WO2016160784A1 - Polariseur à grille de fils utilisant des matériaux solubles dans l'eau - Google Patents

Polariseur à grille de fils utilisant des matériaux solubles dans l'eau Download PDF

Info

Publication number
WO2016160784A1
WO2016160784A1 PCT/US2016/024676 US2016024676W WO2016160784A1 WO 2016160784 A1 WO2016160784 A1 WO 2016160784A1 US 2016024676 W US2016024676 W US 2016024676W WO 2016160784 A1 WO2016160784 A1 WO 2016160784A1
Authority
WO
WIPO (PCT)
Prior art keywords
ribs
coating
conformal
wgp
group
Prior art date
Application number
PCT/US2016/024676
Other languages
English (en)
Inventor
Stew NIELSON
Ted WANGENSTEEN
Fred Lane
Matt LINFORD
Anubhav DIWAN
Original Assignee
Moxtek, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US15/078,549 external-priority patent/US20160291227A1/en
Application filed by Moxtek, Inc. filed Critical Moxtek, Inc.
Publication of WO2016160784A1 publication Critical patent/WO2016160784A1/fr

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • G02B5/3025—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state
    • G02B5/3058—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state comprising electrically conductive elements, e.g. wire grids, conductive particles

Definitions

  • the present application is related generally to wire grid polarizers.
  • Wire grid polarizers can be used to divide light into two different polarization states.
  • One polarization state can pass through the WGP and the other can be absorbed or reflected.
  • the effectiveness or performance of WGPs is based on a very high percent transmission of one polarization (sometimes called Tp) and minimal transmission of an opposite polarization (sometimes called Ts) . It can be beneficial to have high contrast (Tp/Ts) .
  • Tp/Ts The percent reflection of the opposite polarization
  • Rs can also be an important indicator of polarizer performance.
  • Ribs or wires of WGPs especially for polarization of visible or ultraviolet light, can have small, delicate ribs with nanometer-sized pitch, wire-width, and wire-height.
  • WGPs are used in systems (e.g. computer projectors,
  • Water can condense or drop only onto limited portions of a WGP. Because the water can be in one channel but not in an adjacent channel, forces in the water can cause ribs to topple over, thus damaging the WGP.
  • WGP performance can also degrade by corrosion. Water can condense onto the WGP and wick into narrow channels between ribs due to capillary action. The water can then corrode the ribs. Corroded regions can have reduced contrast, changed Rs, or can fail to polarize at all.
  • Oxidization of the ribs can also degrade WGP performance.
  • substantially-pure aluminum is consumed, thus reducing the size of the substantially-pure aluminum wire and changing polarization characteristics of the WGP.
  • Protective coatings have been applied by dipping the WGP in an aqueous solution containing the coating. The coating can adhere to the ribs, then the WGP can be removed from the aqueous solution. Amino phosphonates, as described in U.S. Patent Number 6,785,050, have commonly been applied in this manner. Application of protective coatings by this method has been reasonably successful for some wire materials, such as for example aluminum and silicon, but may be insufficient for WGP protection in extreme environments. Silicon is used in selectively-absorptive WGPs to absorb one polarization of light, and thus reduce Rs. The performance of such silicon-containing WGPs can degrade over time as shown by gradually-increasing Rs.
  • Protective coatings can adversely affect polarizer performance.
  • the coating can cause a reduction of Tp.
  • Thicker coatings may be needed for to provide sufficient oxidation or corrosion protection, but thinner coatings may be preferred in order to minimize performance degradation by the coating.
  • the present invention is directed to various embodiments of WGPs with protective coatings, and methods of making WGPs with protective coatings, that satisfy these needs. Each embodiment may satisfy one, some, or all of these needs.
  • the WGP can comprise ribs located over a surface of a transparent substrate with gaps between at least a portion of the ribs.
  • a material of an exterior surface of the ribs can have a solubility in water of at least 0.015 grams per liter at 25°C.
  • a conformal-coating can be located over the ribs.
  • the method of making a WGP can comprise ( 1 ) obtaining ribs located over a su rface of a transparent substrate, the ribs being elongated, substantially parallel, and situated in an array, with gaps between at least a portion of the ribs, and a material of an exterior of the ribs has a solubility in water of at least 0.015 grams per liter at 25°C; and using an anhydrous method to apply a conformal-coating over the ribs.
  • FIGs . 1-3 are schematic cross-sectional side views of WGPs 10, 20, and 30, each with a conformal-coating 13 located over ribs 12, in accordance with embodiments of the present invention .
  • the conformal-coating 13 in FIG . 1 includes a single layer - a distal conformal-coating 13d.
  • the conformal-coating 13 in FIG. 2 includes two layers - a proximal conformal-coating 13 p and a distal conformal-coating 13d.
  • the conformal-coating 13 in FIG. 3 includes three layers - a proximal conformal-coating 13 p , a middle conformal-coating 13 m , and a distal conformal-coating 13d.
  • FIG. 4 is a schematic cross-sectional side view of a WGP 40 with a conformal-coating 13, including a hydrophobic-layer, designed to keep water 41, on a surface of the ribs 12, in a Cassie-Baxter state, in accordance with an embodiment of the present invention .
  • FIG. 5 is a schematic cross-sectional side view of a WGP 10 with array of ribs 12 located over a surface of a transparent substrate 11, in accordance with an embodiment of the present invention.
  • Each of the ribs 12 can include different regions 14 and 15 with different materials.
  • a conformal-coating 55 with one chemistry can adhere to one region 15 and a conformal-coating 54 with a different chemistry can adhere to a different region 14.
  • FIG . 6 is a schematic perspective-view of a WGP in accordance with an embodiment of the present invention .
  • FIG. 7 is a graphical plot of the relationship between wavelength and reflectance of one polarization (Rs) in : ( 1 ) a WGP that includes germanium, in accordance with an em bodiment of the present invention ; and (2) WGPs that include silicon, in accordance with the prior-art.
