Enhanced defect detection with planar macrocyclic dyes in liquid crystal films

Abstract

A modulator material layer includes a polymer matrix formed of a plurality of cross-linked polymer molecules and a plurality of droplets of liquid crystal within the polymer matrix. Dispersed within the plurality of droplets of liquid crystal are planar macrocyclic dyes. The planar macrocyclic dyes can include one or more of phthalocyanines, porphyrins, naphthalocyanines, metallophthalocyanines, metalloporphyrins, or metallonaphthalocyanines.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to a nonprovisional patent application designated U.S. App. No. 18 / 238,183, filed August 25, 2023, and to a provisional patent application designated U.S. App. No. 63 / 402,079, filed August 30, 2022, the disclosures of which are incorporated herein by reference.

[0002] TECHNICAL FIELD This disclosure relates to electro-optics, and more particularly to macrocyclic dye doping of liquid crystal materials to improve defect detection in electro-optic applications. [Background technology]

[0003] Electro-optic modulators utilizing liquid crystals, particularly nematic curvilinear aligned phases (NCAP) films or polymer dispersed liquid crystal (PDLC) films for modulation, are used in manufacturing to inspect the conductivity of thin film transistors and interconnects in flat panel displays (FPDs). Improved defect detection is needed to quickly resolve smaller defects in FPDs. Existing modulators have limited defect detection capabilities and low sensitivity. Therefore, it would be beneficial to provide a device, system, or method that can ameliorate some of the aforementioned shortcomings. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 7,817,333 [Patent Document 2] U.S. Patent No. 8,801,964 [Patent Document 3] U.S. Patent No. 7,639,319 Summary of the Invention [Problem to be solved by the invention]

[0005] There is a need for systems and techniques that utilize modulators and modulator sensitivities (s-curves) used in array checkers to improve defect detection. [Means for solving the problem]

[0006] In a first embodiment, a modulator material layer is presented. The modulator material layer includes a polymer matrix formed of a plurality of crosslinked polymer molecules, a plurality of droplets of liquid crystal in the polymer matrix, and a planar macrocyclic dye dispersed among the plurality of droplets of liquid crystal. The planar macrocyclic dye can include one or more of phthalocyanine, porphyrin, naphthalocyanine, metallophthalocyanine, metalloporphyrin, or metallonaphthalocyanine. In one embodiment, the planar macrocyclic dye includes one or more of phthalocyanine, porphyrin, or naphthalocyanine. In another embodiment, the planar macrocyclic dye includes one or more of metallophthalocyanine, metalloporphyrin, or metallonaphthalocyanine. For example, the planar macrocyclic dye can be zinc phthalocyanine.

[0007] The planar macrocyclic dye may be 0.002 to 0.5% by weight of the mixture of polymer matrix, liquid crystal and planar macrocyclic dye.

[0008] The modulator material layer can be a nematic curvilinearly aligned 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.

[0009] The droplet size range can be from 0.1 to 10 microns.

[0010] In the absence of an electric field, the liquid crystals can be randomly oriented in the droplets, and when an electric field is applied to the modulator material layer, the liquid crystals can at least partially align along the direction of the electric field.

[0011] The modulator material layer may further include a transparent conductive film disposed on the modulator material layer.

[0012] The modulator material layer can further include a glass substrate, the modulator material layer being one of a direct coating on the glass substrate or a laminate on the glass substrate.

[0013] In a second embodiment, an imaging system is provided. The imaging system includes an illumination source configured to generate illumination light, a sample stage configured to hold a sample, a detector for generating an image of at least a portion of the sample, and an electro-optic modulator positioned in a path of illumination from the illumination source and separated from the sample by an air gap. The electro-optic 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 of a plurality of cross-linked polymer molecules, a plurality of liquid crystal droplets in the polymer matrix, and a planar macrocyclic dye dispersed among the liquid crystal droplets. The planar macrocyclic dye can include one or more of phthalocyanine, porphyrin, naphthalocyanine, metal phthalocyanine, metal porphyrin, or metal naphthalocyanine. For example, the planar macrocyclic dye is zinc phthalocyanine.

[0014] The planar macrocyclic dye may be 0.002 to 0.5% by weight of the mixture of polymer matrix, liquid crystal and planar macrocyclic dye.

[0015] The modulator material layer can be an NCAP film, a PDLC film, a chiral liquid crystal film, a ferroelectric liquid crystal film, or a blue phase liquid crystal film.

