Enhanced defect detection using planar macrocyclic dyes in liquid crystal films

Abstract

The present disclosure relates to a modulator material layer comprising a polymer matrix formed from a plurality of cross-linked polymer molecules and a plurality of droplets of liquid crystal within the polymer matrix. A planar macrocyclic dye is dispersed within the plurality of droplets of the liquid crystal. The planar macrocyclic dye may comprise one or more of a phthalocyanine, a porphyrin, a naphthalocyanine, a metal phthalocyanine, a metal porphyrin, or a metal naphthalocyanine.

Description

[0001] CROSS REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the non-provisional patent application of U.S. application No. 18 / 238,183, filed on August 25, 2023, and assigned, and claims priority to the provisional patent application of U.S. application No. 63 / 402,079, filed on August 30, 2022, and assigned, the disclosures of which are hereby incorporated by reference. Technical Field

[0003] The present disclosure relates to optoelectronics, and more particularly to macrocyclic dye doping in liquid crystal materials to enhance defect detection in optoelectronic applications. Background Art

[0004] Electro-optical modulators modulated using liquid crystals, particularly nematic curvilinear aligned phases (NCAP) films or polymer dispersed liquid crystal (PDLC) films, are used to test the conduction of thin film transistors and interconnects of flat panel displays (FPDs) in manufacturing. Enhanced defect detection is encouraged to resolve smaller defects on FPDs in a rapid manner. Existing modulators have limitations in defect detection capabilities and have low sensitivity. Therefore, it would be advantageous to provide an apparatus, system, or method that can improve some of the disadvantages described above. Systems and techniques are needed to enhance defect detection using modulators and modulator sensitivity (s-curve) used in array inspectors. Summary of the invention

[0005] In a first embodiment, a modulator material layer is provided. The modulator material layer includes: a polymer matrix formed by a plurality of cross-linked polymer molecules; a plurality of droplets of liquid crystal within the polymer matrix; and a planar macrocyclic dye dispersed within the plurality of droplets of liquid crystal. The planar macrocyclic dye may include one or more of the following: phthalocyanine, porphyrin, naphthalocyanine, metallophthalocyanine, metalloporphyrin, or metal naphthalocyanine. In one example, the planar macrocyclic dye includes one or more of phthalocyanine, porphyrin, or naphthalocyanine. In another example, the planar macrocyclic dye includes one or more of metal phthalocyanine, metalloporphyrin, or metal naphthalocyanine. For example, the planar macrocyclic dye may be zinc phthalocyanine.

[0006] The planar macrocyclic dye may be 0.002 wt % to 0.5 wt % of the mixture of the polymer matrix, the liquid crystal, and the planar macrocyclic dye.

[0007] The modulator material layer may be a nematic curve alignment phase (NCAP) film, a polymer dispersed liquid crystal (PDLC) film, a chiral liquid crystal film, a ferroelectric liquid crystal film or a blue phase liquid crystal film.

[0008] The droplet size may range from 0.1 microns to 10 microns.

[0009] In the absence of an electric field, the liquid crystals may be randomly oriented within the plurality of droplets. When an electric field is applied across the modulator material layer, the liquid crystals may be aligned at least partially along the direction of the electric field.

[0010] The modulator material layer may further include a transparent conductive film disposed on the modulator material layer.

[0011] The modulator material layer may further include a glass substrate.The modulator material layer is one of a direct coating on the glass substrate or a stacked layer on the glass substrate.

[0012] In a second embodiment, an imaging system is provided. The imaging system includes: an illumination source configured to generate illumination; a stage configured to hold a sample; a detector for generating an image of at least a portion of the sample; and an electro-optical modulator disposed in the path of the illumination from the illumination source and separated from the sample by an air gap. The electro-optical modulator includes a transparent conductive film and a modulator material layer disposed on the transparent conductive film. The modulator material layer includes: a polymer matrix formed by a plurality of cross-linked polymer molecules; a plurality of droplets of liquid crystal within the polymer matrix; and a planar macrocyclic dye dispersed within the plurality of droplets of liquid crystal. The planar macrocyclic dye may include one or more of the following: phthalocyanine, porphyrin, naphthalocyanine, metal phthalocyanine, metal porphyrin or metal naphthalocyanine. For example, the planar macrocyclic dye is zinc phthalocyanine.

[0013] The planar macrocyclic dye may be 0.002 wt % to 0.5 wt % of the mixture of the polymer matrix, the liquid crystal, and the planar macrocyclic dye.

[0014] The modulator material layer may be an NCAP film, a PDLC film, a chiral liquid crystal film, a ferroelectric liquid crystal film or a blue phase liquid crystal film.

[0015] In the absence of an electric field, the liquid crystals may be randomly oriented within the plurality of droplets. When an electric field is applied across the modulator material layer, the liquid crystals may be aligned at least partially along the direction of the electric field.

