PHOTOCURING AGENTS
20260072348 ยท 2026-03-12
Assignee
Inventors
- Andreas Berkefeld (Darmstadt, DE)
- Sophia BUHBUT (Jerusalem, IL)
- Odelia SAADON (Jerusalem, IL)
- Roy SCHREIBER (Jerusalem, IL)
Cpc classification
G02F1/1335
PHYSICS
H10H29/872
ELECTRICITY
G03F7/0755
PHYSICS
G03F7/0043
PHYSICS
G03F7/162
PHYSICS
International classification
Abstract
A formulation for preparing an optical layer, preferably a particle-free optical layer, preferably to be used for nanoimprint lithography, more preferably to be used for direct UV nanoimprint lithography comprises compound A and a metal oxide precursor. Compound A is represented by the formula: X (NO.sub.2.sup.).sub.n, wherein X and n are defined herein. The formulation may exhibit at least one of properties as an advanced material or as a high performance material. The formulation may be used in the nanotechnology process to make semiconductor device/display device application, for example semiconductor chip, or a liquid crystal, quantum dot, OLED display fabricated on a substrate controlled by semiconductors.
Claims
1. A formulation for preparing an optical layer, preferably a particle-free optical layer, preferably to be used for nanoimprint lithography, more preferably to be used for direct UV nanoimprint lithography, comprising compound A and a metal oxide precursor, wherein the compound A is represented by formula (a1); ##STR00013## wherein X is a cation, preferably a monovalent, divalent, or trivalent cation, more preferably a monovalent cation; when X is a monovalent cation, n is 1; when X is a divalent cation, n is 2; when X is a trivalent cation, n is 3; wherein the metal oxide precursor comprises a group 4, 5, 6, 8, 11, 12, 14 or 15 metal element of the periodic table, more preferably a group 4, 5 or 12 metal element of the periodic table, a ligand and optionally one or more other organic components or substituents and/or one or more other inorganic components.
2. The formulation according to claim 1, wherein X is a monovalent cation represented by formula (a2-1) or (a2-2); ##STR00014## wherein E.sup.1 and E.sup.2 are each independently N or P, preferably N; R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are each independently H, a straight-chain alkyl having 1 to 25 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms; a branched or cyclic structure-containing alkyl having 3 to 25 carbon atoms, preferably 3 to 15 carbon atoms, more preferably 3 to 10 carbon atoms; an aryl having 6 to 25 carbon atoms, preferably from 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms; or NR.sup.7R.sup.8; when R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are each independently an alkyl or an aryl, one or more non-adjacent CH.sub.2 may each be replaced by O, S, CO, COO, OCO, OCOO, CR.sup.7CR.sup.8, or CC; R.sup.7 and R.sup.8 are each independently H, a straight-chain alkyl having 1 to 25 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms; a branched or cyclic structure containing alkyl having 3 to 25 carbon atoms, preferably 3 to 15 carbon atoms, more preferably 3 to 10 carbon atoms; an aryl having 6 to 25 carbon atoms, preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms; and when R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7 and R.sup.8 are each independently an alkyl or an aryl, one or more H may each be replaced by OH, COOH, a straight-chain alkyl having 1 to 6 carbon atoms, or a branched or cyclic structure-containing alkyl having 3 to 6 carbon atoms.
3. The formulation according to claim 2, wherein X is a cation represented by formula (a3); ##STR00015## wherein R.sup.31, R.sup.32, R.sup.33, R.sup.34 and R.sup.35 are each independently H, a straight-chain alkyl having 1 to 25 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms; a branched or cyclic structure-containing alkyl having 3 to 25 carbon atoms, preferably 3 to 15 carbon atoms, more preferably 3 to 10 carbon atoms; an aryl having 6 to 25 carbon atoms, preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms; preferably R.sup.31, R.sup.32, R.sup.33, R.sup.34 and R.sup.35 are H; when R.sup.31, R.sup.32, R.sup.33, R.sup.34 and R.sup.35 are each independently an alkyl or an aryl, one or more non-adjacent CH.sub.2 may each be replaced by O, S, CO, COO, OCO, OCOO, CHCH, or CC; when R.sup.31, R.sup.32, R.sup.33, R.sup.34 and R.sup.35 are each independently an alkyl or an aryl, one or more H may each be replaced by OH, COOH, a straight-chain alkyl having 1 to 6 carbon atoms, or a branched or cyclic structure-containing alkyl having 3 to 6 carbon atoms.
4. The formulation according to claim 1, wherein the metal oxide precursor is represented by any one of formulae (m2-1) to (m2-5); ##STR00016## wherein M.sup.A is Cu, Zn or Bi, preferably Zn, M.sup.B is Al, M.sup.C is Pb, Sn or Ti, preferably Ti, M.sup.D is Nb or V, preferably Nb, M.sup.E is Fe, Cr, Mo or W; A.sup.1 is the ligand represented by formula (m3); A.sup.2, A.sup.3, C, N.sup.1 and N.sup.2 are each independently a group of one or more atoms; n3, n4 n5, n6 and n7 represent a valence of A.sup.2, A.sup.3, C, N.sup.1 and N.sup.2 respectively; n3 and n4 are each independently 1 to 5, more preferably 1 to 3; n5 is 1+ to 5+, more preferably 1+ to 3+; n6 and n7 are 0; NA1, NB1, NC1, ND1 and NE1 are each independently 1 to 50, preferably 2 to 45; NA2, NB2, NC2, ND2 and NE2 are each independently 1 to 55, preferably 1 to 50; NA3, NB3, NC3, ND3, NE3, NA4, NB4, NC4, ND4 and NE4 are each independently 0 to 80, preferably 0 to 70, more preferably 0 to 65; NA5, NB5, NC5, ND5 and NE5 are each independently 0 to 20, preferably 0 to 15, more preferably 0 to 10; NA6, NB6, NC6, ND6, NE6, NA7, NB7, NC7, ND7 and NE7 are each independently 0 to 40, preferably 0 to 30, more preferably 0 to 20; provided that ##STR00017## wherein R.sup.9 is a straight-chain alkyl having 1 to 25 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms; a branched or cyclic structure-containing alkyl having 3 to 25 carbon atoms, preferably 3 to 15 carbon atoms, more preferably 3 to 10 carbon atoms; an aryl having 6 to 25 carbon atoms, preferably from 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms; an aryl-alkylene having 6 to 25 carbon atoms, preferably from 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms; wherein one or more non-adjacent CH.sub.2 may each be replaced by O, S, CO, COO, OCO, OCOO, CR.sup.10CR.sup.11, or CC, preferably replaced by CO, COO, OCO, or OCOO, more preferably CO; R.sup.10 and R.sup.11 are each independently H, a straight-chain alkyl having 1 to 25 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms; a branched or cyclic structure containing alkyl having 3 to 25 carbon atoms, preferably 3 to 15 carbon atoms, more preferably 3 to 10 carbon atoms; an aryl having 6 to 25 carbon atoms, preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms; wherein one or more H may each be replaced by OH, COOH, a straight-chain alkyl having 1 to 6 carbon atoms, or a branched or cyclic structure-containing alkyl having 3 to 6 carbon atoms.