[0016] In the absence of an electric field, the liquid crystals can be randomly oriented in the droplets, and when an electric field is applied to the modulator material layer, the liquid crystals can at least partially align along the direction of the electric field.

[0017] In a third embodiment, a method is presented. The method includes mixing water, liquid crystal, a planar macrocyclic dye, and a plurality of hydrophilic polymer molecules to form an emulsion. The emulsion is coated onto a substrate. The emulsion is then dried. The emulsion produces a modulator material layer including a polymer matrix formed of a plurality of cross-linked polymer molecules, a plurality of droplets of liquid crystal in the polymer matrix, and a planar macrocyclic dye dispersed among the plurality of droplets of liquid crystal. The planar macrocyclic dye can include one or more of phthalocyanines, porphyrins, naphthalocyanines, metal phthalocyanines, metal porphyrins, or metal naphthalocyanines. [Brief explanation of the drawings]

[0018] For a better understanding of the nature and scope of the present disclosure, reference should be made to the following detailed description taken in conjunction with the accompanying drawings.

[0019] [Figure 1] 1 is a cross-sectional view of an electro-optic modulator according to an embodiment of the present disclosure. [Figure 2] 1 illustrates a modulator material layer of an electro-optic modulator, the material layer including liquid crystal droplets and planar macrocyclic dyes dispersed within the liquid crystal droplets, according to an embodiment of the present disclosure. [Figure 3] 10 is a graph showing voltage-transmittance curves obtained through an experiment. [Figure 4] 1 is a schematic diagram illustrating an imaging system according to the present disclosure. [Figure 5] 1 is a flowchart illustrating a method for manufacturing an electro-optic film according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0020] Although the claimed subject matter is described with reference to certain embodiments, other embodiments (including embodiments that do not possess all of the advantages and characteristics described herein) are within the scope of this 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 reference to the appended claims.

[0021] The disclosed embodiments utilize doping of NCAP film and other films of electro-optic modulators used in array checker modulator technology with planar macrocyclic dyes to enhance the contrast ratio between the film's off / on states. Specifically, planar macroscopic dyes can be dispersed in liquid crystal droplets, and NCAP film and other films can be doped with the planar macroscopic dyes. This is believed to improve the signal-to-noise ratio (SNR) and enhance the sensitivity of the modulator for detecting defects in flat panel displays. The addition of macrocyclic planar dyes is believed to improve the detection performance of NCAP film and other films used in array checker modulator technology. The electro-optic modulator can be a component of an imaging system (also known as an automated optical inspection (AOI) system, voltage imaging optical system (VIOS), array checker, etc.).

[0022] A method for fabricating an electro-optic modulator is also described. An embodiment of the method for fabricating an electro-optic modulator involves a first step in which a plastic sheet (such as Mylar) with a transparent conductive layer is coated with an NCAP film or other film. A second layer of plastic sheet is added (with or without a conductive layer). This sandwich structure 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 thin film) is formed on the plastic sheet and then added to the assembly stack.

[0023] U.S. Patent No. 7,817,333, filed February 6, 2007, entitled "Modulator with improved sensitivity and life time"; U.S. Patent No. 8,801,964, filed December 22, 2010, entitled "Encapsulated polymer network liquid crystal material, device and applications"; and U.S. Patent No. 7,639,319, filed April 7, 2005, entitled "Polymer dispersed liquid crystal formulations for modulator fabrication" are each incorporated herein by reference in their entirety.

[0024] FIG. 1 is a cross-sectional view of an electro-optic modulator 100. The electro-optic modulator 100 can include one or more films, layers, or coatings. The one or more film layers selectively transmit light. For example, the electro-optic modulator 100 can include one or more of a hard coating layer 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. Films, layers, or coatings other than those shown or described in the electro-optic modulator 100 are also possible.

[0025] The modulator material layer 108 (also referred to as a sensor layer, liquid crystal layer, polymer matrix layer, etc.) can be applied to the glass substrate 116 in a number of ways, including, but not limited to, direct coating or lamination. An embodiment of a manufacturing method using a lamination process includes a first step of coating the modulator material layer 108 onto a plastic film 112 (e.g., polyethylene terephthalate (PET), also known as Mylar) with a transparent conductive layer 110. The transparent conductive layer 110 generally can comprise any material that is optically transparent and electrically conductive to act as an electrode, such as, but not limited to, indium tin oxide (ITO) or other conductive materials. The modulator material layer 108 can comprise a nematic curvilinear array (NCAP) mixture, a polymer dispersed liquid crystal (PDLC) mixture, or other mixtures. The plastic film 112, as well as the transparent conductive layer 110 and modulator material layer 108, can be laminated onto the glass substrate 116 with an optical adhesive 114. The dielectric mirror film 106 (or thin film) 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. An anti-reflective coating 118 can be applied to the bottom surface of the glass substrate 116. Similarly, the hard coating layer 102 can be cured on the plastic film 104. The hard coating layer 102 can include a thick hard coating and a thinner slip agent layer.