[0016] In a third embodiment, a method is provided. The method includes obtaining an emulsion by mixing water, a liquid crystal, a planar macrocyclic dye, and a plurality of hydrophilic polymer molecules. The emulsion is applied to a substrate. The emulsion is then dried. The emulsion forms a modulator material layer, the modulator material layer comprising: a polymer matrix formed by a plurality of cross-linked polymer molecules; a plurality of droplets of the liquid crystal within the polymer matrix; and the planar macrocyclic dye dispersed within the plurality of droplets of the liquid crystal. The planar macrocyclic dye may include one or more of the following: phthalocyanine, porphyrin, naphthalocyanine, metal phthalocyanine, metal porphyrin, or metal naphthalocyanine. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] For a more complete understanding of the nature and purpose of the present disclosure, reference should be made to the following detailed description taken in conjunction with the accompanying drawings, wherein:

[0018] Figure 1 is a cross-sectional view of an electro-optical modulator according to an embodiment of the present disclosure;

[0019] Figure 2 A view illustrating a modulator material layer of an electro-optical modulator according to an embodiment of the present disclosure, the material layer comprising droplets of liquid crystal, wherein a planar macrocyclic dye is dispersed within the droplets of liquid crystal;

[0020] Figure 3 is a graph showing the experimental voltage-transmittance curve;

[0021] Figure 4 A diagram illustrating an imaging system according to the present disclosure; and

[0022] Figure 5 is a flow chart of a method for manufacturing a photovoltaic thin film according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0023] Although the claimed subject matter will be described in terms of particular embodiments, other embodiments (including embodiments that do not provide all of the benefits and features set forth herein) are also within the scope of the present disclosure. Various structural, logical, process step, and electronic changes may be made without departing from the scope of the present disclosure. Accordingly, the scope of the present disclosure is defined solely by the appended claims.

[0024] Embodiments disclosed herein use doping of planar macrocyclic dyes in NCAP films or other films in electro-optical modulators used in array inspector modulator technology to enhance the contrast ratio between off / on states in the film. Thus, NCAP films or other films may be doped with planar macro-dyes by dispersing the planar macro-dyes in liquid crystal droplets. This will improve the signal-to-noise ratio (SNR) and enhance the sensitivity of the modulator to detect defects in flat panel displays. Thus, the detection capabilities of NCAP films or other films used in array inspector modulator technology will be improved by adding macrocyclic planar dyes. The electro-optical modulator may be a component of an imaging system, also referred to as an automated optical inspection (AOI) system, a voltage imaging optical system (VIOS), an array inspector, or the like.

[0025] A method of making an electro-optical modulator is also described. An embodiment of an electro-optical modulator includes first coating a plastic sheet (e.g., Mylar) with a transparent conductive layer using an NCAP film or other film. A second plastic sheet (with or without a conductive layer) is added. This sandwich is then laminated to a glass substrate using an optical adhesive. The top plastic sheet of the liquid crystal (LC) / polymer sandwich is then peeled off and discarded. A dielectric mirror film (or pellicle) is formed on the plastic sheet and then added to the assembly stack.

[0026] No. 7,817,333, filed on February 6, 2007, entitled “Modulator with improved sensitivity and life time”; No. 8,801,964, filed on December 22, 2010, entitled “Encapsulated polymer network liquid crystal material, device and applications”; and No. 7,639,319, filed on April 7, 2005, entitled “Polymer dispersed liquid crystal formulations for modulator fabrication” are each incorporated herein by reference in their entirety.

[0027] Figure 11 is a cross-sectional view of an electro-optical modulator 100. The electro-optical modulator 100 may include one or more films, layers, or coatings. The one or more film layers selectively allow transmittance of light. For example, the electro-optical modulator 100 may include one or more of the following: a hard coating 102, a plastic film 104, a dielectric mirror film 106, a modulator material layer 108, a transparent conductive layer 110, a plastic film 112, an optical adhesive 114, a glass substrate 116, and / or an anti-reflective coating 118. Other films, layers, or coatings than those illustrated or described with respect to the electro-optical modulator 100 are possible.

[0028] The modulator material layer 108 (also referred to as a sensor layer, liquid crystal layer, polymer matrix layer, or the like) can be applied to the glass substrate 116 by a number of methods, such as, but not limited to, by direct coating or lamination. An embodiment performed using a lamination process includes first coating a plastic film 112 (e.g., polyethylene terephthalate (PET), also referred to as Mylar) with a transparent conductive layer 110 with the modulator material layer 108. The transparent conductive layer 110 can generally include any material that is optically transparent and conductive to be used as an electrode, such as, but not limited to, indium tin oxide (ITO) or another conductive material. The modulator material layer 108 can include a nematic curve aligned phase (NCAP) mixture, a polymer dispersed liquid crystal (PDLC) mixture, or other mixtures. The plastic film 112, and similarly, the transparent conductive layer 110 and the modulator material layer 108 can be laminated to the glass substrate 116 by an optical adhesive 114. A dielectric mirror film 106 (or overcoat) can be formed on the plastic film 104 and then added to the modulator material layer 108 of the assembly stack. In an embodiment, a vacuum assisted attachment process is used.Anti-reflective coating 118 may be applied to the bottom surface of glass substrate 116. Similarly, hard coating 102 may be cured to plastic film 104. Hard coating 102 may include a main hard coating and a thinner slip agent layer.

