WO2009067415A1

WO2009067415A1 - Process for making a color filter

Info

Publication number: WO2009067415A1
Application number: PCT/US2008/083840
Authority: WO
Inventors: Curtis R. Fincher
Original assignee: E. I. Du Pont De Nemours And Company
Priority date: 2007-11-19
Filing date: 2008-11-18
Publication date: 2009-05-28
Also published as: KR20100099184A; JP2011503671A; TW200946979A; JP5453293B2

Abstract

A process for making a color filter, and a color filter made by the process, whereby a substrate having a black matrix which defines a plurality of sub-pixels and has a first surface energy is treated with a reactive surface-active composition to form an intermediate layer having a second surface energy, such that the second surface energy is lower than the first surface energy; the intermediate layer is exposed to radiation in a pattern; the intermediate layer is removed in the sub-pixel areas; a first composition comprising a first colored material is deposited in a first set of sub-pixel areas, a second composition comprising a second colored material is deposited in a second set of sub-pixel areas, where the colored materials are deposited by a precision deposition technique. A third composition comprising a third colored material may optionally be deposited in a third set of sub-pixel areas.

Description

TITLE PROCESS FOR MAKING A COLOR FILTER

RELATED APPLICATION DATA This application claims priority under 35 U. S. C. § 119(e) from

Provisional Application No. 60/988,892 filed on November 19, 2007, which is incorporated by reference in its entirety.

BACKGROUND INFORMATION Field of the Disclosure This disclosure relates in general to a process for making a color filter. More particularly, it relates to a process in which the color material is applied by printing with minimal intermixing of colors. Description of the Related Art

Many imaging displays, and particularly liquid crystal displays, use color filters for providing the different colors. In general, the color filter has transparent substrate, usually glass, on which is formed a black matrix. The matrix defines the pixel areas and provides contrast and light shielding. Different colored dyes or pigments are then applied to the sub- pixel units defined by the black matrix, for example red sub-pixels, green sub-pixels, and blue sub-pixels.

It is known to form the different sub-pixels by a variety of methods. In a pigment dispersion method, a photoresist containing pigments of a specific color is applied, imaged, and developed. This is repeated for the different colors. This method involves a large number of processing steps. The colors can also be applied by thermal transfer or by printing. The printing method has the advantage of speed and convenience. However, when the ink is deposited in each sub-pixel, the level deposited is often higher than that defined by the black matrix. Thus, intermixing of colors may occur in adjacent sub-pixel regions prior to drying. There is a continuing need for improved processes for forming color filters. SUMMARY

There is provided a process for making a color filter, the process comprising: providing a substrate having thereon a black matrix, the matrix defining a plurality of sub-pixels and having a first surface energy; treating the substrate and black matrix with a reactive surface- active composition to form an intermediate layer having a second surface energy, wherein the second surface energy is lower than the first surface energy; exposing the intermediate layer in a pattern with radiation; removing the intermediate layer in the sub-pixel areas; depositing a first composition comprising a first colored material in a first set of sub-pixel areas by a precision liquid deposition technique, and depositing a second composition comprising a second colored material in a second set of sub-pixel areas by a precision liquid deposition technique.

The foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as defined in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS Embodiments are illustrated in the accompanying figures to improve understanding of concepts as presented herein.

FIG. 1 includes a diagram illustrating contact angle. FIG. 2 includes an illustration of a workpiece having a black matrix for a color filter.

FIG. 3 includes an illustration of the workpiece of FIG. 2 treated with a reactive surface-active composition.

FIG. 4 includes an illustration of the workpiece of FIG. 3 after exposure and development.

FIG. 5 includes an illustration of the workpiece of FIG. 4 after deposition of a first colored material. FIG. 6 includes an illustration of the workpiece of FIG. 5 after deposition of a second colored material.

Skilled artisans appreciate that objects in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the objects in the figures may be exaggerated relative to other objects to help to improve understanding of embodiments.

DETAILED DESCRIPTION

There is provided a process for making a color filter, the process comprising: providing a substrate having thereon a black matrix, the matrix defining a plurality of sub-pixels and having a first surface energy; treating the substrate and black matrix with a reactive surface- active composition to form an intermediate layer having a second surface energy, wherein the second surface energy is lower than the first surface energy; exposing the intermediate layer in a pattern with radiation; removing the intermediate layer in the sub-pixel areas; and depositing a first composition comprising a first colored material in a first set of sub-pixel areas by a precision liquid deposition technique, and depositing a second composition comprising a second colored material in a second set of sub-pixel areas by a precision liquid deposition technique.

In one embodiment, the process further comprises depositing a third composition comprising a third colored material in a third set of sub- pixel areas by a precision liquid deposition technique.

In a particular embodiment, the reactive surface-active composition is photocurable.

In another particular embodiment, the intermediate layer is removed by heating.

The foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as defined in the appended claims. Many aspects and embodiments have been described above and are merely exemplary and not limiting. After reading this specification, skilled artisans appreciate that other aspects and embodiments are possible without departing from the scope of the invention. Other features and benefits of any one or more of the embodiments will be apparent from the following detailed description, and from the claims. The detailed description first addresses Definitions and Clarification of Terms followed by the Reactive Surface-active Composition, and the Process. 1. Definitions and Clarification of Terms

Before addressing details of embodiments described below, some terms are defined or clarified.

The term "contained" when referring to a layer, is intended to mean that the layer does not spread significantly beyond the area where it is deposited. The layer can be contained by surface energy affects or a combination of surface energy affects and physical barrier structures.

The term "fluohnated" when referring to an organic compound, is intended to mean that one or more of the hydrogen atoms in the compound have been replaced by fluorine. The term encompasses partially and fully fluohnated materials.

The term "layer" is used interchangeably with the term "film" and refers to a coating covering a desired area. The term is not limited by size. The area can be as large as an entire device or as small as a specific functional area such as the actual visual display, or as small as a single sub-pixel. Layers and films can be formed by any conventional deposition technique, including vapor deposition, liquid deposition (continuous and discontinuous techniques), and thermal transfer.

