UV Reflective Mirror for Display Manufacturing

Abstract

To solve the problem in which a general increase in demand for panel displays requires manufacturers to increase the throughput, increase the size of the panel displays, and lower the downtime for maintenance on a production apparatus used in production of the panel displays.SOLUTION: Disclosed is an apparatus which includes an ultraviolet laser and at least one reflective mirror having a substrate which is made of beryllium, an aluminum metal matrix or silicon carbide. The at least one mirror is adapted to reflect a laser beam generated from the ultraviolet laser, which can then be used on a silicon film used in the production of an electronic display. The laser beam can be used to anneal the silicon film, or in a laser lift-off process for separating the silicon film from a temporary substrate on which the silicon film has been mounted.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001]

[0001] This application claims priority to U.S. Provisional Patent Application No. 62 / 738,210, filed Sep. 28, 2018, and U.S. Provisional Patent Application No. 62 / 723,102, filed Aug. 27, 2018, which are hereby incorporated by reference in their entirety.

Background Art

[0002]

[0002] The present invention relates to an ultraviolet reflective mirror used in the manufacture of electronic displays. In particular, different materials are disclosed for use as a substrate for a mirror used in beam steering of an ultraviolet laser such as an excimer laser, and it is described with particular reference thereto.

[0003]

[0003] Excimer laser annealing (ELA) and laser lift-off (LLO) processes performed on amorphous silicon films have become common techniques used in the manufacture of panel displays such as low temperature polycrystalline silicon LCDs (LTPS-LCDs) and organic light emitting diodes (OLEDs). These panel displays are used in the manufacture of various electronic devices such as mobile phones or cellular phones, computer monitors, televisions, watches, and the like. Due to the increasing general demand for such panel displays, manufacturers are required to increase throughput, increase the size of the panel displays, and reduce downtime for maintenance of the manufacturing equipment used in the manufacture of the panel displays.

Summary of the Invention

[0004]

[0004] The present invention relates to an apparatus including an ultraviolet laser and at least one reflective mirror. The at least one mirror includes a substrate and is configured to reflect a laser beam generated from the ultraviolet laser toward the substrate. The mirror substrate can be manufactured from beryllium, silicon carbide, or an aluminum metal matrix composite (aluminum metal matrix composite). This apparatus can be used in the manufacture of electronic components for a display panel and can be used in the manufacture of electronic components for a display panel.

[0005]

[0005] In various embodiments, an apparatus is disclosed that includes an ultraviolet laser; and at least one reflective mirror including a substrate, wherein the at least one mirror is adapted to reflect a laser beam generated from the ultraviolet laser. The mirror substrate can be manufactured from beryllium, silicon carbide, or an aluminum metal matrix composite.

[0006]

[0006] When the mirror substrate is manufactured from beryllium, the beryllium substrate can be manufactured from any pure beryllium or an alloy of beryllium. In some particular embodiments, the beryllium substrate is selected from at least one of the grades of beryllium having: (a) O-50 having a minimum Be content of 99.5% and a maximum BeO content of 0.5%; (b) S-65 having a minimum Be content of 99% and a maximum BeO content of 1%; (c) I-70 having a minimum Be content of 99% and a maximum BeO content of 0.7%; (d) S-200 having a minimum Be content of 98.5% and a maximum BeO content of 1.5%; (e) I-220 having a minimum Be content of 98% and a maximum BeO content of 2.2%; and (f) I-250 having a minimum Be content of 97.5% and a maximum BeO content of 2.5%.

[0007]

[0007] In some embodiments, the beryllium substrate comprises beryllium and at least one alloy element selected from Al, Ti, Co, Ni, Cu, Pd, Au, Nb, Ag, Ta, V, Cr, Mn, Fe, Mo, W, Re, Zr, Hf, Y, La, Ce, Th, U, Np, Pu, Am, Ca, and Mg The mirror can comprise from about 50 wt% to about 99.99 wt% beryllium and from about 0.01 wt% to about 50 wt% of at least one alloy element.

[0008]

[0008] In certain embodiments, the mirror substrate is made from an aluminum-beryllium composition that can comprise from about 50 wt% to about 99.99 wt% beryllium and from about 0.01 wt% to about 50 wt% aluminum.

[0009]

[0009] When the mirror substrate is made from silicon carbide or an aluminum metal matrix, the silicon carbide or aluminum metal matrix composite can have (i) an optical Figure of Merit (FoM) resonant frequency value of at least 6 for a fused silica substrate, (ii) an optical FoM self-weight deflection value of less than 0.030 for a fused silica substrate; (iii) an optical FoM steady-state thermal distortion coefficient value of less than 0.350 for a fused silica substrate; and (iv) an optical FoM transient thermal distortion coefficient value of less than 0.60 for a fused silica substrate.

[0010]

[0010] The mirror substrate can be manufactured from an aluminum alloy and an aluminum metal matrix composite material of one or more reinforcing materials. Examples of the one or more reinforcing materials can include at least one ceramic material selected from the group consisting of carbides, oxides, silicides, borides, and nitrides.

[0011]

[0011] In some other specific embodiments, silicon carbide can be cited as one or more reinforcing materials. In such embodiments, the metal matrix composite material can include 6061, 6063, 6082, 2009, 2618, or 2124 aluminum alloy reinforced with about 15% to about 40% by volume of silicon carbide.

[0012]

[0012] In additional embodiments, the mirror substrate is in the form of an aluminum-beryllium metal matrix composite material, where aluminum serves as the matrix phase and beryllium is in the form of a reinforcing material / particle. Also, additional reinforcing materials / particles can be present in such metal matrix composite materials.

[0013]

[0013] At least one mirror can further include an ultraviolet reflection coating deposited on the mirror substrate. In some embodiments, a base material such as nickel or a nickel alloy is deposited on the non-coated mirror substrate. On top of the base material, one or more layers of an ultraviolet light reflecting material are deposited. This reflective coating can be a dielectric such as a combination of hafnium oxide (HfO2) and silicon dioxide (SiO2). Another reflective coating can be of the "reinforced aluminum" type composed of an aluminum metal binder having an alternating coating of hafnium oxide and silicon dioxide.

[0014]

[0014] The apparatus can further include a beam homogenizer, a beam expander, a focusing lens, or a beam splitter, as well as combinations of these components.

[0015] Also, receiving an ultraviolet laser device including an ultraviolet laser and at least one reflective mirror including a substrate; generating a laser beam by the ultraviolet laser; and reflecting the laser beam toward a precursor film by at least one reflective mirror to manufacture an electronic component; A method for manufacturing an electronic component including is also disclosed. The mirror substrate can be manufactured from beryllium, silicon carbide, or an aluminum metal matrix composite.

[0015]

[0016] The precursor film may be an amorphous film. The laser beam can be directly reflected onto the precursor film to induce crystallization of the amorphous film (i.e., in an annealing process). Alternatively, the precursor film can be placed on a temporary substrate, and the laser beam can be reflected onto the precursor film through the temporary substrate to separate the precursor film from the temporary substrate (i.e., in a laser lift-off process). The electronic component can be used in an OLED display or an LTPS-LCD display. In some specific embodiments, the precursor film is an amorphous silicon film.

[0016]

[0017] Also, a method of using a display manufacturing apparatus, including reflecting an ultraviolet laser beam onto a silicon film with at least one reflective mirror including a substrate to manufacture an electronic component used in a panel display, the display manufacturing apparatus including an ultraviolet laser and at least one reflective mirror including a substrate. The above method is also disclosed. The mirror substrate can be manufactured from beryllium, silicon carbide, or an aluminum metal matrix composite.