[0029] The light transmission through the modulator material layer 108 can vary depending on the magnitude of the electric field applied to the liquid crystal droplets of the modulator material layer 108. The transparent conductive layer 110 can be capacitively coupled with the sample to induce a local voltage and electric field. The local voltage can generate an electric field. The electric field causes the liquid crystal in the modulator material layer 108 to align in the direction of the electric field.

[0030] Figure 2 is a cross-sectional view of a modulator material layer 108. In one example, the modulator material layer 108 comprises a mixture of NCAPs, but other mixtures are possible. The modulator material layer 108 comprises droplets 202 of liquid crystals suspended in a polymer matrix 204. The modulator material layer 108 comprises a diluent of one or more materials, such as a planar macrocyclic dye 206 dispersed within the droplets 202. The planar macrocyclic dye 206 will be further described herein.

[0031] The NCAP used in the modulator material layer 108 includes droplets 202. Each of the droplets 202 includes a plurality of liquid crystal molecules. The liquid crystal molecules have a temperature transition in the liquid crystal phase. In some embodiments, the size of the droplets 202 is about one micron to five microns. The liquid crystal droplets may include a liquid crystal temperature range. The liquid crystal temperature range refers to the temperature at which the liquid crystal is in a liquid crystal phase (e.g., between a crystalline phase and a liquid phase).

[0032] The droplets 202 of liquid crystal may include any liquid crystal material. For example, the liquid crystal may include, but is not limited to, one or more of: nematic liquid crystal, polymer dispersed liquid crystal, chiral liquid crystal, ferroelectric liquid crystal, blue phase liquid crystal, a mixture of liquid crystal and dichroic dye, cholesteric liquid crystal, or the like. The liquid crystal material may be substantially hydrophobic so that the droplets 202 of liquid crystal material may be formed with the emulsion.

[0033] The modulator material layer 108 also includes a polymer matrix 204. The polymer matrix 204 may include any polymer matrix material. For example, the polymer matrix material may include, but is not limited to, one or more water-based polymers such as polyvinyl alcohol (PVA), urethanes (e.g., polyurethanes), acrylates (e.g., polyacrylates, fluorinated acrylates, silicone acrylates), or water-based latexes. Surfactants may be used to formulate the polymer matrix 204.

[0034] The amount of polymer matrix 204 material may correspond to the strength and stiffness of the sensor material. For example, the weight ratio of liquid crystal material to polymer matrix material may be in the range of about 50 / 50 to about 80 / 20. An increased amount of polymer matrix 204 material may increase the strength and operating voltage of the sensor material.

[0035] The polymer matrix 204 is positioned around the droplet 202 and contains the droplet 202 with the polymer matrix 204. The droplet 202 is then dispersed within the polymer matrix 204. The droplet 202 with the liquid crystal molecules may be anchored to the polymer matrix 204. In an embodiment, the degree of anchoring depends on the chemical properties of the liquid crystal molecules and the polymer matrix 204.

[0036] When no electric field is present, the liquid crystal molecules may be randomly oriented within the droplet 202. When an electric field is applied across the modulator material layer 108, the liquid crystal may be at least partially aligned along the direction of the electric field. In order for this alignment to occur, the molecules overcome anchoring and / or friction with the polymer matrix 204 at the attachment tracks. The orientation of the liquid crystal then changes the transmittance of the modulator material layer 108. For example, when no voltage is applied and the liquid crystal is randomly oriented, the modulator material layer 108 may be opaque. When a voltage is applied and the liquid crystal molecules are at least partially aligned, the modulator material layer 108 may be transparent or translucent. As such, when the electric field is removed, the liquid crystal returns to a random orientation.

[0037] The droplet 202 of liquid crystal may include a switching voltage. The intrinsic switching voltage of the liquid crystal may correspond to the voltage across the modulator material layer at which the light transmission through the electro-optical modulator has the greatest sensitivity to changes in voltage. In many embodiments, the switching voltage corresponds to the electric field strength at which about half of the liquid crystal molecules are substantially aligned with the electric field. For optimal sensitivity, the goal is to invoke the maximum change in transmission with the smallest possible voltage change. Sensitivity can be improved by reducing the intrinsic switching voltage of the liquid crystal material. The operating voltage and sensitivity of the liquid crystal material may be related to one or more factors, such as, but not limited to, the properties of the liquid crystal, the properties of the polymer matrix, the liquid crystal droplet size distribution in the polymer matrix, and / or the interface properties between the polymer matrix and the liquid crystal.

