Die system and method for comparing alignment vectors

Abstract

Embodiments of the present disclosure include a die system and a method for comparing alignment vectors. The die system includes a plurality of dies arranged in a desired pattern. Alignment vectors, such as die vectors, can be determined from edge features of the die. These alignment vectors can be compared to other dies or die patterns in the same system. A method for comparing die to die patterns includes comparing die vectors and / or pattern vectors. Comparison between alignment vectors allows the die pattern to be fixed for the next round of processing. The provided method allows accurate comparison between freshly deposited edge features, enabling accurate die stitching.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to apparatus and methods, and more particularly, methods of designing a die system and comparing alignment vectors. Background Art

[0002] Virtual reality (VR) is generally considered a computer-generated simulated environment in which the user has a distinct physical presence. The VR experience can be generated in three dimensions and viewed through a head-mounted display (HMD), such as glasses or other wearable display devices, that have near-eye display panels as lenses to display the VR environment in place of the real environment.

[0003] However, augmented reality (AR) enables an experience where the user is still able to look through the display lenses of glasses or other HMD devices to view the surrounding environment, and can also view images of virtual objects that are generated for display and appear as part of the environment. AR can include any type of input, such as audio and tactile input, as well as virtual images, graphics, and video that can enhance or amplify the environment experienced by the user. To achieve the AR experience, virtual images are overlaid on the surrounding environment, with optical devices performing the overlay. VR and AR devices can be made by using photolithography to deposit features onto a substrate to produce die. However, due to the large size of VR and AR devices compared to typical semiconductor lithography patterns, multiple dies and patterns must be accurately stitched together to produce a functional device.

[0004] One drawback of this technology is that current stitching methods cannot combine lithographic patterns with sufficient accuracy to ensure a functional device. Additionally, once a lithographic pattern is deposited, determining how to fix the pattern in the next lithography pass becomes complex. Furthermore, there is no easy way to compare the expected critical dimension (CD) of a feature with the actual CD of the feature deposited.

[0005] Therefore, what is needed in the art is the accurate stitching together of dies for AR / VR devices. Summary of the Invention

[0006] Embodiments herein include a die system and a method for comparing alignment vectors. Alignment vectors are determined from die edge features and edge feature patterns. The method for comparing die and die patterns includes comparing die vectors and / or pattern vectors. Comparing the alignment vectors allows the die pattern to be fixed for the next round of processing. The alignment vectors and the method allow for accurate splicing of the die.

[0007] In one embodiment, a die system is provided, comprising a plurality of dies, each of which comprises a plurality of component features and one or more edge regions, each of which comprises one or more edge boundary features and a plurality of edge features.

[0008] In another embodiment, a method for comparing alignment vectors is provided, comprising: determining a first alignment vector v1 for a first die; determining a second alignment vector v2 for a second die; and determining a die-to-die angle θ using the first alignment vector v1 and the second alignment vector v2. 12 ; According to the angle θ between the die 12 changing the first die pattern to a first changed die pattern; and 12 The second die pattern is changed to a second changed die pattern.

[0009] In another embodiment, a method for determining die alignment is provided, comprising: generating a first plurality of edge features on a first die using a first die pattern; generating a second plurality of edge features on a second die using a second die pattern; determining a first alignment vector v1 for the first die; determining a second alignment vector v2 for the second die; and determining an inter-die angle θ using the first alignment vector v1 and the second alignment vector v2. 12 ; changing the first die pattern to a first changed die pattern; and changing the second die pattern to a second changed die pattern. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order that the manner in which the above-described features of the present disclosure can be understood in detail, a more particular description of the present disclosure, briefly summarized above, may be obtained by reference to the embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of its scope, and other equally effective embodiments may be admitted.

[0011] Figure 1A A die system according to one embodiment is described.

[0012] Figure 1B An enlarged portion of a die pattern is illustrated according to one embodiment.

[0013] Figure 1C An enlarged portion of a die is illustrated according to one embodiment.

[0014] Figure 1D An enlarged portion of a die is illustrated according to one embodiment.

[0015] Figure 2 is a flow chart of method operations for comparing two alignment vectors according to one embodiment.

[0016] Figure 3 is a flow chart of method operations for determining die alignment according to one embodiment.