The term "liquid composition" is intended to mean a liquid medium in which a material is dissolved to form a solution, a liquid medium in which a material is dispersed to form a dispersion, or a liquid medium in which a material is suspended to form a suspension or an emulsion. "Liquid medium" is intended to mean a material that is liquid without the addition of a solvent or carrier fluid, i.e., a material at a temperature above its solidification temperature.

The term "liquid medium" is intended to mean a liquid material, including a pure liquid, a combination of liquids, a solution, a dispersion, a suspension, and an emulsion. Liquid medium is used regardless whether one or more solvents are present.

As used herein, the term "over" does not necessarily mean that a layer, member, or structure is immediately next to or in contact with another layer, member, or structure. There may be additional, intervening layers, members or structures.

The term "photocurable" is intended to refer to a radiation-sensitive composition or layer which becomes better adhered to a surface or more difficult to remove from a surface when exposed to radiation.

The term "photocurable surface-active composition" is intended to mean a composition that comprises at least one photocurable material, and when the composition is applied to a layer, the surface energy of that layer is reduced. The term is abbreviated "PCSA", and refers to the composition both before and after exposure to radiation.

The term "polyacid" is intended to mean an organic compound having two or more acid groups.

The term "precision liquid deposition technique" is intended to mean a deposition technique that is capable of depositing one or more materials in a liquid composition over a substrate in a pattern to a thickness no greater than approximately one millimeter. A stencil mask, frame, well structure, patterned layer or other structure(s) may or may not be present during such deposition.

The term(s) "radiating/ radiation" mean(s) adding energy in any form, including heat in any form, the entire electromagnetic spectrum, or subatomic particles, regardless of whether such radiation is in the form of rays, waves, or particles.

The term "radiation-sensitive" when referring to a material, is intended to mean that exposure to radiation results in a change of at least one chemical, physical, or electrical property of the material. The term "reactive surface-active composition" is intended to mean a composition that comprises at least one material which is radiation sensitive, and when the composition is applied to a layer, the surface energy of that layer is reduced. Exposure of the reactive surface-active composition to radiation results in the change in at least one physical property of the composition. The term is abbreviated "RSA", and refers to the composition both before and after exposure to radiation.

The term "surface energy" is intended to refer to the energy required to create a unit area of a surface from a material. A characteristic of surface energy is that liquid materials with a given surface energy will not wet surfaces with a sufficiently lower surface energy.

The term "unsaturated" as it refers to an organic compound, is intended to mean that the compound has at least one carbon-carbon double bond or carbon-carbon triple bond. The term "α,β-unsaturated" is intended to mean that the double or triple bond is in conjugation with an acid functional group.

The term "workpiece" is intended to mean a substrate at any particular point of a process sequence.

As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having" or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Further, unless expressly stated to the contrary, "or" refers to an inclusive or and not to an exclusive or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present). Also, use of "a" or "an" are employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.

Group numbers corresponding to columns within the Periodic Table of the elements use the "New Notation" convention as seen in the CRC Handbook of Chemistry and Physics, 81 ^st Edition (2000-2001 ).

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present invention, suitable methods and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety, unless a particular passage is cited. In case of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.

To the extent not described herein, many details regarding specific materials, processing acts, and circuits are conventional and may be found in textbooks and other sources within the organic light-emitting diode display, photodetector, photovoltaic, and semiconductive member arts. 2. Reactive Surface-Active Composition

The reactive surface-active composition ("RSA") is a radiation- sensitive composition. When exposed to radiation, at least one physical property and/or chemical property of the RSA is changed such that the exposed and unexposed areas can be physically differentiated. Treatment with the RSA lowers the surface energy of the material being treated.

In one embodiment, the RSA is a radiation-hardenable composition. In this case, when exposed to radiation, the RSA can become less soluble or dispersable in a liquid medium, less tacky, less soft, less flowable, less liftable, or less absorbable. Other physical properties may also be affected. In one embodiment, the RSA is a radiation-softenable composition. In this case, when exposed to radiation, the RSA can become more soluble or dispersable in a liquid medium, more tacky, more soft, more flowable, more liftable, or more absorbable. Other physical properties may also be affected.

The radiation can be any type of radiation which results in a physical change in the RSA. In one embodiment, the radiation is selected from infrared radiation, visible radiation, ultraviolet radiation, and combinations thereof. Physical differentiation between areas of the PCSA exposed to radiation and areas not exposed to radiation, hereinafter referred to as "development," can be accomplished by any known technique. Such techniques have been used extensively in the photoresist art. Examples of development techniques include, but are not limited to, application of heat (evaporation), treatment with a liquid medium (washing), treatment with an absorbant material (blotting), treatment with a tacky material, and the like.

In one embodiment, the RSA consists essentially of one or more radiation-sensitive materials. In one embodiment, the RSA consists essentially of a material which, when exposed to radiation, hardens, or becomes less soluble, swellable, or dispersible in a liquid medium, or becomes less tacky or absorbable. In one embodiment, the RSA consists essentially of a material having radiation polymerizable groups. Examples of such groups include, but are not limited to olefins, acrylates, methacrylates and vinyl ethers. In one embodiment, the RSA material has two or more polymerizable groups which can result in crosslinking. In one embodiment, the RSA consists essentially of a material which, when exposed to radiation, softens, or becomes more soluble, swellable, or dispersible in a liquid medium, or becomes more tacky or absorbable. In one embodiment, the RSA consists essentially of at least one polymer which undergoes backbone degradation when exposed to deep UV radiation, having a wavelength in the range of 200-300 nm. Examples of polymers undergoing such degradation include, but are not limited to, polyacrylates, polymethacrylates, polyketones, polysulfones, copolymers thereof, and mixtures thereof.