[0038] The anchoring of the liquid crystal molecules to the polymer matrix 204 can increase the intrinsic operating voltage of the modulator material layer 108. The frictional forces can include anchoring forces that can be associated with static friction of the liquid crystal molecules against the polymer matrix, and can also include dynamic friction associated with relative motion between the liquid crystal molecules and the polymer matrix. Since friction can affect the speed at which the molecules move relative to the surrounding polymer matrix, reduced friction can increase the switching speed of the liquid crystal molecules. Since an increase in voltage can be required to overcome the anchoring of the liquid crystal molecules to the polymer matrix, the increased anchoring can be associated with an increased intrinsic operating voltage of the modulator material layer 108. Therefore, the lower the frictional forces and / or anchoring between the droplet 202 of liquid crystal and the polymer matrix 204, the lower the drive voltage required to switch the liquid crystal molecules and / or liquid crystal from a substantially misaligned condition to a substantially aligned condition with the electric field.

[0039] Planar macrocyclic dye 206 is dispersed within droplets 202 of liquid crystal. For example, planar macrocyclic dye 206 may comprise, consist of, or consist essentially of one or more of: phthalocyanine, porphyrin, or naphthalocyanine. For example, planar macrocyclic dye 206 may also comprise, consist of, or consist essentially of one or more of metal analogs of these species (e.g., metal phthalocyanine, metal porphyrin, or metal naphthalocyanine).

[0040] Typically, the metallophthalocyanine, metalloporphyrin or metallonaphthalocyanine comprises a metal having a charge of +2 or +3. The metal may comprise copper, zinc, platinum, iron, cobalt or tin, although other metals may be used.

[0041] Phthalocyanine is an aromatic organic compound and has a macrocyclic structure that may have the chemical formula (C8H4N2)4H2. Metal complexation of phthalocyanine produces metal phthalocyanine compounds. Some examples of metal complexes of phthalocyanine that may be used are copper, cobalt, zinc, etc.

[0042] Examples of phthalocyanines that can be used in accordance with the present disclosure are presented below, but other phthalocyanines are possible.

[0043]

[0044]

[0045]

[0046] In an example, the planar macrocyclic dye 206 is zinc phthalocyanine.

[0047] Porphyrins are heterocyclic macrocyclic organic compounds in which four modified pyrrole subunits are interconnected via a methine bridge (=CH-) on their alpha carbon atoms. Porphyrins can also bond to metals. Porphyrins can include different tails connected to the initial aromatic ring. Examples of porphyrins that can be used according to the present disclosure are presented below (protoporphyrin, IX, octaethylporphyrin and tetraphenylporphyrin), but other porphyrins are feasible.

[0048]

[0049]

[0050] Naphthalocyanine is a cross-shaped organic molecule with the chemical formula C 48 H 26 N8. It is a derivative of phthalocyanine. Exemplary derivatives are presented below, but other derivatives may be feasible.

[0051]

[0052] The use of planar macrocyclic dye 206 can enhance the optical contrast of materials in NCAP film, PDLC film or other films. When embedded in a droplet 202 of liquid crystal, planar macrocyclic dye 206 darkens the "off" state of NCAP film or other film in a specific illumination wavelength range without significantly changing the on state transmittance, which enhances the contrast ratio. When implemented in an electro-optical modulator used in array inspector technology, planar macrocyclic dye 206 enhances the sensitivity of the modulator's NCAP film or other film to detect defects present in flat panel displays during the manufacturing process of the panel.

[0053] The planar macrocyclic dye 206 may have a weight percentage of 0.002 wt % to 0.5 wt % relative to a liquid crystal mixture that may include a polymer matrix, a liquid crystal, and a planar macrocyclic dye. For example, the weight percentage relative to the liquid crystal mixture may be 0.03%. The dye concentration may vary depending on solubility and chemical affinity with different liquid crystal materials. For example, the weight percentage may be 0.03 wt % to 0.1 wt % of the liquid crystal mixture to provide the best solubility in the liquid crystal mixture. If the planar macrocyclic dye 206 has a weight percentage lower than 0.002 wt %, the contrast ratio between the closed / on states in the film may not be enhanced. If the planar macrocyclic dye 206 has a weight percentage higher than 0.5 wt %, precipitation may occur.

[0054] Figure 3 is a graph showing the experimental voltage-transmittance curve. Figure 3 , it is shown that about 10 wt % of a standard dichroic dye is needed to obtain the same performance as 0.03 wt % of zinc phthalocyanine.

[0055] Figure 4 is a conceptual diagram illustrating an imaging system 300. For purposes of this disclosure, the term "imaging system" may be interchanged with the term "imaging tool". The imaging system 300 may generally include any type of imaging tool suitable for, for example, but not limited to, voltage imaging. Voltage imaging may be used to detect and measure defects in flat-panel thin-film transistor (TFT) arrays. The performance of the TFT array is simulated as if it were assembled into a TFT cell, and then the characteristics of the TFT array are measured by indirectly measuring the actual voltage distribution on the panel using an electro-optical modulator (e.g., electro-optical modulator 100), or so-called voltage imaging. Voltage imaging may be performed by the imaging system 300. The imaging system 300 may include one or more components for inspecting these TFT arrays or other samples.