[0026] The optical transmittance of the modulator material layer 108 can be changed depending on the strength of the electric field applied to the liquid crystal droplets in the modulator material layer 108. The transparent conductive layer 110 can be capacitively coupled to the sample to induce a localized voltage and electric field. The localized voltage can create an electric field. This electric field causes the liquid crystals in the modulator material layer 108 to align in the direction of the electric field.

[0027] 2 is a cross-sectional view of a modulator material layer 108. In one embodiment, the modulator material layer 108 includes an NCAP mixture, although other mixtures are possible. The modulator material layer 108 includes droplets 202 of liquid crystal suspended in a polymer matrix 204. The modulator material layer 108 includes one or more material diluents, such as planar macrocyclic dyes 206, dispersed within the droplets 202. The planar macrocyclic dyes 206 will be described further herein.

[0028] The NCAP used in the modulator material layer 108 includes droplets 202. Each droplet 202 contains a number of liquid crystal molecules. The liquid crystal molecules have a temperature transition in the liquid crystal phase. In some embodiments, the droplets 202 are approximately 1-5 microns in size. The liquid crystal droplets can have a liquid crystal temperature range. The liquid crystal temperature range refers to the temperature at which the liquid crystal is in the liquid crystal phase (e.g., between the crystalline and liquid phases).

[0029] The liquid crystal droplets 202 may comprise any liquid crystal material, including, but not limited to, one or more of nematic liquid crystals, polymer dispersed liquid crystals, chiral liquid crystals, ferroelectric liquid crystals, blue phase liquid crystals, mixtures of liquid crystals and dichroic dyes, cholesteric liquid crystals, etc. The liquid crystal material may be substantially hydrophobic so that an emulsion can be used to form the liquid crystal material droplets 202.

[0030] 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 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. A surfactant may be used to form the polymer matrix 204.

[0031] The amount of polymer matrix 204 material is believed to affect the strength and stiffness of the sensor material. The mass ratio of the liquid crystal material to the polymer matrix material can range, for example, from about 50 / 50 to about 80 / 20. Increasing the amount of polymer matrix 204 material can increase the strength and actuation voltage of the sensor material.

[0032] The polymer matrix 204 surrounds the droplets 202 and contains them, i.e., the droplets 202 are dispersed throughout the polymer matrix 204. The droplets 202 containing the liquid crystal molecules are believed to be anchored to the polymer matrix 204. In one embodiment, the degree of anchoring depends on the chemical properties of the liquid crystal molecules and the polymer matrix 204.

[0033] In the absence of an electric field, the liquid crystal molecules can be randomly oriented in the droplets 202. When an electric field is applied to the modulator material layer 108, the liquid crystals can at least partially align along the direction of the electric field. To achieve this alignment, the molecules overcome adhesion and / or friction with the polymer matrix 204 at the bonding locations. As a result, the liquid crystals orient and change the transmittance of the modulator material layer 108. For example, when no voltage is applied and the liquid crystals are randomly oriented, the modulator material layer 108 is considered opaque. When a voltage is applied and the liquid crystal molecules are at least partially aligned, the modulator material layer 108 is considered transparent or translucent. Subsequently, when the electric field is removed, the liquid crystals return to their random alignment.

[0034] The liquid crystal droplets 202 are considered to have a switching voltage. The intrinsic switching voltage of the liquid crystal is considered to correspond to the voltage applied to the modulator material layer when the optical transmittance of the electro-optic modulator is most sensitive to changes in voltage. In many embodiments, the switching voltage corresponds to the electric field strength at which approximately half of the liquid crystal molecules are approximately aligned by the electric field. To maximize sensitivity, the goal is to produce the largest change in transmittance with as little voltage change as possible. Sensitivity can be improved by reducing the intrinsic switching voltage of the liquid crystal material. The operating voltage and sensitivity of a liquid crystal material are considered to be related to one or more factors, including, but not limited to, the properties of the liquid crystal, the properties of the polymer matrix, the size distribution of the liquid crystal droplets in the polymer matrix, and / or the interface properties between the polymer matrix and the liquid crystal.