[0017]

[0018] Here too, the silicon film may be an amorphous silicon film. The laser beam can be directly reflected onto the silicon film to induce crystallization of the silicon film (i.e., in the annealing process). Alternatively, the silicon film can be placed on a temporary substrate, and the laser beam can be reflected onto the silicon film through the temporary substrate to separate the silicon film from the temporary substrate (i.e., in the laser lift-off process). The electronic component can be used in an OLED display or an LTPS-LCD display.

[0018]

[0019] Also disclosed herein is an ultraviolet reflecting mirror including a mirror substrate; and an ultraviolet reflecting coating deposited on the surface of the mirror substrate. The mirror substrate can be made of beryllium, silicon carbide, or an aluminum metal matrix composite.

[0019]

[0020] Ribs for strengthening the mirror can be included on the back surface of the mirror substrate.

[0021] The present invention also relates to a method and process for manufacturing an aluminum metal matrix composite (MMC) for use as a substrate in the reflective mirror of the present invention. Generally, the manufacture of MMCs can include any suitable method such as powder metal manufacturing (such as powder metallurgy and high energy mixing processes, but not limited thereto) and casting (such as infiltration casting, but not limited thereto). For example, in certain embodiments, in the methods and processes disclosed herein, the mixing / blending of metal powders can be used. Suitable techniques for such mixing include ball milling, mechanical attritors, teamer mills, rotary mills, granulators, and other methods capable of imparting high energy mixing to powder components (such as metal powders, reinforcing particles). Alternatively, the MMC for the substrate can be manufactured by a casting process such as infiltration casting. Such methods and processes enable control over the interface conditions for subsequent mechanical performance or process requirements. As a result, the methods and processes of the present invention provide a cost-effective manufacturing technology capable of manufacturing multiple substrates at once.

[0020]

[0022] In the following, these and other non-limiting features of the present invention are disclosed in more detail.

[0023] The following is a brief description of the drawings, which are presented for the purpose of illustrating representative embodiments disclosed herein and not for the purpose of limiting the same.

Brief Description of the Drawings

[0021]

Figure 1

[0024] FIG. 1 is a cross-sectional view of an ultraviolet reflective mirror used in the formation of an electronic display according to multiple embodiments of the present invention. The mirror includes a mirror substrate and an ultraviolet reflective coating.

Figure 2

[0025] FIG. 2 is a view showing the processing of ribs on the back surface of the mirror substrate.

Figure 3

[0026] Figure 3 is a schematic diagram of an excimer laser device including a reflective mirror having a mirror substrate.

Figure 4

[0027] Figure 4 is a perspective view showing a process of forming a polysilicon film by scanning and irradiating an excimer laser beam on a silicon film.

Figure 5

[0028] Figure 5 is a cross-sectional view schematically showing a laminate from which a thin-film display device has been separated by a laser lift-off process using an excimer laser beam.

Figure 6A

[0029] Figure 6A is a cross-sectional view showing a transfer process for manufacturing a thin-film display device from the laminate of FIG. 5.

Figure 6B

Figure 7

[0030] Figure 7 is a graph showing the optical performance index (FoM) resonance frequency values for substrates of various materials in an excimer laser system beam line system. The y-axis represents the FoM value, which ranges from 0 to 14 at intervals of 2. The x-axis represents various substrate materials.

Figure 8

[0031] Figure 8 is a graph showing the optical performance index (FoM) self-weight deflection values for substrates of various materials in an excimer laser system beam line system. The y-axis represents the FoM value, which ranges from 0.000 to 0.060 at intervals of 0.010. The x-axis represents various substrate materials.

Figure 9

[0032] Figure 9 is a graph showing the optical performance index (FoM) steady-state thermal deformation coefficient values for substrates of various materials in an excimer laser system beam line system. The y-axis represents the FoM value, which ranges from 0.000 to 0.400 at intervals of 0.050. The x-axis represents various substrate materials.

Figure 10

[0033] Figure 10 is a graph showing the transient thermal deformation coefficient values of the optical performance index (FoM) for various material substrates in the excimer laser system beam line system. The y-axis represents the FoM value, ranging from 0.000 to 0.700 at intervals of 0.100. The x-axis represents various substrate materials.

DETAILED DESCRIPTION OF THE INVENTION

[0022]

[0034] A more complete understanding of the components, processes, and devices disclosed in this specification can be obtained by referring to the accompanying drawings. These drawings are merely schematic diagrams based on the convenience and ease of showing the present invention, and thus are not intended to show the relative sizes and dimensions of the device or its components, and / or to define or limit the scope of representative embodiments.

[0023]

[0035] Certain terms are used in the following description for clarity, but these terms are intended to refer only to the specific structures of the embodiments selected for illustration in the drawings and are not intended to define or limit the scope of the present invention. It should be understood that in the drawings and the following description, like numerals indicate components of like function.

[0024]

[0036] The singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise.

[0037] The terms "comprising", "including", "having", "possessing", "able to", "containing", and their variants used in this specification and the claims are intended to be non-limiting transitional phrases, words, or expressions that require the presence of the recited components / processes and tolerate the presence of other components / processes. However, such descriptions should also be construed as describing compositions or processes that "consist of" and "consist essentially of" the recited components / processes, such that the recited components / processes exist together with inevitable impurities that may result from them, and exclude other components / processes.

[0025]

[0038] The numerical values in the specification and claims of this application include values that are the same when rounded to the same number of significant digits, as well as values that differ from such values by less than the experimental error of normal measurement techniques of the type described herein for obtaining those values.

[0026]

[0039] All ranges disclosed in this specification include the indicated endpoints and can be combined independently (e.g., a range of "2 grams to 10 grams" includes the endpoints 2 grams and 10 grams, as well as all intermediate values).

[0027]

[0040] The term "about" can be used to include any numerical value that can be varied without changing the basic function of that value. When used with a range, "about" also discloses the range defined by the absolute values of the two endpoints; for example, "about 2 to about 4" also discloses the range of "2 to 4". The term "about" can refer to plus or minus 10% of the indicated number.

[0028]

[0041] As used herein, the term "ultraviolet light" refers to light having a wavelength of 10 nanometers (nm) to 400 nm.

[0042] Ultraviolet (UV) lasers, such as excimer lasers, are commonly used in processes and apparatuses for the manufacture of electronic devices and microelectronic devices. These devices include, but are not limited to, cellular phones or mobile phones, computer monitors, televisions, watches, etc. Various optical components are used in UV lasers to achieve desired characteristics such as output wavelength, beam steering. UV lasers, such as excimer lasers, rely on coated or uncoated optical components designed for use at specific excimer laser output wavelengths, the most common of which are 157 nm (F2), 193 nm (ArF), 24 8 nm (KrF), 308 nm (XeCl), and 353 nm (XeF) are included. Representative UV optical components include beam turning or steering mirrors, laser resonator optics, beam splitters, lenses, windows, and other components.