[0017] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation. DETAILED DESCRIPTION

[0018] Embodiments of the present disclosure include a die system and a method for comparing alignment vectors. The die system includes a plurality of dies arranged in a desired pattern. Alignment vectors (e.g., die vectors) can be determined from edge features of the die. The alignment vectors can be compared to other dies or die patterns in the same system. The method for comparing dies and die patterns includes comparing die vectors and / or pattern vectors. Comparison between alignment vectors allows the die pattern to be fixed for the next round of processing. The provided method allows accurate comparison between freshly deposited edge features, enabling accurate stitching of dies. Comparing die vectors and pattern vectors allows compensation of the next die pattern due to errors in the first die pattern. Alignment vectors provide a simple method to compare alignment and overlay between dies and die patterns. Embodiments of the present disclosure can be used for, but are not limited to, aligning dies in a die system

[0019] As used herein, the term "about" refers to a difference of + / - 10% from the nominal value. It should be understood that such differences can be included in any value provided herein.

[0020] Figure 1A A die system 100 according to one embodiment is described. The die system 100 is configured as a lens for an optical device such as a VR or AR headset or device. The die system 100 includes any material used for optical devices, such as, but not limited to, glass or plastic.

[0021] As shown in the figure, the die system 100 includes a plurality of dies 101 and a plurality of die patterns 111. Figure 1A As shown, each of the plurality of dies 101 and / or the plurality of die patterns 111 is separated by a solid line. The die pattern 111 is a pattern of material to be grown to produce the desired patterned die 101. Thus, the die system 100 can include the die pattern 111 (i.e., the desired pattern to be produced), the die 101 (i.e., the patterned die), or a mixture of the two at any given point in time.

[0022] Although the plurality of dies 101 and the plurality of die patterns 111 are depicted as a grid pattern, it is contemplated that the plurality of dies 101 and the plurality of die patterns 111 can be presented in any arrangement. Each die 101 and / or die pattern 111 can have the same shape and / or size as any other die and / or die pattern, or some of the dies and / or die patterns can have shapes and / or sizes that are different from the other dies and / or die patterns. The number of dies 101 and / or die patterns 111, the arrangement of the dies and / or die patterns, and the shapes and sizes of the dies and / or die patterns are selected by one skilled in the art to produce a preferred optical device.

[0023] Figure 1B An enlarged portion of a die pattern 111 according to one embodiment is depicted. The die pattern 111 can be any mask used in the art, such as a photolithography mask, a digital mask, or a virtual mask. Figure 1B The enlarged portion of FIG. 1 illustrates exemplary intersections between die patterns 111A, 111B, 111C, and 111D. Figure 1B The corresponding die 101 ( Figure 1C For example, die patterns 111A, 111B, 111C, and 111D are used to generate Figure 1C bare chips 101A, 101B, 101C, and 101D.

[0024] although Figure 1B The die patterns 111A, 111B, 111C, 111D are similar, but it should be understood that the die patterns 111A, 111B, 111C, 111D can be the same as or different from each other, and thus as described below. Figure 1C The deposited dies 101A, 101B, 101C, 101D described in the drawings can be the same or different for each die. Although not shown in FIG. Figures 1B to 1C (These figures depict the die pattern 111 and the corners of the die), but it should be understood that the die pattern extends through the entire die pattern.

[0025] As shown, each die pattern 111 includes an edge pattern region 119 (e.g., die patterns 111A, 111B, 111C, and 111D include edge patterns 119A, 119B, 119C, and 119D, respectively). The edge pattern region 119 is approximately 1 micron to approximately 10 microns wide. The size of the edge pattern region 119 is sufficiently small so that the functionality of the final die 101 is not affected. As shown, the edge pattern region 119 (such as 119A, 119B, 119C, and 119D) includes a plurality of edge feature patterns 112 (such as 112A, 112B, 112C, and 112D) and one or more edge boundary feature patterns 113 (such as 113A, 113B, 113C, and 113D). Each of the plurality of edge feature patterns 112 is separated from each other by distances a and b in the x- and y-directions, respectively. The distances a and b can be the same or different within a given die pattern 111 or between multiple die patterns (e.g., 111A and 111B). The distances a and b can vary throughout a given die pattern 111. The distances a and b can range from about 1 nm to about 5 μm. Although shown as a rectangular grid, it should be understood that the edge feature pattern 112 can have any arrangement.

[0026] The edge boundary feature pattern 113 can have a first portion 113' having a length L' and a second portion 113' having a length L". The lengths L', L" can range from about 100 nm to about 10 μm. The lengths L', L" of a given edge boundary feature pattern 113 can be the same as or different from other edge boundary feature patterns, for example, the length L' of the first portion 113A' of edge boundary feature pattern 113A is different from the length L' of the first portion 113B' of edge boundary feature pattern 113B. Although the edge boundary feature pattern 113 is shown in the figure as having an L-shape, any shape, such as a cross, is also contemplated. The distance d between adjacent first portions 113' (for example, the distance between 113A' and 113C' and the distance d between 113B' and 113D') can be the same or different. Likewise, the distance d between adjacent second portions 113 ″ (eg, the distance d between 113A″ and 113B″ and the distance d between 113C″ and 113D″) can be the same or different. The distance d can be about 50 nm to about 5 μm.

