Method for manufacturing glass laminate, and glass laminate

Abstract

A method for manufacturing a glass laminate, the method comprising forming a film containing a high refractive index material on a glass substrate, wherein the glass substrate contains at least one selected from the group consisting of B2O3, P2O5, and GeO2, and the average linear expansion coefficient of the glass substrate at 50-200°C is 2.5-4.0 ppm / K.

Description

Glass laminate manufacturing method and glass laminate

[0001] The present disclosure relates to a method for manufacturing a glass laminate and a glass laminate.

[0002] In conventional semiconductor assembly processes, a silicon substrate and a glass substrate in wafer form are cut and bonded together, and then assembly is performed by die bonding, wire bonding, molding, etc. In recent years, wafer-level packaging technology, in which a silicon substrate and a glass substrate are bonded together in full-size wafer form, an assembly process is performed, and then cutting is performed, has been attracting attention as a next-generation chip-size package (CSP) technology.

[0003] A heat treatment process is required to bond a silicon substrate and a glass substrate. However, the heat treatment process generates a large residual strain in the substrate. Therefore, in Patent Document 1, the elongation rate α １ and the thermal expansion rate α of the silicon bonded to the glass. ２ Ratio α １ / α ２ In Patent Document 2, a glass for a silicon pedestal used in a semiconductor pressure sensor or the like is proposed, in which the coefficient of thermal expansion is within a specific range. ２ A planar optical circuit for use in optical communications, optical signal processing, optical measurement, etc. has been proposed, which has a core made of silica glass doped with ZnO at a specific concentration.

[0004] Japanese Patent Laid-Open No. 7-247134 Japanese Patent Laid-Open No. 2005-265892

[0005] One embodiment of the glass laminate has a sub-nano-order three-dimensional structure called a meta-atom, which is about one-tenth the wavelength of light, in an arbitrary pattern on a flat transparent glass substrate. In one embodiment of the glass laminate, the meta-atom changes the phase and amplitude of light of a specific wavelength, thereby exhibiting functions such as absorption, reflection, and diffraction. The meta-atom is produced by attaching meta-atom raw materials to a glass substrate, annealing it by heat treatment to form a film, and then processing the film.

[0006] However, the glass substrate used in the glass laminate has a thermal expansion coefficient that is significantly different from that of the raw material of meta-atom, such as silicon, and there has been a problem in that the substrate warps significantly during the heat treatment process in the production of the glass laminate, which has made handling during the production process and mass production of the glass laminate difficult.

[0007] The present disclosure has been made in view of the above, and relates to providing a method for manufacturing a glass laminate and a glass laminate in which warping of a glass substrate and a film formed on the glass substrate is suppressed.

[0008] The present disclosure includes the following aspects: <1> A film containing a high refractive index material is formed on a glass substrate, and the glass substrate is B ２ O ３ , P ２ O ５ , and GeO ２ and the glass substrate has an average linear expansion coefficient of 2.5 to 4.0 ppm / K at 50 to 200°C. ２ O ３ , P ２ O ５ , and GeO ２ <3> The method for producing a glass laminate according to <1>, wherein the total amount of B contained in the glass substrate is more than 11 mol% and less than 38 mol%. ２ O ３ , P ２ O ５ , and GeO ２ <4> The method for producing a glass laminate according to any one of <1> to <3>, wherein the glass substrate is a silicate glass substrate. <5> The method for producing a glass laminate according to <1> or <2>, wherein the main surface of the glass substrate has an area of ​​0.015 m ２The method for producing a glass laminate according to any one of <1> to <4>, wherein the thickness of the glass substrate is 0.1 to 3.0 mm. <6> The method for producing a glass laminate according to any one of <1> to <5>, wherein the thickness of the glass substrate is 0.1 to 3.0 mm. <7> The method for producing a glass laminate according to any one of <1> to <6>, wherein the thickness of the film containing a high refractive index material is 0.00001 to 0.01 times the thickness of the glass substrate. <8> The method for producing a glass laminate according to any one of <1> to <7>, wherein the thickness deviation of the glass substrate is 5 μm or less and the surface roughness of the glass substrate is 5 nm or less. <9> The method for producing a glass laminate according to any one of <1> to <8>, wherein the warpage of the glass substrate on which the film is formed, as measured in accordance with JIS B 0621, is 50 μm or less. <10> The method for producing a glass laminate according to any one of <1> to <9>, wherein the high refractive index material is silicon. <11> The method for producing a glass laminate according to any one of <1> to <10>, comprising forming a metasurface structure on the glass substrate by photolithography, electron beam lithography, or nanoimprint lithography on the film. <12> The method comprises a glass substrate and a metasurface structure containing a high refractive index material, the glass substrate comprising B ２ O ３ , P ２ O ５ , and GeO ２ and the glass substrate has an average linear expansion coefficient of 2.5 to 4.0 ppm / K at 50 to 200°C.

[0009] According to the present disclosure, there are provided a method for manufacturing a glass laminate and a glass laminate in which warping of a glass substrate and a film formed on the glass substrate is suppressed.

[0010] An embodiment of the present disclosure will be described in detail below. However, the present disclosure is not limited to the following embodiment. In the following disclosure, components (including element steps, etc.) are not essential unless otherwise specified. The same applies to numerical values ​​and their ranges, and do not limit the present disclosure.

[0011] In this disclosure, the term "step" includes not only a step that is independent of other steps, but also a step that cannot be clearly distinguished from other steps as long as the purpose of that step is achieved. In this disclosure, numerical ranges indicated using "to" include the numerical values ​​before and after "to" as the lower and upper limits, respectively. In numerical ranges described in stages in this disclosure, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another staged numerical range. Furthermore, in numerical ranges described in this disclosure, the upper or lower limit of that numerical range may be replaced with a value shown in the examples. In this disclosure, when multiple substances corresponding to each component are present in the composition, the content of each component in the composition means the total content of those multiple substances present in the composition, unless otherwise specified. In this disclosure, when multiple elements are listed using "or," this does not exclude the selection of multiple elements in combination unless otherwise specified, unless a technical contradiction occurs. In this disclosure, when elements are described in the singular, this does not exclude the presence of multiple elements unless otherwise specified, unless a technical contradiction occurs. In the present disclosure, multiple exemplary aspects described separately may be combined with each other to form a new aspect, unless they contradict each other.

[0012] <<Method for manufacturing glass laminate>> A method for manufacturing a glass laminate according to the present disclosure includes forming a film containing a high refractive index material on a glass substrate, and the glass substrate is ２ O ３ , P ２ O ５ , and GeO ２ and the glass substrate has an average coefficient of linear expansion (also referred to as average CTE) of 2.5 to 4.0 ppm / K at 50 to 200°C.

[0013] According to the method for producing a glass laminate of the present disclosure, warping of the glass substrate and the film formed on the glass substrate is suppressed.

[0014] Reducing the difference in average CTE between the glass substrate and the high refractive index material before crystallization significantly reduces warpage of the glass substrate and the film containing the crystallized high refractive index material during a heat treatment process, such as crystallizing the high refractive index material. Since the coefficient of linear expansion (CTE) is a material-specific value, it is possible to improve the material to achieve the desired average CTE. However, if a certain concentration of impurities is added (i.e., doped) to match the average CTE between the glass substrate and the high refractive index material attached to the glass substrate, the refractive index and viscosity also change, making it difficult to handle the material during the manufacturing process. For example, if impurities are added at a concentration above a certain level, the average CTE becomes too high, causing tensile stress and making cracks (breaks and / or chips) more likely to occur. Furthermore, if impurities are added at a concentration below a certain level, the average CTE does not increase significantly, resulting in compressive stress and birefringence. According to the manufacturing method of the glass laminate disclosed herein, in order to reduce the difference in average CTE between the glass substrate and the high refractive index material before crystallization, B is added to the glass substrate. ２ O ３ , P ２ O ５ , and GeO ２ The glass substrate contains at least one selected from the group consisting of the following, and the average CTE of the glass substrate at 50 to 200°C is set to 2.5 to 4.0 ppm / K. ２ O ３ , P ２ O ５ , and GeO ２ This is because the dopant content (i.e., the dopant level) increases the average CTE of the glass substrate. This allows the average CTE of the glass substrate to reach a desired value, reducing the difference in average CTE from the high refractive index material before crystallization. Therefore, according to the method for manufacturing a glass laminate of the present disclosure, warping of the glass substrate and the film formed on the glass substrate is suppressed, making it easier to handle and mass-produce in the manufacturing process.