5. The formulation according to one claim 1, wherein the metal oxide precursor is represented by any one of formulae (m4-1) to (m4-5); ##STR00018## wherein na1, nb1, nc1, nd1, and ne1 are each independently 1 to 50, preferably 2 to 45; na2, nb2, nc2, nd2, and ne2 are each independently 1 to 55, preferably 1 to 50; na3, nb3, nc3, nd3, and ne3 are each independently 0 to 20, preferably 0 to 10, more preferably 0 to 5; na4, nb4, nc4, nd4, and ne4 are each independently 1 to 80, preferably 1 to 70, more preferably 1 to 65; na5, nb5, nc5, nd5, and ne5 are each independently 0 to 20, preferably 0 to 10, more preferably 0 to 5; na6, nb6, nc6, nd6, and ne6 are each independently 0 to 20, preferably 0 to 10, more preferably 0 to 5; provided that 2na1=na2+na3+2na4, 3nb1=nb2+nb3+2nb4, 4nc1=nc2+nc3+2nc4, 5nd1=nd2+nd3+2nd4, 6ne1=ne2+ne3+2ne4; M.sup.3 is Cu, Zn or Bi, preferably Zn, M.sup.4 is Al, M.sup.5 is Pb, Sn or Ti, preferably Ti, M.sup.6 is Nb or V, preferably Nb, M.sup.7 is Fe, Cr, Mo or W; R.sup.12 is the ligand represented by formula (m5), and R.sup.13 is an acid; ##STR00019## wherein R.sup.14 is a straight-chain alkyl having 1 to 25 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms; a branched or cyclic structure-containing alkyl having 3 to 25 carbon atoms, preferably 3 to 15 carbon atoms, more preferably 3 to 10 carbon atoms; an aryl-alkylene having 6 to 25 carbon atoms, preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms; wherein one or more non-adjacent CH.sub.2 may each be replaced by O, S, CO, COO, OCO, OCOO, CR.sup.15CR.sup.16, or CC, preferably replaced by CO, COO, OCO, or OCOO, more preferably CO; R.sup.15 and R.sup.16 are each independently H, a straight-chain alkyl having 1 to 25 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms; a branched or cyclic structure containing alkyl having 3 to 25 carbon atoms, preferably 3 to 15 carbon atoms, more preferably 3 to 10 carbon atoms; an aryl having 6 to 25 carbon atoms, preferably from 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms; wherein one or more H may each be replaced by OH, COOH, a straight-chain alkyl having 1 to 6 carbon atoms, or a branched or cyclic structure-containing alkyl having 3 to 6 carbon atoms.
6. The formulation according to claim 1, the ligand stabilizes the remainder of the metal oxide precursor.
7. The formulation according to claim 1, wherein the mole ratio of the compound A to the metal oxide precursor is in the range from 0.6N.sub.A to 1.4N.sub.A, preferably 0.7N.sub.A to 1.3N.sub.A, more preferably 0.75N.sub.A to 1.2N.sub.A, very preferably 0.80N.sub.A to 1.1N.sub.A, when N.sub.A represents the number of ligands contained in one metal oxide precursor.
8. The formulation according to claim 5, wherein R.sup.13 is an acid represented by formula (m6); ##STR00020## wherein R.sup.17 is a straight-chain alkyl having 1 to 25 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms; a branched or cyclic structure-containing alkyl having 3 to 25 carbon atoms, preferably 3 to 15 carbon atoms, more preferably 3 to 10 carbon atoms; an aryl having 6 to 25 carbon atoms, preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms; wherein one or more non-adjacent CH.sub.2 may each be replaced by O, S, CO, COO, OCO, OCOO, CR.sup.18CR.sup.19, or CC; R.sup.18 and R.sup.19 are each independently H, a straight-chain alkyl having 1 to 25 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms; a branched or cyclic structure containing alkyl having 3 to 25 carbon atoms, preferably 3 to 15 carbon atoms, more preferably 3 to 10 carbon atoms; an aryl having 6 to 25 carbon atoms, preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms; wherein one or more H may each be replaced by OH, COOH, a straight-chain alkyl having 1 to 6 carbon atoms, or a branched or cyclic structure-containing alkyl having 3 to 6 carbon atoms.
9. The formulation according to one claim 1, further comprising a solvent selected from one or more members of the group consisting of a secondary linear or branched C3 alcohol, preferably it is selected from isopropanol, 2-butanol, 2-pentanol, 3-pentanol, propylene glycol monoalkyl ethers, preferably it is propylene glycol monomethyl ether, propylene glycol monoethyl ether and/or propylene glycol monopropyl ether, propylene glycol monoalkyl ether acetates, preferably it is propylene glycol monomethyl ether acetate, propylene glycol dialkyl ethers, preferably it is propylene glycol dimethyl ether, alkyl lactate, preferably it is ethyl lactate; wherein the solid content is preferably in the range from 0.1 to 20 mass parts, more preferably 0.5 to 15 mass parts, very preferably 0.8 to 10 mass parts based on 100 parts of the formulation.
10. The formulation according to claim 1, further comprising compound B, wherein the compound B comprises Si; wherein the content of the compound B is preferably in the range from 7 to 50 mass parts, more preferably 10 to 40 mass parts, very preferably 15 to 30 mass parts based on 100 parts of the metal oxide precursor.
11. The formulation according to claim 10, wherein the compound B is represented by formula (c1); ##STR00021## wherein m1 is 0, 1, 2 or 3, preferably 1; R.sup.20 is a straight-chain alkyl having 1 to 15 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, very preferably 1 to 3 carbon atoms; a branched or cyclic structure-containing alkyl having 3 to 15 carbon atoms, preferably 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms; an aryl having 6 to 20 carbon atoms, preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms; wherein one or more non-adjacent CH.sub.2 may each be replaced by O, S, CO, COO, OCO, OCOO, CR.sup.22CR.sup.23, or CC; R.sup.22 and R.sup.23 are each independently H, a straight-chain alkyl having 1 to 25 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms; a branched or cyclic structure containing alkyl having 3 to 25 carbon atoms, preferably 3 to 15 carbon atoms, more preferably 3 to 10 carbon atoms; an aryl having 6 to 25 carbon atoms, preferably from 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms; wherein one or more H may each be replaced by OH, COOH, a straight-chain alkyl having 1 to 6 carbon atoms, or a branched or cyclic structure-containing alkyl having 3 to 6 carbon atoms; wherein R.sup.21 is a straight-chain alkyl having 1 to 25 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms; a branched or cyclic structure-containing alkyl having 3 to 25 carbon atoms, preferably 3 to 15 carbon atoms, more preferably 3 to 10 carbon atoms; a straight-chain alkenyl having 1 to 25 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms; a branched or cyclic structure-containing alkenyl having 3 to 25 carbon atoms, preferably 3 to 15 carbon atoms, more preferably 3 to 10 carbon atoms; an aryl having 6 to 25 carbon atoms, preferably from 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms; wherein one or more non-adjacent CH.sub.2 may each be replaced by O, S, CO, COO, OCO, OCOO, CR.sup.24CR.sup.21, CCR.sup.24R.sup.21, or CC, preferably replaced by OCO; wherein R.sup.24 and R.sup.25 are each independently H, a straight-chain alkyl having 1 to 25 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms; a branched or cyclic structure containing alkyl having 3 to 25 carbon atoms, preferably 3 to 15 carbon atoms, more preferably 3 to 10 carbon atoms; an aryl having 6 to 25 carbon atoms, preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms, very preferably R.sup.24 and R.sup.25 are H; wherein one or more H may each be replaced by OH, COOH, a straight-chain alkyl having 1 to 6 carbon atoms, or a branched or cyclic structure-containing alkyl having 3 to 6 carbon atoms.