[0027] For each die pattern 111, a pattern vector 115 is defined by the direction and distance between two or more features in the pattern. For example, pattern vector 115A is defined by the distance between two edge feature patterns 112A. In another example, pattern vector 115A is defined between edge feature pattern 112A and boundary feature pattern 113A (not shown). In yet another example, pattern vector 115A is defined between edge feature pattern 112A and first portion 113A' of boundary feature pattern 113A (not shown). In each case, each die pattern 111 (e.g., die pattern 111A) has a corresponding pattern vector 115 (e.g., 115A). To compare pattern vectors 115 between corresponding die patterns 111 (e.g., comparing pattern vector 115A of die pattern 111A with pattern vector 115B of die pattern 111B), the definition of pattern vector 115 between corresponding die patterns is consistent. Figure 1B Four die patterns 111A, 111B, 111C, 111D and their corresponding pattern vectors 115A, 115B, 115C, 115D are depicted.

[0028] For virtual or digital masks, the pattern vector 115 can be determined digitally, for example, by measuring distances and angles through the pixels of the mask. For physical masks, the pattern vector 115 can be determined using any desired imaging technique, such as a scanning electron microscope (SEM). Other possible imaging techniques include optical detection using any wavelength of light and bright field detection.

[0029] The pattern vectors 115 between adjacent die patterns 111 are used to compare the correct orientation and position of the die patterns relative to each other. For example, the pattern vector 115A of the die pattern 111A can be compared with the pattern vector 115B of the die pattern 111B. Figure 1B , the depicted pattern vectors 115A, 115B are correctly oriented relative to each other, and thus the die patterns 111A, 111B are correctly aligned.

[0030] Figure 1C An enlarged portion of die 101 is depicted according to one embodiment. Figure 1C The enlarged portion of FIG. 1 shows exemplary intersections between the die 101A, 101B, 101C, and 101D. The die 101A, 101B, 101C, and 101D are based on Figure 1B The depicted patterns are deposited in the corresponding die patterns 111A, 111B, 111C, 111D. Figure 1CThe die 101A, 101B, 101C, 101D are similar, but it is understood that the die 101A, 101B, 101C, 101D can be the same as or different from each other. Depending on the desired function of the optical device, each die 101 is configured to reflect and / or transmit certain wavelengths of light.

[0031] As shown, each die 101 includes an edge region 109 (e.g., die 101A, 101B, 101C, 101D include edge regions 109A, 109B, 109C, 109D, respectively). Each edge region 109 (e.g., 109A, 109B, 109C, 109D) includes a patterned material that corresponds to an equivalent edge pattern region 119 (e.g., 119A, 119B, 119C, 119D) of die pattern 111 (e.g., 111A, 111B, 111C, 111D). Edge region 109 is approximately 1 μm to approximately 10 μm wide. The size of edge region 109 is sufficiently small that the functionality of die 101 is not affected. As shown, edge region 109 (e.g., 109A, 109B, 109C, 109D) includes a plurality of edge features 102 (e.g., 102A, 102B, 102C, 102D) and one or more edge boundary features 103 (e.g., 103A, 103B, 103C, 103D). Each of the plurality of edge features 102 (e.g., 102A, 102B, 102C, 102D) includes a patterned material corresponding to an equivalent edge feature pattern 112 (e.g., 112A, 112B, 112C, 112D). Each of the plurality of edge boundary features 103 (e.g., 103A, 103B, 103C, 103D) includes a patterned material corresponding to an equivalent edge boundary feature pattern 113 (e.g., 113A, 113B, 113C, 113D). Multiple edge features 102 are separated from each other by distances a and b in the x-direction and y-direction, respectively. Within a given die 101, or between multiple dies (e.g., 101A and 101B), the distances a and b can be the same or different. The distances a and b can vary across a given die 101. The distances a and b can range from about 50 nm to about 5000 μm. Although a rectangular grid is shown, it should be understood that the edge features 102 can be arranged in any manner.

[0032] The plurality of edge features 102 include any features used in optical devices known in the art. The plurality of edge features 102 have a CD (such as height and width) of about 10 nm to about 100 μm, such as about 10 nm to about 100 nm, about 20 nm to about 200 nm, or about 60 nm to about 500 nm. According to one embodiment, the plurality of edge features 102 include vias or holes. According to one embodiment, the plurality of edge features 102 include line spaces.

