KR102663213B1 - MLA device having double-sided pattern shield function and manufacturing method thereof - Google Patents

Abstract

A method for manufacturing an MLA device having a double-sided pattern shield function is disclosed. The disclosed MLA device manufacturing method includes a pattern shield forming step of forming upper pattern shields and upper alignment keys and lower pattern shields and lower alignment keys in a matrix arrangement on each of the upper and lower surfaces of the wafer; The upper pattern shields and upper alignment keys and the lower pattern shields and lower alignment keys are sawed on the wafer formed on the upper and lower surfaces, and the upper pattern shield and the upper alignment keys are formed on the upper and lower surfaces. A sawing step of forming a plurality of chips in which the align key, the lower pattern shield, and the lower align key are formed to correspond to each other; and a lens array forming step of forming an upper micro lens array and a lower micro lens array on the upper and lower surfaces of each of the plurality of chips.

Description

MLA device having double-sided pattern shield function and manufacturing method thereof}

The present invention relates to an MLA (Micro Lens Array) device having a double-sided pattern shield function and a method of manufacturing the same.

In the field of projection lighting, especially projection lighting for vehicles, an MLA device is known that implements an image of a predetermined pattern when light emitted from an LED light source is transmitted. Additionally, in order to improve the quality of images implemented by patterns, MLA devices in which patterns are formed in two layers are being developed. Lighting devices using such MLA elements have the advantage of being more space efficient and smaller than lighting devices using existing spherical or aspherical optical systems. Additionally, by combining an LED light source and an MLA element, it is possible to produce a slimmer lighting device. Especially when MLA devices containing two layers of patterned shields are applied in projection lighting. It has the advantage of being able to implement a clearer projection video image and having excellent visibility and sharpness of the video image.

Figure 1 is a diagram for explaining a method of manufacturing a conventional MLA device.

Referring to FIG. 1, the conventional MLA optic manufacturing method includes a step s1 of preparing an upper glass wafer 2a and a lower glass wafer 2b on which pattern shields 3a and 3b are formed, respectively, and pattern shields 3a and 3b. ) forming an optic, that is, a micro lens array (4a, 4b) on the upper surface of the upper glass wafer (2a) and the lower surface of the lower glass wafer (2b) (s2), and the upper glass wafer (2a) It includes a step (s3) of bonding the and lower glass wafers (2b) by epoxy bonding to obtain a bonded body (s3), and a step (s4) of separating the MLA element (1') from the bonded body by sawing the bonded body. At this time, the step of forming the micro lens arrays 4a and 4b uses an imprinting process and includes a process of applying a polymer to a glass wafer and a stamping process of pressing the polymer with a stamp.

However, the prior art is a process of pressing with a stamp, making it difficult to arrange cells in a maximum arrangement on a single wafer, and defects may occur in neighboring MLA optical cells due to the polymer being pushed to the periphery during the stamping process. Here, the MLA optical cell is defined as the state before separation of the MLA device. Additionally, in the conventional technology, sawing is performed after forming a micro lens array at the wafer level, so the production quantity of MLA devices is inevitably low compared to the input glass wafer. Additionally, the conventional method has a high risk of causing misalignment between the upper and lower glass wafers. In addition, in the conventional method, if a defect occurs during the process, the entire wafer or wafer assembly becomes defective, so the production yield is inevitably reduced significantly.

Publication number 10-2019-0078820 (publication date July 5, 2019) Publication number 10-2009-0082469 (publication date: July 30, 2009) Publication number 10-2021-0083587 (publication date: July 7, 2021)

The present invention was devised to solve the problems of the prior art, and provides an MLA device having a double-sided pattern shield function and a method of manufacturing the same.