[0035] The adhesion of the liquid crystal molecules to the polymer matrix 204 can increase the specific actuation voltage of the modulator material layer 108. Frictional forces can be an adhesive force, and friction can be associated with static friction between the liquid crystal molecules and the polymer matrix, as well as kinetic friction associated with the relative motion of the liquid crystal molecules and the polymer matrix. Because friction affects the speed at which molecules move relative to the surrounding polymer matrix, reducing friction can increase the switching speed of the liquid crystal molecules. Because increased voltage is required to overcome the adhesion of the liquid crystal molecules to the polymer matrix, increased adhesiveness can increase the specific actuation voltage of the modulator material layer 108. That is, the smaller the friction and / or adhesiveness between the liquid crystal droplets 202 and the polymer matrix 204, the lower the driving voltage required to switch the liquid crystal molecules and / or the liquid crystal from a nearly unaligned state to a nearly aligned state in response to an electric field.

[0036] Dispersed within the liquid crystal droplets 202 are planar macrocyclic dyes 206. The planar macrocyclic dyes 206 can include, consist of, or consist essentially of, for example, one or more of phthalocyanines, porphyrins, or naphthalocyanines. The planar macrocyclic dyes 206 can also include, consist of, or consist essentially of, for example, one or more metal analogs of these species (such as metallophthalocyanines, metalloporphyrins, metallonaphthalocyanines, etc.).

[0037] Generally, metal phthalocyanines, metal porphyrins, or metal naphthalocyanines contain a metal with a +2 or +3 charge, such as copper, zinc, platinum, iron, cobalt, or tin, although other metals may also be used.

[0038] Phthalocyanines are organic compounds with aromatic macrocyclic structures and can be represented by the formula (C8H4N2)4H2. Metal complexation of phthalocyanines produces metal phthalocyanine compounds. Some examples of metals that can be used in phthalocyanine complexes include copper, cobalt, and zinc. Examples of phthalocyanines that can be used in accordance with the present disclosure are listed below, although other phthalocyanines are possible.

[0039] [ka] [ka] [ka] [ka] [ka]

[0040] In one embodiment, the planar macrocyclic dye 206 is zinc phthalocyanine.

[0041] Porphyrins are heterocyclic macrocyclic organic compounds with four modified pyrrole subunits whose α-carbon atoms are linked together by methine bridges (=CH-). Porphyrins can also bind metals. Porphyrins can contain a variety of side chains (tails) attached to the aromatic ring of the outset. Examples of porphyrins that can be used in accordance with the present disclosure (protoporphyrin IX, octaethylporphyrin, and tetraphenylporphyrin) are shown below, although other porphyrins are also possible.

[0042] [ka] [ka] [ka]

[0043] Naphthalocyanines have the formula C 48 H 26 N8 is a cross-shaped organic molecule. It is a derivative of phthalocyanine. Representative derivatives are shown below, but other derivatives are also possible.

[0044] [ka]

[0045] The planar macrocyclic dye 206 can be used to enhance the optical contrast of materials in NCAP films, PDLC films, or other films. When embedded in liquid crystal droplets 202, the planar macrocyclic dye 206 darkens the NCAP film or other film in the "off" state over a specific wavelength range of illuminating light, increasing the contrast ratio, while not appreciably changing the transmittance in the on state. When incorporated into electro-optic modulators used in array checker technology, the planar macrocyclic dye 206 increases the sensitivity of the NCAP film or other film in the modulator to detect defects present in flat panel displays during the panel manufacturing process.

[0046] The planar macrocyclic dye 206 can have a weight percentage of 0.002 to 0.5 wt % of the liquid crystal mixture (which can include a polymer matrix, liquid crystal, and planar macrocyclic dye). For example, the weight percentage can be 0.03% of the liquid crystal mixture. The dye concentration can vary depending on the solubility and chemical compatibility with the individual liquid crystal materials. For example, the weight percentage can be 0.03 to 0.1 wt % of the liquid crystal mixture to optimize solubility in the liquid crystal mixture. If the weight percentage of the planar macrocyclic dye 206 is less than 0.002 wt %, the contrast ratio between the off and on states of the film may not be large. If the weight percentage of the planar macrocyclic dye 206 is greater than 0.5 wt %, precipitation may occur.