[0033] According to one embodiment, the plurality of edge features 102 comprise pillars, such as those used in metalens arrays. The plurality of edge features 102 can have different shapes depending on the desired spectrum of light to be filtered. The plurality of edge features 102 can be substantially circular, triangular, square, rectangular, or have an uneven shape. The plurality of edge features 102 can be made of any suitable high refractive index material, such as, but not limited to, silicon, silicon oxide, silicon nitride, titanium oxide, tantalum oxide, zirconium oxide, hafnium oxide, gallium arsenide, gallium nitride, and niobium oxide. The plurality of edge features 102 can also be made of metallic materials such as gold, silver, or copper.

[0034] The plurality of edge features 102 have a critical dimension (CD), such as a width or radius, such as from about 20 nm to about 500 nm. The plurality of edge features 102 have a height from about 10 nm to about 2 μm. According to some embodiments, the CD, height, shape, material, and feature separation distance of the plurality of edge features 102 are selected to produce a die 101 that filters all light except a narrow wavelength band.

[0035] In one embodiment, the plurality of edge features 102 are a plurality of circular or elliptical pillars containing silicon dioxide (SiO2), silicon (Si), titanium dioxide (TiO2), gallium nitride (GaN) materials, the pillars having a radius of about 30 nm to 500 nm, the pillars having a height of about 10 nm to 2 μm, and the pillars having a separation of about 30 nm to about 5000 nm.

[0036] The edge boundary feature 103 can have a first segment 103' having a length L' and a second segment 103' having a length L". The lengths L', L" can be from about 100 nm to about 10 μm. The lengths L', L" of a given edge region 109 can be the same as or different from other edge regions, for example, the length L' of the first segment 103A' of edge boundary feature 103A is different from the length L' of the first segment 103B' of edge boundary feature 103B. Although the edge boundary feature 103 is shown in the figure as having an L-shape, any shape, such as a cross, is also contemplated.

[0037] One or more edge boundary features 103 can include the same material as that included in the plurality of edge features 102. The distance d between adjacent first segments 103' (e.g., the distance between 103A' and 103C', and the distance between 103B' and 103D') can be the same or different. Similarly, the distance d between adjacent second segments 103" (e.g., the distance between 103A" and 103B", and the distance between 103C" and 103D") can be the same or different. The distance d can be from about 1 nm to about 5000 μm.

[0038] For each die 101, a die vector 105 is defined by the direction and distance between two features on the die. For example, die vector 105A is defined by the distance between two edge features 102A. In another example, die vector 105A is defined between edge feature 102A and edge boundary feature 103A (not shown). In yet another example, die vector 105A is defined between edge feature 102A and first portion 103A′ of boundary feature 103A (not shown). In each case, each die 101 (e.g., die 101A) has a corresponding die vector 105 (e.g., 105A). Die vector 105 can be determined using an image of die 101 and by measuring the distance between pixels in the image of the die. Images of the die can be produced using any desired imaging technique, such as SEM. Other possible imaging techniques include optical inspection using any wavelength of light and brightfield inspection. One skilled in the art will be able to choose a desired wavelength of light to match the CD of edge boundary feature 103 and edge feature 102. The error in die vector 105 is approximately the size of one pixel. Figure 1C Four dies 101A, 101B, 101C, 101D and their corresponding die vectors 105A, 105B, 105C, 105D are depicted.

[0039] The die vectors 105 between adjacent dies 101 are used to compare the correct orientation and position of multiple die patterns relative to each other. For example, the die vector 105A of die 101A can be compared with the die vector 105B of die 101B. Figure 1C , the die vectors 105A, 105B are shown correctly oriented relative to each other, so the dies 101A, 101B are correctly aligned.

[0040] During the generation of die 101 using die pattern 111, the dimensions of plurality of edge features 102 can differ from plurality of edge feature pattern 112 of die pattern 111. For example, process drift can cause the position of edge feature 102 to shift from edge feature pattern 112, the thickness of edge feature 102 can differ from edge feature pattern 112, the substrate beneath the die can be non-uniform, there may be noise in the acquired image of the die, or there may be errors in the pattern recognition algorithm used to create the image of the die. In these cases, die vector 105 (e.g., Figure 1C The die vector 105A shown in FIG. 1 can be combined with the pattern vector 115 (eg, Figure 1B Therefore, the comparison of die vector 105 and pattern vector 115 is used to refine the die pattern 111 of the next die 101. According to one embodiment, the angle θ defined between die vector 105A and pattern vector 115A is calculated using the following equation: AA’ .

[0041] cos(θ AA’ )=(v A .v A’ ) / (|v A ||v A’ |)

[0042] where |v A | is the absolute value of the die vector, and |v A’ | is the absolute value of the pattern vector. For small angles, this equation simplifies to

[0043] θ AA’ =(v A .v A’ ) / (|v A ||v A’ |)

[0044] Because for small θ AA’ For cos(θ AA’ ) is approximately equal to θ AA’ According to one embodiment, the x-component of the die vector 105A is compared to the x-component of the pattern vector 115A, and the y-component of the die vector 105A is compared to the y-component of the pattern vector 115A. According to one embodiment, the angle θ AA’ The error is less than about 150 arc seconds. The x-component difference, y-component difference, and angle θ AA’ can be used to correct the die pattern 111A, which results in more accurate deposition of the die 101A.