[0015] <Glass Substrate> (Metal Element) The glass substrate used in the method for producing a glass laminate of the present disclosure is preferably a silicate glass substrate, from the viewpoint of reducing contamination of semiconductor production equipment, and may also be a quartz glass substrate.

[0016] The glass substrate is B ２ O ３ , P ２ O ５ , and GeO ２ In order to suppress warpage, the glass substrate contains at least one selected from the group consisting of B ２ O ３ and GeO ２ It is preferable that the composition contains at least one selected from the group consisting of:

[0017] B contained in the glass substrate ２ O ３ , P ２ O ５ , and GeO ２ The total amount of B contained in the glass substrate is preferably more than 11 mol % and less than 38 mol % from the viewpoint of suppressing warpage. ２ O ３ , P ２ O ５ , and GeO ２ From the viewpoint of weather resistance, the total amount of B is preferably 37 mol % or less, more preferably 34 mol % or less or 32 mol % or less, still more preferably 30 mol % or less, and particularly preferably 28 mol % or less. ２ O ３ , P ２ O ５ , and GeO ２ In order to adjust the average coefficient of linear expansion (average CTE), the total amount is preferably 12% or more, more preferably 15% or more, even more preferably more than 20%, still more preferably 21% or more, and particularly preferably 25% or more.

[0018] B on the glass substrate ２ O ３ When B is contained in the glass substrate, it is preferable to reduce B in the glass substrate from the viewpoint of weather resistance. ２ O ３ The content of is preferably less than 38 mol%, more preferably 37 mol% or less, even more preferably 35 mol% or less, particularly preferably 30 mol% or less, and may be 28 mol% or less, 25 mol% or less, 20 mol% or less, or 15 mol% or less. ２ O ３When B is contained, the lower limit is not particularly limited, but in order to adjust the average coefficient of linear expansion (average CTE), B in the glass substrate ２ O ３ The content of P may be 5 mol % or more, 8 mol % or more, 12 mol % or more, 16 mol % or more, or 20 mol % or more. ２ O ５ When the glass substrate contains P, the P content in the glass substrate is reduced from the viewpoint of weather resistance. ２ O ５ The content of P is preferably less than 38 mol%, more preferably 37 mol% or less, even more preferably 30 mol% or less, particularly preferably 25 mol% or less, and may be 20 mol% or less, or 15 mol% or less. ２ O ５ When P is contained in the glass substrate, the lower limit is not particularly limited, but in order to adjust the average coefficient of linear expansion (average CTE), ２ O ５ The content of GeO may be 5 mol % or more, 8 mol % or more, 11 mol % or more, 16 mol % or more, or 20 mol % or more. ２ When GeO is contained in the glass substrate, it is preferable to use GeO ２ The content of GeO is preferably less than 38 mol%, more preferably 37 mol% or less, even more preferably 35 mol% or less, particularly preferably 30 mol% or less, and may be 28 mol% or less, 25 mol% or less, 20 mol% or less, or 15 mol% or less. ２ When GeO is contained in the glass substrate, the lower limit is not particularly limited, but in order to adjust the average coefficient of linear expansion (average CTE), ２ The content of B in the glass substrate may be 5 mol% or more, 8 mol% or more, 12 mol% or more, 15 mol% or more, or 18 mol% or more. ２ O ３ , P ２ O ５ , and GeO ２ The content and total amount of each of the above can be measured by inductively coupled plasma mass spectrometry (ICP-MS).

[0019] On the glass substrate, ２ O ３ , P ２ O ５ , and GeO２ The method for incorporating the element is not particularly limited. Examples of the method include a known doping method, in which the desired element is mixed into a slurry composition that is a raw material for the glass substrate.

[0020] From the viewpoint of reducing contamination of semiconductor manufacturing equipment, the total amount of alkali metal elements in the glass substrate is preferably 200 ppm or less by mass, more preferably 100 ppm or less, and even more preferably 50 ppm or less. The lower limit of the total amount of alkali metal elements in the glass substrate is not particularly limited, and may be 0 ppm or more or more than 0 ppm. The total amount of alkali metal elements in the glass substrate may be 0 to 200 ppm by mass. In the present disclosure, the total amount of alkali metal elements in the glass substrate is calculated by analyzing the content of each alkali metal, such as Na and K, based on an ICP-MS method and calculating the total amount of the analysis results.

[0021] From the viewpoint of reducing contamination of semiconductor manufacturing equipment, the content of each of Ti, Cu, Cr, Ce, Ni, and Zn contained in the glass substrate is preferably 20 ppm or less by mass, more preferably 10 ppm or less, and even more preferably 5 ppm or less. The lower limit of the content of each of Ti, Cu, Cr, Ce, Ni, and Zn contained in the glass substrate is not particularly limited, and each may be 0 ppm or more or more than 0 ppm. The content of each of Ti, Cu, Cr, Ce, Ni, and Zn contained in the glass substrate may be 0 to 20 ppm by mass. In the present disclosure, the content of each of Ti, Cu, Cr, Ce, Ni, and Zn contained in the glass substrate can be measured based on an ICP-MS method.

[0022] From the viewpoint of reducing contamination of semiconductor manufacturing equipment, the total amount of Fe contained in the glass substrate is preferably 100 ppm or less by mass, more preferably 80 ppm or less, and even more preferably 50 ppm or less. The lower limit of the total amount of Fe contained in the glass substrate is not particularly limited, and may be 0 ppm or more or more than 0 ppm. The total amount of Fe contained in the glass substrate may be 0 to 100 ppm by mass. In the present disclosure, the total amount of Fe contained in the glass substrate can be measured based on an ICP-MS method.

[0023] There are no particular limitations on the method for reducing the total amount of alkali metal elements, the contents of Ti, Cu, Cr, Ce, Ni, and Zn, and the total amount of Fe contained in the glass substrate. Examples of such methods include manufacturing a glass substrate using raw materials with higher purity than conventional ones, manufacturing a glass substrate in equipment separated from equipment for manufacturing other products other than the glass substrate of the present disclosure, and manufacturing a glass substrate by controlling the cooling process of the glass substrate (for example, by controlling the material of the cooling device, the cooling medium, and preventing contamination from the surrounding atmosphere during cooling), and these methods may be combined.

[0024] (Composition) The composition of the glass substrate is B ２ O ３ , P ２ O ５ , and GeO ２ and the average linear expansion coefficient of the glass substrate at 50 to 200° C. is 2.5 to 4.0 ppm / K, other components are not particularly limited.

[0025] For example, the composition of the glass is, on a molar basis, SiO ２ : 70 to 75% and B ２ O ３ : 25 to 30% may be used, SiO ２ : 70 to 75% and GeO ２ : 25 to 30% may be used, SiO ２ : 70-75%, B ２ O ３ : 12.5 to 15%, and GeO ２ : 12.5 to 15% is also acceptable.

[0026] Alternatively, the composition of the glass substrate is GeO ２ may be silicate glass doped with GeO at a concentration of 25 to 35 mol %. ２ , P ２ O ５ , and B ２ O ３ The silicate glass may be doped with at least two of the above.

[0027] The glass substrate may contain, as a fining agent, for example, SnO ２ , S.O.３ , Cl, F, etc. may be contained.

[0028] The glass substrate may be coated with, for example, ZnO, Li, in order to improve weather resistance, solubility, devitrification resistance, ultraviolet shielding, infrared shielding, ultraviolet transmission, or infrared transmission. ２ O.W.O. ３ , Nb ２ O ５ , V ２ O ５ , Bi ２ O ３ , MoO ３ , P ２ O ５ , Ga ２ O ３ , I ２ O ５ , In ２ O ５ , or Ge ２ O ５ etc. may be contained.