The MLA device manufacturing method according to one aspect of the present invention includes forming a plurality of upper pattern shields and a plurality of upper alignment keys in a matrix arrangement on the upper surface of a single wafer, wherein the upper pattern shields and the upper alignment keys are formed in a matrix arrangement. forming an upper pattern shield wherein the keys are formed in the same layer from the same metal material; A plurality of lower pattern shields and a plurality of lower alignment keys are formed in a matrix arrangement on the lower surface of the wafer on which the upper pattern shields and the upper alignment keys are formed, wherein the lower pattern shields and the lower alignment keys are formed in a matrix arrangement. forming a lower pattern shield wherein the keys are formed in the same layer from the same metal material; The upper pattern shields and upper alignment keys and the lower pattern shields and lower alignment keys are sawed on the wafer formed on the upper and lower surfaces, and the upper pattern shield and the upper alignment keys are formed on the upper and lower surfaces. A sawing step of forming a plurality of chips in which the align key, the lower pattern shield, and the lower align key are formed to correspond to each other; and a lens array forming step of forming an upper micro lens array and a lower micro lens array on the upper and lower surfaces of each of the plurality of chips.
The MLA device manufacturing method according to another aspect of the present invention includes forming a plurality of upper pattern shields and a plurality of upper alignment keys in a matrix arrangement on the upper surface of a single wafer, wherein the upper pattern shields and the upper aligner forming an upper pattern shield wherein the keys are formed in the same layer from the same metal material; A plurality of lower pattern shields and a plurality of lower alignment keys are formed in a matrix arrangement on the lower surface of the wafer on which the upper pattern shields and the upper alignment keys are formed, wherein the lower pattern shields and the lower alignment keys are formed in a matrix arrangement. forming a lower pattern shield wherein the keys are formed in the same layer from the same metal material; A bonding step of forming a wafer stack by bonding a buffer wafer to a lower surface of the wafer on which the upper pattern shields, the upper alignment keys, and the lower pattern shields and lower alignment keys are formed on upper and lower surfaces; A sawing step of sawing the wafer stack to form a plurality of chips in which the upper pattern shield and upper alignment key and the lower pattern shield and lower alignment key are formed to correspond vertically; and a lens array forming step of forming an upper micro lens array and a lower micro lens array on the upper and lower surfaces of each of the plurality of chips.
In the upper pattern shield forming step, the wafer is placed so that the upper surface of the wafer becomes a work surface, an upper metal layer is deposited on the upper surface of the wafer, and upper PR is coated to completely cover the upper metal layer, By an exposure and development process, the upper PR in the remaining area excluding the area where the upper pattern shields and the upper alignment keys will be formed is removed, and the upper metal layer in the remaining area excluding the area covered by the removed remaining upper PR etching the upper metal layer, and then removing the remaining upper PR to form the upper pattern shields and the upper alignment keys made of metal on the upper surface of the wafer, wherein the lower pattern In the shield formation step, the lower surface of the wafer is placed so that it becomes a work surface, a lower metal layer is deposited on the lower surface of the wafer, the lower PR is coated to entirely cover the lower metal layer, and the wafer is exposed and developed. , removing the lower PR in the remaining area excluding the area where the lower pattern shields and the lower alignment keys will be formed, etching the lower metal layer in the remaining area excluding the area covered by the removed remaining lower PR, and etching the lower PR in the remaining area, excluding the area where the lower pattern shields and the lower alignment keys will be formed. After etching the metal layer, the remaining lower PR is removed to form the lower pattern shields and the lower alignment keys made of metal on the lower surface of the wafer.

According to the present invention, it has the advantage of being able to produce an MLA device with a double-sided pattern shield function at high yield. In the prior art, it is difficult to arrange cells in a maximum arrangement on a single wafer due to the process of pressing with a stamp, but the present invention solves the above problem by performing imprinting after sawing the wafer. Additionally, the present invention can dramatically increase the production quantity of MLA devices compared to the input wafers. Additionally, in the present invention, since both the upper pattern shield and the lower pattern shield are formed on one wafer, problems with poor alignment can be dramatically reduced. In addition, the wafer with the upper pattern shield and lower pattern shield formed is cut into chips and then the upper micro lens array and lower micro lens array are formed, so that if a defect occurs during the process, the entire wafer or wafer assembly becomes defective. Solve it.

1 is a diagram for explaining the prior art.
Figure 2 is a diagram for generally explaining a method of manufacturing an MLA device with a double-sided pattern shield function according to an embodiment of the present invention.
FIG. 3 is a diagram illustrating the steps of forming a pattern on both sides of a wafer in the MLA device manufacturing method shown in FIG. 2.
Figure 4 is a diagram for generally explaining a method of manufacturing an MLA device with a double-sided pattern shield function according to another embodiment of the present invention.
Figures 5 to 7 are diagrams for explaining a double-sided inspection device used to inspect the alignment of an MLA device manufactured using the method shown in Figures 2 and 3.

The present invention will be described below with reference to the attached drawings. It is noted that any structure, material, step or feature in any embodiment disclosed herein may be combined with any structure, material, step or other feature of other embodiments that are part of the present invention to form another embodiment. do. Please note that the detailed description and related drawings do not limit or define the scope of protection of the present invention. The scope of protection of the present invention is defined by the patent claims.