[0056] The electro-optical modulator 100 may be advantageous for several imaging tasks, such as modulating the light source of the imaging system 300 to assist in detecting one or more defects of a sample 311, such as, but not limited to, a TFT array, a liquid crystal display (LCD) panel, an OLED panel, and the like. The TFT array may be formed on a substrate, such as a transparent thin glass plate. The TFT array may include one or more printed layers. The printed layers may be formed on the substrate by several processes, such as, but not limited to, one or more material deposition steps, one or more photolithography steps, one or more etching steps, or the like. Manufacturing may occur in stages, where materials (e.g., indium tin oxide (ITO), etc.) are deposited over previous layers or on a glass substrate according to a process pattern. During manufacturing, the printed layers are manufactured within selected tolerances to properly construct the final device. The printed layers may exhibit defects outside of the selected tolerances. The characteristics of the TFT array may be measured by the imaging system 300 to detect defects.

[0057] In an embodiment, the imaging system 300 includes an illumination source 306 for generating illumination 308. The illumination 308 may include light of one or more selected wavelengths, including but not limited to vacuum ultraviolet radiation (VUV), deep ultraviolet radiation (DUV), ultraviolet (UV) radiation, visible radiation, or infrared (IR) radiation. The illumination source 306 may further generate the illumination 308 to include any selected range of wavelengths. In an embodiment, the illumination source 306 may include a spectrally tunable illumination source for generating the illumination 308 having a tunable spectrum.

[0058] The illumination source 306 may direct illumination 308 to the sample 311 via an illumination path 309. The illumination path 309 may include one or more lenses 312 or additional illumination optical components 314 suitable for modifying and / or adjusting the illumination 308. For example, the one or more illumination optical components 314 may include, but are not limited to, one or more polarizers, one or more filters, one or more beam splitters, one or more diffusers, one or more homogenizers, one or more apodizers, one or more shapers, one or more shutters (e.g., mechanical shutters, electro-optical shutters, acousto-optical shutters, or the like), one or more aperture stops, and / or one or more field stops.

[0059] The imaging system 300 may include an electro-optical modulator 100. The electro-optical modulator 100 is disposed in the path of illumination 308 from an illumination source 306. The electro-optical modulator 100 may modulate one or more characteristics of the illumination 308. During operation, light is transmitted through portions of the electro-optical modulator 100, and defects on or in a sample 311 may be detected by observing changes in reflected or transmitted light. The electro-optical modulator 100 is separated from the sample 311 by an air gap. The electro-optical modulator 100 may be placed at a selected number of microns (e.g., between 5 microns and 75 microns) above the surface of the sample 311 (e.g., a TFT array), and a voltage bias is applied across a transparent electrode of an indium tin oxide (hereinafter, "ITO") layer on the surface of the electro-optical modulator 100. In this manner, the electro-optical modulator 100 is capacitively coupled to the sample 311 so that an electric field associated with the sample 311 is sensed by one or more layers (e.g., a layer including liquid crystal) of the electro-optical modulator 100. The intensity of incident light transmitted through the liquid crystal of the electro-optical modulator is changed (i.e., modulated) based on the electric field strength sensed by the liquid crystal. For example, in the area where the normal pixel is located, a local voltage potential (e.g., capacitive coupling between the sample 311 and the electro-optical modulator 100) is applied to cause one or more thin films of the electro-optical modulator 100 to be locally translucent. In the local translucent area, light from the light source 306 is allowed to pass through the electro-optical modulator 100 and reflect from the sample 311 to travel through to the light collection path 322 (e.g., captured by the detector 304). By way of another example, in the area where no voltage potential is applied (e.g., no capacitive coupling), one or more thin films of the electro-optical modulator 100 remain locally opaque. In the case where the electro-optical modulator 100 is locally opaque, light from the light source 306 is scattered or otherwise prevented from traveling through to the sample 311. Therefore, a transmittance-voltage (TV) curve can be determined by applying a voltage. The intrinsic switching voltage of electromechanical modulator 100 may correspond to the voltage across electromechanical modulator 100 at which light transmission through electromechanical modulator 100 has the greatest sensitivity to changes in voltage. For example, the switching voltage may correspond to an electric field strength at which a given percentage of liquid crystal molecules substantially align with the electric field, allowing light transmission.

[0060] Sample 311 may include a TFT array. For example, sample 311 may include pixel elements disposed between inactive regions. Sample stage 318 may include any device suitable for positioning sample 311 within imaging system 300.

[0061] The detector 304 can be configured to capture radiation (e.g., sample light 320) emitted from the sample 311 through the collection path 322. For example, the collection path 322 can include (but does not necessarily include) the electro-optical modulator 100, a collection lens (e.g., an objective lens), or one or more additional collection path lenses 324. In this regard, the detector 304 can receive radiation reflected or scattered (e.g., via specular reflection, diffuse reflection, and the like) from the sample 311 or generated by the sample 311 (e.g., luminescence associated with absorption of the illumination 308 or the like).

[0062] System 300 may include, but is not limited to, a controller 303. Controller 303 may include one or more processors and memory, and may include or be coupled to a user interface 310.