  • FIGs. 8-9 are schematic views of image projectors 80 and 90 with broadband, selectively-absorptive, WGPs 84, in accordance with embodiments of the present invention.
  • FIG. 10 shows an integrated circuit (IC) inspection tool 100 including a WGP 104, in accordance with embodiments of the present invention.
  • IC integrated circuit
  • FIG. 11 shows a flat panel display (FPD) manufacturing tool 110 including a WGP 114, in accordance with an embodiment of the present invention.
  • FPD flat panel display
  • alkyl refers to a branched, unbranched, or cyclic saturated hydrocarbon group.
  • Alkyls include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, octyl, and decyl, for example, as well as cycloalkyl groups such as cyclopentyl, and cyclohexyl, for example.
  • alkyl can typically be relatively small to facilitate vapor deposition, if overall atomic weight of the molecule is considered, such as for example ⁇ 2 carbon atoms in one aspect, ⁇ 3 carbon atoms in another aspect, ⁇ 5 carbon atoms in another aspect, or ⁇ 10 carbon atoms in another aspect.
  • substituted alkyl refers to an alkyl substituted with one or more substituent groups.
  • heteroalkyl refers to an alkyl in which at least one carbon atom is replaced with a heteroatom. If not otherwise indicated, the term “alkyl” includes unsubstituted alkyl, substituted alkyl, and heteroalkyl.
  • aryl refers to a group containing a single aromatic ring or multiple aromatic rings that are fused together, directly linked, or indirectly linked (such that the different aromatic rings are bound to a common group such as a methylene or ethylene moiety) .
  • Aryl groups include, for example, phenyl, naphthyl, anthryl, phenanthryl, biphenyl, diphenylether, diphenylamine, and benzophenone.
  • substituted aryl refers to an aryl group comprising one or more substituent groups.
  • heteroaryl refers to an aryl group in which at least one carbon atom is replaced with a heteroatom . If not otherwise indicated, the term “aryl” includes unsubstituted aryl, substituted aryl, and heteroaryl .
  • the phrase "bond to the ribs" or similar phrases can mean a direct bond between the chemical and the ribs or a bond to an intermediate layer which is bonded directly, or through other layer(s) to the ribs.
  • these layer(s) can be other conformal-coating(s).
  • the term carbon chain can include at least five carbon atoms in a row in one aspect, at least ten carbon atoms in a row in another aspect, or at least fifteen carbon atoms in a row in another aspect.
  • the term carbon chain can also include ether linkages (C-O-C moieties) .
  • carbon chain includes single, double, and triple carbon to carbon bonds. The carbon atoms can be attached to any element or molecule.
  • elongated means that a length L (see FIG. 6) of the ribs 12 is substantially greater than rib width ⁇ N 12 or rib thickness T i2 (see FIG. 1) .
  • WGPs for ultraviolet or visible light can often have a rib width W 12 between 20 and 100 nanometers and rib thickness Ti 2 between 50 and 500 nanometers; and rib length L of about 1 millimeter to 20 centimeters or more, depending on the application.
  • elongated ribs 12 can have a length L that is many times (even thousands of times) larger than rib width W i2 or rib thickness
  • gap means a space, opening, or divide, separating one rib from another rib.
  • the gap can be filled with a vacuum, gas, liquid, or solid, unless otherwise specified.
  • the unit "seem” means cubic centimeters per minute at 0 °C and 1 atmosphere pressure.
  • the term “substrate” includes a base material, such as for example a glass wafer.
  • the term “substrate” includes a single material, and also includes multiple materials (e.g. layered, composite, or the like), such as for example a glass wafer with at least one thin film on a surface of the wafer used together as the base material.
  • optical structures absorb some light, reflect some light, and transmit some light.
  • the following definitions are intended to distinguish between materials or structures that are primarily absorptive, primarily reflective, or primarily transparent.
  • Each material can be primarily absorptive, primarily reflective, or primarily transparent in a specific wavelength of interest (e.g. all or a portion of the ultraviolet, visible, or infrared spectrums of light) and can have a different property in a different wavelength of interest.
  • absorptive means substantially absorptive of light in the wavelength of interest.
  • absorptive is relative to other materials used in the polarizer. Thus, an absorptive structure will absorb substantially more than a reflective or a transparent structure.
  • Whether a material is "absorptive" is dependent on the wavelength of interest. A material can be absorptive in one wavelength range but not in another.
  • an absorptive structure can absorb greater than 40% and reflect less than 60% of light in the wavelength of interest (assuming the absorptive structure is an optically thick film - i.e.
  • an absorptive material can have a high extinction coefficient (k), relative to a transparent material, such as for example greater than 0.01 in one aspect or greater than 1.0 in another aspect.
  • Absorptive ribs can be used for selectively absorbing one polarization of light.
  • the term "reflective" means substantially reflective of light in the wavelength of interest.
  • a material is "reflective" is relative to other materials used in the polarizer. Thus, a reflective structure will reflect substantially more than an absorptive or a transparent structure.
  • a material can be reflective in one wavelength range but not in another. Some wavelength ranges can effectively utilize highly reflective materials. At other wavelength ranges, especially lower wavelengths where material degradation is more likely to occur, the choice of materials may be more limited and an optical designer may need to accept materials with a lower reflectance than desired.
  • a reflective structure can reflect greater than 80% and absorb less than 20% of light in the wavelength of interest (assuming the reflective structure is an optically thick film - i.e. greater than the skin depth thickness).
  • Metals are often used as reflective materials.
  • Reflective wires can be used for separating one polarization of light from an opposite polarization of light.
  • transparent means substantially transparent to light in the wavelength of interest.