In one embodiment, the RSA consists essentially of at least one reactive material and at least one radiation-sensitive material. The radiation-sensitive material, when exposed to radiation, generates an active species that initiates the reaction of the reactive material. Examples of radiation-sensitive materials include, but are not limited to, those that generate free radicals, acids, or combinations thereof. In one embodiment, the reactive material is polymerizable or crosslinkable. The material polymerization or crosslinking reaction is initiated or catalyzed by the active species. The radiation-sensitive material is generally present in amounts from 0.001 % to 10.0% based on the total weight of the RSA. In one embodiment, the RSA consists essentially of a material which, when exposed to radiation, hardens, or becomes less soluble, swellable, or dispersible in a liquid medium, or becomes less tacky or absorbable. In one embodiment, the reactive material is an ethylenically unsaturated compound and the radiation-sensitive material generates free radicals. Ethylenically unsaturated compounds include, but are not limited to, acrylates, methacrylates, vinyl compounds, and combinations thereof. Any of the known classes of radiation-sensitive materials that generate free radicals can be used. Examples of radiation-sensitive materials which generate free radicals include, but are not limited to, quinones, benzophenones, benzoin ethers, aryl ketones, peroxides, biimidazoles, benzyl dimethyl ketal, hydroxyl alkyl phenyl acetophone, dialkoxy actophenone, trimethylbenzoyl phosphine oxide derivatives, aminoketones, benzoyl cyclohexanol, methyl thio phenyl morpholino ketones, morpholino phenyl amino ketones, alpha halogennoacetophenones, oxysulfonyl ketones, sulfonyl ketones, oxysulfonyl ketones, sulfonyl ketones, benzoyl oxime esters, thioxanthrones, camphorquinones, ketocoumarins, and Michler's ketone. Alternatively, the radiation sensitive material may be a mixture of compounds, one of which provides the free radicals when caused to do so by a sensitizer activated by radiation. In one embodiment, the radiation sensitive material is sensitive to visible or ultraviolet radiation.

In one embodiment, the RSA is a compound having one or more crosslinkable groups. Crosslinkable groups can have moieties containing a double bond, a triple bond, a precursor capable of in situ formation of a double bond, or a heterocyclic addition polymerizable group. Some examples of crosslinkable groups include benzocyclobutane, azide, oxiran, di(hydrocarbyl)amino, cyanate ester, hydroxyl, glycidyl ether, C1 - 10 alkylacrylate, C1 -10 alkylmethacrylate, alkenyl, alkenyloxy, alkynyl, maleimide, nadimide, tri(C1-4)alkylsiloxy, tri(C1 -4)alkylsilyl, and halogenated derivatives thereof. In one embodiment, the crosslinkable group is selected from the group consisting of vinylbenzyl, p- ethenylphenyl, perfluoroethenyl, perfluoroehtenyloxy, benzo-3,4- cyclobutan-1 -yl, and p-(benzo-3,4-cyclobutan-1 -yl)phenyl. In one embodiment, the reactive material can undergo polymerization initiated by acid, and the radiation-sensitive material generates acid. Examples of such reactive materials include, but are not limited to, epoxies. Examples of radiation-sensitive materials which generate acid, include, but are not limited to, sulfonium and iodonium salts, such as diphenyliodonium hexafluorophosphate.

In one embodiment, the RSA consists essentially of a material which, when exposed to radiation, softens, or becomes more soluble, swellable, or dispersible in a liquid medium, or becomes more tacky or absorbable. In one embodiment, the reactive material is a phenolic resin and the radiation-sensitive material is a diazonaphthoquinone.

Other radiation-sensitive systems that are known in the art can be used as well.

In one embodiment, the RSA comprises a fluohnated material. In one embodiment, the RSA comprises an unsaturated material having one or more fluoroalkyl groups. In one embodiment, the fluoroalkyl groups have from 2-20 carbon atoms. In one embodiment, the RSA is a fluorinated acrylate, a fluorinated ester, or a fluorinated olefin monomer. Examples of commercially available materials which can be used as RSA materials, include, but are not limited to, Zonyl® 8857A, a fluorinated unsaturated ester monomer available from E. I. du Pont de Nemours and Company (Wilmington, DE), and

3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11 ,11 ,12,12,12-eneicosafluorododecyl acrylate (H₂C=CHCO2CH2CH2(CF2)9CF₃) available from Sigma-Aldhch Co. (St. Louis, MO).

In one embodiment, the RSA is a fluorinated macromonomer. As used herein, the term "macromonomer" refers to an oligomeric material having one or more reactive groups which are terminal or pendant from the chain. In some embodiments, the macromonomer has a molecular weight greater than 1000; in some embodiments, greater than 2000; in some embodiments, greater than 5000. In some embodiments, the backbone of the macromonomer includes ether segments and perfluoroether segments. In some embodiments, the backbone of the macromonomer includes alkyl segments and perfluoroalkyl segments. In some embodiments, the backbone of the macromonomer includes partially fluorinated alkyl or partially fluorinated ether segments. In some embodiments, the macromonomer has one or two terminal polymerizable or crosslinkable groups. In one embodiment, the RSA is an oligomeric or polymeric material having cleavable side chains, where the material with the side chains forms films with a different surface energy that the material without the side chains. In one embodiment, the RSA has a non-fluohnated backbone and partially fluorinated or fully fluorinated side chains. The RSA with the side chains will form films with a lower surface energy than films made from the RSA without the side chains. Thus, the RSA can be can be applied to a first layer, exposed to radiation in a pattern to cleave the side chains, and developed to remove the side chains. This results in a pattern of higher surface energy in the areas exposed to radiation where the side chains have been removed, and lower surface energy in the unexposed areas where the side chains remain. In some embodiments, the side chains are thermally fugitive and are cleaved by heating, as with an infrared laser. In this case, development may be coincidental with exposure in infrared radiation. Alternatively, development may be accomplished by the application of a vacuum or treatment with solvent. In some embodiment, the side chains are cleavable by exposure to UV radiation. As with the infrared system above, development may be coincidental with exposure to radiation, or accomplished by the application of a vacuum or treatment with solvent.