Figure 2 is a diagram for generally explaining the manufacturing method of an MLA device with a double-sided pattern shield function according to an embodiment of the present invention, and Figure 3 is a diagram showing a pattern on both sides of the wafer in the MLA device manufacturing method shown in Figure 2. This is a drawing showing the forming steps.

Referring to FIG. 2, the MLA device manufacturing method with a double-sided pattern shield function according to an embodiment of the present invention includes an upper pattern shield ( A pattern shield forming step (S11) of forming the 30a) and the lower pattern shields 30b in a matrix array, respectively, and the wafer (S11) in which the upper pattern shields 30a and the lower pattern shields 30b are formed on the upper and lower surfaces. 20) to form a plurality of chips 10 with corresponding upper pattern shields 30a and lower pattern shields 30b on the upper and lower surfaces (S12), and each chip ( 10) includes forming an upper micro-lens array 40a and a lower micro-lens array 40b on the upper and lower surfaces of the device to obtain an MLA device (S13).

The wafer 20 is preferably a transparent glass wafer.

The pattern shield forming step (S11) is specifically shown in FIG. 3.

Referring to FIG. 3, the pattern shield forming step (S11) includes forming upper pattern shields 30a on the upper surface of the wafer 20 (A) and forming a lower pattern shield on the lower surface of the wafer 20. It includes step (B) of forming (30b).

In this embodiment, the upper pattern shield is formed first and then the lower pattern shields are formed, but of course the order can be changed.

To form the upper pattern shields 30a, a wafer 20 made of glass is introduced, and then an upper metal layer M is deposited on the upper surface of the wafer 20. Next, the upper PR (P) is coated to entirely cover the upper metal layer (M). Next, through an exposure and development process, the upper PR (P) in the remaining area except for the area where the upper pattern shields 30a and the upper alignment keys 31a will be formed is removed, thereby forming the upper pattern shield 30a. The upper metal layer (M) is exposed to the outside in the remaining areas excluding the areas where the upper alignment keys 31a and the upper alignment keys 31a will be formed. Next, by etching the upper metal layer (M) in the remaining area except for the area covered by the upper PR (P) and removing the upper PR (P), a plurality of upper patterns made of metal are formed on the upper surface of the glass wafer 20. Shields 30a and a plurality of upper align keys 31a are formed in a matrix arrangement. The shapes of the upper pattern shields 30a can be changed in various ways. Additionally, each of the upper alignment keys 31a is formed to correspond to each of the upper pattern shields 30a. In this embodiment, a pair of upper align keys 31a are formed to face each other diagonally with one upper pattern shield 30a in between.

To form the lower pattern shields 30a, the wafer 20 is placed with the lower surface facing upward, and then a lower metal layer m is deposited on the lower surface of the wafer 20. Next, the lower PR (p) is coated to entirely cover the lower metal layer (m). Next, through the exposure and development process, the lower PR(p) in the remaining area except for the area where the lower pattern shields 30b and the lower alignment keys 31b will be formed is removed, thereby forming the lower pattern shield 30b. The lower metal layer (m) is exposed to the outside in the remaining areas excluding the areas where the and lower align keys 31b will be formed. Next, by etching the lower metal layer (m) in the remaining area except for the area covered by the lower PR (p) and removing the lower PR (p), a plurality of lower patterns made of metal are formed on the lower surface of the glass wafer 20. Shields 30b and a plurality of lower alignment keys 31b are formed in a matrix arrangement. The shapes of the lower pattern shields 30b can be changed in various ways. Additionally, each of the lower alignment keys 31 is formed to correspond to each of the lower pattern shields 30b. In this embodiment, a pair of lower alignment keys 31b are formed to face each other diagonally with one lower pattern shield 30b in between.

An upper pattern shield 30a and an upper align key 31a are formed on the upper surface of the chip 10, and a lower pattern shield 30b and a lower align key 31b are formed on the lower surface of the chip 10. do. The alignment of the upper pattern shield 30a and lower pattern shield 30b can be inspected using the upper alignment key 31a and lower alignment key 31b.