  • a material is substantially more than an absorptive or a reflective structure. b. Whether a material is "transparent" is dependent on the wavelength of interest. A material can be transparent in one wavelength range but not in another.
  • a transparent structure can transmit greater than 90% and absorb less than 10% of light at the wavelength of interest or wavelength range of use, ignoring Fresnel reflection losses.
  • a transparent structure can have an extinction
  • the term "material” refers to the overall material of a particular structure.
  • a structure that is “absorptive” is made of a material that as a whole is substantially absorptive, even though the material may include some reflective or transparent components.
  • a rib made of a sufficient amount of absorptive material so that it substantially absorbs light is an absorptive rib even though the rib may include some reflective or transparent material embedded therein .
  • wire grid polarizers (WGPs or WGP for singular) 10, 20, 30, 40, 50, and 60 are shown comprising ribs 12 located over a surface of a transparent substrate 11.
  • the ribs 12 can be elongated and arranged in a substantially parallel array.
  • the ribs 12 can have a small pitch P (see FIG. 1), such as for example a pitch P of less than 200 nanometers in one aspect or less than 150 nanometers in another aspect.
  • gaps G between at least a portion of the ribs 12 (i.e. a gap G between a rib 12 and an adjacent rib 12).
  • the gaps G can be filled with air in one aspect, a liquid in another aspect, a transparent, solid, dielectric material in another aspect, or combinations thereof.
  • a conformal-coating 13 can be located over the ribs 12.
  • the conformal-coating 13 can also be located over an exposed surface of the substrate 11 ("exposed surface” meaning a surface of the substrate not covered with ribs 12).
  • Use of a conformal-coating 13 can be beneficial because by following a contour of the ribs 12 and an exposed surface of the substrate 11, conformal-coating thickness T p , T m , and Td, can be minimized, thus reducing any detrimental effect of the conformal-coating(s) 13 on WGP performance.
  • the conformal-coating 13 can cover an exposed surface of the ribs 12.
  • the conformal-coating 13 can include a barrier-layer, a hydrophobic-layer, or both .
  • the barrier-layer can include an oxidation-barrier, a moisture-barrier, or both.
  • the conformal-coating 13 can include a single layer (FIG. 1) or multiple, different layers (see FIGs.2-3) across all or substantially all of the ribs 12.
  • the conformal-coating 13 can include at least one of: a proximal conformal-coating 13 p , a middle conformal-coating 13 m , and a distal conformal-coating 13d. It can be important to have sufficient thickness T p , T m , and Td for each of these layers 13 p , 13 m , and 13 d , respectively, of the conformal-coating 13, in order to provide sufficient protection to the ribs 12 and/or to provide a base for an upper layer of the conformal-coating 13.
  • one or more of the proximal conformal-coating 13 p , the middle conformal-coating 13 m , and the distal conformal-coating 13 d can have a thickness T p , T m , or Td that is at least 0.1 in one aspect, at least 0.5 nanometers in another aspect, or at least 1 nanometer in another aspect.
  • T p , T m , and T d are sufficiently small thickness for each of these layers 13 p , 13 m , and 13 d , respectively, of the conformal-coating 13, in order to avoid or minimize degradation of WGP performance caused by the conformal-coating 13.
  • one or more of the proximal conformal-coating 13 p , the middle conformal-coating 13 m , and the distal conformal-coating 13 d can have a thickness T p , Tm, or T d that is less than 2 nanometers in one aspect, less than 3 nanometers in another aspect, less than 5 nanometers in another aspect, less than 10 nanometers in another aspect, less than 15 nanometers in another aspect, or less than 20 nanometers in another aspect.
  • These thickness values can be a minimum thickness or a maximum thickness at any location of the conformal-coating 13, or simply a thickness at a location of the conformal-coating 13.
  • Each layer of the conformal-coating 13 can be a monolayer.
  • a conformal-coating 55 with one chemistry can adhere to one region 15 and a conformal-coating 54 with a different chemistry can adhere to a different region 14.
  • the chemistry of multiple, different, conformal-coatings can be selected such that different regions of the WGP, with different chemistries, can be protected.
  • the conformal-coating 13 can include a hydrophobic-layer.
  • hydrophobic-layer can include a phosphonate conformal-coating, which can include :
  • each R 1 can independently be a hydrophobic group
  • Z can be a bond to the ribs
  • R 5 can be any suitable chemical element or group.
  • R 5 can be a phosphonate-reactive-group, R 1 , or R 6 .
  • the phosphonate-reactive-group can be a chemical element or group likely to react to form an additional bond Z to the ribs 12, such as for example -CI, -OR 6 , -OCOR 6 , or -OH.
  • Each R 5 can
  • the hydrophobic-layer can alternatively or in addition include a silane conformal-coating, which can include chemical formula ( 1), chemical formula (2), or combinations thereof:
  • r can be a positive integer
  • X can be a bond to the ribs
  • each R 3 can be independently a suitable chemical element or a group.
  • Each R 1 as mentioned above, can independently be a hydrophobic group.
  • Each R 3 can be independently selected from the group consisting of: a silane-reactive-group, -H, R 1 , and R 6 .
  • R 6 was defined above.
  • Each silane- reactive-group can be independently selected from the group consisting of: -CI, - OR 6 , -OCOR 6 , -N(R 6 ) 2 , and -OH.
  • R 3 and/or R 5 can be a small group, such as for example -OCH 3 , to allow easier vapor-deposition. Benefits of vapor-deposition are described below.
  • the hydrophobic-layer can alternatively or in addition include a sulfur conformal-coating, which can include :
  • T can be a bond to the ribs and each R 1 , as mentioned above, can independently be a hydrophobic group.
  • each rib 12 can include different regions 15 and 14, such as an upper-rib 15 and a lower-rib 14.
  • the lower-rib 14 can be sandwiched between the upper-rib 15 and the substrate 11.
  • At least one of these (lower-rib 14 or upper-rib 15) can be reflective (e.g. aluminum for visible light) and can be called a wire.