12. (canceled)
13. A method for preparing an optical layer containing a metal oxide, preferably a particle-free optical layer containing a metal oxide, to be used for nanoimprint lithography, more preferably to be used for direct UV nanoimprint lithography, comprising the following step (i); (i) coating the formulation according to claim 1 above a substrate to form an optical layer, preferably the substrate is a silicon wafer; preferably by spin-coating, more preferably by spin-coating with 500 to 6,000 RPM for 5 to 100 seconds, very preferably by spin-coating with 1,000 to 5,000 RPM for 10 to 70 seconds, most preferably spin-coating with 1,500 to 4,500 RPM for 15 to 50 seconds.
14. The method according to claim 13, further comprising the following step (ii); (ii) heating the optical layer at 35 to 200 C. for 1 to 100 minutes, preferably at 40 to 150 C. for 1 to 50 minutes, more preferably at 45 to 100 C. for 1 to 20 minutes.
15. The method according to claim 13, further comprising the following step (iii); (iii) irradiating light to the optical layer, preferably the light is UV; preferably the light intensity is in the range from 150 to 500 mW/cm.sup.2, more preferably 200 to 400 mW/cm.sup.2, very preferably 250 to 350 mW/cm.sup.2; preferably the wavelength of the light is in the range from 100 to 500 nm, more preferably 250 to 450 nm, very preferably 350 to 400 nm; preferably the irradiation time is in the range from 1 to 120 minutes, preferably 5 to 100 minutes, more preferably 7 to 75 minutes.
16. An optical layer, preferably a particle-free optical layer, preferably to be used for nanoimprint lithography, more preferably to be used for direct UV nanoimprint lithography, produced by the method according to claim 13, wherein the thickness of the optical layer is in the range from 1 to 700 nm, preferably from 3 to 600 nm, more preferably 5 to 500 nm, very preferably 7 to 400 nm.
17. A method for producing a patterned optical layer comprising the following steps (iv) and (v); (iv) producing an optical layer by the method according to claim 13, and (v) forming a pattern by pressing a mold onto the optical layer, (vi) optionally, heating the patterned optical layer, preferably at 35 to 200 C. for 1 to 100 minutes, more preferably at 40 to 150 C. for 1 to 50 minutes, very preferably at 45 to 100 C. for 1 to 20 minutes, (vii) optionally, irradiating light to the patterned optical layer, preferably the light is UV, preferably the light intensity is in the range from 150 to 500 mW/cm.sup.2, more preferably 200 to 400 mW/cm.sup.2, very preferably 250 to 350 mW/cm.sup.2; preferably the wavelength of the light is in the range from 100 to 500 nm, more preferably 250 to 450 nm, very preferably 350 to 400 nm; preferably the irradiation time is in the range from 1 to 120 minutes, preferably from 5 to 100 minutes, more preferably 7 to 75 minutes.
18. A patterned optical layer produced by the method of claim 17.
19. An optical device comprising the patterned optical layer of claim 18 and a substrate.
20. A display device comprising at least one functional medium configured to direct and modulate a light or configured to emit light; and the patterned optical layer of claim 18.
21. A display device comprising at least one functional medium configured to direct and modulate a light or configured to emit light; and the optical device of claim 19.
Description
BRIEF DESCRIPTION OF DRAWINGS
[0027]
[0028]
[0029]
[0030]
[0031]
DEFINITION OF THE TERMS
[0032] In the context of the present invention, the term ligand as used herein, refers to an ion or molecule attached to a metal atom by coordinate bonding.
[0033] The term formulation medium or the plural term formulation media as used herein, denote one or more compounds serving as a solvent, suspending agent, carrier and/or matrix for the metal oxide precursor compound and any other component included in the formulation. Formulation media are generally inert compounds that do not react with said metal oxide precursor compounds and said other components. Formulation media may be liquid compounds, solid compounds or mixtures thereof. Typically, formulation media are organic compounds.
[0034] The term surfactant as used herein, refers to an additive that reduces the surface tension of a given formulation.
[0035] The term wetting and dispersion agent as used herein, refers to an additive that increases the spreading and filling properties of a given formulation. In this way, the tendency of the molecules to adhere to each other is reduced.
[0036] The term adhesion promoter as used herein, refers to an additive that increases the adhesion of a given formulation.
[0037] The term polymer matrix as used herein, refers to an additive that acts as a macromolecular matrix for one or more components of a given formulation.
[0038] The term optical layer as used herein, refers to a layer of an intermediate. Nanostructure may be formed by pressing a mold onto said layer as the method of the present invention below shows.
[0039] The term optical device as used herein, relates to a device containing one or more optical components for forming a light beam including, but not limited to, gratings, lenses, prisms, mirrors, optical windows, filters, polarizing optics, UV and IR optics, and optical coatings. Preferred optical devices in the context of the present invention are augmented reality (AR) glasses and/or virtual reality (VR) glasses, mixed reality (MR) glasses.
[0040] The term display device as used herein, is a kind of an optical device configured to output/present information in visual or tactile form. Examples are Liquid crystal display (LCD), Light emitting diode display (LED display), organic light emitting display (OLED), micro-LED display, quantum dot display (QLED), AR display, VR display, MR display, plasma (PDP) display, electroluminescent (ELD) display.
DETAILED DESCRIPTION OF THE INVENTION
[0041] Hereinafter, embodiments of the present invention are described in detail.
[Formulation for Preparing an Optical Layer]
[0042] The formulation for preparing an optical layer, preferably a particle-free optical layer, preferably to be used for nanoimprint lithography, more preferably to be used for direct UV nanoimprint lithography, according to the present invention (hereafter referred to as the formulation) comprises, essentially consists of, compound A and a metal oxide precursor, [0043] wherein the compound A is represented by formula (a1);
##STR00002## [0044] wherein X is a cation, preferably a monovalent, divalent, or trivalent cation, more preferably a monovalent cation; [0045] when X is a monovalent cation, n is 1; when X is a divalent cation, n is 2; when X is a trivalent cation, n is 3; [0046] wherein the metal oxide precursor comprises a group 4, 5, 6, 8, 11, 12, 14 or 15 metal element of the periodic table, more preferably a group 4, 5 or 12 metal element of the periodic table, a ligand and optionally one or more other organic components or substituents and/or one or more other inorganic components.
[Compound A]
[0047] The formulation comprises the compound A represented by formula (a1);
##STR00003## [0048] wherein X is a cation, preferably a monovalent, divalent, or trivalent cation, more preferably a monovalent cation; [0049] when X is a monovalent cation, n is 1; when X is a divalent cation, n is 2; when X is a trivalent cation, n is 3.
[0050] It is believed that the 365 nm UV irradiation triggers decomposition of compound A from an electronically excited state which releases an equivalent amount of a radical species. The radical initiates a radical chain reaction that results in the eventual degradation of at least one of the ligands of the metal oxide precursor to generate a metal oxide.