In one embodiment, the RSA comprises a material having a reactive group and second-type functional group. The second-type functional groups can be present to modify the physical processing properties or the photophysical properties of the RSA. Examples of groups which modify the processing properties include plasticizing groups, such as alkylene oxide groups. Examples of groups which modify the photophysical properties include charge transport groups, such as carbazole, triarylamino, or oxadiazole groups. In one embodiment, the RSA reacts with the underlying area when exposed to radiation. The exact mechanism of this reaction will depend on the materials used. After exposure to radiation, the RSA is removed in the unexposed areas by a suitable development treatment. In some embodiments, the RSA is removed only in the unexposed areas. In some embodiments, the RSA is partially removed in the exposed areas as well, leaving a thinner layer in those areas. In some embodiments, the RSA that remains in the exposed areas is less than 50A in thickness. In some embodiments, the RSA that remains in the exposed areas is essentially a monolayer in thickness. In a particular embodiment, the RSA is a photocurable surface- active composition ("PCSA") comprising a material selected from the group consisting of a fluohnated ester of an α,β-unsaturated polyacid, a fluorinated imide of an α,β-unsaturated polyacid, and combinations thereof. The acid groups can be selected from the group consisting of carboxylic acid, sulfonic acid, phosphoric acid, and combinations thereof. In some embodiments, the polyacid is a polycarboxylic acid. In some embodiments, the polyacid is linear. In some embodiments, the polyacid is branched. In some embodiments, the polyacid may contain more than one unsaturated unit. In some embodiments, the polyacid is substituted. In some embodiments, this substitution incorporates one or more oxygen atoms into the hydrocarbon backbone of the unsaturated polyacid. In some embodiments, this substitution is pendant to the hydrocarbon backbone of the unsaturated polyacid. In some embodiments, this substitution contains fluorine atoms. In some embodiments, all of the acid groups are in conjugation with the unsaturated group or groups. In some embodiments, only one of the acid groups is in conjugation with an unsaturated group. In some embodiments, the PCSA is at least 50% fluorinated, by which is meant that 50% of the available hydrogens bonded to carbon have been replaced by fluorine. In some embodiments, the PCSA is at least 60% fluorinated; in some embodiments, at least 70% fluorinated. In some embodiments, the PCSA is an ester or imide of an α,β-unsaturated, polyacid which is not aromatic. Examples of non-aromatic α,β-unsaturated polyacids include, but are not limited to, fumaric, maleic, itaconic, 2,2-dimethyl-4-methylenepentanedioic acid, muconic, 2- methyleneglutahc, and acotinic acids and oligomers of methacrylic acid. The PCSA may comprise one or more fluorinated esters or imides of unsaturated polyacids or fluorinated esters or imides of unsaturated polyacids in combination with fluorinated unsaturated monoacids.

In some embodiments, the ester is formed using a fluorinated alcohol, RfOH. The Rf group has 4-15 carbon atoms, 0-5 oxo oxygen atoms contained within the carbon atom chain, and at least 4 fluorine atoms, with the proviso that there is no fluorine atom on the carbon atom bearing OH. The fluorinated alcohol may be linear or branched, saturated or unsaturated. In some embodiments the alcohol has one of the formulas below:

HO-(CR¹R²)-(CH2)s-{(CRaF2-aO_b)t-(CR=CRO_b)w}-CHcF_3-c or

HO-(CR¹R²)-CH[(CH2)s-{(CRaF_2-aO_b)t-(CR=CRO_b)_w}-CH_cF3-c]2 where a, b, c, p, s, t, and w are the same or different at each occurrence and are integers, and a = 0-2, b = 0-1 , c = 0-3,

R = H or (CHaF_2-3)_PF,

R , R = H or C_pH2p+i,

P = 1 -3, s = 0-5, t = 2-15, and w = 0-2.

The groups within the brackets { } can be arranged in any order. In some embodiments, 1 < s < 4. In some embodiments, s = 2 or 3. In some embodiments, 4 < t + w < 12. In some embodiments, c = 0. In some embodiments, w = 0 or 1. In some embodiments, a = 0. In some embodiments, R = H or CF₃. In some embodiments, R¹ = R² = H. In some embodiments, R¹ = R² = CH₃.

Some non-limiting examples of fluorinated alcohols include:

In some embodiments, the amide is formed using a fluohnated amine, RfNH₂. The Rf group has 4-15 carbon atoms, 0-5 oxo oxygen atoms contained within the carbon atom chain, and at least 4 fluorine atoms, with the proviso that there is no fluorine atom on the carbon atom bearing NH₂. The fluohnated amine may be linear or branched, saturated or unsaturated. In some embodiments the amine has one of the formulas below: H₂N-(CR¹ R²)-(CH2)s-{(CRaF_2-aOb)t-(CR=CROb)w}-CHcF3-c or H2N-(CR¹)[-(CH2)s-{(CRaF2-aO_b)t-(CR=CRO_b)w}-CHcF_3-c]2 where a, b, c, s, t, and w are the same or different at each occurrence and are integers, and a = 0-2, b = 0-1 , c = 0-3,

R = H or (CHaF_2-3)_PF, R , R = H or C_pH2p+i, P = 1 -3, S = 0-5, t = 2-15, and w = 0-2.

Some non-limiting examples of amines include:

Additional examples of fluorinated alcohols and amines can be found in, for example, J. Fluorine Chemistry 77 (1996) 193-194; J. Fluorine Chemistry 80 (1996) 135-144; and U.S. Patents 6,479,612 and

7,138,551 .

When the PCSA is an ester, all of the acid groups of the α,β-unsaturated polyacid are estehfied and at least one acid group is esterified with a fluoroalkyl group. In some embodiments, all of the acid groups of the α,β-unsaturated polyacid are esterified with fluoroalkyl groups.

When the PCSA is an imide, all of the acid groups of the α,β-unsaturated polyacid are imidized and at least two of the acid groups are imidized with a fluoroalkyl group. In some embodiments, all of the acid groups of the α,β-unsaturated polyacid are imidized with fluoroalkyl groups.

The PCSA may further comprise fluohnated esters or imides of an α,β-unsaturated polyacids in combination with fluorinated esters or fluorinated imides or amides of α,β-unsaturated monoacids. These esters, amides and imides can be made from the alcohols and amines described above. Examples of α,β-unsaturated monoacids include, but are not limited to acrylic acid, methacrylic acid, α-hydroxymethacrylic acid and α-chloromethacrylic acid. The PCSA may further comprise adjuvants including stabilizers, flow-enhancers, plasticizers, photoinitiators, photo-radical generators and other components designed to enhance the processes described herein.