  • At least one of these (lower-rib 14 or upper-rib 15) can be absorptive or transparent and can be called a rod.
  • the rod can be absorptive and can be the upper-rib 15, and the wire can be the lower-rib 14. See US 7,961,393 which is incorporated by reference herein.
  • the rod can be the upper-rib 15, can be made of silicon, and the silane conformal- coating 55 can preferentially adhere to the silicon upper-rib 15; and the wire can be the lower-rib 15, can be made of aluminum, and the phosphonate conformal- coating 54 can preferentially adhere to the aluminum lower-rib 15.
  • X can be a bond to the rod.
  • X can be -O-Si.
  • T and/or Z can be a bond to the wire.
  • T and/or Z can be -O-Metal, where Metal is a metal atom .
  • the silane conformal-coating can preferentially attach to one material (e.g . silicon) and the phosphonate conformal-coating or the sulfur conformal-coating can preferentially attach to another material (e.g. a metal) to provide protection to multiple rib 12 materials.
  • the chemicals in the hydrophobic-layer include molecules that each has multiple bonds T, Z, and/or X to the ribs 12.
  • each molecule forming multiple bonds X more of the underlying surface (e.g . rib 12, proximal conformal-coating 13 p , or middle conformal-coating 13 m ) can be bound and thus unavailable for bonding or interaction with undesirable chemicals, such as water for example.
  • multiple bonds to the surface can improve resiliency of the hydrophobic-layer because it can be less likely for multiple bonds Z/X/T to fail than for a single bond Z/X/T to fail.
  • R 1 can be:
  • R 7 can be a hydrophobic group as described above, g can be an integer from 1 to 3, and R 8 can be moiety ( 1), moiety (2), moiety (3), or combinations thereof:
  • the central atom A can be selected from group III, IV, or V in the periodic table in one aspect or can be selected from the group consisting of carbon, nitrogen, phosphorous, and silicon in another aspect.
  • R 5 Another way for molecules in the hydrophobic-layer to form multiple bonds Z, and/or X to the ribs 12 is for R 5 to be Z and/or for R 3 to be X. This can be accomplished if, in the phosphonate chemistry as applied, R 5 is a
  • R 3 is a silane-reactive-group.
  • the hydrophobic group can be or can include a carbon chain in one aspect and can include at least one halogen bonded to a carbon in another aspect.
  • the carbon chain can include a perfluorinated group including at least 1 carbon atom in one aspect or at least 3 carbon atoms in another aspect.
  • the perfluorinated group can include less than 20 carbon atoms in another aspect, less than 30 carbon atoms in another aspect, or less than 40 carbon atoms in another aspect.
  • the perfluorinated group can have at least 4 carbon atoms to provide a hydrophobic chain. It can be beneficial for the perfluorinated group to not be too long or have too many carbon atoms in order to maintain a high enough vapor pressure to allow vapor-deposition .
  • the carbon chain of R 1 can include CF 3 (CF 2 ) n . Due to the high electronegativity of fluorine, it can be beneficial to have a hydrocarbon chain to separate the perfluorinated group from the phosphorous or sulfur.
  • the carbon chain of R 1 can include CF3(CF 2 ) n (CH2 where n can be an integer within the boundaries of 0 ⁇ n ⁇ 20 in one aspect or 4 ⁇ n ⁇ 10 in another aspect, and m can be an integer within the boundaries of 0 ⁇ m ⁇ 5 in one aspect or 2 ⁇ m ⁇ 5 in another aspect.
  • each molecule in the phosphonate conformal- coating (excluding the bond to the ribs Z), each molecule in the silane
  • conformal-coating (excluding the bond to the ribs X), and/or each molecule in the sulfur conformal-coating (excluding the bond to the ribs T), can have a molecular weight of at least 100 grams per mole in one aspect, at least 150 grams per mole in another aspect, or at least 400 grams per mole in another aspect, and less than 600 grams per mole in one aspect, less than 1000 grams per mole in another aspect, or less than 1500 grams per mole in another aspect.
  • the bond between silicon (Si) and R 1 can be a silicon to carbon bond (Si-C) ; the bond between phosphorous (P) and R 1 can be a phosphorous to carbon bond (P- C); and/or the bond between sulfur (S) and R 1 can be a sulfur to carbon bond (S-C).
  • the hydrophobic-layer located on the ribs 12 can provide a hydrophobic surface, which can be a superhydrophobic surface, depending on the chemistry and the structure of the ribs, such as pitch P and rib width Wi 2 .
  • the WGP and conformal-coating 13 can include a hydrophobic-layer and can be capable of keeping water 41, on a surface of the ribs 12, in a Cassie-Baxter state.
  • Having water on the WGP 10 in a Cassie-Baxter state can be beneficial because the water 41 does not substantially enter or remain in the gaps G, thus avoiding or reducing corrosion on sides of the ribs 12 and avoiding or reducing toppling of the ribs 12 due to water's tensile forces. Also, if the water 41 is in a Cassie-Baxter state, the water can more easily roll off the surface of the WGP, often carrying dust particles with it.
  • a water contact angle A can be greater than 110° in one aspect, greater than 120° in another aspect, greater than 130° in another aspect, or greater than 140° in another aspect.
  • At least one of the lower-rib 14 or upper-rib 15 can be reflective (e.g. aluminum for visible light) and can be called a wire and at least one can be absorptive or transparent and can be called a rod.
  • the rod can be made of silicon, an absorptive material for visible light.
  • Silicon-containing, selectively-absorptive WGPs have been used in image projectors.
  • Selectively- absorptive WGPs can substantially allow one polarization (e.g. p-polarized light) to pass through and can absorb an opposite polarization (e.g. s-polarized light) .
  • the p-polarized light can be used for forming the image.
  • Ghosting of the projected image can be reduced by the WGP absorbing the s- polarized light.
  • Some image projectors separate light into three different light beams. One of these light beams can have a wavelength of about 450 nm, another can have a wavelength of about 550 nm, and the third can have a wavelength of about 650 nm . In order to optimize polarization of each light beam, different WGP designs can be used for each different light beam .