[0029] The glass substrate is made of ZrO ２ , Y ２ O ３ , La ２ O ３ , TiO ２ , and SnO ２ The total amount of Y may be 2% or less, preferably 1% or less, and more preferably 0.5% or less, expressed as mole percentage based on oxides. ２ O ３ , La ２ O ３ and TiO ２ This also contributes to improving the Young's modulus of the glass substrate.

[0030] Considering the environmental impact of glass substrates, ２ O ３ and Sb ２ O ３ In consideration of stable float molding, it is preferable that the glass substrate does not substantially contain ZnO. In consideration of preventing crystallization, the glass substrate should preferably contain Al. ２ O ３In the present disclosure, "substantially free of a specific substance" means that the specific substance is not contained at all, or that the specific substance may be contained as an impurity that is inevitably mixed in during production.

[0031] (Average coefficient of linear expansion (average CTE)) B ２ O ３ , P ２ O ５ , and GeO ２ increases the average CTE of the glass substrate depending on its content (i.e., dopant level). From the viewpoint of suppressing warpage of the glass substrate and warpage of the film containing a high refractive index material, in the method for producing a glass laminate of the present disclosure, the average CTE of the glass substrate at 50 to 200°C is 2.5 to 4.0 ppm / K, preferably 2.8 to 3.8 ppm / K, and more preferably 3.0 to 3.6 ppm / K. When the high refractive index material is silicon, the average CTE value of the glass substrate is particularly preferable. Note that, in the present disclosure, the average CTE at 50 to 200°C is the average CTE measured by the method specified in JIS R3102 (1995), in the temperature range of 50 to 200°C for measuring the coefficient of linear expansion (CTE).

[0032] Furthermore, if the interfacial adhesion between the glass substrate and the high refractive index material is weak, cracks and wrinkles will occur on the film containing the high refractive index material. By setting the average CTE of the glass substrate at 50 to 200°C to 2.5 to 4.0 ppm / K, the interfacial adhesion between the glass substrate and the high refractive index material is strengthened.

[0033] From the viewpoint of suppressing warpage of the glass substrate and warpage of the film containing a high refractive index material, the difference in average CTE between the glass substrate and the high refractive index material described below before crystallization at 50 to 200° C. is preferably within ±0.5 ppm / K, more preferably within ±0.3 ppm / K, and even more preferably within ±0.1 ppm / K. For example, the difference in average CTE between the glass substrate and the high refractive index material before crystallization at 50 to 200° C. can be determined from the difference between the average CTE of the glass substrate at 50 to 200° C. and the average CTE of the high refractive index material before crystallization at 50 to 200° C.

[0034] (Size) The glass laminate, which is currently in the development phase, is manufactured in small piece sizes, and warping of the glass substrate and the film containing the high refractive index material due to the heat treatment process is minimal. However, when mass-producing glass laminates at substrate sizes common in semiconductor processes, the influence of warping, which was not apparent in the previous small piece sizes, becomes more pronounced as the glass laminate becomes larger. The area of ​​the main surface of the glass substrate is 0.015 m ２ The area is preferably 0.015 m or more. ２ If the area is 0.025 m, a large number of glass laminate pieces can be manufactured from a single glass substrate. Furthermore, the warpage suppression effect of the manufacturing method of the present disclosure is also increased. ２ More preferably, 0.04 m or more ２ More preferably, 0.05 m or more ２ The above is particularly preferred. The larger the area of ​​the main surface, the more optical components can be obtained from the glass laminate, improving mass productivity and reducing variations in the quality of the optical components, which is preferable. There is no particular upper limit to the area of ​​the main surface of the glass substrate, and it is within 1 m ２ The area of ​​the main surface of the glass substrate may be, for example, 0.015 to 1 m ２ That's fine too.

[0035] In the present disclosure, the main surface of the glass substrate refers to the surface of the glass substrate on which a film containing a high refractive index material is formed. The area of ​​the main surface of the glass substrate can be measured by image analysis using a transmission type dimension measuring instrument or the like.

[0036] When glass laminates are mass-produced in sizes that are common substrate sizes in semiconductor processes, such as a diameter of 6 inches (150 mm) for circular substrates or a side length of 6 inches (150 mm) or more for square substrates, the larger size of the glass laminate makes the effects of warping, which were not apparent with previous small piece sizes, more pronounced. When the glass substrate is circular, the diameter of the glass substrate is preferably 6 inches (150 mm) or more, more preferably 8 inches (200 mm) or more, and even more preferably 12 inches (300 mm) or more. The upper limit of the diameter of the glass substrate is not particularly limited, and may be 50 inches (1270 mm) or less. The diameter of the glass substrate may be, for example, 6 to 50 inches. When the glass substrate is square, the length of one side of the glass substrate is preferably 6 inches (150 mm) or more, more preferably 8 inches (200 mm) or more, and even more preferably 12 inches (300 mm) or more. The upper limit of the length of one side of the glass substrate is not particularly limited, and may be 50 inches (1270 mm) or less. The length of one side of the glass substrate may be, for example, 6 to 50 inches.

[0037] (Thickness) The thickness of the glass substrate is not particularly limited, and from the viewpoint of utilizing existing semiconductor manufacturing equipment for the production of the glass laminate and the viewpoint of back-grinding efficiency, it is preferably 3.0 mm or less, more preferably 2.0 mm or less, and even more preferably 1.0 mm or less. The lower limit of the thickness of the glass substrate is not particularly limited, and may be 0.1 mm or more, or may be 0.5 mm or more. The thickness of the glass substrate may be, for example, 0.1 to 3.0 mm. Furthermore, when a thinner laminate is desired, the thickness of the glass substrate can be further reduced by grinding and polishing only the glass substrate side of the glass laminate (i.e., the surface opposite to the surface on which the film containing the high refractive index material is formed) in the manufacturing process of the glass laminate, and in that case the thickness of the glass substrate will be even thinner than 0.5 mm. Since the susceptibility to warping also varies depending on the thickness of the film containing the high refractive index material, the thickness of the film containing the high refractive index material is preferably 0.00001 to 0.01 times, more preferably 0.0001 to 0.005 times, and even more preferably 0.0001 to 0.0035 times the thickness of the glass substrate. In the present disclosure, the thickness of the glass substrate is measured by an optical interference thickness measurement method. The optical interference thickness measurement method involves measuring the phase difference of reflected light from the front and back surfaces using, for example, an optical interference thickness measurement device (FlatMaster 200) from Corning-Tropel.

[0038] (Thickness Deviation (TTV)) From the viewpoint of processing the crystallized high refractive index material with high precision, the thickness deviation (TTV) of the glass substrate is preferably 5 μm or less, more preferably 3 μm or less, and even more preferably 1 μm or less. When the thickness deviation of the glass substrate is 5 μm or less, the film thickness uniformity of the high refractive index material within the plane of the glass laminate is improved, and the variation in optical property quality can be reduced, leading to improved productivity of optical components obtained from the glass laminate. The lower limit of the thickness deviation of the glass substrate is not particularly limited and may be 0 μm or more. The thickness deviation of the glass substrate may be, for example, 0 to 5 μm. In the present disclosure, the thickness deviation of the glass substrate is measured by optical interferometry.

[0039] From the viewpoint of processing a crystallized high refractive index material with high precision, the warp of the glass substrate (the difference between the maximum and minimum deviations of the central surface from a reference surface) is preferably 50 μm or less, more preferably 30 μm or less, and even more preferably 20 μm or less. The lower limit of the warp of the glass substrate is not particularly limited and may be 0 μm or more. The warp of the glass substrate may be, for example, 0 to 50 μm. In the present disclosure, the warp of the glass substrate is measured by optical interferometry.