In some embodiments, the PCSA is selected from the group consisting of bis(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl)fumarate; bis(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl)maleate; bis(3,3,4,4,6,6,7,7,8,8,8-undecafluoro-5-oxa-octyl)maleate; bis(3,3,5,5,6,6,7,7,8,8,8-undecafluorooctyl) maleate;

4,4,5,5,6,6,7,7,8,8,9,9,10,10,11 ,11 ,11 -heptadecafluoroundecyl maleimide; bis(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl) itaconate; bis(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl)-cis,cis-muconate;

and combinations thereof.

In general, PCSA materials can be made using techniques which are known in organic chemistry. 3. Process

In the process described herein, there is provided a substrate having thereon a black matrix. This is treated with a reactive surface- active composition to form an intermediate layer. The intermediate layer is exposed in a pattern with radiation and then removed in the sub-pixel areas. A pattern of at least two different colors is then deposited in the sub-pixel areas by a precision liquid deposition technique.

Substrates with a black matrix are well known in the color filter art, and any materials known to the art can be used. The substrate can be inorganic or organic. Examples of substrates include, but are not limited to glasses, ceramics, and polymeric films, such as polyester and polyimide films. The substrate may or may not include electronic components, circuits, or conductive members. The substrate is generally transparent, and in some embodiments, the substrate is glass.

The black matrix can be inorganic or organic. Inorganic materials include metals and metal oxides, such as chromium and chromium oxides. The matrix is generally formed using standard photolithographic techniques. For most printing applications, the black matrix is organic, with a thickness (perpendicular to the plane of the substrate) sufficient to provide containment of the ink from sub-pixel to sub-pixel. The black organic material can be applied overall and patterned photolithographically, or the black material may itself be a photoresist. Materials useful as the organic black matrix are well known and include, but are not limited to, epoxies, polyimides, polyacrylates, and polymethacrylates. In some embodiments, the black matrix comprises an inorganic portion and an organic portion, as described in, for example, U.S. patent 7,050,130.

The substrate and black matrix are then treated with an RSA to form an intermediate layer. The surface energy of the intermediate layer is lower than that of the substrate and lower than that of the black matrix. The RSA may be applied using any known deposition technique, including liquid deposition, application as a melt, thermal transfer from a donor sheet, and vapor deposition.

In one embodiment, the RSA is applied without adding it to a solvent. In one embodiment, the RSA is applied by vapor deposition.

In one embodiment, the RSA is applied by a condensation process. If the RSA is applied by condensation from the vapor phase, and the surface layer temperature is too high during vapor condensation, the RSA can migrate into the pores or free volume of an organic substrate surface. In some embodiments, the organic substrate is maintained at a temperature below the glass transition temperature or the melting temperature of the substrate materials. The temperature can be maintained by any known techniques, such as placing the first layer on a surface which is cooled with flowing liquids or gases. In one embodiment, the RSA is applied to a temporary support prior to the condensation step, to form a uniform coating of RSA. This can be accomplished by any deposition method, including liquid deposition, vapor deposition, and thermal transfer. In one embodiment, the RSA is deposited on the temporary support by a continuous liquid deposition technique. The choice of liquid medium for depositing the RSA will depend on the exact nature of the RSA itself. In one embodiment, the RSA is a fluorinated material and the liquid medium is a fluorinated liquid. Examples of fluorinated liquids include, but are not limited to, perfluorooctane, thfluorotoluene, and hexafluoroxylene. In one embodiment, the material is deposited by spin coating. The coated temporary support is then used as the source for heating to form the vapor for the condensation step. In one embodiment, the RSA is a liquid at room temperature and is applied by liquid deposition over the substrate and black matrix. The liquid RSA may be film-forming or it may be absorbed or adsorbed onto the surface of the substrate and black matrix. In one embodiment, the liquid RSA is cooled to a temperature below its melting point in order to form the intermediate layer. In one embodiment, the RSA is not a liquid at room temperature and is heated to a temperature above its melting point, deposited on the substrate and black matrix, and cooled to room temperature to form the intermediate layer. For liquid deposition, the method may be continuous or discontinuous. Continuous liquid deposition techniques, include but are not limited to, spin coating, roll coating, curtain coating, dip coating, slot-die coating, spray coating, and continuous nozzle coating. Discontinuous liquid deposition techniques include, but are not limited to, ink jet printing, gravure printing, flexographic printing and screen printing.

In one embodiment, the RSA is deposited from a liquid composition. The liquid deposition method can be continuous or discontinuous, as described above. In one embodiment, the RSA liquid composition is deposited using a continuous liquid deposition method. The choice of liquid medium for depositing the RSA will depend on the exact nature of the RSA material itself. In one embodiment, the RSA is a fluorinated material and the liquid medium is a fluohnated liquid. Examples of fluorinated liquids include, but are not limited to, perfluorooctane, trifluorotoluene, and hexafluoroxylene. In some embodiments, the RSA treatment comprises a first step of forming a sacrificial layer over the substrate and black matrix, and a second step of applying an Intermediate layer over the sacrificial layer. The sacrificial layer is one which is more easily removed than the Intermediate layer by whatever development treatment is selected. Thus, after exposure to radiation, as discussed below, the Intermediate layer and the sacrificial layer are removed in either the exposed or unexposed areas in the development step. The sacrificial layer is intended to facilitate complete removal of the Intermediate layer is the selected areas and to protect the underlying layer from any adverse affects from the reactive species in the Intermediate layer.

After the RSA treatment to form the intermediate layer, the intermediate layer is exposed patternwise to radiation. The type of radiation used will depend upon the sensitivity of the RSA as discussed above. As used herein, the term "patternwise" indicates that only selected portions of a material or layer are exposed. Patternwise exposure can be achieved using any known imaging technique. In one embodiment, the pattern is achieved by exposing through a mask. In one embodiment, the pattern is achieved by exposing only select portions with a laser. The time of exposure can range from seconds to minutes, depending upon the specific chemistry of the RSA used. When lasers are used, much shorter exposure times are used for each individual area, depending upon the power of the laser. The exposure step can be carried out in air or in an inert atmosphere, depending upon the sensitivity of the materials.