[0029]

[0043] Two representative processes for using UV lasers in the manufacture of electronic devices are excimer laser annealing (ELA) and laser lift-off (LLO). In ELA, an excimer laser is used to generate, for example, polysilicon films for thin-film transistors (TFTs) and capacitors used in electronic displays such as LTPS-LCD and / or OLED panels. Generally, an amorphous silicon film is polycrystallized by scanning and irradiating the exposed surface of the amorphous silicon film with an excimer laser beam, that is, by a heat treatment process. Among the polycrystallization methods, ELA is widely used. This is because this method enables polycrystallization at relatively low temperatures and can form polysilicon films with excellent properties including relatively high electron mobility.

[0030]

[0044] The LLO process generally refers to a method of separating a material from a substrate by irradiating an excimer laser at the material-substrate interface. For example, in the manufacture of a functional display film, first, a thin polymer film is deposited on a temporary glass carrier substrate. A circuit backplane (i.e., a matrix of TFTs) is constructed on the polymer layer, and subsequently, a display front plane including layers for electrodes and microcapsules is constructed. Next, during the LLO process, the excimer laser is irradiated at the polymer-substrate interface through the carrier glass substrate. As a result, only the polymer in direct contact with the glass substrate evaporates. The polymer film is peeled off from the hard glass substrate to form a thin, lightweight, and durable functional display is formed.

[0031]

[0045] For both ELA and LLO processes, one or more mirror-like reflective components can be used to vary the path of the excimer laser beam as desired. For example, the laser beam can be split or directed as needed. Beam steering is often required in ELA processes to ensure that the laser beam irradiates the exposed surface of the amorphous silicon film.

[0032]

[0046] Previously used mirrors in excimer lasers use quartz as the substrate material, on which a UV reflective coating is applied. However, quartz has low rigidity and low thermal conductivity, and tends to prevent rapid temperature homogenization throughout the substrate. Without the ability to efficiently homogenize temperature, mirrors made from quartz have an increased likelihood of mirror distortion resulting from the thermal gradient generated by the irradiation of the excimer laser onto the mirror.

[0033]

[0047] Beryllium is a metal that has highly desirable properties for application in reflective components such as mirrors. These include high rigidity (Young's modulus = 303 GPa), low density (1.85 g / cc), high elastic modulus (130 GPa), high specific heat (1925 J / kg·K), high thermal conductivity (216 W / m·K), low linear thermal expansion rate (11.4×10 6 / °K), and a favorable thermal diffusivity (0.21 m² / h). In contrast, quartz has lower rigidity (Young's modulus = 74.5 GPa), higher density (2.2 g / cc), lower specific heat (741 J / kg·K), and lower thermal conductivity (1.36 W / m·K). Due to these properties, beryllium is potentially a better substrate material than quartz by reducing the optical distortion of the reflective coating due to thermal degradation.

[0034]

[0048] The higher specific heat of beryllium means that for any given mass and temperature change, beryllium can absorb more heat compared to quartz. On an equal weight basis, beryllium has the highest thermal conductivity among all metals, and its coefficient of thermal expansion is very close to those of stainless steel, titanium, nickel alloys, cobalt alloys, and other common structural materials. This combination of thermal properties gives beryllium better stability in mirrors over a temperature range from about -250°C to about 275°C. The high thermal diffusivity of beryllium ensures rapid temperature equalization, which tends to eliminate or greatly reduce the distortion that can result from thermal gradients.

[0035]

[0049] In certain embodiments, the mirror substrate is fabricated from an aluminum-beryllium composition that combines the advantages of both beryllium and aluminum. The aluminum-beryllium composition exhibits an elastic modulus-to-density ratio that is four times higher than that of aluminum or steel. The thermal conductivity of the aluminum-beryllium composition can be increased to about 210 W / mK (watts per meter kelvin), which is about 25% higher than that of typical aluminum metal matrix composites such as Al6061.

[0036]

[0050] The apparatus used in the steering of ultraviolet (UV) lasers during these manufacturing processes typically includes a series of prisms and mirrors that ensure coverage of the entire amorphous silicon surface. The present invention relates to a mirror for use in reflecting UV laser light. This mirror includes a beryllium substrate and a UV reflective coating. These mirrors can be used in UV excimer laser annealing and laser lift-off processes and, preferably, have improved thermal stress and increased rigidity, so that the laser processing speed can be increased and the downtime between maintenance cycles can be reduced.

[0037]

[0051] Referring to FIG. 1, a representative beryllium-based mirror 124 is shown. The mirror includes a substrate having a front surface 130 and a rear surface 131 128. An ultraviolet reflective layer 135 is present on the front surface 130. The mirror substrate can be manufactured from beryllium, silicon carbide, or an aluminum metal matrix.

[0038]

[0052] Generally, in embodiments where the mirror substrate is made from beryllium, the beryllium mirror substrate can be made from any pure beryllium or an alloy of beryllium. Beryllium is available in several grades suitable for the substrate 128. These optical grades include: O-50 (minimum Be content of 99.5%, maximum BeO content of 0.5%); S-65 (minimum Be content of 99%, maximum BeO content of 1%); I-70 (minimum Be content of 99%, maximum BeO content of 0.7%); S-200 (minimum Be content of 98.5%, maximum BeO content of 1.5%); I-220 (minimum Be content of 98%, maximum BeO content of 2.2%); and I-250 (minimum Be content of 97.5%, minimum BeO content of 2.5%).

[0039]

[0053] Substantially all beryllium substrates are products derived from powder metallurgy. Beryllium powder is prepared by chipping previously cast ingots and mechanically grinding the chips to an appropriate particle size distribution for consolidation into billets of essentially full density by powder metallurgy techniques. The mechanical grinding system used to produce beryllium powder of a given particle size distribution affects the properties of the fully dense objects produced using the powder. This is most pronounced at the level of the minimum tensile elongation that can be produced in any direction at room temperature.

[0040]

[0054] Then, the beryllium powder for manufacturing the substrate 128 may have a particle size of less than 1 micron. In other embodiments, the beryllium-containing powder may have a particle size of less than 200 microns. In certain embodiments, the beryllium-containing powder may have a particle size of from about 10 nanometers to about 200 microns, such as from about 5 to 40 microns. The particle size is D 50 , or the diameter at which 50% cumulative percentage of the particles is given on a volume basis. In other words, 50% of the particles of a given volume have a smaller diameter and 50% of the particles have a larger diameter.

[0041]

[0055] In some embodiments, the substrate of the reaction mixture used to form the beryllium substrate 128 consists essentially of only beryllium powder. In other embodiments, the reaction mixture further comprises at least one alloying element that is not beryllium. Non-limiting examples of alloying elements include Ti, Co, Ni, Cu, Pd, Au, Nb, Ag, Ta, V, Cr, Mn, Fe, Mo, W, Re, Zr, Hf, Y, La, Ce, Th, U, Np, Pu, Am, Ca, and Mg. In certain embodiments, the alloying element is selected from the group consisting of titanium, zirconium, niobium, tantalum, hafnium, and molybdenum.

[0042]

[0056] In some embodiments, the reaction mixture can include 50 to 99.99 wt% beryllium powder and 0.01 to 50 wt% of at least one alloying element. The alloying element is intended to react with the beryllium powder.

[0043]

[0057] In other embodiments, the mirror substrate is manufactured from an aluminum metal matrix composite (MMC). Using MMC for the mirror substrate can be advantageous because the elastic modulus and coefficient of thermal expansion of the MMC can improve the figure of merit (FoM) value of the substrate (i.e., the value used to characterize the performance of the substrate relative to another substrate).