[0051] In a preferable embodiment, X of the formula (a1) is a monovalent cation represented by formula (a2-1) or (a2-2);
##STR00004## [0052] wherein E.sup.1 and E.sup.2 are each independently N or P, preferably N; R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are each independently H, a straight-chain alkyl having 1 to 25 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms; a branched or cyclic structure-containing alkyl having 3 to 25 carbon atoms, preferably 3 to 15 carbon atoms, more preferably 3 to 10 carbon atoms; an aryl having 6 to 25 carbon atoms, preferably from 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms; or NR.sup.7R.sup.8; [0053] when R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are each independently an alkyl or an aryl, one or more non-adjacent CH.sub.2 may each be replaced by O, S, CO, COO, OCO, OCOO, CR.sup.7CR.sup.8, or CC; [0054] R.sup.7 and R.sup.8 are each independently H, a straight-chain alkyl having 1 to 25 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms; a branched or cyclic structure containing alkyl having 3 to 25 carbon atoms, preferably 3 to 15 carbon atoms, more preferably 3 to 10 carbon atoms; an aryl having 6 to 25 carbon atoms, preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms; and [0055] when R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7 and R.sup.8 are each independently an alkyl or an aryl, one or more H may each be replaced by OH, COOH, a straight-chain alkyl having 1 to 6 carbon atoms, or a branched or cyclic structure-containing alkyl having 3 to 6 carbon atoms.
[0056] It is believed that the 365 nm UV irradiation more effectively triggers degradation of compound A from an electronically excited state which releases an equivalent amount of a radical species when the cation of the compound A has a structure represented by the formula (a2-1) or (a2-2). The radical initiates a radical chain reaction that results in the eventual degradation of at least one of the ligands of the metal oxide precursor to generate a metal oxide.
[0057] In a more preferable embodiment, X of the formula (a1) is a cation represented by formula (a3);
##STR00005## [0058] wherein R.sup.31, R.sup.32, R.sup.33, R.sup.34 and R.sup.35 are each independently H, a straight-chain alkyl having 1 to 25 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms; a branched or cyclic structure-containing alkyl having 3 to 25 carbon atoms, preferably 3 to 15 carbon atoms, more preferably 3 to 10 carbon atoms; an aryl having 6 to 25 carbon atoms, preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms; preferably R.sup.31, R.sup.32, R.sup.33, R.sup.34 and R.sup.35 are H; when R.sup.31, R.sup.32, R.sup.33, R.sup.34 and R.sup.35 are each independently an alkyl or an aryl, one or more non-adjacent CH.sub.2 may each be replaced by O, S, CO, COO, OCO, OCOO, CHCH, or CC; [0059] when R.sup.31, R.sup.32, R.sup.33, R.sup.34 and R.sup.35 are each independently an alkyl or an aryl, one or more H may each be replaced by OH, COOH, a straight-chain alkyl having 1 to 6 carbon atoms, or a branched or cyclic structure-containing alkyl having 3 to 6 carbon atoms.
[0060] It is believed that 365 nm UV irradiation furthermore effectively triggers degradation of compound A from an electronically excited state which releases an equivalent amount of a radical species when the cation of the compound A has a structure represented by the formula (a3). The radical initiates a radical chain reaction that results in the eventual degradation of at least one of the ligands of the metal oxide precursor to generate a metal oxide.
[0061] Examples of the compound A include NH.sub.4.sup.+NO.sub.2.sup., NH.sub.3CH.sub.3.sup.+NO.sub.2.sup., NH.sub.2(CH.sub.3).sub.2.sup.+NO.sub.2.sup., NH(CH.sub.3).sub.3.sup.+NO.sub.2.sup., PH.sub.4.sup.+NO.sub.2.sup., PH.sub.3CH.sub.3.sup.+NO.sub.2.sup., PH.sub.2(CH.sub.3).sub.2.sup.+NO.sub.2.sup., PH(CH.sub.3).sub.3.sup.+NO.sub.2.sup., NH.sub.2C(NH.sub.2).sub.2.sup.+NO.sub.2.sup., NH.sub.2CH(NH.sub.2).sup.+NO.sub.2.sup., NH.sub.2C(CH.sub.3)NH.sub.2.sup.+NO.sub.2.sup. and NH.sub.2C(CH.sub.3).sub.2.sup.+NO.sub.2.sup..
[0062] The formulation may either comprise one kind of the compound A or two or more kinds of the compound A having different structures from each other. The formulation preferably comprises one kind of compound A.
[0063] The mole ratio of the compound A to the metal oxide precursor may be in the range from 0.6NA to 1.4NA, preferably 0.7NA to 1.3NA, more preferably 0.75NA to 1.2NA, very preferably 0.80NA to 1.1NA, where NA represents the number of ligands contained in one metal oxide precursor.
[0064] It is believed that 365 nm UV irradiation furthermore effectively triggers degradation of compound A from an electronically excited state which releases an equivalent amount of a radical species when the mole ratio of the compound A to the metal oxide precursor is in the above-mentioned range. The radical initiates a radical chain reaction that results in the eventual degradation of at least one of the ligands of the metal oxide precursor to generate a metal oxide.
[Metal Oxide Precursor]
[0065] The formulation comprises the metal oxide precursor comprising a group 4, 5, 6, 8, 11, 12, 14 or 15 metal element of the periodic table, more preferably a group 4, 5 or 12 metal element of the periodic table, a ligand and optionally one or more other organic components or substituents and/or one or more other inorganic components.
[0066] In a preferable embodiment, the metal oxide precursor is represented by any one of formulae (m2-1) to (m2-5), preferably formula (m2-1), (m2-3) or (m2-4);
##STR00006## [0067] wherein [0068] M.sup.A is Cu, Zn or Bi, preferably Zn, [0069] M.sup.B is Al, [0070] M.sup.C is Pb, Sn or Ti, preferably Ti, [0071] M.sup.D is Nb or V, preferably Nb, [0072] M.sup.E is Fe, Cr, Mo or W; [0073] A.sup.1 is the ligand represented by formula (m3); [0074] A.sup.2, A.sup.3, C, N.sup.1 and N.sup.2 are each independently a group of one or more atoms; [0075] n3, n4 n5, n6 and n7 represent a valence of A.sup.2, A.sup.3, C, N.sup.1 and N.sup.2 respectively; [0076] n3 and n4 are each independently 1 to 5, more preferably 1 to 3; [0077] n5 is 1+ to 5+, more preferably 1+ to 3+; [0078] n6 and n7 are 0; [0079] NA1, NB1, NC1, ND1 and NE1 are each independently 1 to 50, preferably 2 to 45; [0080] NA2, NB2, NC2, ND2 and NE2 are each independently 1 to 55, preferably 1 to 50; [0081] NA3, NB3, NC3, ND3, NE3, NA4, NB4, NC4, ND4 and NE4 are each independently 0 to 80, preferably 0 to 70, more preferably 0 to 65; [0082] NA5, NB5, NC5, ND5 and NE5 are each independently 0 to 20, preferably 0 to 15, more preferably 0 to 10; [0083] NA6, NB6, NC6, ND6, NE6, NA7, NB7, NC7, ND7 and NE7 are each independently 0 to 40, preferably 0 to 30, more preferably 0 to 20; [0084] provided that
##STR00007## [0085] wherein R.sup.9 is a straight-chain alkyl having 1 to 25 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms; a branched or cyclic structure-containing alkyl having 3 to 25 carbon atoms, preferably 3 to 15 carbon atoms, more preferably 3 to 10 carbon atoms; an aryl having 6 to 25 carbon atoms, preferably from 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms; an aryl-alkylene having 6 to 25 carbon atoms, preferably from 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms; [0086] wherein one or more non-adjacent CH.sub.2 may each be replaced by O, S, CO, COO, OCO, OCOO, CR.sup.10CR.sup.11, or CC, preferably replaced by CO, COO, OCO, or OCOO, more preferably CO; [0087] R.sup.10 and R.sup.11 are each independently H, a straight-chain alkyl having 1 to 25 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms; a branched or cyclic structure containing alkyl having 3 to 25 carbon atoms, [0088] preferably 3 to 15 carbon atoms, more preferably 3 to 10 carbon atoms; an aryl having 6 to 25 carbon atoms, preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms; [0089] wherein one or more H may each be replaced by OH, COOH, a straight-chain alkyl having 1 to 6 carbon atoms, or a branched or cyclic structure-containing alkyl having 3 to 6 carbon atoms.