In one embodiment, the radiation is selected from the group consisting of ultra-violet radiation (10-390 nm), visible radiation (390-770 nm), infrared radiation (770-10⁶ nm), and combinations thereof, including simultaneous and serial treatments. In one embodiment, the radiation is thermal radiation. In one embodiment, the exposure to radiation is carried out by heating. The temperature and duration for the heating step is such that at least one physical property of the intermediate layer is changed, without damaging any underlying layers. In one embodiment, the heating temperature is less than 250⁰C. In one embodiment, the heating temperature is less than 150⁰C.

In one embodiment, the radiation is ultraviolet or visible radiation. In one embodiment, the radiation is deep UV radiation, having a wavelength in the range of 200-300 nm. In another embodiment, the ultraviolet radiation is of somewhat longer wavelength, in the range 300- 400 nm.

The patternwise exposure to radiation results in exposed regions of intermediate layer and unexposed regions of intermediate layer. In some embodiments, the exposed regions of the intermediate layer are more easily removed and coincide with the sub-pixel areas. In some embodiments, the unexposed regions of the intermediate layer are more easily removed and coincide with the sub-pixel areas. Patternwise exposure to radiation and treatment to remove exposed or unexposed regions is well known in the art of photoresists.

In one embodiment, the exposure of the intermediate layer to radiation results in a change in the solubility or dispersibility of the intermediate layer in solvents. When the exposure is carried out patternwise, this can be followed by a wet development treatment. The treatment usually involves washing with a solvent which dissolves, disperses or lifts off one type of area. In one embodiment, the patternwise exposure to radiation results in ^solubilization of the exposed areas of the intermediate layer, and treatment with solvent results in removal of the unexposed areas of the intermediate layer. In one embodiment, the exposure of the intermediate layer to visible or UV radiation results in a reaction which decreases the volatility of the intermediate layer in exposed areas. When the exposure is carried out patternwise, this can be followed by a thermal development treatment. The treatment involves heating to a temperature above the volatilization or sublimation temperature of the unexposed material and below the temperature at which the material is thermally reactive. For example, for a polymerizable monomer, the material would be heated at a temperature above the sublimation temperature and below the thermal polymerization temperature. It will be understood that RSA materials which have a temperature of thermal reactivity that is close to or below the volatilization temperature, may not be able to be developed in this manner.

In one embodiment, the exposure of the intermediate layer to radiation results in a change in the temperature at which the material melts, softens or flows. When the exposure is carried out patternwise, this can be followed by a dry development treatment. A dry development treatment can include contacting an outermost surface of the element with an absorbent surface to absorb or wick away the softer portions. This dry development can be carried out at an elevated temperature, so long as it does not further affect the properties of the originally unexposed areas.

After the development step, the intermediate layer is substantially removed in the sub-pixel areas and remains over the black matrix. The balck matrix areas, covered with the intermediate layer, will have a lower surface energy than the sub-pixel areas which are substantially free of intermediate layer material.

One way to determine the relative surface energies, is to compare the contact angle of a given liquid on a layer. As used herein, the term "contact angle" is intended to mean the angle Φ shown in Figure 1. For a droplet of liquid medium, angle Φ is defined by the intersection of the plane of the surface and a line from the outer edge of the droplet to the surface. Furthermore, angle Φ is measured after the droplet has reached an equilibrium position on the surface after being applied, i.e. "static contact angle". A variety of manufacturers make equipment capable of measuring contact angles.

In some embodiments, the surface energy of the substrate is high enough so that it is wettable by many conventional solvents. In some embodiments, the substrate is wettable by phenylhexane with a contact angle no greater than 40°.

The intermediate layer has a surface energy which is lower than the surface energy of the substrate. In some embodiments, treatment of the intermediate layer with phenylhexane results in a contact angle of at least 70°. The thickness of the Intermediate layer can depend upon the ultimate end use of the material. In some embodiments, the Intermediate layer is at least 100A in thickness. In some embodiments, the Intermediate layer is in the range of 100-3000A; in some embodiments 1000-2000A. A first composition comprising a first colored material is then deposited in a first set of sub-pixel areas by a precision liquid deposition technique. A second composition comprising a second colored material is then deposited in a second set of sub-pixel areas by a precision liquid deposition technique. In some embodiments, a third composition comprising a third colored material is deposited in a third set of sub-pixel areas by a precision liquid deposition technique. In some embodiments, one or more additional colored materials are deposited in one or more additional sub-pixel areas by a precision liquid deposition technique. For transmissive color filters, three colors are generally used: red, green and blue. For reflective color filter, four colors are generally used: yellow, magenta, cyan, and black. It will be understood that different colors may be used and that the colors can be tailored to the desired end use. The colored materials that can be used to form color filters are well known in the art. They can be organic, inorganic, or organometallic. Types of materials include polymeric oligomehc, metallic, alloy, ceramic, and composite materials. Some examples of materials which can be used include, but are not limited to, phthalocyanines, isoindolinones, benzimidazolones, quinophthalones, quinacridones, dioxazines, thioindigos, epindolindiones, anthanthrones, isoviolanthrones, indanthrones, imidazobenzimidazolones, pyrazoloquinazolones, diketopyrrolopyrroles, and bisaminoanthrones.

The first composition is a liquid composition comprising a first colored material dissolved or dispersed in a first liquid medium. The second composition comprises a second colored material dissolved or dispersed in a second liquid medium. Similarly, third and additional compositions, if included, comprise third or additional colored material dissolved or dispersed in liquid media. The liquid media can be the same or different, aqueous or non-aqueous. The compositions may include a binder resin. Examples of binder resins include polyacrylamides, polyvinyl alcohol, cellulose, and the like. Other additives may be present, such as dispersants, surfactants, humectants, biocides, rheology modifiers, sequestrants, pH adjesters, penetrants, etc. The liquid composition is chosen to have a surface energy that is greater than the surface energy of the RSA patterned layer, but approximately the same as or less than the surface energy of the untreated substrate layer. Thus, the liquid composition will wet the pixel areas, but will be repelled from the RSA-treated areas of the black matrix. The liquid may spread onto the RSA-treated areas of the black matrix, but it will de-wet.