[0063] The collection path 322 may further include any number of collection optical components 326 for directing and / or modifying the illumination collected by the electro-optical modulator 100, including but not limited to one or more filters, one or more polarizers, or one or more stops. In addition, the collection path 322 may include a field stop for controlling the spatial extent of the sample imaged onto the detector 304, or an aperture stop for controlling the angular extent of the illumination from the sample used to produce the image on the detector 304. In another embodiment, the collection path 322 includes an aperture stop positioned in a plane conjugate to the back focal plane of the optical element to provide telecentric imaging of the sample. In an embodiment, the imaging system 300 includes a beam splitter 328 oriented so that the electro-optical modulator 100 can simultaneously direct the illumination 308 to the sample 311 and collect radiation emitted from the sample 311.

[0064] Detector 304 may include any type of optical detector suitable for measuring illumination received from sample 311. For example, detector 304 may include, but is not limited to, a charge coupled device (CCD) detector, a time delay integration (TDI) detector, a photomultiplier tube (PMT), an avalanche photodiode (APD), a complementary metal oxide semiconductor (CMOS) sensor, or the like. In another embodiment, detector 304 may include a spectral detector suitable for identifying the wavelength of light emitted from sample 311.

[0065] The controller 303 may be communicatively coupled to the detector 304. The controller 303 may include one or more processors configured to perform any of the various process steps. In an embodiment, the controller 303 is configured to generate and provide one or more control signals configured to perform one or more adjustments to one or more processing tools based on the image signal 313 from the detector 304.

[0066] The one or more processors of the controller 303 may include any processor or processing element known in the art. For the purposes of the present disclosure, the term "processor" or "processing element" may be broadly defined to encompass any device having one or more processing or logic elements (e.g., one or more microprocessor devices, one or more application specific integrated circuit (ASIC) devices, one or more field programmable gate arrays (FPGAs), or one or more digital signal processors (DSPs)). In this sense, the one or more processors may include any device configured to execute algorithms and / or instructions (e.g., program instructions stored in a memory). In one embodiment, the one or more processors may be embodied as a desktop computer, a mainframe computer system, a workstation, an image computer, a parallel processor, a networked computer, or any other computer system configured to execute a program (which is configured to operate the imaging system 300 or operate in conjunction with the imaging system 300), as described throughout the present disclosure. In addition, different subsystems of the system 300 may include processors or logic elements suitable for implementing at least a portion of the steps described in the present disclosure. Therefore, the above description should not be interpreted as limiting the embodiments of the present disclosure but is merely illustrative. Furthermore, the steps described throughout this disclosure may be performed by a single controller or, alternatively, multiple controllers. Additionally, the controller 303 may include one or more controllers housed in a common housing or within multiple housings. In this manner, any controller or combination of controllers may be individually packaged as a module suitable for integration into the imaging system 300. Furthermore, the controller 303 may analyze the data received from the detector 304 and feed the data to additional components within the imaging system 300 or external to the imaging system 300.

[0067] The memory medium may include any storage medium known in the art suitable for storing program instructions that can be executed by the associated one or more processors. For example, the memory medium may include a non-transitory memory medium. By way of another example, the memory medium may include, but is not limited to, a read-only memory (ROM), a random access memory (RAM), a magnetic or optical storage device (e.g., a disk), a tape, a solid-state drive, and the like. It should be further noted that the memory medium may be housed in a common controller housing with the one or more processors. In one embodiment, the memory medium may be remotely located relative to the physical location of the one or more processors and the controller 303. For example, the one or more processors of the controller 303 may access a remote memory (e.g., a server) that is accessible via a network (e.g., the Internet, an intranet, and the like).

[0068] The user interface 310 is communicatively coupled to the controller 303. The user interface 310 may include, but is not limited to, one or more desktop computers, laptop computers, tablet computers, and the like. In an embodiment, the user interface 310 includes a display for displaying data of the system 300 to the user. The display of the user interface 310 may include any display known in the art. For example, the display may include, but is not limited to, a liquid crystal display (LCD), a display based on an organic light emitting diode (OLED), or a cathode ray tube (CRT) display. Those skilled in the art will recognize that any display device capable of being integrated with the user interface 310 is suitable for implementation in the present disclosure. In an embodiment, the user may input selections and / or instructions via a user input device of the user interface 310 in response to data displayed to the user.

[0069] Reference Figure 5 , a flow chart describing the method 400. The method may also be referred to as a process for manufacturing an electro-optical modulator. The embodiments and implementation techniques previously described herein in the context of the electro-optical modulator 100 and the modulator material layer 108 should be interpreted as extending to the method 400. However, it should be further noted that the method is not limited to the architecture of the electro-optical modulator 100.

[0070] In step 410, water, a surfactant, and a defoamer are mixed to form a surfactant mixture. The step may include mixing for an extended duration (e.g., mixing overnight). The defoamer may include silica / mineral oil (e.g., surface treated silica) or the like.

[0071] In step 420, the mixture is mixed with liquid crystal and at least one planar macrocyclic dye 206. The mixing with the liquid crystal can be pre-mixed at high speed and heat can be used. The mixture of liquid crystal and planar macrocyclic dye can be mixed with the solution prepared in step 410 at high speed or shear rate.