Referring again to FIG. 2, in step S13, an upper micro lens is formed to cover the upper and lower pattern shields 30a and 30b on each of the upper and lower surfaces of the chip 10 obtained through the above-described process. An array 40a and a lower micro lens array 40b are formed. Each of the upper micro-lens array 40a and lower micro-lens array 40b may be composed of a plurality of dome lenses arranged in a matrix. Additionally, each of the dome lenses has a width and height ranging from tens to hundreds of micrometers. Additionally, in order to form the upper micro-lens array 40a and the lower micro-lens array 40b, an imprinting process may be performed in which polymer is applied to the upper or lower surface of the chip 10 and then stamped. . For convenience of illustration, only three micro lenses constituting the upper or lower micro lens array are shown, but note that this does not limit the present invention.

Figure 4 is a diagram for explaining a method of manufacturing an MLA device with a double-sided pattern shield function according to another embodiment of the present invention.

Referring to FIG. 4, the method of manufacturing an MLA device with a double-sided pattern shield function according to the present embodiment includes upper pattern shields 30a on both sides of the wafer 20, that is, the upper and lower surfaces of the wafer 20. A pattern shield forming step (S21) of forming the and lower pattern shields 30b in a matrix array, respectively, and the upper pattern shields 30a and lower pattern shields 30b of the wafer 20 formed on the upper and lower surfaces. A step (S22) of bonding a buffer wafer 50 made of glass to the lower surface, the wafer 20 having the upper pattern shields 30a and the lower pattern shields 30b formed on the upper and lower surfaces, and By sawing a wafer stack including a buffer wafer 50 bonded to the lower surface of the wafer 20, a plurality of chips ( 10) forming step (S23) and forming the upper micro lens array 40a and lower micro lens array 40b on the upper and lower surfaces of each chip 10' to obtain an MLA device (1) Includes.

At this time, the step S22 of bonding the buffer wafer 50 is performed to increase the optical path length of the MLA device 1. According to this embodiment, that is, the MLA device 1 manufactured by adding the step (S22) of bonding the buffer wafer 50 includes an upper glass layer 20' and a lower glass layer 50', A lower pattern shield 30b formed on the lower surface of the upper glass layer 20' and interposed between the upper glass layer 20' and the lower glass layer 50', and the upper glass layer 20' An upper pattern shield 30a formed on the upper surface of the upper surface, an upper micro lens array 40a formed on the upper surface of the upper glass layer 20' to cover the upper pattern shield 30a, and the lower glass layer ( 20') and includes a lower micro lens array 40b formed on the lower surface.

A double-sided simultaneous measurement device as shown in FIGS. 5 to 7 can be used to align the upper surface (first surface) and the lower surface (second surface) of the MLA device manufactured as described above.

Referring to Figures 5 to 7, the double-sided simultaneous measurement device is a device for simultaneously acquiring images of the first side 11 and the second side 12 of the MLA element 1 having a height difference.

Additionally, the double-sided simultaneous measurement device includes a lighting unit 100, a two-pass regulator 200, and a camera 300.

The lighting unit 100 forms an image on the first surface 11 of the MLA element 1, and then irradiates light capable of forming an image by passing through the first surface 11 and reaching the second surface 12. It is configured to do so. The lighting unit 100 may include, for example, an LED or LED. Here, the first surface 11 may be a surface on which the upper pattern shield and upper alignment key described above are formed, and the second surface 12 may be a surface on which the lower pattern shield and lower align key described above are formed.

The double-sided simultaneous measurement device may include a beam splitter 110, wherein a portion of the light emitted from the lighting unit 100 is transmitted to the first side 11 and the second side of the MLA element 1. Some of the light can be reflected downward to be guided to (12). Additionally, the beam splitter 110 may transmit some of the light emitted from the first surface 11 and the second surface 12 of the MLA element 1 toward the two-pass regulator 200. In addition, a light reflection unit 120 is provided that reflects the first pass light and the second pass light that passed through the two-pass regulator 200 toward the camera 300.

If the lighting unit 100 is located at a different location, for example, at a location opposite to the two-pass regulator 200 with respect to the light-transmitting substrate 100, the beam splitter 110 may be omitted.

The camera 300 receives and processes the light of the first path coming from the first side 11 of the MLA element 1 and the light of the second path coming from the second side 12. It is composed. As will be described below, the light of the first pass and the light of the second pass are substantially transmitted by the two-pass regulator 200 despite the difference in height between the first surface 11 and the second surface 12. Since they have the same working distances, the camera 300 receives the light of the first pass and the light of the second pass of substantially the same working distance at almost the same time to create a shape or pattern image of the first surface 11. It is possible to simultaneously acquire an image of the shape or pattern of the second surface 12.