[0045] Figure 1DAn enlarged portion of die 101 is depicted according to one embodiment. Figure 1D The enlarged portion of FIG. 1 shows the intersection of four dies 101E, 101F, 101G, and 101H, including edge regions 109E, 109F, 109G, and 109H, respectively. Figure 1C (which shows the intersection of four dies 101A, 101B, 101C, 101D that are correctly aligned) Figure 1D The intersection of four dies 101E, 101F, 101G, 101H is shown as not being properly aligned. For example, the dies 101E, 101F, 101G, 101H are shown not being at approximately 90 degrees to each other, such that the corners of each die do not meet at approximately 90 degrees.

[0046] For each die 101, a die vector 105 is defined by the direction and distance between two features on the die. For example, die vector 105E is defined by the distance between two edge features 102E. In another example, die vector 105E is defined between edge feature 102E and boundary feature 103E (not shown). In yet another example, die vector 105E is defined between edge feature 102E and first portion 103E′ of boundary feature 103E (not shown). In each case, each die 101 (e.g., die 101E) has a corresponding die vector 105 (e.g., 105E). Figure 1D Four dies 101E, 101F, 101G, 101H and their corresponding die vectors 105E, 105F, 105G, 105H are depicted.

[0047] The die vectors 105 between adjacent die patterns 111 are used to compare the correct orientation and position of multiple die patterns relative to each other. For example, the die vector 105E of die 101E can be compared with the die vector 105F of die 101F. Figure 1D , the die vectors 105E, 105F are shown as not being correctly oriented relative to each other, and thus the dies 101E, 101F are not properly aligned.

[0048] Therefore, the comparison of the die vector 105E of the die 101E and the die vector 105F of the die 101F is used to improve the corresponding die pattern 111E, 111F deposited by the next die 101E, 101F. According to one embodiment, the angle θ defined between the die vector 105E and the die vector 105F is EF is calculated using the following equation:

[0049] cos(θ EF )=(v E .v F ) / (|v E||v F |)

[0050] Among them, |v E | is the absolute value of the die vector 105E, |v F | is the absolute value of the die vector 105F. For small angles, the equation simplifies to:

[0051] θ EF =(v E .v F ) / (|v E ||v F |)

[0052] Because for small θ EF For cos(θ EF ) is approximately equal to θ EF According to one embodiment, the x-component of die vector 105E is compared with the x-component of die vector 105F, and the y-component of die vector 105E is compared with the y-component of die vector 105F. EF can be used to correct the die pattern, which results in more accurate deposition of the die 101E, 101F. According to one embodiment, the angle θ EF The error is less than about 150 arc seconds. Figure 1D In the die 101 described in FIG. , the angle θ EF Roughly the same as the angular misalignment between adjacent dies 101E, 101F.

[0053] As described above, the alignment vectors can be used to compare features of the die 101 and / or die pattern 111 to each other. The alignment vectors can include the die vector 105 ( Figure 1C to Figure 1D ) and pattern vector 115 (in Figure 1B Possible combinations of comparisons between alignment vectors include, but are not limited to, comparisons between die vectors 105 of adjacent dies 101 (e.g., comparisons between die vectors 105A and 105B), comparisons between pattern vectors 115 of adjacent die patterns 111 (e.g., comparisons between pattern vectors 115A and 115B), and comparisons between die vectors 105 and pattern vectors 115 (e.g., comparisons between die vector 105A and pattern vector 115A). While comparisons between two alignment vectors are described above and below, it should be understood that any number of alignment vector comparisons can be performed.

[0054] Furthermore, although the die 101 of the die system 100 are shown in the figure as being in the same xy plane in a single layer (eg, Figure 1C The depicted dies 101A, 101B, 101C, and 101D; Figure 1D The illustrated die 101E, 101F, 101G, 101H), but the alignment vector can be determined for the die of different layers, and can be as follows Figure 2 and Figure 3 Comparison of alignment vectors in different layers is performed as described in

[15] .

[0055] Figure 2 is a flow chart of the operation of method 200 for comparing alignment vectors according to one embodiment. Figure 2 The operations of method 200 are described, but those skilled in the art will understand that any system configured to perform the operations of the method, in any order, falls within the scope of the embodiments described herein.