[0072] In step 430, a hydrophilic polymer aqueous emulsion is then mixed with the mixture to obtain an emulsion containing droplets of liquid crystals. The hydrophilic polymer aqueous emulsion may include a hydrophilic polyurethane or the like. By emulsifying the liquid crystal material, the electrical properties of the liquid crystal material may be improved. The liquid crystal may form smaller droplets dispersed within the polymer material. The size of the droplets of the liquid crystal is in the range of between 0.1 microns to 10 microns and may include an average size of 1 micron to 3 microns. When no electric field is applied, the liquid crystal molecules may be randomly oriented within the droplets. The liquid crystal / polymer material may be emulsified in any manner, such as, but not limited to, mechanical force using a high-speed blade. A crosslinking agent (e.g., a polyethylenimine or carbodiimide-based crosslinking agent) may be added in the range of 0.05% to 3%, followed by manual shaking to mix it into the emulsion.

[0073] The emulsion is evacuated in step 440. The emulsion is evacuated under vacuum.

[0074] In step 450, the emulsion is coated onto a substrate. The substrate may include PET Mylar coated with ITO. For example, the substrate may include a transparent conductive layer 110 and a plastic film 112. Many wet coating methods may be used. Examples include wire wound rod coating, doctor blade coating, slot die coating, extrusion coating, spin coating, spray coating, ink jet coating, etc.

[0075] In step 460, the emulsion is dried. The emulsion may be dried at room temperature for a first duration and at an elevated temperature (e.g., in an oven at 40°C) for a second duration. By drying, internal water is evaporated from the mixture. As the water evaporates, the droplets 202 of liquid crystal remain dispersed within the polymer matrix 204 and the polymer matrix crosslinks. The dried emulsion forms the modulator material layer 108. The liquid crystal molecules may be anchored to the polymer matrix. The degree of anchoring depends on the liquid crystal molecules, surfactant, and polymer chemistry. When an electric field is applied across the liquid crystal material, the liquid crystal molecules and / or droplets may be aligned at least partially along the direction of the electric field. In order for this alignment to occur, the liquid crystal molecules and / or droplets overcome anchoring and / or friction with the polymer at the attachment tracks.

[0076] It is further contemplated that each of the embodiments of the methods described above may include any other steps of any other method described herein.

[0077] Although the planar macrocyclic dyes have been described as being added to an electro-optical modulator of an imaging system, this is not intended as a limitation of the present disclosure. Further upon careful consideration, the planar macrocyclic dyes may be added to several water-based polymers. Such water-based polymers may include several beneficial applications, such as smart window technology, sensors, or other NCAP liquid crystal films. In solvent-based systems, PDLC films, polymer stabilized liquid crystals (PSLCs), polymer stabilized cholesteric liquid crystals (PSCLCs), chiral liquid crystals, ferroelectric liquid crystals, or blue phase liquid crystals may be similarly improved.

[0078] NCAP films may be suitable for making very large area light valves and displays. NCAP films are generally water-based and can be further divided into several subcategories. For example, subcategories of NCAP films include water-soluble polymers, such as polyvinyl alcohol (PVA) or urethane. Due to the hydrophilic nature of water-soluble polymers, water-soluble polymers may be sensitive to moisture. NCAP films based on water-soluble polymers may include two-phase materials containing liquid crystals and water / polymer solutions. By another example, subcategories of NCAP films include latex-based materials. Latex-based NCAP films may include three-phase materials containing water, liquid crystals, and latex-based materials. Latex-based materials include non-water-soluble polymers. Latex particles may be dispersed in water together with liquid crystals. These latex particles may "fuse" into a continuous polymer phase that is irreversible once water is removed. Some applications using this latex-based NCAP have long-term optoelectronic stability. After drying, the liquid crystals are distributed in the polymer (latex or residual polymer (such as PVA)). Any of these NCAP films may benefit from the embodiments disclosed herein.

[0079] One or more surfactants (eg, wetting agents) may be added to the aqueous mixture during formation of the modulator material layer 108. The surfactants may improve the ability of the modulator material layer 108 to spread due to reduced surface tension.

[0080] As used throughout this disclosure, the term "sample" generally refers to a substrate formed of a semiconductor or non-semiconductor material (e.g., thin film glass or the like). For example, the semiconductor or non-semiconductor material may include, but is not limited to, single crystal silicon, gallium arsenide, indium phosphide, or glass material. The sample may include one or more layers. For example, these layers may include, but are not limited to, resists (including photoresists), dielectric materials, conductive materials, and semiconductive materials. Many different types of these layers are known in the art, and the term sample as used herein is intended to cover samples on which all types of these layers can be formed. One or more layers formed on the sample may be patterned or unpatterned. For example, the sample may include multiple dies each having repeatable patterned features. The formation and processing of these material layers may ultimately lead to a finished device. Many different types of devices may be formed on the sample, and the term sample as used herein is intended to cover samples on which any type of device known in the art is manufactured. In addition, for the purposes of this disclosure, the terms sample and wafer should be interpreted as interchangeable. Additionally, for the purposes of this disclosure, the terms patterning device, mask, and reticle should be interpreted as interchangeable.