[0090] It is believed that 365 nm UV irradiation more effectively triggers degradation of compound A from an electronically excited state which releases an equivalent amount of a radical species when the metal oxide precursor is represented by any one of the formulae (m2-1) to (m2-5). The radical initiates a radical chain reaction that results in the eventual degradation of at least one of the ligands of the metal oxide precursor to generate a metal oxide.
[0091] In a more preferable embodiment, the metal oxide precursor is represented by any one of formulae (m4-1) to (m4-5), preferably formula (m4-1), (m4-3) or (m4-4);
##STR00008## [0092] wherein [0093] na1, nb1, nc1, nd1, and ne1 are each independently 1 to 50, preferably 2 to 45; na2, nb2, nc2, nd2, and ne2 are each independently 1 to 55, preferably 1 to 50; na3, nb3, nc3, nd3, and ne3 are each independently 0 to 20, preferably 0 to 10, more preferably 0 to 5; na4, nb4, nc4, nd4, and ne4 are each independently 1 to 80, preferably 1 to 70, more preferably 1 to 65; na5, nb5, nc5, nd5, and ne5 are each independently 0 to 20, preferably 0 to 10, more preferably 0 to 5; na6, nb6, nc6, nd6, and ne6 are each independently 0 to 20, preferably 0 to 10, more preferably 0 to 5; [0094] provided that 2na1=na2+na3+2na4, 3nb1=nb2+nb3+2nb4, 4nc1=nc2+nc3+2nc4, 5nd1=nd2+nd3+2nd4, 6ne1=ne2+ne3+2ne4; [0095] M.sup.3 is Cu, Zn or Bi, preferably Zn, [0096] M.sup.4 is Al, [0097] M.sup.5 is Pb, Sn or Ti, preferably Ti, [0098] M.sup.6 is Nb or V, preferably Nb, [0099] M.sup.7 is Fe, Cr, Mo or W; [0100] R.sup.12 is the ligand represented by formula (m5), and R.sup.13 is an acid;
##STR00009## [0101] wherein R.sup.14 is a straight-chain alkyl having 1 to 25 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms; a branched or cyclic structure-containing alkyl having 3 to 25 carbon atoms, preferably 3 to 15 carbon atoms, more preferably 3 to 10 carbon atoms; an aryl-alkylene having 6 to 25 carbon atoms, preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms; [0102] wherein one or more non-adjacent CH.sub.2 may each be replaced by O, S, CO, COO, OCO, OCOO, CR.sup.15CR.sup.16, or CC, preferably replaced by CO, COO, OCO, or OCOO, more preferably CO; [0103] R.sup.15 and R.sup.16 are each independently H, a straight-chain alkyl having 1 to 25 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms; a branched or cyclic structure containing alkyl having 3 to 25 carbon atoms, preferably 3 to 15 carbon atoms, more preferably 3 to 10 carbon atoms; an aryl having 6 to 25 carbon atoms, preferably from 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms; [0104] wherein one or more H may each be replaced by OH, COOH, a straight-chain alkyl having 1 to 6 carbon atoms, or a branched or cyclic structure-containing alkyl having 3 to 6 carbon atoms.
[0105] It is believed that 365 nm UV irradiation furthermore effectively triggers degradation of compound A from an electronically excited state which releases an equivalent amount of a radical species when the metal oxide precursor is represented by any one of the formulae (m4-1) to (m4-5). The radical initiates a radical chain reaction that results in the eventual degradation of at least one of the ligands of the metal oxide precursor to generate a metal oxide.
[0106] In a furthermore preferable embodiment, R.sup.13 is an acid represented by formula (m6);
##STR00010## [0107] wherein R.sup.17 is a straight-chain alkyl having 1 to 25 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms; a branched or cyclic structure-containing alkyl having 3 to 25 carbon atoms, preferably 3 to 15 carbon atoms, more preferably 3 to 10 carbon atoms; an aryl having 6 to 25 carbon atoms, preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms; wherein one or more non-adjacent CH.sub.2 may each be replaced by O, S, CO, COO, OCO, OCOO, CR.sup.18CR.sup.19, or CC; [0108] R.sup.18 and R.sup.19 are each independently H, a straight-chain alkyl having 1 to 25 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms; a branched or cyclic structure containing alkyl having 3 to 25 carbon atoms, preferably 3 to 15 carbon atoms, more preferably 3 to 10 carbon atoms; an aryl having 6 to 25 carbon atoms, preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms; [0109] wherein one or more H may each be replaced by OH, COOH, a straight-chain alkyl having 1 to 6 carbon atoms, or a branched or cyclic structure-containing alkyl having 3 to 6 carbon atoms.
[0110] It is believed that 365 nm UV irradiation furthermore effectively triggers degradation of compound A from an electronically excited state which releases an equivalent amount of a radical species when the metal oxide precursor contains an acid represented by the formula (m6). The radical initiates a radical chain reaction that results in the eventual degradation of at least one of the ligands of the metal oxide precursor to generate a metal oxide.
[0111] In another furthermore preferable embodiment, the metal oxide precursor comprises the ligand represented by the formula (m51);
##STR00011## [0112] wherein R.sup.141 is a straight-chain alkyl having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 5 to 10 carbon atoms; a branched or cyclic structure-containing alkyl having 3 to 20 carbon atoms, preferably 3 to 10 carbon atoms, more preferably 5 to 10 carbon atoms; an aryl having 6 to 20 carbon atoms, preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms; wherein one or more H may each be replaced by OH, COOH, a straight-chain alkyl having 1 to 6 carbon atoms, or a branched or cyclic structure-containing alkyl having 3 to 6 carbon atoms.
[0113] It is believed that one or more of the ligands of the metal oxide precursor get removed further easily by the radical generated by irradiating the compound A when the ligand is represented by the formula (m51).