[0047] The experimental voltage-transmittance curves are shown in Figure 3. As shown in Figure 3, approximately 10% by weight of a standard dichroic dye was required to achieve the same performance as 0.03% by weight of zinc phthalocyanine.

[0048] FIG. 4 is a conceptual diagram illustrating an imaging system 300. For purposes of this disclosure, the term "imaging system" is interchangeable with the term "imaging tool." Imaging system 300 may generally include any suitable type of imaging tool, such as, 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 a TFT array is simulated by incorporating it into a TFT cell, and the TFT array is then characterized by indirectly measuring the actual voltage distribution on the panel or by voltage imaging using a so-called electro-optic modulator (e.g., electro-optic modulator 100). Voltage imaging may be performed by imaging system 300. Imaging system 300 may include one or more components for verifying such TFT arrays and other samples.

[0049] The electro-optic modulator 100 may be advantageous in many imaging operations, such as adjusting the light source of the imaging system 300 to facilitate detection of one or more defects in the sample 311 (such as, but not limited to, a TFT array, a liquid crystal display (LCD) panel, or an OLED panel). The TFT array may be formed on a substrate, such as a thin, transparent glass plate. The TFT array may include one or more printed layers. The printed layers may be formed on the substrate in a number of processes, including, but not limited to, one or more material deposition steps, one or more lithography steps, and one or more etching steps. Fabrication may be performed in stages, such as depositing materials (e.g., indium tin oxide (ITO)) onto a previously fabricated layer or onto the glass substrate, according to a process scheme. During fabrication, the printed layers are fabricated to within a specified tolerance to ensure the final device is properly constructed. The printed layers may exhibit defects outside the specified tolerance. The TFT array's characteristics may be measured by the imaging system 300 to detect the defects.

[0050] In one embodiment, the imaging system 300 includes an illumination source 306 that generates illumination light 308. The illumination light 308 can include light of one or more selected wavelengths, including, but not limited to, vacuum ultraviolet radiation (VUV), deep ultraviolet radiation (DUV), ultraviolet (UV), visible light, or infrared (IR). The illumination source 306 can also generate illumination light 308 that includes any selected range of wavelengths. In an embodiment, the illumination source 306 can include a spectrally tunable illumination source for generating illumination light 308 with a tunable spectrum.

[0051] The illumination source 306 can direct illumination light 308 to the sample 311 via an illumination path 309. The light path 309 can include one or more lenses 312 or additional illumination optical elements 314 suitable for modifying and / or conditioning the illumination light 308. For example, the one or more illumination optical elements 314 can 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, etc.), one or more aperture stops, and / or one or more field stops.

[0052] The imaging system 300 can include an electro-optic modulator 100. The electro-optic modulator 100 is positioned in the path of illumination light 308 from an illumination source 306. The electro-optic modulator 100 can adjust one or more properties of the illumination light 308. In operation, light passes through a portion of the electro-optic modulator 100, and changes in the reflected or transmitted light can be observed to detect defects on or within a sample 311. The electro-optic modulator 100 is separated from the sample 311 by an air gap. The electro-optic modulator 100 is positioned a selected number of microns (e.g., between 5 and 75 microns) above the surface of the sample 311 (e.g., a TFT array), and a voltage bias is applied to a transparent electrode, typically a layer of indium tin oxide (hereinafter "ITO"), on the surface of the electro-optic modulator 100. The electro-optic modulator 100 and the sample 311 are then capacitively coupled, and the electric field associated with the sample 311 is sensed in one or more layers (e.g., layers containing liquid crystals) of the electro-optic modulator 100. Based on the strength of the electric field sensed in the liquid crystal, the intensity of light incident through the liquid crystal of the electro-optic modulator is changed (i.e., adjusted). For example, when a local voltage potential is applied to a region of a normal pixel (e.g., capacitive coupling between the sample 311 and the electro-optic modulator 100), one or more films of the electro-optic modulator 100 become locally translucent. In the locally translucent areas, light from the light source 306 passes through the electro-optic modulator 100, reflects off the sample 311, and is directed toward the collection pathway 322 (e.g., captured by the detector 304). As another example, in areas where no voltage potential is applied (e.g., no capacitive coupling), one or more films of the electro-optic modulator 100 remain locally opaque. If electro-optic modulator 100 is locally opaque, light from light source 306 will be scattered or otherwise prevented from reaching sample 311. Thus, a voltage can be applied to determine a transmittance-voltage (TV) curve. The intrinsic switching voltage of electro-optic modulator 100 can be considered to correspond to the voltage applied to electro-optic modulator 100 when the optical transmittance of electro-optic modulator 100 is most sensitive to changes in voltage. For example, the switching voltage can be considered to correspond to the electric field strength when the electric field causes a predetermined percentage of liquid crystal molecules to substantially align and transmit light.