[0081] Although the present disclosure has been described with respect to one or more specific embodiments, it will be understood that other embodiments of the present disclosure may be made without departing from the scope of the present disclosure. Therefore, the present disclosure is deemed to be limited only by the appended claims and reasonable interpretation thereof.

Claims

1. A modulator material layer, comprising: a polymer matrix formed from a plurality of cross-linked polymer molecules; a plurality of droplets of liquid crystal within the polymer matrix; and A planar macrocyclic dye is dispersed within the plurality of droplets of the liquid crystal.

2. The modulator material layer of claim 1, wherein the planar macrocyclic dye comprises one or more of: phthalocyanine, porphyrin, naphthalocyanine, metallophthalocyanine, metalloporphyrin or metallonaphthalocyanine.

3. The modulator material layer of claim 2, wherein the planar macrocyclic dye comprises one or more of a phthalocyanine, a porphyrin, or a naphthalocyanine.

4. The modulator material layer of claim 2, wherein the planar macrocyclic dye comprises one or more of a metal phthalocyanine, a metal porphyrin, or a metal naphthalocyanine.

5. The modulator material layer of claim 2, wherein the planar macrocyclic dye is zinc phthalocyanine.

6. The modulator material layer of claim 1, wherein the planar macrocyclic dye is 0.002 wt% to 0.5 wt% of the mixture of the polymer matrix, the liquid crystal and the planar macrocyclic dye.

7. The modulator material layer according to claim 1, wherein the modulator material layer is a nematic curve aligned phase (NCAP) film. 8 . The modulator material layer according to claim 1 , wherein the modulator material layer is a polymer dispersed liquid crystal (PDLC) film, a chiral liquid crystal film, a ferroelectric liquid crystal film or a blue phase liquid crystal film.

9. A modulator material layer according to claim 1, wherein the size of the droplets is in the range of 0.1 microns to 10 microns.

10. A modulator material layer according to claim 1, wherein when no electric field is present, the liquid crystals are randomly oriented within the plurality of droplets, and wherein when an electric field is applied across the modulator material layer, the liquid crystals are at least partially aligned along the direction of the electric field.

11. The modulator material layer of claim 1, further comprising a transparent conductive film disposed on the modulator material layer.

12. The modulator material layer of claim 1, further comprising a glass substrate, wherein the modulator material layer is one of a direct coating on the glass substrate or a stacked layer on the glass substrate.

13. An imaging system comprising: an illumination source configured to generate illumination; a stage configured to hold a sample; a detector for generating an image of at least a portion of the sample; and an electro-optical modulator disposed in a path of illumination from the illumination source and separated from the sample by an air gap, wherein the electro-optical modulator comprises: Transparent conductive films; A modulator material layer, which is disposed on the transparent conductive film, and the modulator material layer comprises: a polymer matrix formed from a plurality of cross-linked polymer molecules; a plurality of droplets of liquid crystal within the polymer matrix; and A planar macrocyclic dye is dispersed within the plurality of droplets of the liquid crystal.

14. The imaging system of claim 13, wherein the planar macrocyclic dye comprises one or more of: a phthalocyanine, a porphyrin, a naphthalocyanine, a metallophthalocyanine, a metalloporphyrin, or a metallaphthalocyanine.

15. The imaging system of claim 14, wherein the planar macrocyclic dye is zinc phthalocyanine.

16. The imaging system of claim 13, wherein the planar macrocyclic dye is 0.002 wt% to 0.5 wt% of the mixture of the polymer matrix, the liquid crystal, and the planar macrocyclic dye.

17. The imaging system of claim 13, wherein the modulator material layer is a nematic curve aligned phase (NCAP) film.

18. The imaging system of claim 13, wherein the modulator material layer is a polymer dispersed liquid crystal (PDLC) film, a chiral liquid crystal film, a ferroelectric liquid crystal film, or a blue phase liquid crystal film.

19. The imaging system of claim 13, wherein in the absence of an electric field, the liquid crystals are randomly oriented within the plurality of droplets, and wherein when an electric field is applied across the modulator material layer, the liquid crystals are at least partially aligned along the direction of the electric field.

20. A method comprising: An emulsion is obtained by mixing water, liquid crystal, planar macrocyclic dye and multiple hydrophilic polymer molecules; coating the emulsion onto a substrate; and drying the emulsion, wherein the emulsion forms a modulator material layer, the modulator material layer comprising: a polymer matrix formed from a plurality of cross-linked polymer molecules; a plurality of droplets of the liquid crystal within the polymer matrix; and The planar macrocyclic dye is dispersed in the plurality of droplets of liquid crystal, The planar macrocyclic dye comprises one or more of the following: phthalocyanine, porphyrin, naphthalocyanine, metallophthalocyanine, metalloporphyrin or metallonaphthalocyanine.

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