Thin film transistor substrate provided with protective film and method for producing same

Patent metadata

Field	Value
Publication number	US-10916661-B2
Application number	US-201716463511-A
Country	US
Kind code	B2
Filing date	Nov 27, 2017
Priority date	Nov 28, 2016
Publication date	Feb 9, 2021
Grant date	Feb 9, 2021

Abstract

The present invention relates to providing a thin film transistor substrate containing a protective film, which can impart high driving stability. The thin film transistor substrate contains a thin film transistor and a protective film containing a cured product of a siloxane composition which covers the thin film transistor, wherein the thin film transistor has a semiconductor layer made of an oxide semiconductor, and wherein the siloxane composition contains polysiloxane, a fluorine-containing compound, and a solvent.

First claim

The invention claimed is:

1. A thin film transistor substrate comprising:
a thin film transistor; and
a protective film comprising a cured product of a siloxane composition, covering said thin film transistor,
wherein said thin film transistor has a semiconductor layer made of an oxide semiconductor,
wherein said siloxane composition comprises:
a polysiloxane;
a fluorine-containing compound which is a compound represented by the following formula (M):
R 4 Si(OR 5 ) 3   (M)

wherein
R 4 is a completely or partially fluorine-substituted hydrocarbon group having 1 to 8 carbon atoms, and
R 5 represents an alkyl group having 1 to 5 carbon atoms; and
a solvent, and
where said polysiloxane comprises a repeating unit represented by the following general formula (Ia):

wherein
R 1 is hydrogen; a monovalent to trivalent, straight-chain, branched or cyclic, saturated or unsaturated, aliphatic hydrocarbon group having 1 to 30 carbon atoms; or a monovalent to trivalent, aromatic hydrocarbon group having 6 to 30 carbon atoms;
wherein in said aliphatic hydrocarbon group and said aromatic hydrocarbon group, one or more methylene groups are unsubstituted or substituted with an oxy group, an imide group or a carbonyl group, one or more hydrogens are unsubstituted or substituted with fluorine, a hydroxy group or an alkoxy group, and one or more carbons are unsubstituted or substituted with silicon; and
when R 1 is divalent or trivalent, R 1 connects the Si atoms to each other, which are included in a plurality of the repeating units.

2. The substrate according to claim 1 , wherein said polysiloxane further comprises a repeating unit represented by the following general formula (Ib):

3. The substrate according to claim 2 , wherein said polysiloxane comprises:
polysiloxane (I) obtained by hydrolysis and condensation of a silane compound represented by the following formula (ia) and a silane compound represented by the following formula (ib) in the presence of a basic catalyst:
R 1′ [Si(OR a ) 3 ] p   (ia)

Si(OR a ) 4   (ib)

wherein
R 1′ is hydrogen; a monovalent to trivalent, linear, branched or cyclic, saturated or unsaturated, aliphatic hydrocarbon group having 1 to 30 carbon atoms; or a monovalent to trivalent, aromatic hydrocarbon group having 6 to 30 carbon atoms;
wherein in said aliphatic hydrocarbon group and said aromatic hydrocarbon group, one or more methylene groups are unsubstituted or substituted with an oxy group, an imide group or a carbonyl group, one or more hydrogens are unsubstituted or substituted with fluorine, a hydroxy group or an alkoxy group, and one or more carbons are unsubstituted or substituted with silicon; and

R a represents an alkyl group having 1 to 10 carbon atoms,
wherein the film after prebaking of polysiloxane (I) is soluble in 5 mass % aqueous solution of tetramethylammonium hydroxide, and dissolution rate of the film is 1,000 Å/sec or less;

p is 1 to 3;
and

polysiloxane (II) obtained by hydrolysis and condensation of at least of a silane compound represented by said formula (ia) in the presence of an acidic or basic catalyst, wherein the film after prebaking of polysiloxane (II) is soluble in 2.38 mass % aqueous solution of tetramethylammonium hydroxide, and dissolution rate of the film is 100 Å/sec or more.

4. The substrate according to claim 1 , wherein said fluorine-containing compound is a photo sensitizer.

5. The substrate according to claim 4 , wherein said photosensitizer further contains a photosensitizer that is free of fluorine atom.