[0053] The sample 311 may include a TFT array. For example, the sample 311 may include pixel elements interposed between inactive areas. The sample stage 318 may include any device suitable for positioning the sample 311 within the imaging system 300.

[0054] Detector 304 can be positioned to capture radiation (e.g., sample light 320) emitted from sample 311 and passed through collection path 322. For example, collection path 322 may (but need not) include electro-optic modulator 100, a collection lens (e.g., an objective lens), or one or more additional collection path lenses 324. In this manner, detector 304 can receive radiation reflected or scattered from sample 311 (e.g., by specular reflection, diffuse reflection, etc.) or radiation emitted from sample 311 (e.g., emission due to absorption of illumination light 308, etc.).

[0055] The system 300 may include, but is not limited to, a controller 303. The controller 303 may include one or more processors and memory, and may also include or be connected to a user interface 310.

[0056] The light collection path 322 may further include any number of collection elements 326 for directing and / or conditioning the illumination light collected by the electro-optic modulator 100. Collection elements 326 may include, but are not limited to, one or more filters, one or more polarizers, or one or more blocks. The light collection path 322 may further include a field stop to control the spatial extent of the sample imaged onto the detector 304, or an aperture stop to control the angular extent of the illumination light from the sample used to image onto the detector 304. In another embodiment, the light collection path 322 includes an aperture stop located tangent to the back focal plane of the optical elements to generate a telecentric image of the sample. In an embodiment, the imaging system 300 includes a beam splitter 328 positioned to collect radiation emitted from the sample 311 while the electro-optic modulator 100 directs the illumination light 308 toward the sample 311.

[0057] Detector 304 may include any type of optical detector suitable for measuring illumination light 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, etc. In another embodiment, detector 304 may include a spectroscopic detector suitable for ascertaining the wavelength of light emitted from sample 311.

[0058] The controller 303 may be in communication with 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 send one or more control signals to one or more processing means configured to make one or more adjustments based on the image signal 313 from the detector 304.

[0059] The one or more processors of the controller 303 may include any processor or processing element known in the art. For purposes of this 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, one or more processors may include any device configured to execute algorithms and / or instructions (e.g., program instructions stored in memory). In certain embodiments, the one or more processors may be embodied as a desktop computer, mainframe computer system, workstation, image computer, parallel processor, network computer, or any other computer system that executes programs in operation or in conjunction with the imaging system 300 described in this disclosure. Additionally, the various subsystems of system 300 may include processors or logic elements suitable for performing at least some of the steps described herein. Accordingly, the foregoing should not be construed as limiting the embodiments disclosed herein, but rather as merely illustrative. Furthermore, the steps described herein may be performed by a single controller or by multiple controllers. Controller 303 may also include one or more controllers housed in a common housing or multiple housings. Thus, any controller or combination of controllers may be packaged separately as a module suitable for incorporation into imaging system 300.Additionally, the controller 303 may analyze data received from the detector 304 and send the data to additional components within the imaging system 300 or external to the imaging system 300 .

[0060] The storage medium may include any storage medium known in the art suitable for storing program instructions executable by one or more associated processors. For example, the storage medium may include a non-transitory storage medium. As another example, the storage medium may include, but is not limited to, read-only memory (ROM), random access memory (RAM), magnetic or optical storage devices (e.g., disks), magnetic tape, solid-state drives, etc. Moreover, the storage medium may be housed within a controller enclosure common to one or more processors. In some embodiments, the storage medium may be located remotely from the physical location of one or more processors and controller 303. For example, one or more processors of controller 303 may access a remote storage device (e.g., a server) accessible via a network (e.g., the Internet, an intranet, etc.).

[0061] The user interface 310 can be in communication with the controller 303. The user interface 310 can include, but is not limited to, one or more desktops, laptops, tablets, etc. In embodiments, the user interface 310 includes a display used to display system 300 data to a user. The display of the user interface 310 can include any display known in the art. For example, the display can include, but is not limited to, a liquid crystal display (LCD), an organic light-emitting diode (OLED) display, or a cathode ray tube (CRT) display. Those skilled in the art will appreciate that any display device that can be incorporated into the user interface 310 is suitable for practicing the present disclosure. In embodiments, the user can make selections and / or enter commands through a user input device of the user interface 310 in response to data presented to the user.