  • Graphical silicon-plots Si in FIG. 7 show the relationship between wavelength and reflectance of one polarization (e.g. reflectance of s-polarization Rs) of a selectively-absorptive WGP that includes silicon.
  • the first silicon-plot Si(l) is for with a WGP having a silicon thickness selected for optimal (low) Rs at around 450 nanometers.
  • the second silicon-plot Si(2) is for with a WGP having a silicon thickness selected for optimal (low) Rs at around 550 nanometers.
  • the third silicon-plot Si(3) is for with a WGP having a silicon thickness selected for optimal (low) Rs at around 650 nanometers. It would be simpler, and
  • FIG. 7 Also shown in FIG. 7 is a graphical germanium-plot Ge of the relationship between wavelength and reflectance of one polarization (e.g . s-polarization) of a selectively-absorptive WGP that includes germanium.
  • the WGP that includes germanium has better Rs across 2/3 of wavelengths from 400-700 nm.
  • use of a WGP that includes germanium can provide a benefit of improved s from about 500-700 nm .
  • one WGP design can be used for at least two of the light beams (e.g. 550 and 650) .
  • a rod in a selectively-absorptive WGP can include at germanium .
  • the rod can include at least 20 mass percent germanium in one aspect, at least 50 mass percent germanium in another aspect, at least 80 mass percent germanium in another aspect, or at least 95 mass percent germanium in another aspect.
  • a difficulty of using germanium is that it has a soluble oxide (about 4.5 g/L at 25°C).
  • WGP performance can decrease if the polarizer, with an exterior of the rib 12 including germanium / germanium oxide, is immersed into an aqueous solution .
  • aqueous solution can be for applying a protective coating (e.g. amino phosphonate as taught in U.S. Patent Number 6,785,050 which is incorporated herein by reference).
  • a protective coating e.g. amino phosphonate as taught in U.S. Patent Number 6,785,050 which is incorporated herein by reference.
  • Such protective coatings can be important to avoid corrosion of the WGP.
  • WGPs made with such water-soluble materials can also benefit from anhydrous- immersion and / or vapor-deposition for applying the conformal-coating(s) 13.
  • an anhydrous method can be helpful if a material of an exterior of the ribs 12 has solubility in water of at least 0.015 grams per liter at 25°C in one aspect, at least 0.02 grams per liter at 25°C in another aspect, at least 0.05 grams per liter at 25°C in another aspect, at least 0.5 grams per liter at 25°C in another aspect, at least 1 gram per liter at 25°C in another aspect, at least 2 grams per liter at 25°C in another aspect, or at least 4 grams per liter at 25°C in another aspect.
  • vapor- deposition methods include chemical vapor-deposition (CVD), low-pressure CVD (LPCVD), plasma-enhanced CVD, physical vapor-deposition (PVD), atomic layer deposition (ALD), thermoreactive diffusion, electron-beam deposition,
  • CVD chemical vapor-deposition
  • LPCVD low-pressure CVD
  • PVD physical vapor-deposition
  • ALD atomic layer deposition
  • thermoreactive diffusion electron-beam deposition
  • Anhydrous-immersion can include submersion of the WGP in an anhydrous, liquid bath.
  • a solvent that will not dissolve rib 12 materials can be selected.
  • Vapor-deposition can be preferred over immersion because of reduced process-waste disposal problems, reduced health hazards, reduced or no undesirable residue from rinsing, and vapor-deposition can be done with standard semiconductor processing equipment.
  • the oxidation-barrier and the moisture-barrier described below can be applied by ALD.
  • Some embodiments of the hydrophobic-layer have a sufficiently- high vapor pressure and can be applied by vapor-deposition.
  • the conformal-coating 13 can include a barrier-layer.
  • the barrier-layer can include an oxidation-barrier, a moisture-barrier, or both .
  • the barrier-layer can include a metal oxide, or layers of different metal oxides.
  • Oxidation of WGP ribs 12 can degrade performance of the WGP, by adversely affecting contrast or Rs.
  • An oxidation-barrier can reduce oxidation of the ribs 12, and thus reduce or avoid such WGP performance degradation.
  • the term "oxidation-barrier" means a first material capable of reducing the ingress of oxygen into a second material, which may cause the second material to oxidize.
  • An oxidation barrier can be placed on the ribs 12 to protect the ribs 12 from oxidation.
  • Non-limiting examples of chemicals that can be used as an oxidation- barrier include : aluminum oxide, silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, or combinations thereof.
  • WGP corrosion can degrade WGP performance. For example, water can condense onto the WGP and wick into narrow channels between ribs due to capillary action. The water can then corrode the ribs. Corroded regions can have reduced contrast, changed s, or can fail to polarize at all .
  • a moisture-barrier can resist corrosion. A moisture-barrier can protect the ribs 12 from water or other corrosion. Examples of chemicals that can be used as a moisture-barrier include : hafnium oxide, zirconium oxide, or combinations thereof.
  • the barrier-layer can include rare earth oxides, for example, oxides of scandium, yttrium, lanthanum, cerium, praseodymium, neodymium,
  • rare earth oxides can be at least part of the oxidation-barrier, the moisture-barrier, or both.
  • the barrier-layer can be distinct from the ribs 12, meaning ( 1) there can be a boundary line or layer between the ribs 12 and the barrier-layer; or (2) there can be some difference of material of the barrier-layer relative to a material of the ribs 12.
  • a native aluminum oxide can form at a surface of aluminum ribs 12.
  • a layer of aluminum oxide (oxidation-barrier) can then be applied to the ribs (e.g . by ALD). This added layer of aluminum oxide can be important, because a thickness and / or density of the native aluminum oxide can be insufficient for protecting a core of the ribs 12 (e.g. substantially pure aluminum) from oxidizing.
  • the oxidation-barrier (AI 2 O3) has the same material composition as a surface (Al 2 0 3 ) of the ribs 12, the oxidation-barrier can still be distinct due to ( 1) a boundary layer between the oxidation-barrier and the ribs 12 and / or (2) a difference in material properties, such as an increased density of the oxidation-barrier relative to the native aluminum oxide.
  • a silicon dioxide conformal-coating can be located between the silane conformal-coating and the ribs 12.