6. The substrate according to claim 1 , wherein in said siloxane composition, the ratio of the number of fluorine atoms derived from said fluorine-containing compound to the number of silicon atoms derived from said polysiloxane is 0.002 to 0.4.

7. The substrate according to claim 1 , wherein said siloxane composition is a positive type photosensitive siloxane composition comprising at least two types of polysiloxane having different alkali dissolution rate, a diazonaphthoquinone derivative, a fluorine-containing compound and a solvent.

8. The substrate according to claim 1 , having a second protective film on said protective film.

9. A method for manufacturing the thin film transistor substrate according to claim 1 , which comprises:
a step of preparing a siloxane composition comprising polysiloxane, a fluorine-containing compound and a solvent, wherein said polysiloxane comprises a repeating unit represented by the following general formula (Ia):

where
R 1 is hydrogen a monovalent to trivalent, straight-chain, branched or cyclic, saturated or unsaturated, aliphatic hydrocarbon group having 1 to 30 carbon atoms; or a monovalent to trivalent, aromatic hydrocarbon group having 6 to 30 carbon atoms;
wherein in said aliphatic hydrocarbon group and said aromatic hydrocarbon group, one or more methylene groups are unsubstituted or substituted with an oxy group, an imide group or a carbonyl group, one or more hydrogens are unsubstituted or substituted with fluorine, a hydroxy group or an alkoxy group, and one or more carbons are unsubstituted or substituted with silicon; and
when R 1 is divalent or trivalent, R 1 connects the Si atoms to each other, which are included in a plurality of the repeating units;
a step of coating a thin film transistor with said siloxane composition to form a protective film precursor layer;
a step of conducting thermal curing of said protective film precursor layer to form a protective film;
a step of conducting additional heating of the formed protective film; and
a step of subjecting the thin film transistor comprising said protective film to annealing treatment.

10. The method according to claim 9 , wherein said additional heating is conducted at the same as or higher temperature than the temperature of said thermal curing.

11. The method according to claim 9 , wherein said additional heating is conducted at the same as or higher temperature than the temperature of said annealing treatment.

12. The method according to claim 9 , wherein said annealing treatment is conducted at 250° C. or higher and at 450° C. or lower.

13. The method according to claim 9 , wherein said annealing treatment is conducted in an oxygen atmosphere.

14. A siloxane composition for manufacturing a thin film transistor substrate comprising:
a polysiloxane;
a fluorine-containing compound which is a compound represented by the following formula (M):
R 4 Si(OR 5 ) 3   (M)

wherein
R 4 is a completely or partially fluorine-substituted hydrocarbon group having 1 to 8 carbon atoms, and
R 5 represents an alkyl group having 1 to 5 carbon atoms; and
a solvent,
wherein said polysiloxane comprises a repeating unit represented by the following general formula (Ia):

where
R 1 is hydrogen; a monovalent to trivalent, straight-chain, branched or cyclic, saturated or unsaturated, aliphatic hydrocarbon group having 1 to 30 carbon atoms; or a monovalent to trivalent, aromatic hydrocarbon group having 6 to 30 carbon atoms;
wherein in said aliphatic hydrocarbon group and said aromatic hydrocarbon group, one or more methylene groups are unsubstituted or substitut

Assignees

• Merck Patent Gmbh

Inventors

• Uraoka Yukiharu
• Ishikawa Yasuaki
• Yoshida Naofumi
• Taniguchi Katsuto
• Nonaka Toshiaki

Classifications

• H10P95/90

  Thermal treatments, e.g. annealing or sintering · CPC title

• H10P14/6922

  the material containing Si, O and at least one of H, N, C, F or other non-metal elements, e.g. SiOC, SiOC:H or SiONC · CPC title

• H10P14/6686

  the compound being a molecule comprising at least one silicon-oxygen bond and the compound having hydrogen or an organic group attached to the silicon or oxygen, e.g. a siloxane · CPC title

• H10P50/28

  of insulating materials · CPC title

• H10P14/6342

  Liquid deposition, e.g. spin-coating, sol-gel techniques or spray coating · CPC title