[0040] (Amount of Warpage) In all processes from the glass substrate to the production of the glass laminate, the amount of warpage of the glass substrate on which a film containing a high refractive index material is formed is preferably 50 μm or less, more preferably 30 μm or less, and even more preferably 20 μm or less. Suppressing the amount of warpage to 50 μm or less reduces the impact of warpage in the manufacturing process in mass production. The lower limit of the amount of warpage of the glass substrate on which a film containing a high refractive index material is formed may be 0 μm or more. The amount of warpage of the glass substrate may be, for example, 0 to 50 μm. In the present disclosure, the amount of warpage of the glass substrate is defined as the flatness measured according to JIS B 0621:1984 (ISO 1101:1983).

[0041] (Surface Roughness (Ra)) From the viewpoint of processing a crystallized high refractive index material with high precision, the surface roughness (Ra) of the glass substrate is preferably 5 nm or less, more preferably 3 nm or less, and even more preferably 1 nm or less. The lower limit of the surface roughness of the glass substrate is not particularly limited, and may be 0 nm or more. The surface roughness of the glass substrate may be, for example, 0 to 5 nm. In the present disclosure, the surface roughness of the glass substrate is measured by atomic force microscopy (AFM).

[0042] (End Face Surface Roughness) From the viewpoint of preventing debris and dust generation, the end face surface roughness of the glass substrate is preferably 50 nm or less, more preferably 25 nm or less, and even more preferably 10 nm or less. The lower limit of the end face surface roughness of the glass substrate is not particularly limited, and may be 0 nm or more. The end face surface roughness of the glass substrate may be, for example, 0 to 50 nm. In the present disclosure, the end face surface roughness of the glass substrate is measured using a laser microscope.

[0043] (Edge Shape) From the viewpoint of preventing damage due to physical contact of the edge surface during the manufacturing process and packaging, the edge shape of the glass substrate is preferably slightly chamfered, more preferably C-chamfered, and even more preferably R-chamfered.

[0044] (Shape) From the viewpoint of manufacturing a glass laminate with high precision, the shape of the glass substrate is preferably circular. The shape of the glass substrate may be elliptical or rectangular. In order to match with the high refractive index material to be attached and annealed, the glass substrate may have a notch at the edge, and if the glass substrate is circular, part of the periphery of the glass substrate may be straight.

[0045] (Refractive index) P ２ O ５ and GeO ２ increases the refractive index of the glass substrate depending on its content (i.e., dopant level). ２ O ３ The dopant lowers the refractive index of the glass substrate depending on its content (i.e., dopant level). The refractive index of the glass substrate at 589.6 nm is preferably 1.00 to 2.00, more preferably 1.20 to 1.80, and even more preferably 1.40 to 1.60. In the present disclosure, the refractive index can be measured using a precision refractometer in accordance with the V-block method (JIS B 7071-2:2018 (ISO 21395-2:2022)).

[0046] The glass substrate has a devitrification viscosity (ηTL) of 10 ３．８ The devitrification viscosity is preferably 10 d·Pa·s or more. ３．８ If the viscosity is d·Pa·s or more, it is easy to form stably. ４．０ d·Pa·s or more is more preferable, and 10 ４．２ The devitrification viscosity is more preferably d·Pa·s or more. The devitrification viscosity is determined from the glass viscosity at the glass devitrification temperature by determining the coefficients of the Fulcher equation from the results of measuring the glass viscosity of the molten glass at a high temperature (1000 to 1600°C) using a rotational viscometer, and then using the Fulcher equation using the coefficients.

[0047] The glass substrate preferably has a Young's modulus of 70 GPa or more. If the Young's modulus is 70 GPa or more, warping or cracking of the glass substrate occurring during the slow cooling process in manufacturing the glass substrate can be more effectively suppressed. In addition, breakage due to contact with high refractive index materials or peripheral members can be more effectively suppressed. The Young's modulus is more preferably 72 GPa or more, even more preferably 75 GPa or more, and particularly preferably 78 GPa or more. The Young's modulus can be measured by an ultrasonic pulse method.

[0048] The Young's modulus is preferably 100 GPa or less. If the Young's modulus is 100 GPa or less, the brittleness of the glass can be reduced, and chipping during cutting and dicing of the glass substrate can be reduced. The Young's modulus is more preferably 90 GPa or less, and even more preferably 87 GPa or less. The Young's modulus may be, for example, 70 to 100 GPa.

[0049] The glass substrate has a density of 2.60 g / cm ３ Preferably, the density is 2.60 g / cm or less. ３ If the density is 2.50 g / cm or less, the glass substrate is lightweight and the deflection of the glass substrate due to its own weight can be reduced. ３ More preferably, 2.40 g / cm or less ３ The following is even more preferred: The density can be measured by Archimedes' method using a glass block of about 20 g containing no bubbles.

[0050] The density is 2.10 g / cm ３ The density is preferably 2.10 g / cm or more. ３ If the density is 2.20 g / cm or more, the Vickers hardness of the glass increases, making the glass surface less susceptible to scratches. ３ More preferably, 2.30 g / cm ３ The above is more preferable.

[0051] The density of defects contained in the glass substrate is 1 / cm ２The following is preferable. Defects contained in a glass substrate refer to bubbles, scratches, metal foreign matter such as platinum, and unmelted raw materials present on the surface or inside of the glass substrate, and refer to defects having a size of 0.5 μm or more and 1 mm or less. If the defects are larger than 1 mm, they can be easily identified visually, and it is easy to exclude substrates having defects. If the defects are smaller than 0.5 μm, they are sufficiently small that they will not affect the characteristics of the elements even when used as cover glass for CMOS sensors or LCOS.

[0052] In conventional semiconductor assembly processes, the assembly process is performed after cutting the glass substrate, so if there is a defect in the glass substrate, the defective substrate can be removed early in the assembly process. On the other hand, in wafer-level packaging, the glass laminate is singulated at the end of the assembly process, so if there is a defect in the glass substrate, the defective glass substrate can only be removed at the end of the assembly process. As such, in wafer-level packaging, high-quality defect management is required because an increase in the density of defects in the glass substrate results in a significant increase in costs. The defect density is 0.1 / cm. ２ More preferably, 0.01 particles / cm or less ２ The following is even more preferred:

[0053] The glass substrate preferably has a glass transition point (Tg) of 700°C or higher. If the Tg is 700°C or higher, dimensional changes in the glass substrate can be further reduced during the heat treatment process. The Tg is more preferably 720°C or higher, and even more preferably 740°C or higher. The glass transition point can be measured using a thermomechanical analyzer (TMA) according to the method specified in JIS R3103-3 (2001) (ISO 7884-8:1987).

[0054] The glass substrate has a mass loss in hydrofluoric acid (HF) solution (hereinafter also referred to as HF mass loss) of 0.01 to 0.20 (mg / cm ２ Here, the HF mass loss is the loss per unit area and unit time (mg / cm) when the glass substrate is immersed in a 5% by mass aqueous solution of hydrofluoric acid at 25°C. ２ ) / min).

[0055] After annealing the glass substrate with the high refractive index material, it can be directly incorporated as part of a device. For example, the glass substrate is incorporated into the device as a cover glass. In this case, it is preferable to slim the glass substrate to miniaturize the device. Therefore, it is preferable that the glass substrate has a high slimming rate. The HF mass loss is used as an indicator of the slimming rate of the glass substrate.

[0056] HF mass reduction amount is 0.01 (mg / cm) ２ ) / min or more, the productivity of the slimming step is improved, which is preferable. ２ ) / minute or less is preferable because defects such as uneven etching depth and loss of smoothness of the glass substrate surface, which occur in the slimming step, can be prevented.

[0057] Glass laminates can be used in optical applications such as optical sensing and optical lenses, for example, as components for face recognition and camera lenses. In this case, if the photoelastic constant of the glass substrate is high, the glass substrate will have birefringence due to stress generated during the device packaging process or during device use. As a result, color changes occur in the light incident on the device, which can lead to poor image quality such as color unevenness.

[0058] To prevent such poor image quality, the photoelastic constant of the glass substrate is preferably 37 nm / (MPa·cm) or less, more preferably 35.0 nm / (MPa·cm) or less, and even more preferably 33 nm / (MPa·cm) or less.