  • the silicon dioxide conformal-coating can help the silane conformal-coating 14 bond to the ribs 12.
  • the silicon dioxide conformal-coating can be the proximal conformal-coating 13 p or the middle conformal-coating 13 m , or an additional layer of the conformal-coating 13 located between the middle conformal-coating 13 m and the distal conformal- coating 13d.
  • the oxidation-barrier can be less effective at resisting corrosion .
  • the moisture-barrier and / or hydrophobic-layer can be less effective at resisting oxidation.
  • it can be beneficial to combine both an oxidation-barrier with a moisture-barrier and / or hydrophobic-layer.
  • the moisture-barrier can resist corrosion, it can eventually break down. Thus, it can be beneficial to minimize exposure of the moisture-barrier to water.
  • a hydrophobic-layer can minimize or prevent condensed water on the WGP from attacking the moisture-barrier, thus extending the life of the moisture-barrier and the WGP. If the hydrophobic-layer perfectly covers the ribs 12, and never breaks down, then a moisture-barrier might not be needed. But, due to imperfections in manufacturing, there can be locations on the ribs 12 that are not covered, or less densely covered, by the hydrophobic-layer. The moisture-barrier can provide protection to these locations. Also, the
  • hydrophobic-layer can break down over time.
  • the moisture-barrier can provide protection after such breakdown. Therefore, it can be beneficial to combine both a moisture-barrier and a hydrophobic-layer.
  • the hydrophobic-layer keeps water on the ribs 12 in a Cassie-Baxter state, then rib 12 damage, which could otherwise be caused by tensile forces in water in the gaps G, can be avoided. Also, the water can roll off the surface of the WGP, often carrying dust particles with it, in a self-cleaning fashion.
  • WGP 10 in FIG. 1 includes a conformal-coating 13 with one layer: a distal conformal-coating 13 d .
  • the distal conformal-coating 13 d can be the oxidation- barrier, the moisture-barrier, or the hydrophobic-layer.
  • WGP 20 in FIG. 2 includes a conformal-coating 13 with two layers : a proximal conformal-coating 13 p located closer to the ribs 12 and substrate 11 and a distal conformal-coating 13d located over the proximal conformal-coating 13 p .
  • the proximal conformal-coating 13 p and the distal conformal-coating 13d can comprise oxidation-barrier(s), moisture-barrier(s), and / or hydrophobic- layer(s) .
  • WGP 30 in FIG. 3 includes a conformal-coating 13 with three layers: the proximal conformal-coating 13 p , the distal conformal-coating 13d, and a middle conformal-coating 13 m located between the proximal conformal-coating 13 p and the distal conformal-coating 13d.
  • the proximal conformal-coating 13 p , the middle conformal-coating 13 m , and the distal conformal-coating 13d can comprise oxidation-barrier(s), moisture-barrier(s), and / or hydrophobic-layer(s) .
  • the moisture-barrier can provide corrosion protection to the oxidation-barrier.
  • the oxidation-barrier can provide a good substrate for deposition of the moisture-barrier, resulting in a less porous moisture-barrier.
  • the same moisture protection may be obtained by a relatively thinner moisture-barrier. This can be important because the moisture-barrier can degrade WGP performance, but such degradation can be minimized by reduced moisture-barrier thickness.
  • the moisture-barrier can provide an improved surface for attachment of the hydrophobic-layer (if used) .
  • the hydrophobic-layer can be located over the barrier-layer (i.e. the hydrophobic-layer can be the distal conformal-coating 13 d ) in order to best keep moisture from entering the gaps G and to minimize or eliminate moisture exposure of the underlying layer(s) in the conformal-coating 13 (e.g. the proximal conformal-coating 13 p and also possibly the middle conformal-coating 13 m ) .
  • Image projector 80 can comprise a light source 81, color-splitting optics 82, color-combining optics 88, a projection lens system 85, one or more spatial light modulators 87, and one or more WGPs 84.
  • the light source 81 can emit a beam of light 83, which can initially be unpolarized.
  • the color-splitting optics 82 can be located to receive at least part of the beam of light 83 and can split the beam of light 83 into multiple, differently-colored light beams (colored beams) 83 c .
  • the colored beams 83 c can be primary colors.
  • Color-combining optics 88 can be located to receive and can recombine at least some of the colored beams 83 c into a combined beam or final beam 83f.
  • Color-combining optics 88 are sometimes called X-Cubes, X-Cube prisms, X- prisms, light recombination prisms, or cross dichroic prisms.
  • Color-combining optics 88 are used in computer projectors for combining different colors of light into a single image to be projected.
  • X-Cubes are typically made of four right angle prisms, with dichroic coatings, that are cemented together to form a cube.
  • the projection lens system 85 can be located to receive the combined beam 83f and can project a colored image 83, onto a screen 86.
  • exemplary projection lens systems 85 are described in U.S. Patent Numbers 6,585,378 and 6,447, 120, which are hereby incorporated herein by reference in their entirety.
  • One spatial light modulator 87 can be located to receive, in each light path between the color-splitting optics 82 and the color-combining optics 88, one of the colored beams 83 c .
  • Each spatial light modulator 87 can have a plurality of pixels. Each pixel can receive a signal. The signal can be an electronic signal. Depending on whether or not each pixel receives the signal, the pixel can rotate a polarization of, or transmit or reflect without causing a change in polarization of, incident light.
  • the spatial light modulator(s) 87 can be a liquid crystal device / display (LCD) and can be transmissive, reflective, or transflective.
  • Each WGP 84 can be located in one of the colored beams 83 c prior to entering the spatial light modulator 87, after exiting the spatial light modulator 87, or both.
  • the WGP(s) 84 help form the colored image 83j by transmitting, reflecting, or absorbing light of each pixel depending on the type of WGP 84 and whether each pixel received the signal.
  • FIG. 9 Another type of image projector 90 is shown in FIG. 9, and can comprise a light source 91, a projection lens system 85, a spatial light modulator 87, and a WGP 84.