[0056] The method 200 begins at operation 210, where a first alignment vector v1 is determined. As described above, the first alignment vector can be the die vector 105 or the pattern vector 115. The first alignment vector v1 can be determined using any suitable lithography tool or metrology tool known in the art.

[0057] According to some embodiments, the first alignment vector v1 is die vector 105A. The first alignment vector v1 is defined by a first x-component and a first y-component. The first x-component is equal to the x-distance between two edge features in the plurality of edge features 102A of the first die 101A, while the first y-component is equal to the y-distance between two edge features in the plurality of edge features of the first die. According to some embodiments, the first alignment vector v1 is pattern vector 115. The first alignment vector v1 is defined by a first x-component and a second y-component. The first x-component is equal to the x-distance between two edge feature patterns in the plurality of edge feature patterns 112A of the first die pattern 111A, while the first y-component is equal to the y-distance between the same two edge feature patterns in the plurality of edge feature patterns of the first die pattern.

[0058] At operation 220, a second alignment vector v2 is determined. The second alignment vector v2 can be determined by using any suitable lithography tool or metrology tool in the art.

[0059] According to some embodiments, the second alignment vector v2 is die vector 105B. The second alignment vector v2 is defined by a second x-component and a second y-component. The second x-component is equal to the x-distance between two edge features of the plurality of edge features of the second die 101B, and the second y-component is equal to the y-distance between two edge features of the plurality of edge features of the second die.

[0060] According to some embodiments, the second alignment vector v2 is the pattern vector 115B. The second alignment vector v2 is defined by a second x-component and a second y-component. The second x-component is equal to the x-distance between two edge feature patterns in the plurality of edge feature patterns 112B of the second die pattern 111B, and the second y-component is equal to the y-distance between two edge feature patterns in the plurality of edge feature patterns of the second die pattern. In operation 230, the die-die angle θ 12 Determined by using a first alignment vector v1 and a second alignment vector v2.

[0061] According to one embodiment, the angle θ 12 It is calculated using the following equation:

[0062] cos(θ 12 )=(v1.v2) / (|v1||v2|)

[0063] Where |v1| is the absolute value of the first alignment vector v1, and |v2| is the absolute value of the second alignment vector v2. For small angles, the equation simplifies to:

[0064] θ 12 =(v1.v2) / (|v1||v2|),

[0065] Because for small θ 12 For cos(θ 12 ) is approximately equal to θ 12 .

[0066] At operation 240, one or more corrections to be performed on the first die pattern 111A and / or the second die pattern 111B are determined. According to one embodiment, determining the one or more corrections to be performed on the first die pattern 111A and the second die pattern 111B includes: 12 The first die pattern is changed into a first changed die pattern, and the first die pattern is changed into a first changed die pattern according to the angle θ 12 The second die pattern is changed into a second changed die pattern.

[0067] The second alignment vector v2 is similar to the first alignment vector v1; that is, the inter-die angle θ between the alignment vectors v1 and v2 is expected to be 12 is small. For example, in embodiments where the first alignment vector v1 is a die vector for a die pattern (e.g., die vector 105A for die 101A) and the second alignment vector v2 is a pattern vector for a die pattern (e.g., pattern vector 115A for die pattern 111A), a small inter-die angle θ is expected for deposited dies similar to the die pattern. 12 However, due to process drift or other factors listed above, large die-to-die angles θ12 It can be indicated that die 101A and the associated die pattern do not match die pattern 111A, so one or more corrections can be made in future die patterns. For example, pattern features of die pattern 111A can be shifted if features of the corresponding die are not in the correct location.

[0068] In another example, in an embodiment where the first alignment vector v1 is a die vector for a first die pattern (e.g., die vector 105A for die 101A) and the second alignment vector v2 is a die vector for a second die pattern (e.g., die vector 105B for die 101B), a small inter-die degree θ is expected for adjacent dies that are similar to each other. 12 However, due to process drift or other factors listed above, large die-to-die angles θ 12 It can indicate that adjacent dies do not match, so one or more corrections can be made in future die patterns. For example, if two dies are not properly aligned (e.g., Figure 1D The illustrated die 101E, 101F) can adjust the angle of the entire second die pattern relative to the first die pattern.

[0069] Figure 3 is a flow chart of the operations of a method 300 for determining die alignment according to one embodiment. Figure 3 The operations of method 300 are described, but those skilled in the art will understand that any system configured to perform the method operations, in any order, falls within the scope of the embodiments described herein.

[0070] The method 300 begins at operation 310 where a first die 101A is deposited and a first plurality of edge features 102A is created. The first die 101A can be created using a first die pattern 111A, as described above.

[0071] At operation 320, a second die 101B is deposited and a second plurality of edge features 102B is produced. The second die 101B can be produced using a second die pattern 111B, as described above.