The two-pass regulator 200 operates on a first pass of light coming from the first side 11 of the MLA device 1 and a second path of light coming from the second side 12 of the MLA device 1. During this passage, the first pass and the second pass are configured to be redefined so that the working distance of the first pass and the working distance of the second pass are the same.

In addition, the camera 300 can simultaneously receive the light of the first pass and the light of the second pass, which are substantially equal to the walking distance, so that the image of the first side and the image of the second side can be simultaneously received. It can be obtained.

In this embodiment, the two-pass regulator 200 reflects the first polarized light among the light from the first side 11 or the second side 12 of the MLA element 1 and the second polarized light A polarizing plate 210 that transmits light, a first mirror 230 that reflects the light reflected from the polarizing plate 210 back toward the polarizing plate 210, and a first mirror 230 that transmits the light transmitted through the polarizing plate 210 back to the polarizing plate. A second mirror 250 reflecting toward (210), a first λ/4 wave plate 220 disposed between the polarizing plate 210 and the first mirror 230, and the polarizing plate 210. It includes a second λ/4 wave plate 240 disposed between the second mirrors 250.

The first λ/4 wave plate 220 rotates the light by 45 degrees when heading from the polarizing plate 210 to the first mirror 230 and when heading from the first mirror 230 to the polarizing plate 210. By converting the phase, the light is converted into second polarized light that transmits through the polarizer 210. In addition, the second λ/4 wave plate 240 transmits light when the light is directed from the polarizer 210 to the second mirror 250 and when the light is directed from the second mirror 250 to the polarizer 210. are each phase-shifted by 45 degrees to transform the light into first polarization reflected by the polarizer 210.

The two-pass regulator 200 connects the light of the first pass reaching from the first surface 11 of the MLA element 1 to the light receiving lens 320 of the camera 300 and the first pass of the MLA element 1. The first pass of light reaching from the second surface 12 to the light receiving lens 320 of the camera 300 can be formed as follows.

First, the working distance of the first pass is the distance A from the first surface 11 to the polarizer 210, the round trip distance 2a between the polarizer 210 and the first mirror 230, and the It is determined by the sum of the distance C from the polarizing plate 210 to the light receiving lens 320 on the camera 30 side. In this embodiment, the distance C is determined as the sum of the distance C1 from the polarizer 210 to the light reflection unit 120 and the distance C2 from the light reflection unit 120 to the camera side light receiving lens 320. It can happen.

In addition, the working distance of the second pass is the height difference h between the first surface 11 and the second surface 12, the distance A from the second surface 12 to the polarizer 210, and , is determined by the sum of the round trip distance 2b between the polarizer 210 and the second mirror 250 and the distance C from the polarizer 210 to the light receiving lens 320 on the camera 30 side. As mentioned, the distance C is determined by the sum of the distance C1 from the polarizer 210 to the light reflection unit 120 and the distance C2 from the light reflection unit 120 to the camera side water tube lens 320. You can.

Therefore, the working distance WD1 of the first pass and the working distance WD2 of the second pass can be expressed as a relational expression as follows.

WD1 = A + 2a + C (or, C1+C2)

WD2 = A + 2b + C (or, C1+ C2) + h

In addition, h, 2a and 2b are defined by the relational expression h ≈ 2a - 2b The distance b between the mirrors 250 is determined. Accordingly, the working distance WD1 of the first pass and the working distance WD2 of the second pass are substantially the same, and accordingly, the camera 30 is positioned on the first side 11 and the second side of the MLA element 1 ( 12) images can be acquired simultaneously.

At this time, the first image and the second image appear to overlap. A configuration may be needed to view the first image and the second image separately. To this end, as well shown in FIG. 4, the two-pass regulator 200 includes a first color filter 270 that passes only light in the first wavelength range among the light in the first pass, and light in the second pass. It further includes a second color filter 280 that passes only light in the second wavelength range. Accordingly, the image of the first surface implemented by the light of the first pass and the image implemented by the light of the second pass may be displayed in different colors and can be easily distinguished. In applications that do not require color differentiation, the first color filter 270 and the second color filter 280 may be omitted.

Meanwhile, the two-pass regulator 200 may be manufactured using a polarization beam splitter (PBS) cube 201. The PBS cube 201 can be manufactured by combining two right-angled triangular prisms with a polarizing material layer formed on an inclined plane so that the polarizing material layer is in contact with them. In the PBS cube 201 manufactured in this way, the polarizer 210 is formed in the form of an inclined plane connecting the corners of the PBS cube 201 in a diagonal direction.