[0044]

[0058] The MMC of the present invention is a composite material including a metal matrix and reinforcing particles dispersed within the metal matrix. The metal matrix phase is usually continuous, while the reinforcing particles usually form a dispersed phase within the metal matrix phase. When it is desirable for the mirror substrate 128 to be an MMC, appropriate reinforcing particles can be added to the remaining volume together with the metal powder, and the MMC can be formed by compression. In certain embodiments, the compression can be performed by hot isostatic pressing (HIP). The metal powder and the reinforcing particles should be mixed together by high-energy techniques to distribute the reinforcing particles throughout the resulting metal matrix. Suitable techniques for this mixing include ball milling, mechanical attritors, attrition mills, rotary mills, granulators, and other methods that impart high-energy mixing to the powder components. Mechanical alloying should be completed in an inert atmosphere using, for example, nitrogen or argon gas to avoid excessive oxidation of the powder. The processing parameters should be selected to achieve a uniform distribution of the reinforcing particles within the metal matrix. The powder from the high-energy mixing stage can be degassed to remove residual moisture from the powder surface, which can be completed at 120°C to 500°C. The metal matrix phase is usually continuous, while the reinforcing particles usually form a dispersed phase within the metal matrix phase. When it is desirable for the mirror substrate 128 to be an MMC, appropriate reinforcing particles can be added to the remaining volume together with the metal powder, and the MMC can be formed by compression. In certain embodiments, the compression can be performed by hot isostatic pressing (HIP). The metal powder and the reinforcing particles should be mixed together by high-energy techniques to distribute the reinforcing particles throughout the resulting metal matrix. Suitable techniques for this mixing include ball milling, mechanical attritors, attrition mills, rotary mills, granulators, and other methods that impart high-energy mixing to the powder components. Mechanical alloying should be completed in an inert atmosphere using, for example, nitrogen or argon gas to avoid excessive oxidation of the powder. The processing parameters should be selected to achieve a uniform distribution of the reinforcing particles within the metal matrix. The powder from the high-energy mixing stage can be degassed to remove residual moisture from the powder surface, which can be completed at 120°C to 500°C.

[0045]

[0059] Generally, the production of MMCs can include any suitable methods such as powder metal production (such as powder metallurgy and high-energy mixing processes discussed above (but not limited to these)), and casting (such as infiltration casting (but not limited to these)).

[0046]

[0060] One suitable infiltration casting process is liquid metal infiltration. Liquid metal infiltration generally refers to a process of melting one or more raw metal materials at the required temperature, flowing or injecting them into a porous preform, and solidifying them within and around the preform. This process can be regarded as a non-pressure infiltration casting method.

[0047]

[0061] Other non-limiting examples of infiltration casting techniques suitable for manufacturing the MMC substrates described herein include squeeze casting, pressure casting, die casting, gravity casting, etc. For example, the MMC substrates of the present invention can be formed using a representative squeeze casting technique. Squeeze casting is generally based on pressure solidification. In the squeeze casting process, a solid blank can first be preheated to a desired temperature and placed in a die, or alternatively, the solid blank can be preheated within the die. Next, one or more molten base metal materials (e.g., aluminum, aluminum alloy, and MMC) are injected into the die containing the solid blank. The die is placed on the bed of a hydraulic press. The press is advanced to close the mold cavity and pressurize the liquid metal. The pressure is maintained until solidification of the substrate is complete. Next, the press can be opened and the substrate can be ejected. Squeeze casting results in the formation of high-quality near-net-shape castings with a smooth surface and excellent microstructure without pores due to the high pressure used during solidification.

[0048]

[0062] In some embodiments, the metal powder may contain aluminum or an aluminum alloy in a metal matrix. The aluminum alloy may contain at least one element selected from chromium, copper, lithium, magnesium, nickel, and silicon. It should be noted that as used herein, "aluminum" refers to aluminum having only the impurities present, i.e., pure aluminum, whereas the term "aluminum alloy" as used herein refers to an alloy of aluminum having a significant amount of other elements.

[0049]

[0063] The aluminum alloy used in the aluminum metal matrix composite material may be any 2xxx series aluminum alloy having copper as the main alloying element, any 5xxx series aluminum alloy having magnesium as the main alloying element, any 6xxx series aluminum alloy having magnesium and silicon as the main alloying elements, any 7xxx series aluminum alloy having zinc as the main alloying element, or any 8xxx series aluminum alloy having other elements (such as iron and silicon) as the main alloying element. The specific aluminum alloy intended to be used in the present invention Examples of the specific aluminum alloys intended to be used include 2009, 2124, 2618, 6061, 6063, and 6082 aluminum alloys having the following compositions (weight % for each element).

[0050]

Table 1

[0051]

[0064] In certain embodiments, the reinforcing particles may comprise at least one ceramic material selected from carbides, oxides, silicides, borides, and nitrides. Specific examples of the reinforcing particles include silicon carbide, titanium carbide, boron carbide, silicon nitride, titanium nitride, zirconium oxide, aluminum oxide, aluminum nitride, and titanium oxide. The reinforcing particles may have an average particle size (D50) in the range of 0.1 micrometer (μm) to 0.5 μm, for example, about 0.3 μm. The average particle size is defined as the particle size at which 50% (by volume) of the total volume of the particles is accumulated. In other words, 50% of the particles have a diameter larger than the average particle size, and 50% of the particles have a diameter smaller than the average particle size.

[0052]

[0065] In a further embodiment, the aluminum metal matrix composite also includes beryllium. In this particular case, since beryllium has a melting point much higher than that of aluminum, beryllium can be regarded as reinforcing particles within the metal matrix formed by aluminum. Other reinforcing particles as described above may also be present in this aluminum-beryllium metal matrix composite.

[0053]

[0066] In certain embodiments, the MMC is a 6061, 6063, 6082, 2009, 2618, or 2124 aluminum alloy reinforced with about 15 vol% to about 40 vol% silicon carbide. Other reinforcing particles can also be used instead of silicon carbide.

[0054]

[0067] In a more specific embodiment, the MMC can be manufactured from a 6061 aluminum alloy reinforced with 40 vol% silicon carbide particles. The 6061 aluminum alloy reinforced with 40 vol% silicon carbide particles is commercially available from Materion under the trade name SupremEX 640. The physical properties of the 6061 aluminum alloy reinforced with 40 vol% silicon carbide particles are as follows.

[0055]

Table 2

[0056]

[0068] In other specific embodiments, the MMC can be manufactured from a 6061 aluminum alloy reinforced with 20 vol% silicon carbide particles. The physical properties of the 6061 aluminum alloy reinforced with 20 vol% silicon carbide particles are as follows.

[0057]

Table 3

[0058]

[0069] In a more specific embodiment, the MMC can be manufactured from a 2124 aluminum alloy reinforced with 25 vol% silicon carbide particles. The 2124 aluminum alloy reinforced with 25 vol% silicon carbide particles is commercially available from Materion under the trade name Supremex 225. The physical properties of the 2124 aluminum alloy reinforced with 25 vol% silicon carbide particles include the following. The physical properties of the 2124 aluminum alloy reinforced with 25 vol% silicon carbide particles include the following.

[0059]

Table 4

[0060]

[0070] In a specific embodiment, the MMC can be manufactured from a 2124 aluminum alloy reinforced with 17 vol% silicon carbide particles. The 2124 aluminum alloy reinforced with 17 vol% silicon carbide particles is commercially available from Materion under the trade name Supremex 217XG. The physical properties of the 2124 aluminum alloy reinforced with 17 vol% silicon carbide particles include the following.