[0114] Examples of the metal oxide precursor include Zn.sub.4O(2-ethylhexanoate).sub.6, Ti.sub.44(OH).sub.4O.sub.62(2-ethylhexanoic acid).sub.4(2-ethylhexanoate).sub.48(H.sub.2O).sub.2, Al.sub.32(benzoate).sub.36(OiPr).sub.4028, (NH.sub.4).sub.6[Bi.sub.6O.sub.4(citrate).sub.3(H.sub.2O).sub.3], Zn.sub.6(OH.sub.2)(O.sub.2CtBu).sub.8(pyridine-2,6-dimethanol), Ti.sub.16(OH).sub.2O.sub.20(propionic acid).sub.20(O.sup.tBu).sub.2, Sn.sub.6O.sub.6(O.sup.tBu).sub.6(OAc).sub.6, Nb.sub.8O.sub.12(2-naphthoate).sub.12(OEt).sub.4, [Mo.sub.3O.sub.2(OAc).sub.6(H.sub.2O).sub.3].sup.2+, [W.sub.3O.sub.2(O.sub.2CC.sub.6H.sub.5).sub.6(H.sub.2O).sub.3].sup.2+.
[0115] The ligand stabilizes the remainder of the metal oxide precursor.
[0116] It is believed that the optical layer containing the metal oxide is formed by the removal of one or more ligands of the metal oxide precursor in a radical chain reaction by the radicals generated by UV irradiation of the compound A. The following formula represents an example of a considered reaction with said removal.
Zn.sub.4O(O.sub.2CR).sub.6+6GdnHNO.sub.2.fwdarw.4ZnO+6Gdn+6NO+6CO.sub.2+3H.sub.2O+3R.sub.2.
[0117] In the formula above, Gdn is guanidinium, the compound A is GdnHNO.sub.2, the metal oxide precursor is Zn.sub.4O(O.sub.2CR).sub.6, the ligand is O.sub.2CR.
[0118] The formulation may either comprise one kind of the metal precursor or two or more kinds of the metal precursor having different structures from each other. The formulation preferably comprises one kind of the metal precursor.
[0119] The formulation may comprise one or more metal oxide precursors that are not represented by any one of the formulae (m2-1) to (m2-5). When the total molar amount of the metal oxide precursor(s) represented by any one of the formulae (m2-1) to (m2-5) contained in the formulation is nm and the total molar amount of the whole metal oxide precursor(s) contained in the formulation is n.sub.total, n.sub.m/n.sub.total preferably equals 0.8-1 or n.sub.m/n.sub.total100 preferably equals 80 to 100%, more preferably 0.9-1 or 90 to 100%, and even more preferably 0.95-1 or 95 to 100%. It is also a preferred embodiment that all the metal oxide precursor(s) contained in the formulation are represented by the formulae (m2-1) to (m2-5) (n.sub.m/n.sub.total=100%).
[Solvent]
[0120] The formulation may further comprise a solvent. The solvent is selected from one or more members of the group consisting of a secondary linear or branched C3 alcohol, preferably it is selected from isopropanol, 2-butanol, 2-pentanol, 3-pentanol, propylene glycol monoalkyl ethers, preferably it is propylene glycol monomethyl ether, propylene glycol monoethyl ether and/or propylene glycol monopropyl ether, propylene glycol monoalkyl ether acetates, preferably it is propylene glycol monomethyl ether acetate, propylene glycol dialkyl ethers, preferably it is propylene glycol dimethyl ether, and alkyl lactate, preferably it is ethyl lactate.
[0121] It is believed that both the compound A and the metal oxide precursor are sufficiently soluble in one of the above-described solvents.
[0122] The boiling point of the solvent is preferably in the range from 35 to 100 C., more preferably 40 to 90 C., very preferably 45 to 80 C.
[0123] It is believed that pre-baking after coating the formulation effectively removes the solvent.
[0124] When the formulation comprises the solvent, the solid content is preferably in the range from 0.1 to 20 mass parts, more preferably 0.5 to 15 mass parts, very preferably 0.8 to 10 mass parts based on 100 parts of the formulation.
[0125] The term solid content used herein refers to the total amount of all the components except for the solvent contained in the formulation.
[Compound B]
[0126] The formulation may further comprise compound B comprising Si.
[0127] In a preferable embodiment, the compound B is represented by formula (c1).
##STR00012## [0128] wherein m1 is 0, 1, 2 or 3, preferably 1; [0129] R.sup.20 is a straight-chain alkyl having 1 to 15 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, very preferably 1 to 3 carbon atoms; a branched or cyclic structure-containing alkyl having 3 to 15 carbon atoms, preferably 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms; an aryl having 6 to 20 carbon atoms, preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms; [0130] wherein one or more non-adjacent CH.sub.2 may each be replaced by O, S, CO, COO, OCO, OCOO, CR.sup.22CR.sup.23, or CC; [0131] R.sup.22 and R.sup.23 are each independently H, a straight-chain alkyl having 1 to 25 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms; a branched or cyclic structure containing alkyl having 3 to 25 carbon atoms, preferably 3 to 15 carbon atoms, more preferably 3 to 10 carbon atoms; an aryl having 6 to 25 carbon atoms, preferably from 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms; [0132] wherein one or more H may each be replaced by OH, COOH, a straight-chain alkyl having 1 to 6 carbon atoms, or a branched or cyclic structure-containing alkyl having 3 to 6 carbon atoms; [0133] wherein R.sup.21 is a straight-chain alkyl having 1 to 25 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms; a branched or cyclic structure-containing alkyl having 3 to 25 carbon atoms, preferably 3 to 15 carbon atoms, more preferably 3 to 10 carbon atoms; a straight-chain alkenyl having 1 to 25 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms; a branched or cyclic structure-containing alkenyl having 3 to 25 carbon atoms, preferably 3 to 15 carbon atoms, more preferably 3 to 10 carbon atoms; an aryl having 6 to 25 carbon atoms, preferably from 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms; [0134] wherein one or more non-adjacent CH.sub.2 may each be replaced by O, S, CO, COO, OCO, OCOO, CR.sup.24CR.sup.25, CCR.sup.24R.sup.25, or CC, preferably replaced by OCO; wherein R.sup.24 and R.sup.25 are each independently H, a straight-chain alkyl having 1 to 25 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms; a branched or cyclic structure containing alkyl having 3 to 25 carbon atoms, preferably 3 to 15 carbon atoms, more preferably 3 to 10 carbon atoms; an aryl having 6 to 25 carbon atoms, preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms, very preferably R.sup.24 and R.sup.25 are H; [0135] wherein one or more H may each be replaced by OH, COOH, a straight-chain alkyl having 1 to 6 carbon atoms, or a branched or cyclic structure-containing alkyl having 3 to 6 carbon atoms.
[0136] It is believed that the compound B reacts with the metal oxide precursor to form metal oxide nanoparticles covered with ligands containing Si. 365 nm UV irradiation triggers degradation of compound A from an electronically excited state to release an equivalent amount of a radical species. The radical species initiates a radical chain reaction that eventually results in removal of at least one of the organic substituents at Si from the metal oxide nanoparticle.
[0137] The content of the compound B is preferably in the range from 7 to 50 mass parts, more preferably 10 to 40 mass parts, very preferably 15 to 30 mass parts based on 100 parts of the metal oxide precursor.
