being characterized by the presence of nitrogen or sulfur atoms in a polymer backbone; and

further comprises 0.1 to 12 wt % single wall carbon nanotubes and an organic protic acid having 1 to 30 carbons, said acid at a molar equivalent amount of about 25% to about 100% of the nitrogen or sulfur atoms in the polymer backbone.