[0061]

Table 5

[0062]

[0071] In other embodiments, the MMC can be manufactured from a 6063, 6082, 2009, or 2618 series aluminum alloy reinforced with about 10 vol% to about weight volume% silicon carbide particles, such as about 15 vol% to about 30 vol%, or about 20 vol% to about 25 vol% silicon carbide particles.

[0063]

[0072] In some specific embodiments, the MMC is manufactured from a 2009 series aluminum alloy reinforced with 15 vol% silicon carbide particles. The physical properties of the 2009 series aluminum alloy reinforced with 15 vol% silicon carbide particles include the following.

[0064]

Table 6

[0065]

[0073] In still other embodiments, the mirror substrate can be made from 100% silicon carbide, also known as carborundum (not in particulate form). Such a substrate can be produced by sintering SiC particles together or by other means known in the art.

[0066]

[0074] In still other embodiments, the mirror substrate is made from an aluminum-beryllium composition. The aluminum-beryllium composition combines the high modulus of elasticity and low density characteristics of beryllium with the manufacturing and mechanical property behavior of aluminum. The aluminum-beryllium composition provides excellent specific stiffness and machining characteristics. The aluminum-beryllium metal matrix composite does not exhibit sensitivity to machining damage and does not require post-machining etching like beryllium. When beryllium is alloyed with aluminum to form a metal matrix composite, it provides a combination of high specific modulus, low density, and high heat capacity compared to common structural materials.

[0067]

[0075] The aluminum-beryllium composition can contain from about 50 wt% to 99.99 wt% beryllium and from 0.01 to about 50 wt% aluminum. In some embodiments, the aluminum-beryllium composition contains at least 60 wt% beryllium and at least 30 wt% aluminum. By varying the ratio of beryllium to aluminum, the physical, thermal, and mechanical properties of the aluminum-beryllium composition can be varied. The resulting alloy is a mixture of aluminum and beryllium that retains the properties of the metals and, in this case, contains a mixture of multiple metal phases (due to the large difference in melting points between aluminum and beryllium).

[0068]

[0076] One example of an aluminum-beryllium composition is manufactured using about 62 wt% beryllium and about 38 wt% aluminum, which is in the form of a metal matrix composite. Such a combination is commercially available from Materion under the trade name AlBeMet® 162. The physical properties of AlBeMet® 162 include the following.

[0069]

Table 7

[0070]

[0077] Figure 2 is a view showing the back surface of the mirror substrate. In this regard, the mirror substrate is typically formed as a solid blank having the overall desired shape of the mirror. Referring back to Figure 1, the blank has a front surface 130 and a back surface 131, and a thickness 133 between the two surfaces. The blank can be machined with various cutting tools to form an open-backed mirror having a smooth surface and ribs 137 that support the surface as shown in Figure 2.

[0071]

[0078] The mirror substrate blank can be manufactured by performing hot isostatic pressing (HIP) of the powder discussed above, followed by machining to obtain the desired shape of the mirror substrate. In HIP, the metal powder is injected into a metal can or container having an appropriate or desired shape. The container is evacuated by degassing at a temperature higher than about 670 °C, and then the degassing tube is sealed. Next, the container is placed inside a HIP autoclave unit, which is pressurized to a height of about 15 ksi with a gas (e.g., argon) and heated to a temperature of about 1250 °C or less. The mirror blank can be formed to a density of nearly 100% due to the ability of the HIP press to consolidate the powder within the sealed and vacuum-degassed container. Next, the container can be removed from the HIP autoclave and a further annealing process can be performed. The resulting blank has the same shape as the container.

[0072]

[0079] The HIP process advantageously produces solid blanks without voids. Further, since HIP applies pressure in all directions, the non - directionality of the final product is better maintained than in uniaxial vacuum hot pressing. HIP can generally be used to produce mirror substrate blanks having relatively simple shapes.

[0073]

[0080] Mirror substrate blanks can also be produced by cold isostatic pressing. In some embodiments, the material is produced by a gas atomization process that produces spherical powders with a fine microstructure. The powders are densified by three consolidation processes, each resulting in different mechanical properties. In some embodiments, isotropic spherical aluminum - beryllium is cold isostatically pressed (CIP) into a semi - dense billet, and then the billet is canned for subsequent extrusion to produce an extrusion bar.

[0074]

[0081] Mirror substrate blanks can also be produced by performing a near - net - shape forming (NNS) process and then machining the NNS blank. The NNS process can include a combination of hot and cold isostatic pressing (HIP and CIP) and vacuum sintering. In the CIP process, the near - net - shape blank is produced from metal powder by using a flexible polymer bag and shaping it to the desired blank shape. The CIP process is useful for parts having more complex shapes. Vacuum sintering is performed following the CIP process, and HIP is performed if a density close to 100% is required. Sintering seals the surface - connected pores, so a container for the HIP process is not required. If necessary, the blank can be hot - formed into the final desired shape. The blank can be hot - formed into the final desired shape.

[0075]

[0082] Regardless of whether it is produced by HIP or NNS, the final conversion of the mirror substrate blank to the ultraviolet - reflecting mirror 124 generally involves three basic steps: machining the mirror substrate 128, polishing the front face 130 of the mirror substrate, and coating the surface with an ultraviolet - reflecting material 135.

[0076]

[0083] Any machining operation using a cutting tool material should be performed without applying stress to the workpiece (i.e., the mirror substrate 128). Thus, in some embodiments, a low-stress machining technique using gas bearings within a machine tool is used to achieve a high level of machining accuracy. Using these low-stress machining techniques, the mirror substrate surface 130 can be finished to a low surface roughness of about 15 angstroms (Å) (root mean square (rms)).

[0077]

[0084] Next, the ultraviolet reflective layer 13 is applied or formed on the surface 130 of the mirror substrate 128. In some embodiments, a base material composed of a metal such as nickel or a nickel alloy is deposited on the uncoated mirror substrate. One or more layers of an ultraviolet reflective material are deposited on this base layer. This reflective coating may be a dielectric such as a layer formed from a combination of hafnium oxide (HfO2) and silicon dioxide. Another reflective coating may be of the "enhanced aluminum" type that applies alternating layers of (i) an aluminum metal binder and hafnium oxide, and (ii) an aluminum metal binder and silicon dioxide to the mirror substrate.

[0078]

[0085] Next, referring to FIG. 3, a laser annealing apparatus 100 is shown. The apparatus 100 includes a laser beam generator 110 that generates a raw laser beam LB that passes through an optical system 120. The laser beam LB is generally an excimer laser, which is a form of laser that can emit ultraviolet light having a wavelength between 10 nanometers and 400 nanometers (nm). An excimer laser typically uses a combination of a rare gas (argon, krypton, or xenon) and a reactive gas (fluorine or chlorine). Under appropriate conditions of electrical stimulation and high pressure, laser light in the ultraviolet range is generated.

[0079]

[0086] The optical system 120 can include other optical components such as a beam homogenizer or beam expander 122, a reflection mirror 124, and a focusing lens 126. A beam splitter can also be used. Depending on the operation and arrangement of the components within the device, one or more of these components can be present. Using these optical components, the laser beam LB can be split into a plurality of linear laser beams, and then homogenized and overlapped (focused) to finally form a single linear laser beam having a desired beam width and beam length. Note that the optical system 120 is shown functionally divided in this way only for convenience of explanation. The optical system 120 can generally include any optical component that can homogenize or expand the energy distribution of the laser beam LB.