[0062] 5, a flow chart of method 400 will be described. This method may also be referred to as a manufacturing process for an electro-optic modulator. The embodiments and implementation techniques previously described with respect to electro-optic modulator 100 and modulator material layer 108 should be construed as extending to method 400. However, it should be noted that this method is not intended to limit the structural concept of electro-optic modulator 100.

[0063] In step 410, water, a surfactant, and an antifoaming agent are mixed to form a surfactant mixture. This step may include extended mixing (e.g., overnight mixing). The antifoaming agent may include silica / mineral oil (e.g., surface-treated silica).

[0064] In step 420, this mixture is mixed with liquid crystals and at least one planar macrocyclic dye 206. The mixture containing the liquid crystals can be premixed at high speed, or heat can be used. The liquid crystal and planar macrocyclic dye mixture can be mixed with the solution prepared in step 410 at high speed or shear rate.

[0065] Next, in step 430, an aqueous emulsion of a hydrophilic polymer is mixed with the mixture to obtain an emulsion containing liquid crystal droplets. The aqueous emulsion of a hydrophilic polymer may include, for example, a hydrophilic polyurethane. Emulsifying the liquid crystal material is believed to improve the electrical performance of the liquid crystal material. The liquid crystal is believed to form smaller droplets dispersed within the polymer material. The liquid crystal droplet size is believed to range from 0.1 to 10 microns, with an average diameter of 1 to 3 microns. The liquid crystal molecules are believed to be randomly oriented within the droplets when no electric field is applied. The liquid crystal / polymer material can be emulsified by any method, including, but not limited to, mechanical force using a high-speed blade. A cross-linking agent (e.g., polyaziridine or carbodiimide-based cross-linking agent) can be added in a range of 0.05% to 3%, followed by hand shaking to form the emulsion.

[0066] The emulsion is degassed in step 440. The emulsion is degassed under vacuum.

[0067] In step 450, the emulsion is coated onto a substrate. The substrate can include ITO-coated PET Mylar. For example, the substrate can include a transparent conductive layer 110 and a plastic film 112. Many wet coating methods can be used. Examples include wire wound rod, doctor blade, slot die, extrusion, spinning, spraying, inkjet, etc.

[0068] In step 460, the emulsion is dried. The emulsion can be dried for an initial period at room temperature and then for a subsequent period at a higher temperature (e.g., 40°C in an oven). Drying evaporates the water in the mixture. As the water evaporates, the liquid crystal droplets 202 remain dispersed in the polymer matrix 204, and the polymer matrix is ​​cross-linked. The dried emulsion becomes the modulator material layer 108. The liquid crystal molecules are believed to be anchored to the polymer matrix. The degree of anchoring depends on the chemical properties of the liquid crystal molecules, surfactant, and polymer. When an electric field is applied to the liquid crystal material, the liquid crystal molecules and / or droplets can at least partially align along the direction of the electric field. For such alignment to occur, the liquid crystal molecules and / or droplets overcome the adhesion and / or friction with the polymer at the bonding sites.

[0069] It is also contemplated that each of the above method embodiments may include any other step(s) of any other method(s) described therein.

[0070] While the incorporation of planar macrocyclic dyes into electro-optic modulators in imaging systems has been described, this is not intended to limit the scope of the present disclosure. It is also contemplated that planar macrocyclic dyes may be incorporated into many water-based polymers. Such water-based polymers may have many beneficial applications, including smart window technology, sensors, and 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 also be improved.

[0071] NCAP films are considered suitable for the fabrication of very large-area light valves and displays. NCAP films are generally water-based and can be further divided into several subclasses. For example, one subclass of NCAP films contains water-soluble polymers such as polyvinyl alcohol (PVA) and urethane. Water-soluble polymers are considered moisture-sensitive due to the hydrophilic nature of the water-soluble polymer. Water-soluble polymer-based NCAP films can include two-phase materials containing liquid crystals and a water / polymer solution. As another example, one subclass of NCAP films contains latex-based materials. Latex-based NCAP films can include three-phase materials containing water, liquid crystals, and latex-based materials. Latex-based materials contain water-insoluble polymers. Latex particles are considered dispersed in water along with the liquid crystals. These latex particles can irreversibly "fuse" into a continuous polymer phase once the water is removed. Some latex-based NCAP films have long-term electro-optical stability. After drying, the liquid crystal is dispersed in the polymer (either latex or residual polymer such as PVA). All of these NCAP films are believed to be useful in the embodiments disclosed herein.