[0059] The alpha ray emission rate of the glass substrate is 0.5 C / cm ２ h or less is preferable, and 0.3 C / cm ２ h or less is more preferable, and 0.1 C / cm ２ h or less is particularly preferred, and 0.05 C / cm ２ ・It is most preferable that the number be less than h. The unit C means the number of counts.

[0060] For example, glass laminates can be used as IR cut filters for CCD and CMOS image sensor elements. In this case, when alpha rays emitted from a glass substrate are incident on an element such as an image sensor, the energy of the alpha rays induces hole-electron pairs, potentially causing soft errors that momentarily result in bright or white spots on the image. Therefore, using a glass substrate with low alpha-ray emission can help prevent such defects. Furthermore, the amount of alpha-ray emission can be reduced by using high-purity raw materials with low radioisotope content and low alpha-ray emission as the raw material for the glass substrate. Furthermore, preventing radioisotopes from being mixed into the molten glass from furnace materials in glass manufacturing equipment during the glass melting and fining process can effectively reduce the amount of alpha-ray emission. "Amount of alpha-ray emission" can be measured using a gas flow proportional counter or other measuring device.

[0061] (Surface Treatment of Glass Substrate) The surface of the glass substrate may be partially or entirely surface-treated. If the surface-treated glass substrate is used, impurities (e.g., alkali metal elements) contained in the glass substrate are less likely to elute during the manufacturing process of the glass laminate, and process contamination due to contamination is less likely to occur. The method of surface treatment is not particularly limited, and examples include formation of a protective film (i.e., a protective film for preventing contaminant elution, such as a SiO film) and alkali leaching treatment of the outermost layer.

[0062] (Method for manufacturing glass substrate) The method for manufacturing the glass substrate used in the method for manufacturing the glass laminate of the present disclosure is not particularly limited, and the glass substrate can be manufactured by a known method. The method for manufacturing the glass substrate may include a melting step of heating glass raw materials to obtain molten glass, a fining step of removing bubbles from the molten glass, a forming step of forming the molten glass into a sheet shape to obtain a glass ribbon, and a gradual cooling step of gradual cooling the glass ribbon to room temperature.

[0063] The glass substrate may be manufactured by a sintering method. ２ O ３ , P ２ O ５ , and GeO ２and (c) mixing at least one selected from the group consisting of B to prepare a slurry composition, applying the slurry composition to a support in the form of a sheet, drying the sheet, and sintering the sheet. ２ O ３ , P ２ O ５ , and GeO ２ At least one selected from the group consisting of:

[0064] In addition, the method of applying a sheet-like coating to a support, drying it to obtain a sheet, and then sintering the sheet can produce a thinner glass substrate than a method including obtaining a glass ribbon.

[0065] The method for manufacturing a glass substrate may further include treating the surface of the glass substrate (surface treatment step). The method for manufacturing a glass substrate may further include slimming the glass substrate (slimming step). The slimming step may be, for example, a polishing step of back grinding or wet etching. For example, silicate glass has a slow back grinding rate and is easily broken, but B ２ O ３ , P ２ O ５ , and GeO ２ When at least one selected from the group consisting of: is contained, the back grinding rate becomes faster.

[0066] [Preparation of Slurry Composition] The slurry composition is obtained by mixing at least an inorganic powder, a binder, and an organic solvent. In addition, as described below, a dispersant, a plasticizer, an antifoaming agent, etc. can be mixed. The mixing method is not particularly limited, and a conventionally known method can be used.

[0067] Inorganic powders include silica powder, B ２ O ３ , P ２ O ５ , and GeO ２ etc.

[0068] The type of binder is not particularly limited, and examples thereof include polyvinyl alcohol-based resins such as polyvinyl alcohol, cellulose-based resins such as methyl cellulose, ethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, and cellulose acetate phthalate, acrylic resins such as poly(meth)acrylate, nitrile-based resins such as polyacrylonitrile and polymethacrylonitrile, urethane-based resins such as polyurethane, vinyl-based resins such as polyethylene, polypropylene, polyvinylidene fluoride, polyvinylidene chloride, polyvinyl fluoride, and vinyl acetate, rubber-based resins such as styrene-butadiene rubber, and epoxy-based resins. One binder can be used alone, or two or more binders can be used in combination. Commercially available binders may also be used.

[0069] Organic solvents are selected taking into consideration compatibility with binders, dispersants and plasticizers (described below), the desired properties of the sheet, the process load they can withstand, and other factors. Examples of organic solvents include hydrocarbons such as toluene, xylene, and methylcyclohexane; alcohols such as ethanol, n-propanol, isopropanol, n-butanol, and terpineol; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ethers such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, and propylene glycol monomethyl ether; and esters such as ethyl acetate, butyl acetate, isobutyl acetate, and propylene glycol monomethyl ether acetate. These organic solvents can be used alone or in combination of two or more.

[0070] Other Components The slurry composition may be prepared so as to contain dispersants, plasticizers, antifoaming agents, rheology control agents, wetting agents, and the like as other components.

[0071] Examples of dispersants include surfactant-type dispersants and polymer dispersants. Dispersants can be used alone or in combination of two or more. Examples of surfactant-type dispersants include alkylamine salts, aliphatic or aromatic quaternary ammonium salts, heterocyclic quaternary ammonium salts such as pyridinium and imidazolium, aliphatic or heterocyclic phosphonium or sulfonium salts, and acetylene glycol. Examples of polymer dispersants include polymers having primary to tertiary amines, quaternary ammonium bases, quaternary phosphonium bases, carboxylic acid groups, hydrochloric acid groups, or phosphate groups in the polymer main chain or side chain; homopolymers of acrylic acid or its salts; and homopolymers, copolymers, and block copolymers of aminocarboxylic acid, polyamine, polyurethane, and polyacrylate types. Commercially available dispersants may also be used.

[0072] Examples of the plasticizer include adipic acid-based, phthalic acid-based, terephthalic acid ester-based, triethylene glycol diester-based, and epoxy-based plasticizers. More specifically, bis(2-ethylhexyl) adipate, diisononyl adipate, diisodecyl adipate, di-2-ethylhexyl phthalate, diisononyl phthalate, diisodecyl phthalate, diundecyl phthalate, dibutyl phthalate, dioctyl phthalate, butyl benzyl phthalate, dioctyl terephthalate, triethylene glycol bis(2-ethylhexanoate), (2-ethylhexanoyloxy)triethylene glycol benzoate, triethylene glycol dibenzoate, di-2-ethylhexyl epoxyhexahydrophthalate, di-2-ethylhexyl azelate, di-2-ethylhexyl sebacate, diepoxystearyl epoxyhexahydrophthalate, and epoxidized soybean oil can be used. The plasticizers may be used singly or in combination of two or more. Commercially available products or reagents may be used as the plasticizer.

[0073] [Coating] Subsequently, the prepared slurry composition may be coated onto a support in the form of a sheet.

[0074] Examples of the support include resin films. Thermoplastic resin films are typically used as the resin film, and specific examples include polyethylene terephthalate films, polypropylene films, polyethylene films, polycarbonate films, polyethylene naphthalate films, polyarylate films, and nylon films. Among these resin films, polyethylene terephthalate films and polyethylene naphthalate films are preferred from the viewpoints of heat resistance, chemical resistance, and releasability after lamination. The thickness of the support is not particularly limited, and is typically 1 to 200 μm, preferably 2 to 100 μm, and more preferably 3 to 80 μm, from the viewpoint of workability and the like.

[0075] Coating Method: As a method for coating the slurry composition onto a support in the form of a sheet, a known wet coating method is used, such as spin coating, doctor blade method, reverse roll coater method, spray coating, dip coating, die coating, curtain coating, screen coating, inkjet method, flow coating, gravure coating, bar coating, flexo coating, slit coating, roll coating, sponge roll coating, and squeegee coating.

[0076] [Drying] The slurry composition may be applied to a support in the form of a sheet, followed by drying to obtain a sheet. Drying is a process of removing organic solvents and the like from the slurry composition applied to a support in the form of a sheet, followed by drying. Drying conditions are appropriately set depending on the type and amount of the organic solvent used, etc.

[0077] A sheet is obtained through the steps described above.