[0072] At operation 210, a first alignment vector v1 is determined. The first alignment vector v1 is the die vector 105A. The first alignment vector v1 is defined by a first x-component and a first y-component. The first x-component is equal to the x-distance between two edge features of the plurality of edge features 102A of the first die 101A, and the first y-component is equal to the y-distance between the same two edge features of the plurality of edge features of the first die. The first alignment vector v1 can be determined using any suitable metrology tool known in the art.

[0073] At operation 220, a second alignment vector v2 is determined. The second alignment vector v2 is die vector 105B. The second alignment vector v2 is defined by a second x-component and a second y-component. The second x-component is equal to the x-distance between two edge features of the plurality of edge features of the second die 101B, and the second y-component is equal to the y-distance between the same two edge features of the plurality of edge features of the second die. The second alignment vector v2 can be determined using any suitable metrology tool known in the art.

[0074] At operation 230 , the inter-die angle θ 12 Determined by using a first alignment vector v1 and a second alignment vector v2.

[0075] The inter-die angle θ 12 Use the following equation to calculate:

[0076] cos(θ 12 )=(v1.v2) / (|v1||v2|)

[0077] Where |v1| is the absolute value of the first alignment vector v1, and |v2| is the absolute value of the second alignment vector v2. For small angles, the equation simplifies to:

[0078] θ 12 =(v1.v2) / (|v1||v2|),

[0079] Because for small θ 12 For cos(θ 12 ) is approximately equal to θ 12 .

[0080] At operation 330, the first alignment vector v1 and the second alignment vector v2 are compared to determine corrections to be made to the first die pattern 111A. In one embodiment, the first die pattern 111A is used as a reference die, and alignment correction data is stored by the metrology tool and simultaneously transmitted to the lithography tool. At operation 340, the alignment correction data is used to correct the alignment of the second die during the next exposure cycle. Thus, the alignment correction data is used to produce a first modified die pattern 111A'. The first modified die pattern 111A' incorporates the improvements from the comparison of the first alignment vector v1 and the second alignment vector v2.

[0081] At operation 340, the first alignment vector v1 and the second alignment vector v2 are compared to determine corrections to be made to the second die pattern 111B. The second die pattern 111B is modified to a second modified die pattern 111B'. The second modified die pattern 111B' incorporates improvements from the comparison of the first alignment vector v1 and the second alignment vector v2. According to one embodiment, the second modified die pattern 111B' incorporates some or all of the alignment correction data determined in operation 330.

[0082] As described above, a die system and a method for comparing alignment vectors are disclosed herein. The die system includes a plurality of dies arranged in a desired pattern. Alignment vectors, such as die vectors, can be determined from edge features of the dies. The alignment vectors can be compared with other dies or die patterns in the same system. The method for comparing dies and die patterns includes comparing die vectors and / or pattern vectors. Comparing the alignment vectors allows the die pattern to be fixed for the next round of processing.

[0083] The provided method allows accurate comparison between just-deposited edge features, enabling accurate stitching of dies. Comparing the die vector and pattern vector allows compensation for the next die pattern (due to errors in the first die pattern). Alignment vectors provide a simple method to compare alignment and overlay between a die and a die pattern.

[0084] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, the scope of which is to be determined by the claims that follow.

Claims

1. A lens for a virtual reality or augmented reality device, comprising: A plurality of dies, wherein each die is configured to reflect and / or transmit some wavelength of light, each die comprising: multiple component features; and One or more edge regions, each edge region comprising: One or more edge boundary features; and A plurality of edge features, the plurality of edge features comprising pillars used in a metalens array, each edge feature filtering a spectrum of light.

2. The lens of claim 1, wherein the plurality of element features comprises one or more pillars or vias.

3. The lens according to claim 1, wherein The lens includes a central region of the plurality of element features; The one or more edge boundary features at least partially surround the central region; The plurality of edge features are disposed adjacent to the edge boundary feature, and Each edge is configured to be separated from each other by a predetermined distance.

4. The lens of claim 1 , wherein the plurality of element features comprises one or more line spaces.

5. The lens of claim 1, wherein the spacing between the plurality of element features is different than the spacing between the plurality of edge features.

6. A method for comparing alignment vectors, comprising the steps of: Determining a first alignment vector v1 for the first die and the first die pattern; determining a second alignment vector v2 for the second die and the second die pattern; Determine the inter-die angle θ using the first alignment vector v1 and the second alignment vector v2 12 ; According to the inter-die angle θ 12 changing the first die pattern to a first changed die pattern; as well as According to the inter-die angle θ 12 changing the second die pattern to a second changed die pattern, wherein the first alignment vector is a first die vector or a first pattern vector, the first die vector being defined by a direction and a distance between two features in the first die, and the first pattern vector being defined by a direction and a distance between two features in the first pattern, wherein the second alignment vector is a second die vector defined by a direction and a distance between two features in the second die or a second pattern vector defined by a direction and a distance between two features in the second pattern; and Each of the first die and the second die is configured to reflect and / or transmit some wavelengths of light and includes a plurality of element features and one or more edge regions, and each edge region includes one or more edge boundary features and a plurality of edge features, the plurality of edge features including pillars used in a metalens array, each edge feature filtering a spectrum of light.