[0072] One or more surfactants (e.g., wetting agents) may be added to the aqueous mixture when forming the modulator material layer 108. The surfactants are believed to reduce surface tension, making it easier for the modulator material layer 108 to spread.

[0073] As used herein, the term "sample" generally refers to a substrate of semiconductor or non-semiconductor material (e.g., thinned glass, etc.). Examples of semiconductor or non-semiconductor materials include, but are not limited to, single-crystal silicon, gallium arsenide, indium phosphide, or glass materials. A sample can include one or more layers. For example, such layers can include, but are not limited to, resist (including photoresist), dielectric materials, conductive materials, and semiconductor materials. Many different types of such layers are known in the art, and the term "sample" as used herein is intended to encompass a sample upon which any type of such layer can be formed. The one or more layers formed on a sample may or may not include a pattern. For example, a sample may include multiple dies, each with a repeating pattern. The formation and processing of such material layers ultimately results in a completed device. Many different types of devices can be formed on a sample, and the term "sample" as used herein is intended to encompass a sample upon which any type of device known in the art can be fabricated. Additionally, for purposes of this disclosure, the terms "sample" and "wafer" should be considered interchangeable. Additionally, for purposes of this disclosure, the terms "patterning device," "mask," and "reticle" should be considered interchangeable.

[0074] While the present disclosure has been described in connection with one or more detailed embodiments, it should be understood that other embodiments of the present disclosure may be made without departing from the scope of the present disclosure, and therefore, the present disclosure is to be limited only by the appended claims and their reasonable interpretation.

Claims

1. a modulator material layer comprising: the modulator material layer a polymer matrix formed of a plurality of cross-linked polymer molecules; a plurality of droplets of liquid crystal in the polymer matrix; a planar macrocyclic dye dispersed in a plurality of droplets of said liquid crystal; 10. A modulator material layer comprising:

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

3. 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. 3. 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. 3. The modulator material layer of claim 2, wherein said planar macrocyclic dye is zinc phthalocyanine.

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

7. 10. The modulator material layer of claim 1, wherein said modulator material layer is a nematic curvilinearly aligned phase (NCAP) film.

8. 10. The modulator material layer of 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. 2. The modulator material layer of claim 1, wherein the droplet size range is from 0.1 to 10 microns.

10. 2. The modulator material layer of claim 1, wherein the liquid crystal is randomly oriented in the droplets in the absence of an electric field, and when an electric field is applied to the modulator material layer, the liquid crystal is at least partially aligned along the direction of the electric field.

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

12. 10. 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 laminate on the glass substrate.

13. An image forming system, comprising: the image forming system, an illumination source arranged to generate illumination light; a sample stage arranged to hold a sample; a detector for generating an image of at least a portion of the sample; an electro-optic modulator disposed in a light path from the illumination source and separated from the sample by an air gap; Including, The electro-optic modulator comprises: a transparent conductive film; a layer of modulator material disposed on the transparent conductive film; Including, the modulator material layer a polymer matrix formed of a plurality of cross-linked polymer molecules; a plurality of droplets of liquid crystal in the polymer matrix; a planar macrocyclic dye dispersed in a plurality of droplets of said liquid crystal; An image forming system comprising:

14. 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 metallonaphthalocyanine.

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

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

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

18. 14. 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. 14. The imaging system of claim 13, wherein the liquid crystals are randomly oriented in the droplets in the absence of an electric field, and when an electric field is applied to the modulator material layer, the liquid crystals at least partially align along the direction of the electric field.

20. 1. A method comprising: The method comprises: mixing water, a liquid crystal, a planar macrocyclic dye, and a plurality of hydrophilic polymer molecules to obtain an emulsion; coating the emulsion onto a substrate; drying the emulsion; Including, The emulsion is a polymer matrix formed of a plurality of cross-linked polymer molecules; a plurality of droplets of liquid crystal in the polymer matrix; a planar macrocyclic dye dispersed in a plurality of droplets of said liquid crystal; creating a modulator material layer comprising: The method, wherein the planar macrocyclic dye comprises one or more of a phthalocyanine, a porphyrin, a naphthalocyanine, a metallophthalocyanine, a metalloporphyrin, or a metallonaphthalocyanine.

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