  • the light source 91 can sequentially emit multiple, differently-colored light beams (colored beams) 93.
  • the colored beams 93 can be primary colors.
  • the projection lens system 85 can be located to receive the colored beams 93 and can project a colored image 83i onto a screen 86.
  • the projection lens system 85, spatial light modulator 87, WGP 84, colored image 83,, and screen 86 were described above.
  • the spatial light modulator 87 can be located to receive, in a light path between the light source 91 and the projection lens system 85, the colored beams 93.
  • the WGP 84 can be located in the colored beams 93 prior to entering the spatial light modulator 87 and after exiting the spatial light modulator 87.
  • Integrated circuits can be made of semiconductor material and can include nanometer-sized features. ICs can be used in various electronic devices (e.g. computer, motion sensor, etc.). Defects in the IC can cause the electronic device to fail . Thus, inspection of the IC can be important for avoiding failure of the electronic device, while in use by the consumer. Such inspection can be difficult due to the small feature-size of IC components. Light, with small wavelengths (e.g. ultraviolet), can be used to inspect small feature-size components. It can be difficult to have sufficient contrast between these small feature-size components and defects or their surroundings. Use of polarized light can improve integrated circuit (IC) inspection contrast. It can be difficult to polarize the small wavelengths of light (e.g.
  • An IC inspection tool 100 is shown in FIG. 10, comprising a light source 101 and a stage 102 for holding an IC wafer 103.
  • the light source 101 can be located to emit an incident light-beam 105 (e.g . visible, ultraviolet, or x- ray) onto the IC wafer 103.
  • the incident light-beam 105 can be directed to the wafer 103 by optics (e.g. mirrors) .
  • the incident light-beam 105 can have an acute angle of incidence 109 with a face of the wafer 103.
  • a WGP 104 (according to an embodiment described herein) can be located in, and can polarize, the incident light-beam 105.
  • a detector 107 e.g. CCD
  • An electronic circuit 108 can be configured to receive and analyze a signal from the detector 107 (the signal based on the output light- beam 106 received by the detector 107) .
  • a WGP 104 (according to an embodiment described herein) can be located in, and can polarize, the output light-beam 106.
  • FPDs flat panel displays
  • FPDs can include an aligned polymer film and liquid crystal.
  • An FPD manufacturing tool 110 is shown in FIG.
  • the light source 111 can emit ultraviolet light 115.
  • the WGP 114 can be located between the light source 111 and the stage 112 and can polarize the ultraviolet light 115.
  • Exposing the FPD 113 to polarized ultraviolet light 115 can align the polymer film . See US Patents 8,797,643 and 8,654,289, both incorporated herein by reference. Exposing the FPD 113 to polarized ultraviolet light 115 can help repair the FPD 113. See US Patent 7,697, 108, which is incorporated herein by reference.
  • a method of making a WGP can include some or all of the following steps. The steps can be performed in the order shown, or alternate order: 1. Obtaining ribs 12 located over a surface of a transparent substrate 11. The ribs 12 and the transparent substrate 11 can have properties as described above. There can be gaps G between at least a portion of the ribs 12. See FIG. 6.
  • This step may be done before applying one or more of the following : a proximal conformal-coating 13 p , a middle conformal-coating 13 m , and a distal conformal-coating 13d.
  • Exposing the WGP to ultraviolet light and ozone can be done
  • a duration of this step can be less than two minutes in one aspect or less than 20 minutes in another aspect.
  • Plasma cleaning can generate more reactive groups on the surface (i .e. surface of the ribs 12, proximal conformal-coating 13 p , or middle conformal-coating 13 m ), thus improving bonding of the distal conformal-coating 13d.
  • Non-limiting examples of plasmas include 0 2 , H 2 , Ar, and N 2 .
  • Plasma cleaning can be performed at various temperatures, such as for example between 140 °C and 200 °C.
  • the gas can include water vapor.
  • the water vapor can have a pressure of less than 100 Torr.
  • This step can increase the number of hydroxy! groups on the
  • underlying surface e.g . ribs 12, proximal conformal-coating 13 p , or middle conformal-coating 13 m
  • proximal conformal-coating 13 p proximal conformal-coating 13 p
  • middle conformal-coating 13 m middle conformal-coating 13 m
  • Baking can improve bonding of the hydrophobic-layer.
  • a. Baking temperature examples The WGP can be baked at greater than between 100 °C in one aspect, greater than 130 °C in another aspect, or greater than 150 °C in another aspect; and less than 300 °C in one aspect, less than 320 °C in another aspect, or less than 400 °C in another aspect.
  • the WGP can be baked for at least 5 minutes, at least 10 minutes in another aspect; and less than 60 minutes in one aspect or less than 90 minutes in another aspect.
  • One, two, or every layer of the conformal coating can have one or more of the following characteristics :
  • 1. can cover the underlying layer, e.g . an exposed surface of the ribs 12, the proximal conformal-coating 13 p , or middle conformal-coating 13 p ;
  • 3. can be applied at an elevated temperature, such as for example at least 300°C in one aspect, at least 350°C in another aspect, at least 400°C in another aspect; and less than 500°C in one aspect or less than 600°C in another aspect;
  • 4. can include a metal oxide
  • d is 1, 2, or 3
  • e is 1, 2, or 3
  • g is 0, 1, or 2
  • d+e+g 4;
  • each R 1 is independently a hydrophobic group
  • R 2 is a silane-reactive-group
  • each silane-reactive-group is independently selected from : -CI, -OR 6 , - OCOR 6 , -N(R 6 ) 2 , and -OH ;
  • R 4 is a phosphonate-reactive-group
  • each phosphonate-reactive-group is independently selected from : -CI, -OR 6 , -OCOR 6 , and -OH;
  • each R 6 is independently an alkyl group, an aryl group, or
  • the hydrophobic group, the phosphonate-reactive-group, the silane-reactive- group, R 5 , R 3 , and R 5 can have the properties as described above.
  • the silane chemical and the phosphonate chemical can be applied sequentially or simultaneously.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Polarising Elements (AREA)