[0078] [Sintering] The method for producing a glass substrate may include sintering the sheet after removing the organic components.

[0079] Degreasing The organic components of the obtained sheet may be burned to obtain a degreased body.

[0080] The resulting degreased body may be sintered to obtain a sintered body. The degreased body may be sintered in air, vacuum, or an inert gas atmosphere.

[0081] <High Refractive Index Material> In the present disclosure, a high refractive index material refers to a material having a refractive index of 2.0 or higher. The upper limit of the refractive index is not particularly limited and is, for example, 4.0 or lower. The refractive index may be, for example, 2.0 to 4.0. The refractive index can be measured using a precision refractometer according to the V-block method. The high refractive index material used in the manufacturing method of a glass laminate of the present disclosure can be appropriately selected depending on the application of the glass laminate. For example, silicon may be selected for use in infrared sensing, and titania may be selected for use in a visible light lens. The high refractive index material may be silicon, single crystal silicon, polycrystalline silicon, amorphous silicon, polysilicon, silicon oxide, silicon nitride, titanium oxide (titania), gallium nitride, or gallium phosphide.

[0082] (Thickness) Generally, thicker materials have high rigidity and are less prone to warping, while thinner materials have low rigidity and are more prone to warping. According to the method for producing a glass laminate of the present disclosure, warping is suppressed even when the film containing a high refractive index material (also referred to as a high refractive index material layer) formed on the glass substrate is thin (i.e., when a thin film containing a high refractive index material is formed on the glass substrate). The thickness of the high refractive index material layer is not particularly limited, and from the viewpoint of easily manifesting the effects of the method for producing a glass laminate of the present disclosure, it is preferably 1 μm or less, more preferably 500 nm or less, and even more preferably 200 nm or less. The lower limit of the thickness of the high refractive index material layer is not particularly limited and may be 10 nm or more. The thickness of the high refractive index material layer may be, for example, 10 nm to 1 μm. In the present disclosure, the thickness of the high refractive index material layer is measured by an optical interference thickness measurement method. The optical interference thickness measurement method involves measuring the phase difference of reflected light from the front and back surfaces using, for example, an optical interference thickness measurement device (FlatMaster 200) from Corning-Tropel.

[0083] The glass laminate is formed by forming a film containing a high refractive index material on the glass substrate of the present disclosure. Because the difference in average CTE between the high refractive index material before crystallization and the glass substrate is small, warping of the glass substrate and the film containing the high refractive index material is small during a heat treatment process in which the high refractive index material attached to the glass substrate is annealed. Furthermore, the laminate substrate can be obtained, for example, by bonding a glass substrate and a crystallized high refractive index material with a peelable adhesive layer sandwiched between them. The peelable adhesive layer preferably contains an inorganic substance.

[0084] <Manufacturing of Glass Laminate> The method for manufacturing a glass laminate of the present disclosure includes forming a film containing a high refractive index material on a glass substrate. In one embodiment, the glass substrate may be cleaned. Forming a film containing a high refractive index material on the glass substrate may include attaching or depositing the high refractive index material on the glass substrate. In one embodiment, for example, a low-pressure chemical vapor deposition (LPCVD) method (e.g., SiH ４ The high refractive index material may be deposited on the glass substrate using a plasma enhanced chemical vapor deposition (PECVD) process, a high-density plasma chemical vapor deposition (HDPCVD) process, and / or any of a wide variety of alternative chemical vapor deposition (CVD) processes. The high refractive index material may be deposited on the glass substrate using a plasma enhanced chemical vapor deposition (PECVD) process, a high-density plasma chemical vapor deposition (HDPCVD) process, and / or any of a wide variety of alternative chemical vapor deposition (CVD) processes. The high refractive index material may be deposited such that the film comprising the high refractive index material has a thickness of 210 to 250 nm.

[0085] Forming a film including a high refractive index material on a glass substrate may include annealing the high refractive index material deposited on the glass substrate (also referred to as a heat treatment process). Annealing the high refractive index material crystallizes the high refractive index material to form a film. The deposited high refractive index material is annealed at an appropriate temperature for a time sufficient to reduce absorption losses and improve the transmission efficiency of the glass laminate. That is, rather than simply annealing to crystallize, harden, or stabilize the high refractive index material, the annealing process is carried out at an appropriate temperature and for a sufficient amount of time for the specific purpose of reducing absorption losses of optical radiation within a target operating bandwidth. In various embodiments, high refractive index materials that are not generally considered practical for use at optical frequencies are preferably annealed to reduce absorption losses by as much as 35%, thereby making the high refractive index material suitable for use at optical frequencies. For example, if the high refractive index material is polysilicon, the polysilicon may be annealed at a temperature of 900-1100°C for 30-90 minutes, depending on the polysilicon thickness, the target operating frequency band, and other target property functionality. For example, the optical properties of high refractive index materials may be improved by adding an inert atmosphere gas (e.g., argon, N) to reduce the extinction coefficient at shorter wavelengths. ２ This may be improved by annealing the high refractive index material at temperatures above 1000° C. for an hour or more in a refrigerated or refrigerated oven (eg, a refrigerated or refrigerated room).

[0086] A film containing a high refractive index material formed on a glass substrate may be formed into a metasurface structure by photolithography (e.g., deep ultraviolet lithography), electron beam lithography, or nanoimprint lithography.

[0087] The method of manufacturing a glass laminate of the present disclosure may include applying a resist (e.g., photoresist) onto the annealed layer of high refractive index material. In one embodiment, the resist may be a negative photoresist, such as Ma-N2403, or a positive photoresist, in which the masking and etching processes may be reversed or otherwise modified. In one embodiment, a lithography process, such as electron beam lithography (EBL) or another nanolithography technique, is used to define a pattern of deflector element diameters included in the glass laminate. The pattern of deflector element diameters may be repeated one or more times, and the pattern of deflector element diameters may be selected to provide a target deflection pattern for optical radiation within a target operating bandwidth.

[0088] The method for manufacturing a glass laminate of the present disclosure may also include developing the resist. In one embodiment, electron beam lithography (e-beam lithography: EBL) of the photoresist, developing the photoresist, and hard baking the photoresist (e.g., to generate a hard-baked photoresist pattern) may be performed. The photoresist is specifically developed to have a mask pattern corresponding to a target array of pillar diameters for the glass laminate. The target array of pillars may be a two-dimensional array of pillars with a pattern of diameters as contemplated and described in this disclosure or in the previously cited publications incorporated by reference. The target array of pillars is selected to achieve a specific polarization response for a targeted wavelength range according to either a reflective glass stack design, a diffractive glass stack design, a refractive glass stack design, or a filtering glass stack design.

[0089] The method of manufacturing a glass laminate of the present disclosure may include etching the annealed high refractive index material according to a mask pattern of the developed photoresist. In one embodiment, a partial etch of the high refractive index material where the resist was not developed may be performed. This first etch removes a portion of the high refractive index material between pillars protected by the photoresist cap on top, but does not etch the high refractive index material down to the glass substrate. This partial etch thus produces partially formed nanopillars of high refractive index material with a layer of unetched high refractive index material between adjacent partially formed pillars (nanopillars). According to various embodiments, this first etch may include a reactive ion etching (RIE) process (e.g., using HBr and / or Cl). ２ The method may include an RIE method using a fluorine atom or an iodine atom.

[0090] In one embodiment, the resist may be removed to reveal pillars (or other shaped deflector elements) of high refractive index material extending from the glass substrate. In one embodiment, not only one-dimensional rows of pillars can be fabricated, but two-dimensional arrays of pillars can also be fabricated. This fabrication method may be used to fabricate each glass stack pixel or glass stack subpixel separately, after which the individual glass stack pixels or glass stack subpixels can be bonded together. Alternatively, this fabrication method may be used to fabricate a complete two-dimensional array of glass stack pixels or glass stack subpixels as a single unit.