Additionally, the first mirror 230 and the second mirror 250 are formed to face two orthogonal surfaces of the PBS cube 201. A first color filter 270 and the first λ/4 wave plate 220 are interposed between the first mirror 230 and one side of the PBS cube 201, and the second mirror 250 and A second color filter 280 and the second λ/4 wave plate 240 may be interposed between the other side of the PBS cube 201.

Since the remaining configuration is the same as the previous embodiment, description is omitted to avoid duplication.

The present invention is not limited to the above-described embodiments and can be implemented with various modifications.

10: Chip 20: Wafer
30a: upper pattern shield 30b: lower pattern shield
40a: upper micro-lens array 40b: lower micro-lens array

Claims (5)

A plurality of upper pattern shields and a plurality of upper alignment keys are formed in a matrix arrangement on the upper surface of one wafer, wherein the upper pattern shields and the upper alignment keys are formed of the same metal material and in the same layer. pattern shield forming step;
A plurality of lower pattern shields and a plurality of lower alignment keys are formed in a matrix arrangement on the lower surface of the wafer on which the upper pattern shields and the upper alignment keys are formed, wherein the lower pattern shields and the lower alignment keys are formed in a matrix arrangement. forming a lower pattern shield wherein the keys are formed in the same layer from the same metal material;
The upper pattern shields and upper alignment keys and the lower pattern shields and lower alignment keys are sawed on the wafer formed on the upper and lower surfaces, and the upper pattern shield and the upper alignment keys are formed on the upper and lower surfaces. A sawing step of forming a plurality of chips in which the align key, the lower pattern shield, and the lower align key are formed to correspond to each other; and
A method of manufacturing an MLA device having a double-sided pattern shield function, comprising a lens array forming step of forming an upper micro lens array and a lower micro lens array on the upper and lower surfaces of each of the plurality of chips. A plurality of upper pattern shields and a plurality of upper alignment keys are formed in a matrix arrangement on the upper surface of one wafer, wherein the upper pattern shields and the upper alignment keys are formed of the same metal material and in the same layer. pattern shield forming step;
A plurality of lower pattern shields and a plurality of lower alignment keys are formed in a matrix arrangement on the lower surface of the wafer on which the upper pattern shields and the upper alignment keys are formed, wherein the lower pattern shields and the lower alignment keys are formed in a matrix arrangement. forming a lower pattern shield wherein the keys are formed in the same layer from the same metal material;
A bonding step of forming a wafer stack by bonding a buffer wafer to a lower surface of the wafer on which the upper pattern shields, the upper alignment keys, and the lower pattern shields and lower alignment keys are formed on upper and lower surfaces;
A sawing step of sawing the wafer stack to form a plurality of chips in which the upper pattern shield and upper alignment key and the lower pattern shield and lower alignment key are formed to correspond vertically; and
A method of manufacturing an MLA device having a double-sided pattern shield function, comprising a lens array forming step of forming an upper micro lens array and a lower micro lens array on the upper and lower surfaces of each of the plurality of chips. In claim 1 or claim 2,
In the upper pattern shield forming step, the wafer is placed so that the upper surface of the wafer becomes a work surface, an upper metal layer is deposited on the upper surface of the wafer, and upper PR is coated to completely cover the upper metal layer, Through an exposure and development process, the upper PR in the remaining area excluding the area where the upper pattern shields and the upper alignment keys will be formed is removed, and the upper metal layer in the remaining area excluding the area covered by the removed remaining upper PR etching the upper metal layer, removing the remaining upper PR, and forming the upper pattern shields and the upper alignment keys made of metal on the upper surface of the wafer,
In the lower pattern shield forming step, the lower surface of the wafer is placed so that the lower surface becomes a work surface, a lower metal layer is deposited on the lower surface of the wafer, lower PR is coated to entirely cover the lower metal layer, exposure and development are performed. Through the process, the lower PR in the remaining area excluding the area where the lower pattern shields and the lower alignment keys will be formed is removed, and the lower metal layer in the remaining area excluding the area covered by the removed remaining lower PR is etched. , After etching the lower metal layer, the remaining lower PR is removed to form the lower pattern shields and the lower alignment keys made of metal on the lower surface of the wafer. A double-sided pattern shield function. MLA device manufacturing method having. An MLA device manufactured by the method according to claim 1. An MLA device manufactured by the method according to claim 2.

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