[Acid]
[0138] The formulation may further comprise an acid selected from one or more members of the group consisting of sulfonic acids, hydrochloric acid and carboxylic acids, preferably hydrochloric acid.
[0139] It is believed that one or more of the above-described acids hydrolyze the compound B. The hydrolyzed compound B reacts with the metal oxide precursor to form nanoparticles covered by ligands containing Si.
[Additives]
[0140] The formulation may optionally comprise one or more additives selected from surfactants, wetting and dispersion agents, adhesion promoters, and polymer matrices.
[0141] Or, in some embodiments, the formulation of the present invention does not contain any additives.
[Use]
[0142] In another aspect, the present invention also relates to use of the formulation of the present invention for preparing an optical layer, preferably a particle-free optical layer, preferably to be used for nanoimprint lithography, more preferably to be used for direct UV nanoimprint lithography.
[Method for Preparing an Optical Layer Containing a Metal Oxide]
[0143] In another aspect, the present invention also relates to a method (hereafter referred to as the method) for preparing an optical layer containing a metal oxide, preferably a particle-free optical layer containing a metal oxide, preferably to be used for nanoimprint lithography, more preferably to be used for direct UV nanoimprint lithography, comprising the following step (i); [0144] (i) coating the formulation of the present invention above a substrate to form an optical layer, preferably the substrate is a silicon wafer or glass, more preferably glass; preferably by spin-coating, more preferably by spin-coating with 500 to 6,000 RPM for 5 to 100 seconds, very preferably by spin-coating with 1,000 to 5,000 RPM for 10 to 70 seconds, most preferably spin-coating with 1,500 to 4,500 RPM for 15 to 50 seconds.
[0145] In a preferable embodiment, the method may further comprise the following step (ii); [0146] (ii) heating the optical layer at 35 to 200 C. for 1 to 100 minutes, preferably at 40 to 150 C. for 1 to 50 minutes, more preferably at 45 to 100 C. for 1 to 20 minutes.
[0147] The step (ii) may be carried out under air atmosphere, atmospheres with increased noble gas content or atmospheres with increased N.sub.2 content, preferably under air atmosphere or atmospheres with increased noble gas content, more preferably under air atmosphere or atmospheres with increased argon content.
[0148] The step (ii) may serve the purpose to remove the excessive solvent in the formulation.
[0149] In a more preferable embodiment, the method may further comprise the following step (iii); [0150] (iii) irradiating light to the optical layer, preferably the light is UV; preferably the light intensity is in the range from 150 to 500 mW/cm.sup.2, more preferably 200 to 400 mW/cm.sup.2, very preferably 250 to 350 mW/cm.sup.2; preferably the wavelength of the light is in the range from 100 to 500 nm, more preferably 250 to 450 nm, very preferably 350 to 400 nm; preferably the irradiation time is in the range from 1 to 120 minutes, preferably 5 to 100 minutes, more preferably 7 to 75 minutes.
[0151] The step (iii) may serve the purpose to convert the metal oxide precursor or metal oxide precursor mixture layers on the substrate into a metal oxide layer. Moreover, the final properties of the metal oxide layer may be adjusted by the step (iii).
[Optical Layer]
[0152] In another aspect, the present invention also relates to an optical layer, preferably a particle-free optical layer, preferably to be used for nanoimprint lithography, more preferably to be used for direct UV nanoimprint lithography produced by the method of the present invention.
[0153] The thickness of the optical layer is in the range from 1 to 700 nm, preferably from 3 to 600 nm, more preferably 5 to 500 nm, very preferably 7 to 400 nm.
[Method for Producing a Patterned Optical Layer]
[0154] In another aspect, the present invention also relates to a method for producing a patterned optical layer comprising the following steps (iv) and (v); [0155] (iv) producing an optical layer by the method, [0156] (v) forming a pattern by pressing a mold onto the optical layer, [0157] (vi) optionally, heating the patterned optical layer, preferably at 35 to 200 C. for 1 to 100 minutes, more preferably at 40 to 150 C. for 1 to 50 minutes, very preferably at 45 to 100 C. for 1 to 20 minutes, [0158] (vii) optionally, irradiating light to the patterned optical layer, preferably the light is UV, preferably the light intensity is in the range from 150 to 500 mW/cm.sup.2, more preferably 200 to 400 mW/cm.sup.2, very preferably 250 to 350 mW/cm.sup.2; preferably the wavelength of the light is in the range from 100 to 500 nm, more preferably 250 to 450 nm, very preferably 350 to 400 nm; preferably the irradiation time is in the range from 1 to 120 minutes, preferably from 5 to 100 minutes, more preferably 7 to 75 minutes.
[Patterned Optical Layer]
[0159] In another aspect, the present invention also relates to a patterned optical layer produced by the method of the present invention.
[Optical Device]
[0160] In another aspect, the present invention also relates to optical device comprising the patterned optical layer of the present invention and a substrate.
[0161] The substrates are preferably made of inorganic or organic base materials, more preferably inorganic base materials. The inorganic base materials include materials selected from the group consisting of ceramics, glass, fused silica, sapphire, silicon, silicon nitride and quartz. The geometry of the substrate is not specifically limited, however, preferred are sheets or wafers.
[Display Device]
[0162] Finally, the present invention relates to display device comprising at least one functional medium configured to modulate a light or configured to emit light; and the patterned optical layer of the present invention, or the optical device of the present invention.
[0163] Examples of said display device is selected from a Liquid crystal display (LCD), Light emitting diode display (LED display), organic light emitting display (OLED), micro-LED display, quantum dot display (QLED), Augmented Reality (AR) hardware, Virtual Reality (VR) hardware, Mixed Reality (MR) hardware, plasma (PDP) display and an electroluminescent (ELD) display. Said AR, VR and MR hardware are also called as AR, VR and MR display. Preferably said display device is AR hardware, VR hardware or MR hardware.
[0164] The present invention is further illustrated by the examples following hereinafter which shall in no way be construed as limiting. The skilled person will acknowledge that various modifications, additions and alternations may be made to the invention without departing from the spirit and scope of the invention as defined in the appended claims.
WORKING EXAMPLES
Analytics and Measurement Methods
[0165] Ellipsometry is used to determine layer thickness, refractive index (n) and absorption index (k) of a metal oxide layer. Measurements are performed using an ellipsometer M2000 from J. A. Woolam and three different angles of incidence (65, 70 and 75). The measurement data is analyzed with software CompleteEase from J. A. Woolam, applying a Gen-Osc fitting model for obtaining refractive index (n) as well as absorption index (k). The optical constants are averaged from five measured points on each wafer.
[0166] All chemicals for synthesis described are purchased from Sigma Aldrich and used without further purification, unless differently mentioned elsewhere.
[0167] UV/vis measurements are performed using a Cary 7000 spectrometer from Agilent. UV LED irradiation is performed by an in-house built 365 LED source.