[0091] In one embodiment, removal of the photoresist mask layer may be performed to expose the partially formed pillars of high refractive index material and the unetched layer of high refractive index material along the substrate. The photoresist removal process may include, for example, O ２ Plasma removal, H ２Plasma stripping, application of 1-methyl-2-pyrrolidone (NMP), application of dimethyl sulfoxide (DMSO), combinations thereof, and / or alternative photoresist removal processes may be included.

[0092] In one embodiment, a second etch of the high refractive index material may be performed to remove the unetched layer of high refractive index material and complete the formation of nanopillars extending from the substrate. This second etch of the high refractive index material may slightly reduce the height of the partially formed nanopillars. Furthermore, it may completely remove any remaining photoresist from the nanopillars. This two-step etching process allows the second etch to set the height of the pillars to achieve the target pillar height. As detailed in this disclosure, the photoresist is removed between the first and second etches.

[0093] In one embodiment, a glass laminate may be manufactured having an array of passive deflector elements of various diameters extending from a substrate.

[0094] According to various embodiments, the glass stack pattern includes a rectangular (e.g., square) array of pillars of varying diameters corresponding to a target reflective pattern. In some cases, manufacturing techniques may limit the maximum size of a rectangular cell having an array of pillars. For example, tiles measuring approximately 1 cm on each side may be fabricated using a given manufacturing process (e.g., a CMOS process). Any number of these tiles may then be combined to form a glass stack having a rectangular aperture with a target length and width. While electron beam lithography is limited to device fabrication at the micron scale, or even millimeter scale, repeated tiling of the same pillar diameter array and combining adjacent tiles enables the fabrication of much larger devices.

[0095] For example, an array of pillars may be defined with various diameters to fit within micron- or millimeter-scale apertures. During fabrication, the pattern may be repeated as many times as desired to create much larger devices. For example, using a CMOS process, a device with a diameter of approximately 1.2 cm may be fabricated. ２ A 300 mm glass substrate can be used in a CMOS process to produce a glass laminate of approximately 1 cm ２ Multiple individual rectangular glass laminates can be produced, ranging in size from 100 mm to 120 mm. Glass laminates manufactured using CMOS fabrication techniques can be appropriately sized for use in smaller electronic devices (e.g., cell phones, computers, personal electronic devices, cameras, etc.).

[0096] In contrast, deep ultraviolet lithography may be used to produce glass stacks over the entire surface of a 300 mm glass substrate. Again, very small (e.g., micron- or millimeter-scale) square tiles may be replicated as many times as desired using the deep ultraviolet lithography process to produce rectangular glass stacks on the surface of the glass substrate. Display optics for satellites or other imaging devices may use relatively large glass stacks manufactured using deep ultraviolet lithography techniques.

[0097] In yet another embodiment, tiles are replicated in a nanoimprint lithography process to form 1 m (e.g., for digital display applications or large-scale optical imaging applications). ２ The above glass laminates may be produced by a nanoimprint lithography process, where a base tile defining an array of pillars with varying diameters can be replicated as many times as desired to produce glass laminates with target lengths and widths.

[0098] For example, nanoimprint lithography may be used to fabricate a glass laminate directly over an RGB display or directly over a digital imaging sensor. A glass laminate fabricated over an RGB display can deflect light from each individual LED in a target direction perpendicular to the plane of the display. This glass laminate can increase the effective brightness of each pixel and reduce crosstalk between individual red, green, and blue subpixels.

[0099] In one embodiment, the glass laminate associated with the blue subpixel (or other color channel subpixel) may be configured to modify the amount of light scattered during off-angle viewing of an RGB display. For example, blue light may be scattered more off-angle (e.g., in a direction other than perpendicular to the plane of the display) than the red and green color channels. Thus, a viewer of an RGB display may perceive a color shift toward the blue spectrum during off-angle viewing. In this manner, the glass laminate on an RGB display may be configured to normalize or equalize the amount of light scattered off-angle from each of the red, green, and blue subpixels.

[0100] According to various embodiments, the design of the array of pillars in each glass laminate is selected for compatibility with a particular manufacturing process. For example, the ratio of the height of each pillar to its diameter (or width) may be less than 3. Features with such aspect ratios can be lithographically defined and etched using CMOS processes. Similarly, high refractive index materials are generally considered to be CMOS compatible. However, other materials, such as titanium dioxide, are not used in the fabrication of glass laminates to maintain manufacturing process compatibility.

[0101] In one embodiment, a Bayer color filter implemented using glass stacks overlaid on an imaging sensor may be fabricated and may have red, green, and blue color filters. In one embodiment, the glass stacks described in this disclosure may enhance existing color filters (e.g., Bayer color filters, etc.) of a digital imaging sensor. For example, a discrete glass stack having a green frequency response may be matched to focus light radiation onto green subpixel color filters of an existing color filter array on the digital imaging sensor. Similarly, glass stacks having red and blue frequency responses may be matched to focus or otherwise direct light radiation onto red and blue subpixel color filters, respectively, of an existing color filter array on a digital imaging sensor or LED display.

[0102] In one embodiment, a narrowband pixel-mapping color filter implemented using a glass laminate may be fabricated. The glass laminate, or an array of multiple glass laminates, may be utilized in conjunction with a digital imaging sensor that does not have a traditional color filter array. In one embodiment, the correspondence of the red, green, and blue pixels of the glass laminate is used to provide a one-to-one correspondence to the sub-pixel detectors of the underlying digital imaging sensor.

[0103] For example, each of the three red glass laminates may be associated with a corresponding red sub-pixel detector element of the underlying digital imaging sensor. Similarly, each of the three green glass laminates may be associated with a separate green sub-pixel detector element of the digital imaging sensor, and each of the three blue glass laminates may be associated with a separate blue sub-pixel detector element of the digital imaging sensor. The effective bandwidth (e.g., the 3Db bandwidth) of each glass laminate may be in the range of 50-80 nm. Thus, a red glass laminate centered at 650 nm may propagate optical radiation between 625-675 nm, for example. For example, green and blue glass laminates centered at 535 nm and 490 nm, respectively, may propagate optical radiation of a similar bandwidth to the sub-pixel detector elements of the underlying digital imaging sensor.

[0104] In one embodiment, a subpixel multi-band color filter implemented using glass stacks may be fabricated, in which each glass stack is replaced with an array of nine subpixel glass stacks. The underlying digital imaging sensor may still include only nine subpixel detector elements. Thus, each array of nine subpixel glass stacks directs light radiation onto a single subpixel detector element of the digital imaging sensor.

[0105] In one embodiment, the red glass stack is replaced with an array of nine subpixel glass stacks. The central subpixel glass stack exhibits a central operating bandwidth of 650 nm. The surrounding eight subpixel glass stacks have operating bandwidths centered at wavelengths offset from the central subpixel glass stack by ±20 nm, ±15 nm, ±10 nm, and ±5 nm. Collectively, the array of nine subpixel glass stacks transmits a wider bandwidth of optical radiation to the subpixel detector elements of the underlying digital imaging sensor than would be possible using a single glass stack. Using the exemplary effective operating bandwidth of 50 nm above, the nine subpixel glass stacks can transmit optical radiation from 605 to 695 nm to the subpixel detector elements of the underlying digital imaging sensor.

[0106] In one embodiment, each glass stack can be replaced with an array of N subpixel glass stacks, where N is an integer value greater than 2. The tuning frequency offset of each subpixel glass stack of the plurality of subpixel glass stacks can be selected to achieve a target collective operating bandwidth.

[0107] In one embodiment, a subwavelength multi-band color filter implemented using glass stacks may be fabricated. The subwavelength multi-band color filter includes a glass stack filter for red, a glass stack filter for green, and a glass stack filter for blue that are subwavelength in size. As described above, the subwavelength multi-band color filter may effectively function as a two-dimensional array of flat prisms that directs red, green, and blue light emissions to corresponding sub-pixel detector elements of an underlying digital imaging sensor.

[0108] In one embodiment, an exemplary display system may be fabricated utilizing input and output glass stack couplers in conjunction with a waveguide. A controller and RGB laser assembly transmit optical radiation to a display engine that generates an RGB display. The input glass stack coupler combines the generated RGB optical radiation for transmission along the length of a waveguide. The output glass stack coupler receives the transmitted optical radiation and separates it from the waveguide for visualization to a user's eye (e.g., via frequency-selective focusing onto a target plane).