The first composition is applied by a precision liquid deposition technique into a first set of sub-pixel areas. The second composition is applied by a precision liquid deposition technique into a second set of sub- pixel areas. Similarly, the third and additional compositions, if included, are applied by a precision liquid deposition technique into third and additional sub-pixel areas. Any precision liquid deposition technique can be used. In some embodiments, the precision liquid deposition technique is ink jet printing. In some embodiments, the precision liquid deposition technique is continuous nozzle printing. Such printing techniques have been described in, for example, published US applications 2006/0145598 and 2006/0144276.

In some embodiments, the liquid compositions of the colored materials further comprise a radiation-curable material. The radiation- curable materials can be crosslinked by exposure to radiation, which can be the same as or different from the radiation used to expose the RSA. In some embodiments, the radiation-curable material is photocurable and crosslinked by exposure to UV or visible radiation. The crosslinking increases the robustness and solvent resistance of the colored film in the subpixel areas. In some embodiments, after crosslinking, the colored compositions can be applied to the subpixel areas one or more additional times to increase the color saturation and density.

Radiation-curable materials are well known in the art. Examples of crosslinkable groups include, but are not limited to vinyl, acrylate, perfluorovinylether, 1 -benzo-3,4-cyclobutane, siloxane, cyanate groups, cyclic ethers (epoxides), cycloalkenes, and acetylenic groups. One general class of photocurabie system comprises a curable reactive materia! (generally oiigorneric or polymeric in nature) together with an initiator component which on exposure to the appropriate radiation, reacts with the curable component thereby to cross-link it or cure it. A particular embodiment of this sort of photocurabie system comprises polyvinyl alcohol as curable component together with a diazo initiator Another general class of photocurabie system, comprises an ethyiemcaiiy unsaturated curable material (again generally ohgomeπc or polymeric in nature) together with a photoinitiator which, on exposure to the appropriate radiation, gives rise to free radicals which initiate polymerisation of the double bonds" in the curable component Examples of photocurabie materials which may be used in this second general class of photocurabie systems include multifunctional acrylate oligomers such as pentaerythπtol triacrylate, tπmethylolpropane tπacrySate and ethylene glycol polyacrylate Other photosensitive materials are-those which may be obtained by reacting multifunctional isocyanate compounds with ethyiemcaiiy unsaturated compounds containing a group containing an active hydrogen atom such as a hydroxy! group or carboxyhc acid group Examples of suitable isocyanates include hexarnethylene di-isocyanate, tolylene dι- isocyanate or isophorone dπsocyanate, or dimers or Iπmers formed therefrom Suitable unsaturated compounds containing active hydrogen include, for example, hydroxyi-ethy! acrylale hydroxyelhyi melhacrylale, acrylic acid and methacryiic acid. A further class of UV sensitive curable materials are those formed by the reaction of poly-epoxy compounds^' (so-called "epoxy resins") with ethyiemcaiiy unsaturated acids such as acrylic acid or methacryiic acid, which reaction products may simply be termed "epoxy acrylates" The epoxy compound may be a simple glycidyl ether such as ethylene glycol diglycidyi ether or phenyl glycidy! ether or a bis-phenol A/epichlorohydrin add uct Further epoxy resins which may be employed are epoxy πovoSak resins, including epoxy phenyl novolak and epoxy cresoi novolak resins In order to render the epoxy acrylate material soluble or developable by aqueous alkaline solutions, the epoxy acrylate resin may be reacted with one or more dicarboxylic acid anhydrides (serving to introduce free carboxyi groups into the final epoxy acrylate) Suitable dicarboxyiic acid anhydrides for this purpose includes succinic, staconic, maieic and phthalic anhydrides. A wide variety of photoinitiators are known for use in photocurabie systems and examples of these include anthraquinones such 2-etby!- anthraquinone, 2-methyi- aπthraquinone and 1 -chioro~anthraquinone; thioxaπthones such as 2,4-dimethyJ-thioxanthones, 2,4-diethyi- thioxanthones and 2-chloro-thioxaπthones; ketals such as benzyl-dimethyl ketal and acetophenone-dimethy!-ketyi_s benzopbenones, and benzoin and ethers thereof. These photoinitiators can be alone or in admixture and may also be used together with photopoiymerizatioπ accelerators such as benzoic acid type accelerators or tertiary amine accelerators. In some embodiments, there is provided a process for making a color filter, the process comprising: providing a substrate having thereon a black matrix, the matrix defining a plurality of sub-pixels and having a first surface energy; treating the substrate and black matrix with a reactive surface- active composition to form an intermediate layer having a second surface energy, wherein the second surface energy is lower than the first surface energy; exposing the intermediate layer in a pattern with a first radiation; removing the intermediate layer in the sub-pixel areas; depositing a first composition comprising a first colored material and a photocurabie material in a first set of sub-pixel areas by a precision liquid deposition technique, to form a first set of first colored films; depositing a second composition comprising a second colored material in a second set of sub-pixel areas by a precision liquid deposition technique, to form a first set of second colored films; depositing a third composition comprising a third colored material in a third set of sub-pixel areas by a precision liquid deposition technique, to form a first set of third colored films; exposing the first sets of colored films to a second radiation; depositing the first composition over the first set of first colored films in the first set of sub-pixel areas, to form a second set of first colored films; and exposing the second set of first colored films to the second radiation, wherein the first composition can be deposited before or after the second and third compositions. In some embodiments of the above process, the second composition further comprises a photocurable material, the third composition further comprises a photocurable material, and the process further comprises: depositing the second composition over the first set of second colored films in the second set of sub-pixel areas, to form a second set of second colored films; depositing the third composition over the first set of third colored films in the third set of sub-pixel areas, to form a second set of third colored films; and exposing the second sets of second and third colored films to the second radiation, wherein the steps of exposing the second set of first colored films and exposing the second sets of second and third colored films can be carried out simultaneously. One particular embodiment of the process described herein is shown schematically in FIGs. 2-6. In FIG. 2, a workpiece 20 is shown having a black matrix 200 with openings 210 for sub-pixels. The substrate is not explicitly shown as a layer, but the surface is visible through the sub- pixel openings. Although the sub-pixels are shown as square, they may be of different shapes, such as rectangular or oval. In some embodiments, the sub-pixel openings in the black matrix are in the form of parallel stripes. FIG. 3 shows an intermediate layer 220 formed by treatment with an RSA. The sub-pixel openings are also covered by the intermediate layer at areas 211. After exposure to radiation patternwise where the pixel areas are not exposed, and development, the intermediate layer is removed in the sub-pixel areas 210 as shown in FIG. 4. A first composition comprising a first colored material is applied by a precision liquid deposition technique to a first set of sub-pixels 230 as shown in FIG. 5. A second composition comprising a second colored material is applied by a precision liquid deposition technique to a second set of sub-pixels 240 as shown in FIG. 6.