7. The method according to claim 6, wherein: The first alignment vector v1 is the first die vector, The first alignment vector v1 is defined by a first x-component and a first y-component, the first x-component being equal to an x-distance between two edge features of the plurality of edge features of the first die, the first y-component being equal to a y-distance between two edge features of the plurality of edge features of the first die, The second alignment vector v2 is the second die vector, The second alignment vector v2 is defined by a second x-component and a second y-component, The second x-component is equal to an x-distance between two edge features of the plurality of edge features of the second die, and The second y-component is equal to a y-distance between two edge features of the plurality of edge features of the second die.

8. The method of claim 7, wherein determining the inter-die angle θ 12 include: Solve the following equation: cos(θ 12 )=(v1.v2) / (|v1||v2|), where |v1| is the absolute value of the first alignment vector v1, and |v2| is the absolute value of the second alignment vector v2.

9. The method according to claim 6, wherein: the first alignment vector being the first die vector, The first alignment vector v1 is defined by a first x-component and a first y-component, the first x-component being equal to an x-distance between two edge features of the plurality of edge features of the first die, the first y-component being equal to a y-distance between two edge features of the plurality of edge features of the first die, the second alignment vector is the second pattern vector, The second alignment vector v2 is defined by a second x-component and a second y-component, The second x-component is equal to an x-distance between two edge feature patterns of the plurality of edge feature patterns of the second die pattern, and The second y-component is equal to a y-distance between two edge feature patterns of the plurality of edge feature patterns of the second die pattern.

10. The method of claim 9, wherein determining the inter-die angle θ 12 include: Solve the following equation: cos(θ 12 )=(v1.v2) / (|v1||v2|), where |v1| is the absolute value of the first alignment vector v1, and |v2| is the absolute value of the second alignment vector v2. The method of claim 9 , wherein the plurality of edge features comprises one or more vias.

12. The method of claim 9, wherein the plurality of edge features comprises one or more line spaces.

13. A method for determining die alignment, comprising: generating a first plurality of edge features on the first die using a first die pattern; generating a second plurality of edge features on the second die using the second die pattern; determining a first alignment vector v1 for the first die; determining a second alignment vector v2 for the second die; Determine the inter-die angle θ using the first alignment vector v1 and the second alignment vector v2 12 ; According to the inter-die angle θ 12 changing the first die pattern to a first changed die pattern; as well as According to the inter-die angle θ 12 changing the second die pattern to a second changed die pattern, wherein the first alignment vector is a first die vector or a first pattern vector, the first die vector being defined by a direction and a distance between two features in the first die, and the first pattern vector being defined by a direction and a distance between two features in the first pattern, wherein the second alignment vector is a second die vector or a second pattern vector, the second die vector being defined by a direction and a distance between two features in the second die, and the second pattern vector being defined by a direction and a distance between two features in the second pattern; wherein each of the first die and the second die is configured to reflect and / or transmit some wavelengths of light and comprises a plurality of element features and one or more edge regions, wherein each edge region comprises one or more edge boundary features, and wherein the edge features comprise pillars used in a metalens array, each edge feature filtering a spectrum of light. 14 . The method of claim 13 , wherein the method is repeated by using the first altered die pattern as the first die pattern and the second altered die pattern as the second die pattern.

15. The method of claim 13, wherein: The first alignment vector v1 is the first die vector, The first alignment vector v1 is defined by a first x-component and a first y-component, the first x-component being equal to an x-distance between two edge features of the first plurality of edge features of the first die, the first y-component being equal to a y-distance between two edge features of the first plurality of edge features of the first die, The second alignment vector v2 is the second die vector, The second alignment vector v2 is defined by a second x-component and a second y-component, The second x-component is equal to the x-distance between two edge features of the second plurality of edge features of the second die, and The second y-component is equal to a y-distance between two edge features of the second plurality of edge features of the second die.

16. The method of claim 15, wherein determining the inter-die angle θ 12 include: Solve the following equation: cos(θ 12 )=(v1.v2) / (|v1||v2|), where |v1| is the absolute value of the first alignment vector v1, and |v2| is the absolute value of the second alignment vector v2. The method of claim 13 , wherein the plurality of component features comprises one or more pillars.

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