Example 1
[0168] 122.5 mg of Zn.sub.4O(2-ethylhexanoate).sub.6 and 58.8 mg of guanidinium nitrite are dissolved in 2.45 mL of isopropanol. The solution is irradiated with 300 mW/cm.sup.2 of a 365 nm UV LED for 0, 10 and 60 minutes. A precipitate is formed during the irradiation and is filtered off. A UV/visible spectrum is recorded of the filtrate at all the three irradiation times. The recorded UV/visible spectrum is shown by
Example 2
[0169] A solution prepared from 100 mg of Ti.sub.44(OH).sub.4O.sub.62(2-ethylhexanoic acid).sub.4(2-ethylhexanoate).sub.48(H.sub.2O).sub.2 and 50 mg of guanidinium nitrite are dissolved in 2 mL of isopropanol. The solution is irradiated for 0 and 60 minutes with 300 mW/cm.sup.2 of a 365 nm UV LED. A precipitate is formed during the irradiation and is filtered off. A UV/visible spectrum is recorded of the filtrate. The recorded UV/visible spectrum is shown by
Example 3
[0170] 27 mg of Zn.sub.4O(2-ethylhexanoate).sub.6 and 12 mg of guanidinium nitrite are dissolved in 540 L of isopropanol. A 100 L portion of this solution is transferred to a thermal gravimetric analysis (TGA) crucible and dried at 60 C.
[0171] The residual mass at 800 C. is 13% of the initial mass (mass loss is 86.9%). The residual mass is consistent with the formation of zinc oxide (theoretical mass loss 81.6%). The result of the TGA is shown by
Example 4
[0172] 25 mg of Zn.sub.4O(2-ethylhexanoate).sub.6 and 12 mg of guanidinium nitrite are dissolved in 0.5 mL of isopropanol. 100 L of the solution is spin coated onto a precleaned 2-inch silicon wafer (4000 RPM, 25 sec.), baked at 60 C. for 3 min., and finally exposed to 365 nm light with 300 mW/cm.sup.2 for 10 min. under ambient conditions affording a homogeneous film. The optical properties of the film are shown by Table 1.
TABLE-US-00001 TABLE 1 Optical properties Pre-bake (60 C.) Curing@365 nm Refractive index 1.50 1.51 Absorption (k value) 4.74E03 4.32E03 Film thickness (nm) 369 357
Example 5
[0173] 25 mg of Zn.sub.4O(2-ethylhexanoate).sub.6 and 12 mg of guanidinium nitrite are dissolved in 0.5 mL of isopropanol. 100 L of the solution is spin coated onto a precleaned 2-inch silicon wafer (4000 RPM, 25 sec.), baked at 60 C. for 3 min. and finally exposed to 300 mW/cm.sup.2 365 nm light for 10 min. under an argon atmosphere affording a homogeneous film. The optical properties of the film are shown by Table 2.
TABLE-US-00002 TABLE 2 Optical properties Pre-bake (60 C.) Curing@365 nm Refractive index 1.54 1.55 Absorption (K value) 1.22E02 1.25E02 Thickness (nm) 377 361
Example 6A
[0174] 25 mg of Ti.sub.44(OH).sub.4O.sub.62(2-ethylhexanoic acid).sub.4(2-ethylhexanoate).sub.48(H.sub.2O).sub.2 and 12 mg or 24 mg of guanidinium nitrite are dissolved in 0.5 mL of PGME. 100 L of the solution is spin coated onto oxygen activated 2 silicon wafer (2000 RPM, 25 sec.) followed by baking at 60 C. for 5 minutes and photocuring with 300 mW/cm.sup.2 at 365 nm for 10 minutes resulting in a homogeneous film. The optical properties of the film are shown by Table 3.
TABLE-US-00003 TABLE 3 Optical properties Pre-bake (60 C.) Curing@365 nm Refractive index 1.63 1.64 Absorption (k value) 5.8E04 6.38E04 Film thickness (nm) 224 214
Example 6B
[0175] 25 mg of Ti.sub.44(OH).sub.4O.sub.62(2-ethylhexanoic acid).sub.4(2-ethylhexanoate).sub.48(H.sub.2O).sub.2 and 12 mg or 24 mg of guanidinium nitrite are dissolved in 0.5 mL of PGME. 100 L of the solution is spin coated onto oxygen activated 2-inch silicon wafer (2000 RPM, 25 sec.) followed by baking at 60 C. for 5 minutes and photocuring with 300 mW/cm.sup.2 at 365 nm for 10 minutes resulting in a homogeneous film. The optical properties of the film are shown by Table 4.
TABLE-US-00004 TABLE 4 Optical properties Pre-bake (60 C.) Curing@365 nm Refractive index 1.59 1.60 Absorption (k value) 5.93E04 1.85 E02 Film thickness (nm) 310 279
Example 7
[0176] 4.08 mL of octyltriethoxysilane is added to 650 mL of PGME in a 1 L round bottom flask. 5 mL of 2M HCl is added and the solution is stirred at room temperature for 20 h. 11.65 mL of niobium ethoxide is added and the solution is heated to 80 C. for 2 h while stirring. The resulting solution is concentrated by rotor evaporation to 30% w/w.
[0177] 25 mg of guanidinium nitrite is dissolved in 15 mL of PGME. 3 mL of this solution is used to dissolve 100 L of the 30% w/w PGME solution of Nb.sub.2O.sub.5 nanoparticles covered by octyl silane ligands. 100 L of the resulting solution is spin-coated onto a 2-inch Si wafer at 4000 RPM for 25 seconds and then baked at 60 C. for 5 minutes to remove the solvent. The film is exposed to 300 mW/cm.sup.2 365 nm light for 15 min. The optical properties of the film are shown by Table 5.
TABLE-US-00005 TABLE 5 Optical properties Pre-bake (60 C.) Curing@365 nm Refractive index 1.68 1.70 Absorption (k value) 8.23E05 2.53E05 Film thickness (nm) 27 25
Example 8
[0178] 1.55 mL of 3-(trimethoxysilyl)propyl methacrylate is added to 650 mL of PGME in a 1 L round bottom flask. 5 mL of 2M HCl is added and the solution is stirred at room temperature for 20 h. 11.65 mL of niobium ethoxide is added and the solution is heated to 80 C. for 2 h while stirring. The resulting solution is concentrated by rotor evaporation to 30% w/w.
[0179] 25 mg of guanidinium nitrite is dissolved in 15 mL of PGME. 3 mL of this solution is used to dissolve 100 L of the 30% w/w PGME solution of Nb.sub.2O.sub.5 nanoparticles covered by 3-methacryloxypropyl silane ligands. 100 L of the resulting solution is spin-coated onto a 2-inch Si wafer at 4000 RPM for 25 seconds and then baked at 60 C. for 5 minutes to remove the solvent. The film is exposed to 300 mW/cm.sup.2 365 nm light for 15 min. The optical properties of the film are shown by Table 6.
TABLE-US-00006 TABLE 6 Optical properties Pre-bake (60 C.) Curing@365 nm Refractive index 1.68 1.70 Absorption (k value) 8.23E05 2.53E05 Film thickness (nm) 27 25
Comparative Example 1
[0180] An experiment is performed the same way as Example 1 except for not including Zn.sub.4O(2-ethylhexanoate).sub.6 into the solution. The recorded UV/visible spectrum is shown by
Comparative Example 2
[0181] An experiment is performed the same way as Example 3 except for not including guanidinium nitrite into the solution. The result of TGA is shown by
[0182] It is observed that Zn.sub.4O(2-ethylhexanoate).sub.6 evaporates to the extent that its residual mass is less than 0.