[0109] The method for manufacturing a glass laminate of the present disclosure may include a step of slimming a glass substrate having a metasurface structure. The slimming step may be, for example, a back-grinding polishing step or wet etching. For example, silicate glass has a slow back-grinding rate and is prone to cracking, but B ２ O ３ , P ２ O ５ , and GeO ２ The back grinding rate can be increased by adding at least one selected from the group consisting of: The glass substrate may be thinned to a thickness of 0.2 to 0.4 mm by back grinding.

[0110] The method for manufacturing a glass laminate of the present disclosure may include dicing a glass substrate having a metasurface structure. The dicing method is not particularly limited and may be stealth dicing or wet blade dicing.

[0111] <Glass Laminate> The glass laminate of the present disclosure is manufactured by the method for manufacturing a glass laminate of the present disclosure. The glass laminate of the present disclosure has a glass substrate and a metasurface structure including a high refractive index material, and the glass substrate is B ２ O ３ , P ２ O ５ , and GeO ２ and the glass substrate has an average linear expansion coefficient of 2.5 to 4.0 ppm / K at 50 to 200°C.

[0112] The descriptions regarding the glass laminate, glass substrate, high refractive index material, average CTE, etc. of the glass laminate of the present disclosure are the same as those described above in the manufacturing method of the glass laminate of the present disclosure. The glass laminate of the present disclosure is preferably a metalens.

[0113] The glass laminate of the present disclosure has a metasurface structure. The metasurface structure is formed on a glass substrate. The glass laminate can function as a lens by controlling the phase distribution of light. The metasurface structure is preferably a nanostructure, and more preferably a nanopillar structure.

[0114] The metasurface structure may be arranged two-dimensionally in the xy plane. The shape of the metasurface structure may be a rotationally symmetric shape such as a cylindrical shape or a square prism shape, or an asymmetric nanofin shape. The metasurface structure may be, for example, a cylinder with a diameter φ and a height H. In the glass laminate, this metasurface structure may be arranged periodically with a period U. In the metasurface structure, the diameter φ may have multiple values. In the metasurface structure, the height H may have only one value or multiple values. The diameter φ and the period U may be equal to or less than the wavelength of the light used.

[0115] The metasurface structures are arranged, for example, in a lattice pattern. The height H of the metasurface structures may be 10 to 1000 nm. The size of the metasurface structures is about 1 / 10 of the wavelength to be affected, and may be 100 to 1000 nm when acting in the near-infrared wavelength range, for example. The spacing L between adjacent metasurface structures may be 100 to 1000 nm.

[0116] The glass laminate can control the phase distribution of light by adjusting the arrangement of the metasurface structures, as well as the size and period of each metasurface structure. By adjusting the size and period of the metasurface structures, the focal length of the glass laminate can be made the same regardless of the wavelength of the incident light.

[0117] The present disclosure will be described in more detail below with reference to examples, but the present disclosure is not limited to the following examples as long as it does not deviate from the gist of the disclosure. Examples 1 to 7 are examples, and Examples 8 to 12 are comparative examples.

[0118] <Production of Glass Laminate> Glass having the composition, refractive index, and average CTE shown in Table 1 below was used as the glass substrate.

[0119] Details of the glass substrates used in Examples 1 to 7 are as follows: Size: 12-inch (300 mm) diameter wafer Thickness: 0.3 mm Plate thickness deviation (TTV): 5 μm Surface roughness (Ra): 5 nm or less

[0120] Amorphous silicon (average CTE of 3.2 ppm / K at 50 to 200° C. before crystallization) was used as the high refractive index material.

[0121] That is, in the glass substrates used in Examples 1 to 7, the difference in average CTE between the glass substrate and the high refractive index material before crystallization at 50 to 200° C. was within ±0.5 ppm / K.

[0122] A high refractive index material was coated on the surface of a glass substrate using a chemical vapor deposition apparatus. The high refractive index material deposited on the glass substrate was annealed (heat treatment process) to crystallize the high refractive index material, forming a film (0.5 μm thick) containing the high refractive index material on the glass substrate. The thickness of the film containing the high refractive index material was 0.0001 times the thickness of the glass substrate. The amount of warping of the glass substrate on which the film containing the high refractive index material was formed was measured in accordance with JIS B 0621 and evaluated according to the following criteria. The results are shown in Table 1.

[0123] A: The amount of warpage of the glass substrate is 20 μm or less. B: The amount of warpage of the glass substrate is more than 20 μm and not more than 30 μm. C: The amount of warpage of the glass substrate is more than 30 μm and not more than 50 μm. D: The amount of warpage of the glass substrate is more than 50 μm.

[0124] Furthermore, for Examples 1 to 7, a resist was applied onto the annealed high-refractive-index material layer and developed. According to the mask pattern of the developed resist, the annealed high-refractive-index material was etched by photolithography, electron beam lithography, or nanoimprint lithography to form a metasurface structure (nanopillar structure).

[0125]

[0126] That is, in Examples 1 to 7, a manufacturing method of a glass laminate and a glass laminate were obtained in which warping of the glass substrate and the film formed on the glass substrate was suppressed.

[0127] The disclosure of Japanese Patent Application No. 2024-154987, filed on September 9, 2024, is incorporated herein by reference in its entirety. In addition, all documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually indicated to be incorporated by reference.

[0128] As described above, the method for manufacturing a glass laminate according to the present disclosure provides a method for manufacturing a glass laminate in which warping of the glass substrate and the film formed on the glass substrate is suppressed, and a glass laminate manufactured by the method can be obtained. The glass laminate according to the present disclosure is used in applications such as meta-optical components (e.g., metalenses), thermal control components using metamaterial technology, and electromagnetic wave control components for reconfigurable intelligent surfaces (RIS) including metasurface technology.

Claims

1. A film containing a high refractive index material is formed on a glass substrate, and the glass substrate is B ２ O ３ , P ２ O ５ , and GeO ２ and the glass substrate has an average linear expansion coefficient of 2.5 to 4.0 ppm / K at 50 to 200°C.

2. B contained in the glass substrate ２ O ３ , P ２ O ５ , and GeO ２ The method for producing a glass laminate according to claim 1 , wherein the total amount of is more than 11 mol % and less than 38 mol %.

3. B contained in the glass substrate ２ O ３ , P ２ O ５ , and GeO ２ The method for producing a glass laminate according to claim 1 or 2, wherein the total amount of is more than 20 mol%.

4. The method for producing a glass laminate according to claim 1 or 2, wherein the glass substrate is a silicate glass substrate.

5. The area of ​​the main surface of the glass substrate is 0.015 m ２ The method for producing a glass laminate according to claim 1 or 2, wherein the method is as described above.

6. The method for producing a glass laminate according to claim 1 or 2, wherein the glass substrate has a thickness of 0.1 to 3.0 mm.

7. The method for producing a glass laminate according to claim 1 or 2, wherein the thickness of the film containing a high refractive index material is 0.00001 to 0.01 times the thickness of the glass substrate.

8. The method for producing a glass laminate according to claim 1 or 2, wherein the thickness deviation of the glass substrate is 5 μm or less and the surface roughness of the glass substrate is 5 nm or less.

9. The method for producing a glass laminate according to claim 1 or 2, wherein the amount of warpage of the glass substrate on which the film is formed, measured in accordance with JIS B 0621, is 50 μm or less.

10. The method for manufacturing a glass laminate according to claim 1 or 2, wherein the high refractive index material is silicon.

11. A method for manufacturing a glass laminate described in claim 1 or 2, comprising forming a metasurface structure on the glass substrate by photolithography, electron beam lithography, or nanoimprint lithography on the film.

12. A glass substrate and a metasurface structure including a high refractive index material, wherein the glass substrate is B ２ O ３ , P ２ O ５ , and GeO ２ and the glass substrate has an average linear expansion coefficient of 2.5 to 4.0 ppm / K at 50 to 200°C.

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