[0080]

[0087] The mirror 124 of the optical system 120 changes the path of the laser light generated from the laser beam generation unit 110 in a direction different from the original path of the laser beam LB. As shown in FIG. 3, the mirror 124 changes the path of the laser beam LB in a direction perpendicular to the original laser beam path. In other words, the mirror 124 reflects or directs the laser beam to project it onto the focusing lens 126 so that the laser beam irradiates the exposed surface of the substrate 140 used in the manufacture of the electronic display. The mirror 124 can be connected to a motor (not shown) and a drive system that enable changing the position of the mirror with respect to the laser beam generator 110.

[0081]

[0088] The focusing lens 126 focuses the split linear laser beam to form a single linear laser beam. Preferably, the split linear laser beam is focused on the exposed upper surface of the substrate 140. That is, the split linear laser beams are overlapped with each other to form a single linear laser beam. A cylindrical lens can be used as the focusing lens 126. After irradiating the single linear laser beam output from the optical system 120 onto the substrate 140, the linear laser beam scans the exposed upper surface of the substrate 140 by moving it in a direction perpendicular to the longitudinal direction of the linear laser beam at a fixed scanning pitch. Alternatively, the stage 150 for holding the substrate 140 can be moved in a direction opposite to the direction in which the linear laser beam moves. In some embodiments, as a result of irradiating the output laser beam onto the exposed surface of the substrate 140, the amorphous silicon thin film is annealed to generate a polysilicon film. In other words, the polysilicon film is formed by excimer laser annealing (ELA). More generally, an amorphous film can be formed from a precursor film by excimer laser annealing.

[0082]

[0089] Figure 4 shows a perspective view of a process for forming a polysilicon film used in the manufacture of an electronic display such as an organic light emitting diode display. The polysilicon film is formed using an ELA apparatus that scans and irradiates an excimer laser beam in accordance with the embodiment of FIG. 3 described above. As shown in FIG. 4, the electronic display includes a substrate body 140, a buffer layer 142 formed on the substrate body 140, and an amorphous film 144 formed on the buffer layer 142. The substrate body 140 is formed as an insulating substrate manufactured from glass, quartz, ceramic, plastic, etc., or a flexible substrate manufactured from plastic. The buffer layer 142 prevents the intrusion of unnecessary elements such as impurity atoms or moisture and planarizes the surface. However, the buffer layer 142 is not necessarily required and can be omitted. The amorphous film 144 is generally used to manufacture a semiconductor layer (not shown) included as part of a thin film transistor (not shown). The amorphous film 144 is formed by scanning and irradiating a laser beam LB on a precursor film (not shown). In order to manufacture a silicon film, an amorphous silicon film can be heat-treated before laser irradiation in order to form a microcrystalline silicon film.

[0083]

[0090] As shown here, in order to polycrystallize a relatively large area, the laser beam LB can be scanned and irradiated on the amorphous silicon film two or more times. The laser beam LB can be scanned and irradiated so as to partially overlap in the width direction for process tolerance. As shown here, the laser beam LB is advanced in the direction of the arrow to form two single irradiation regions SS and a double irradiation region DS showing the overlap of the laser scan. The polysilicon film 144 can be divided into a single irradiation region SS where the laser beam LB is irradiated once and a double irradiation region DS where the laser beam LB is irradiated twice.

[0084]

[0091] Furthermore, when the dual irradiation region DS receives a different laser energy from the single irradiation region SS, or when the desired energy distribution profile of the linear laser beam changes (for example, the thickness of the substrate or the amorphous silicon film changes during annealing), an adjustment device for adjusting the shape of the linear laser beam and regulating the energy distribution profile can be included in the device 100 of FIG. 3. In particular, the device 100 can include a focusing lens adjustment device (not shown) that can change the vertical distance (i.e., closer or farther from the mirror 124) and the rotation angle of the focusing lens 126. Thus, the desired energy distribution profile of the laser beam can be changed, but the desired energy distribution profile of the laser beam can still be obtained by using the focusing lens adjustment device without the need to reset the optical system 120.

[0085]

[0092] The reflective mirror of the present invention can be used in other electronic display forming processes that require the use of a laser, such as, for example, a laser lift-off (LLO) process. In LLO, a precursor film is deposited on a temporary substrate, and other processing operations and structures are created on the surface opposite the thin film. Next, a laser beam is induced through the temporary substrate and irradiated onto the substrate-film interface. Thereby, the precursor film can be removed from the temporary substrate (i.e., the film is "lifted off" from the substrate), and the precursor thin film can be transferred to a permanent substrate having desired characteristics. The reflective mirror of the present invention can also be used in other systems such as UV lithography, ophthalmic surgery, and dental surgery systems in addition to ELA or LLO.

[0086]

[0086]

[0093] Referring to FIG. 5, a laminate suitable for LLO processing is shown. The laminate of FIG. 5 includes a thin film 244 formed on a temporary substrate 240. The interface between the thin film 244 and the temporary substrate 240 is indicated by reference numeral 242. The interface 242 may simply be a part of the thin film 244 or may be a layer formed of a sacrificial material that can be decomposed by an excimer laser.

[0087]

[0094] The temporary substrate 240 is formed from a material having durability in a high-temperature film-forming process for forming a desired thin film 244. The temporary substrate 240 can be formed from a material having a bandgap energy greater than the bandgap energy corresponding to the wavelength of the laser beam so that the laser beam can pass through the temporary substrate 240. The temporary substrate 240 may be a transparent substrate. The temporary substrate 240 can be formed of any one of sapphire, quartz, glass, magnesium oxide (MgO), lanthanum aluminate (LaAlO3), fused silica, or zirconia.

[0088]

[0095] To remove the thin film 244, as shown in FIG. 3, the laser energy can be focused onto the interface 242 using the optical system 120 (including the beam homogenizer or expander 122, the beryllium mirror 124, and the focusing lens 126) described above.

[0089]

[0096] The thin film 244 has a structure used to form a functional unit of a desired electronic display device. The thin film 244 can be formed of an inorganic material such as a semiconductor or polysilicon, or a metal. Alternatively, the thin film 244 can be formed of amorphous silicon or polysilicon for a display device. More generally, this thin film is called a precursor film.

[0090]

[0097] FIGS. 6A and 6B are cross-sectional views showing an example of a transfer process for manufacturing a display device using LLO. At the first position shown in FIG. 6A, the interface 242 is targeted by the laser device 100 so that the thin film 244 is separated from the temporary substrate 240. At the same time, the thin film 244 can be brought into close contact with and temporarily adhered to the circumferential surface of the transfer roll 250. This process is performed on one side (here the bottom) of the transfer roll.

[0091]

[0098] At the same time, as shown in FIG. 6B, on the opposite side of the transfer roll, the permanent substrate 260 is run, and the thin film 244 is transferred from the transfer roll 250 to the surface of the permanent substrate 260 at the second position of the transfer roll. Here, the permanent substrate 260 and the thin film 244 constitute a display device. If necessary, an adhesive layer 270 can be further coated on the permanent substrate 260 to strengthen the bond between the permanent substrate 260 and the thin film 244.