Abstract

La présente invention se rapporte à un polariseur à grille de fils (WGP) (10) dont les performances peuvent être améliorées grâce à l'utilisation de certains matériaux solubles dans l'eau. Ces matériaux solubles dans l'eau peuvent être protégés par un revêtement enrobant (13) qui peut être appliqué à l'aide d'un procédé anhydre, par exemple un dépôt en phase vapeur.
PCT/US2016/024676 2015-04-03 2016-03-29 Polariseur à grille de fils utilisant des matériaux solubles dans l'eau WO2016160784A1 (fr)

Applications Claiming Priority (14)

Application Number Priority Date Filing Date Title
US201562142854P 2015-04-03 2015-04-03
US62/142,854 2015-04-03
US201562190188P 2015-07-08 2015-07-08
US62/190,188 2015-07-08
US201562209024P 2015-08-24 2015-08-24
US62/209,024 2015-08-24
US201562216782P 2015-09-10 2015-09-10
US62/216,782 2015-09-10
US201562242883P 2015-10-16 2015-10-16
US62/242,883 2015-10-16
US201562265773P 2015-12-10 2015-12-10
US62/265,773 2015-12-10
US15/078,549 US20160291227A1 (en) 2015-04-03 2016-03-23 Wire Grid Polarizer with Water-Soluble Materials
US15/078,549 2016-03-23

Publications (1)

Publication Number Publication Date
WO2016160784A1 true WO2016160784A1 (fr) 2016-10-06

Family

ID=57007520

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2016/024676 WO2016160784A1 (fr) 2015-04-03 2016-03-29 Polariseur à grille de fils utilisant des matériaux solubles dans l'eau

Country Status (1)

Country Link
WO (1) WO2016160784A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2021517980A (ja) * 2018-04-12 2021-07-29 モックステック・インコーポレーテッド 偏光子ナノインプリントリソグラフィ

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003096105A1 (fr) * 2002-05-09 2003-11-20 Moxtek, Inc. Polariseur a grille de fils resistant a la corrosion et son procede de fabrication
US20070252293A1 (en) * 2006-04-28 2007-11-01 Konica Minolta Opto, Inc. Method for manufacturing an optical film having a convexoconcave structure, optical film, wire grid polarizer and retardation film
US20110052802A1 (en) * 2008-04-08 2011-03-03 Asahi Glass Company, Limited Process for producing wire-grid polarizer
US20120107530A1 (en) * 2010-10-28 2012-05-03 Fujifilm Corporation Printing paper for printing stereoscopic image, stereoscopic image printed matter, and method for providing stereoscopic image
US20130128358A1 (en) * 2010-05-31 2013-05-23 Dexerials Corporation Polarizing plate and method for producing polarizing plate

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003096105A1 (fr) * 2002-05-09 2003-11-20 Moxtek, Inc. Polariseur a grille de fils resistant a la corrosion et son procede de fabrication
US20070252293A1 (en) * 2006-04-28 2007-11-01 Konica Minolta Opto, Inc. Method for manufacturing an optical film having a convexoconcave structure, optical film, wire grid polarizer and retardation film
US20110052802A1 (en) * 2008-04-08 2011-03-03 Asahi Glass Company, Limited Process for producing wire-grid polarizer
US20130128358A1 (en) * 2010-05-31 2013-05-23 Dexerials Corporation Polarizing plate and method for producing polarizing plate
US20120107530A1 (en) * 2010-10-28 2012-05-03 Fujifilm Corporation Printing paper for printing stereoscopic image, stereoscopic image printed matter, and method for providing stereoscopic image

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2021517980A (ja) * 2018-04-12 2021-07-29 モックステック・インコーポレーテッド 偏光子ナノインプリントリソグラフィ
JP7294590B2 (ja) 2018-04-12 2023-06-20 モックステック・インコーポレーテッド 偏光子ナノインプリントリソグラフィ

Similar Documents

Publication Publication Date Title
US11513272B2 (en) Wire grid polarizer with silane protective coating
US10054717B2 (en) Oxidation and moisture barrier layers for wire grid polarizer
US10025015B2 (en) Wire grid polarizer with phosphonate protective coating
US10534120B2 (en) Wire grid polarizer with protected wires
US10139536B2 (en) Embedded wire grid polarizer with high reflectivity on both sides
US10656309B2 (en) Overcoat wire grid polarizer having overcoat layer spanning air-filled channels
WO2016160786A1 (fr) Polariseur à grille de fils à revêtement protecteur en silane
WO2016160784A1 (fr) Polariseur à grille de fils utilisant des matériaux solubles dans l'eau
WO2016160795A1 (fr) Polariseur à grille métallique à revêtement de protection en phosphonate
JP2004260081A (ja) 紫外域用反射ミラー装置及びそれを用いた投影露光装置
EP3545344A1 (fr) Polariseur à grille de fil de finition
JP7200510B2 (ja) 配向方法及び光配向装置
CN112639547B (zh) 耐用的高性能线栅偏振器
JP2005258028A (ja) 光学部品及び投写型表示装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 16773981

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 16773981

Country of ref document: EP

Kind code of ref document: A1