Note that not all of the activities described above in the general description or the examples are required, that a portion of a specific activity may not be required, and that one or more further activities may be performed in addition to those described. Still further, the order in which activities are listed are not necessarily the order in which they are performed. In the foregoing specification, the concepts have been described with reference to specific embodiments. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of invention.

Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any feature(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature of any or all the claims.

It is to be appreciated that certain features are, for clarity, described herein in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any subcombination. The use of numerical values in the various ranges specified herein is stated as approximations as though the minimum and maximum values within the stated ranges were both being preceded by the word "about." In this manner, slight variations above and below the stated ranges can be used to achieve substantially the same results as values within the ranges. Also, the disclosure of these ranges is intended as a continuous range including every value between the minimum and maximum average values including fractional values that can result when some of components of one value are mixed with those of different value. Moreover, when broader and narrower ranges are disclosed, it is within the contemplation of this invention to match a minimum value from one range with a maximum value from another range and vice versa.

Claims

CLAIMS What is claimed is:

1. A process for making a color filter, the process comprising: providing a substrate having thereon a black matrix, the matrix defining a plurality of sub-pixels and having a first surface energy; treating the substrate and black matrix with a reactive surface- active composition to form an intermediate layer having a second surface energy, wherein the second surface energy is lower than the first surface energy; exposing the intermediate layer in a pattern with radiation; removing the intermediate layer in the sub-pixel areas; and depositing a first composition comprising a first colored material in a first set of sub-pixel areas by a precision liquid deposition technique, and depositing a second composition comprising a second colored material in a second set of sub-pixel areas by a precision liquid deposition technique.

2. The process of Claim 1 , further comprising depositing a third composition comprising a third colored material in a third set of sub-pixel areas by a precision liquid deposition technique.

3. The process of Claim 1 , wherein the radiation is selected from the group consisting of visible radiation and UV radiation.

4. The process of Claim 1 , wherein removing the intermediate layer is accomplished by a treatment selected from the group consisting of application of heat, treatment with a liquid medium, treatment with an absorbant material, and treatment with a tacky material.

5. The process of Claim 1 , wherein the precision liquid deposition technique is selected from the group consisting of ink jet printing and continuous nozzle printing.

6. The process of Claim 1 , wherein the reactive surface-active composition is photocurable.

7. The process of Claim 6, wherein the reactive surface-active composition comprises a material selected from the group consisting of a fluorinated ester of an α,β-unsaturated polyacid, a fluohnated imide of an α,β-unsaturated polyacid, and combinations thereof.

8. The process of Claim 7, wherein the reactive surface-active compositions is selected from the group consisting of bis(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl)fumarate; bis(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl)maleate; bis(3,3,4,4,6,6,7,7,8,8,8-undecafluoro-5-oxa-octyl)maleate; bis(3,3,5,5,6,6,7,7,8,8,8-undecafluorooctyl) maleate; 4,4,5,5,6,6,7,7,8,8,9,9,10,10,11 ,11 ,11 -heptadecafluoroundecyl maleimide; bis(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl) itaconate; bis(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl)-cis,cis-muconate;

and combinations thereof.

9. The process of Claim 7, wherein the intermediate layer is removed by heating.

10. A color filter comprising a glass substrate, a black matrix defining sub-pixel areas, a first set of sub-pixels comprising a first colored material, and a second set of sub-pixels comprising a second colored material, and further comprising a reactive surface-active material over the black matrix and separating sub-pixel areas.

11. A process for making a color filter, the process comprising: providing a substrate having thereon a black matrix, the matrix defining a plurality of sub-pixels and having a first surface energy; treating the substrate and black matrix with a reactive surface- active composition to form an intermediate layer having a second surface energy, wherein the second surface energy is lower than the first surface energy; exposing the intermediate layer in a pattern with a first radiation; removing the intermediate layer in the sub-pixel areas; depositing a first composition comprising a first colored material and a photocurable material in a first set of sub-pixel areas by a precision liquid deposition technique, to form a first set of first colored films; depositing a second composition comprising a second colored material in a second set of sub-pixel areas by a precision liquid deposition technique, to form a first set of second colored films; depositing a third composition comprising a third colored material in a third set of sub-pixel areas by a precision liquid deposition technique, to form a first set of third colored films; exposing the first sets of colored films to a second radiation; depositing the first composition over the first set of first colored films in the first set of sub-pixel areas, to form a second set of first colored films; and exposing the second set of first colored films to the second radiation, wherein the first composition can be deposited before or after the second and third compositions.

12. The process of Claim 11 , wherein the second composition further comprises a photocurable material, the third composition further comprises a photocurable material, the process further comprising: depositing the second composition over the first set of second colored films in the second set of sub-pixel areas, to form a second set of second colored films; depositing the third composition over the first set of third colored films in the third set of sub-pixel areas, to form a second set of third colored films; and exposing the second sets of second and third colored films to the second radiation, wherein the steps of exposing the second set of first colored films and exposing the second sets of second and third colored films can be carried out simultaneously.