[0092]

[0099] Using aluminum MMC or silicon carbide as the mirror substrate in the ultraviolet reflecting mirror of such a manufacturing apparatus provides improved performance that surpasses that of conventional fused silica-based mirrors and meets increased production requirements. For example, FIGS. 7 to 10 show the optical FoM values (i.e., values used to characterize the performance of various substrate materials relative to each other) including substrates formed from M MC or silicon carbide and fused silica-based substrates. In particular, in FIGS. 7 to 10, bar (1) represents sintered silicon carbide; bar (2) represents an aluminum metal matrix composite material commercially available under the trade name Supremex® 640XA from Materion ; bar (3) represents a metal matrix composite material of aluminum and 30 volume% silicon carbide; bar (4) represents fused silica; bar (5) represents molybdenum; bar (6) represents a 6061 aluminum alloy; bar (7) represents tungsten.

[0093]

[0100] Figure 7 shows the optical FoM resonance frequency values. In Figure 7, higher FoM resonance frequency values are desired for the substrate. Thus, as shown, the desirability of the substrate generally decreases from left to right. The thick horizontal line on the graph of Figure 7 represents the FoM resonance frequency value of fused silica (i.e., bar (4)), which is preferably the minimum value to be achieved (i.e., a FoM value of at least 6). As can be seen in Figure 7, the molybdenum, aluminum 6061, and tungsten substrates did not achieve this preferred FoM value. In contrast, substrates formed from sintered silicon carbide or aluminum-based MMC achieved the preferred FoM value. In other words, the sintered silicon carbide and MMC substrates functioned much better than the fused silica-based substrate, i.e., the sintered silicon carbide was superior to all other substrates.

[0094]

[0101] Figure 8 shows the optical FoM self-weight deflection values. In Figure 8, lower FoM self-weight deflection values are desired for the substrate. Thus, as shown, the desirability of the substrate also generally decreases from left to right here. The thick horizontal line on the graph of Figure 8 represents the FoM self-weight deflection value of fused silica (i.e., bar (4)), which is preferably the maximum value to be achieved (i.e., a FoM value less than 0.030). As can be seen in Figure 8, the molybdenum, aluminum 6061, and tungsten substrates did not achieve this preferred FoM value. In contrast, substrates formed from sintered silicon carbide or aluminum-based MMC achieved the preferred FoM value. In other words, the sintered silicon carbide and MMC substrates also functioned much better than the fused silica-based substrate here, i.e., the sintered silicon carbide was superior to all other substrates.

[0095]

[0102] Figure 9 shows the optical FoM steady-state thermal deformation coefficient values. In Figure 9, lower FoM steady-state thermal deformation coefficient values are desired for the substrate. Thus, as shown, the desirability of the substrate generally decreases from left to right here as well. The thick horizontal line on the graph of Figure 9 represents the FoM steady-state thermal deformation coefficient value of fused silica (i.e., bar (4)), which is preferably the maximum value to be achieved (i.e., a FoM value less than 0.350). As can be seen in Figure 9, all other substrates achieved this preferred FoM value. In other words, the sintered silicon carbide and MMC substrates functioned much better here than the fused silica-based substrate, i.e., the sintered silicon carbide was superior to all other substrates.

[0096]

[0103] Finally, Figure 10 shows the optical FoM transient thermal deformation coefficient values. In Figure 10, lower FoM transient thermal deformation coefficient values are desired for the substrate. Thus, as shown, the desirability of the substrate generally decreases from left to right here as well. The thick horizontal line on the graph of Figure 10 represents the FoM transient thermal deformation coefficient value of fused silica (i.e., bar (4)), which is preferably the maximum value to be achieved (i.e., a FoM value less than 0.600). As can be seen in Figure 10, all other substrates achieved this preferred FoM value. In other words, the sintered silicon carbide and MMC substrates functioned much better here than the fused silica-based substrate, i.e., the sintered silicon carbide was superior to all other substrates.

[0097]

[0104] Thus, the substrate of the present invention is preferably made from a material having (i) at least 6 optical FoM resonance frequency values with respect to the fused silica substrate, (ii) an optical FoM self weight removal value of less than 0.030 with respect to the fused silica substrate, (iii) an optical FoM steady-state thermal strain coefficient value of less than 0.350 with respect to the fused silica substrate, and (iv) an optical FoM transient thermal strain coefficient value of less than 0.600 with respect to the fused silica substrate.

[0098]

[0105] Using the disclosed beryllium-containing material for the substrate in the ultraviolet reflective mirror of such a manufacturing apparatus provides improved performance over previous quartz-based mirrors and meets increased production requirements. For example, in addition to the higher rigidity of beryllium, the ability of beryllium to dissipate heat faster than quartz allows for an increase in the raster processing speed of the laser that utilizes the mirrors of the present invention without affecting the resolution. Accordingly, throughput can be increased, larger displays can be manufactured without the damage that can occur in quartz mirrors due to the long-term thermal stress inherent in the manufacture of larger displays, and downtime for maintenance of the manufacturing apparatus can be reduced.

[0099]

[0106] It is apparent that the features disclosed above and other features and alternative forms of the applications, or alternatives thereof, can be combined in many other different systems or applications. Various unforeseen or unanticipated substitutions, modifications, variations, or improvements therein can subsequently be made by those skilled in the art, and these are also intended to be encompassed by the following claims. Specific embodiments of the present invention are as follows. [Embodiment 1] An ultraviolet laser; and At least one reflective mirror configured to reflect a laser beam generated from the ultraviolet laser; Including; The at least one mirror includes a mirror substrate made of beryllium, an aluminum metal matrix composite material, or silicon carbide, an apparatus. [Embodiment 2] The mirror substrate is (a) O-50 having a minimum Be content of 99.5% and a maximum BeO content of 0.5%; (b) S-65 having a minimum Be content of 99% and a maximum BeO content of 1%; (c) I-70 having a minimum Be content of 99% and a maximum BeO content of 0.7%; (d) S-200 having a minimum Be content of 98.5% and a maximum BeO content of 1.5%; (e) I-220 having a minimum Be content of 98% and a maximum BeO content of 2.2%; and (f) I-250 having a minimum Be content of 97.5% and a maximum BeO content of 2.5%; The apparatus according to Embodiment 1, comprising a grade of beryllium selected from at least one of [Embodiment 3] The mirror substrate includes beryllium and at least one alloying element selected from Al, Ti, Co, Ni, Cu, Pd, Au, Nb, Ag, Ta, V, Cr, Mn, Fe, Mo, W, Re, Zr, Hf, Y, La, Ce, Th, U, Np, Pu, Am, Ca, and Mg, the apparatus according to Embodiment 1. [Embodiment 4] The mirror substrate includes about 50 wt% to about 99.99 wt% beryllium and about 0.01 wt% to about 50 wt% of the at least one alloying element, the apparatus according to Embodiment 3. [Embodiment 5] The mirror substrate is made of silicon carbide or an aluminum metal matrix composite material, (i) An optical performance index (FoM) resonance frequency value of at least 6 for a fused silica substrate; (ii) An optical FoM self-weight deflection value of less than 0.030 for a fused silica substrate; (iii) An optical FoM steady-state thermal deformation coefficient value of less than 0.350 for a fused silica substrate; and (iv) An optical FoM transient thermal deformation coefficient value of less than 0.600 for a fused silica substrate; The apparatus according to Embodiment 1, having [Embodiment 6] The mirror substrate is made of an aluminum alloy and an aluminum metal matrix composite material of one or more reinforcing particles, the apparatus according to Embodiment 1. [Embodiment 7] The apparatus according to aspect 6, wherein the one or more reinforcing particles include at least one ceramic material selected from the group consisting of carbides, oxides, silicides, borides, and nitrides. [Aspect 8] The apparatus according to aspect 6, wherein the one or more reinforcing particles include silicon carbide. [Aspect 9] The apparatus according to aspect 6, wherein the metal matrix composite material includes 6061, 6063, 6082, 2009, 2618, or 2124 aluminum alloy reinforced with about 15 vol% to about 40 vol% of silicon carbide. [Aspect 10] The apparatus according to aspect 1, wherein the mirror substrate is manufactured from an aluminum-beryllium composition in the form of an alloy or a metal matrix composite material. [Aspect 11] The apparatus according to aspect 10, wherein the aluminum-beryllium composition includes at least 60 wt% of beryllium and at least 30 wt% of aluminum. [Aspect 12] The apparatus according to any one of aspects 1 to 11, wherein the at least one reflective mirror further includes an ultraviolet reflective coating deposited on the mirror substrate. [Aspect 13] The apparatus according to aspect 12, wherein the ultraviolet reflective coating includes a base layer deposited on the mirror substrate and at least one dielectric layer on the base layer. [Aspect 14] The ultraviolet reflective coating is a layer manufactured from a combination of hafnium dioxide (HfO 2 ) and silicon dioxide (SiO 2 ), or the ultraviolet reflective coating is formed from alternating layers of (i) a coating formed from aluminum and hafnium dioxide, and (ii) a coating formed from aluminum and silicon dioxide. The apparatus according to aspect 12. [Aspect 15] The apparatus according to any one of aspects 1 to 14, further including a beam homogenizer, a beam expander, a focusing lens, or a beam splitter. [Aspect 16] A method for manufacturing an electronic component, comprising: receiving an ultraviolet laser device including an ultraviolet laser and at least one reflective mirror including a mirror substrate; generating a laser beam by the ultraviolet laser; and reflecting the laser beam toward a precursor film with the at least one reflective mirror to manufacture the electronic component. The method includes wherein the mirror substrate is manufactured from beryllium, an aluminum metal matrix composite material, or silicon carbide. [Aspect 17] The method according to aspect 16, wherein the precursor film is an amorphous film. [Aspect 18] The method according to aspect 17, wherein the laser beam is directly reflected onto the precursor film to induce crystallization of the amorphous film. [Aspect 19] The method according to aspect 17, wherein the precursor film is placed on a temporary substrate, and the laser beam is reflected onto the precursor film through the temporary substrate to separate the precursor film from the temporary substrate. [Aspect 20] The method according to aspect 16, wherein the electronic component is used in an OLED display or an LTPS-LCD display. [Aspect 21] A method of using a display manufacturing apparatus, comprising: reflecting an ultraviolet laser beam onto a silicon film by at least one reflection mirror to manufacture an electronic component used in a panel display; including the display manufacturing apparatus includes an ultraviolet laser, and the at least one reflection mirror includes a mirror substrate made of beryllium, an aluminum metal matrix composite material, or silicon carbide. [Aspect 22] The method according to aspect 21, wherein the silicon film is an amorphous silicon film. [Aspect 23] The method according to aspect 21, wherein the laser beam is directly reflected onto the silicon film to induce crystallization of the silicon film. [Aspect 24] The method according to aspect 21, wherein the silicon film is placed on a temporary substrate, and the laser beam is reflected onto the silicon film through the temporary substrate to separate the silicon film from the temporary substrate. [Aspect 25] The method according to aspect 21, wherein the electronic component is used in an OLED display or an LTPS-LCD display. [Aspect 26] An ultraviolet reflection mirror, comprising: a mirror substrate; and an ultraviolet reflection coating deposited on the surface of the mirror substrate; including the substrate is made of beryllium, an aluminum metal matrix composite material, or silicon carbide. [Aspect 27] The mirror according to aspect 26, wherein the back surface of the mirror substrate includes ribs for strengthening the mirror.

Claims

1. An ultraviolet reflective mirror, 6061, 6063, 6082, 2009, 2618, or 2124 aluminum alloys, and One or more types of reinforcing particles dispersed within an aluminum metal matrix % to 40 vol. % of silicon carbide reinforcing particles having an average particle size (D50) in the range of 0.1 μm to 0.5 μm; and an ultraviolet reflective coating deposited on a surface of said mirror substrate; The ultraviolet reflective mirror.

2. 10. The UV reflective mirror of claim 1, wherein the aluminum metal matrix composite (MMC) mirror substrate comprises 6061 aluminum alloy.

3. 10. The UV reflective mirror of claim 1, wherein the aluminum metal matrix composite (MMC) mirror substrate comprises 2124 aluminum alloy.

4. The UV-reflective coating comprises a base layer deposited on the mirror substrate and at least one dielectric layer on the base layer, or the UV-reflective coating comprises hafnium dioxide (HfO ２ ) and silicon dioxide (SiO ２ 2. The ultraviolet reflective mirror of claim 1, wherein the ultraviolet reflective coating is formed from alternating layers of (i) a coating formed from an aluminum metal binder and hafnium oxide and (ii) a coating formed from an aluminum metal binder and silicon dioxide.

5. An ultraviolet laser device, comprising: Ultraviolet laser; and 13. At least one ultraviolet reflective mirror according to claim 1 configured to reflect a laser beam generated from the ultraviolet laser; The above device.

6. A method for manufacturing an electronic component, comprising: receiving an ultraviolet laser device including an ultraviolet laser and at least one reflective mirror including the mirror substrate of the ultraviolet reflective mirror of claim 1; generating a laser beam with said ultraviolet laser; and reflecting the laser beam off the at least one reflective mirror toward a precursor film to produce the electronic component; The above method.

7. The method of claim 6 , wherein the precursor film is an amorphous film.

8. The method of claim 6, wherein the electronic component is used in an organic light emitting diode (OLED) display or a low temperature polycrystalline silicon liquid crystal display (LTPS-LCD).

9. 8. The method of claim 7, wherein the laser beam is reflected directly onto the precursor film to induce crystallization of the amorphous film.

10. 8. The method of claim 7, wherein the precursor film is disposed on a temporary substrate, and the laser beam is reflected through the temporary substrate onto the precursor film to separate the precursor film from the temporary substrate.

11. A method of using a display manufacturing apparatus, comprising the steps of: reflecting the ultraviolet laser beam by at least one reflecting mirror onto a silicon film to fabricate electronic components used in panel displays; Including, The method of claim 1 , wherein the display manufacturing equipment includes an ultraviolet laser and the at least one reflective mirror, the at least one reflective mirror being the ultraviolet reflective mirror of claim 1 .

12. The method of claim 11 , wherein the silicon film is an amorphous silicon film.

13. 12. The method of claim 11, wherein the ultraviolet laser beam is reflected directly onto the silicon film to induce crystallization of the silicon film.

14. 12. The method of claim 11, wherein the silicon film is mounted on a temporary substrate, and the ultraviolet laser beam is reflected through the temporary substrate onto the silicon film to separate the silicon film from the temporary substrate.

15. The method of claim 11, wherein the electronic component is used in an organic light emitting diode (OLED) display or a low temperature polycrystalline silicon liquid crystal display (LTPS-LCD).

16. The ultraviolet laser device of claim 5, further comprising one or more of a beam homogenizer, a beam expander, a focusing lens, and a beam splitter.

Images