KR20240003179A - Chalcogenide composite lens module including silicon meta lens and manufacturing method thereof - Google Patents

Abstract

The present invention includes: a first lens; a lens protection window built into the lower part of the first lens; and a metalens including at least one metasurface having a plurality of nanostructures disposed on an upper portion of the lens protection window. The first lens may be made of a chalcogenide material, and the lens protection window may be made of silicone.

Description

Chalcogenide composite lens module including silicon meta lens and manufacturing method thereof}

The present invention relates to a chalcogenide composite lens module including a metalens, and more specifically, to a chalcogenide infrared composite lens module including a silicon metalens and a method of manufacturing the same.

Infrared transmission lenses are an essential optical component for thermal imaging camera systems, and demand for night vision goggles, vehicle night vision, and security/surveillance cameras is expanding. Recently, ultra-small infrared camera modules that can be mounted on mobile phones have been commercialized. Among infrared rays, the use of cameras in the far infrared band (wavelength range 8-12 ㎛) (LWIR; long-wavelength infrared) is rapidly increasing in various civil fields. Crystalline materials and chalcogenide glass materials are used as far-infrared band lens materials. Chalcogenide glass refers to a glass material composed of a binary or higher composition system containing one or more chalcogen elements of sulfur (S), selenium (Se), and tellurium (Te). For example, chalcogenide glass (ChGs) is a glass made by combining chalcogen elements with Ga, In, Si, Ge, Sn, Sb, Bi, Ag, Cd, Zn, etc. Crystalline materials (Ge, ZnSe, ZnS, Si, etc.) have the disadvantage of low mass production because they require a precision direct machining process using diamond. On the other hand, chalcogenide glass has the advantage of excellent price competitiveness in terms of mass production as it can be applied to the molding process.

Meanwhile, typically, when a chalcogenide lens is mounted on an infrared camera, the chalcogenide lens is located on top of the infrared lens. Since chalcogenide glass is highly brittle and vulnerable to scratches, a chalcogenide lens protective window is needed to protect the chalcogenide lens from the external environment. In the prior art, when manufacturing an infrared camera module, a protective window is provided to physically/chemically protect the chalcogenide lens from the external environment. At this time, when assembling the protective window and chalcogenide lens, they are separated at a certain distance. There is a problem in that the volume of the infrared camera module increases due to the separation distance, and the assembly cost increases because the space must be maintained in a vacuum state to minimize infrared absorption in the space.

The present invention aims to solve the above-described problems and other problems associated therewith.

One exemplary object of the present invention is to provide a composite lens module including a chalcogenide lens and/or a metalens.

One exemplary purpose of the present invention is to provide an optical device including a composite lens module.

One exemplary purpose of the present invention is to provide a method for manufacturing a composite lens module using a chalcogenide molding process.

The technical challenges to be achieved by the composite lens module according to the technical spirit of the technology disclosed in this specification are not limited to the challenges to solve the problems mentioned above, and other challenges not mentioned will become clear to those skilled in the art from the description below. It will be understandable.

A composite lens module according to an embodiment for achieving an object of the present invention includes a first lens; and a lens protection window built into the lower portion of the first lens, wherein the first lens may be made of a chalcogenide material, and the lens protection window may be made of silicon.

According to one embodiment, the composite lens module may further include a metalens including at least one metasurface including a plurality of nanostructures disposed on an upper portion of the lens protection window.

According to one embodiment, the nanostructure may be made of germanium, lead telluride (PbTe), silicon, or a combination thereof.

According to one embodiment, the chalcogenide material includes at least one element selected from the group consisting of sulfur (S), selenium (Se), and telenium (Te); and arsenic (As), boron (B), aluminum (Al), gallium (Ga), indium (In), silicon (Si), germanium (Ge), tin (Sn), antimony (Sb), and bismuth (Bi). ), silver (Ag), cadmium (Cd), zinc (Zn), and thallium (Tl).

According to one embodiment, the first lens may have a curved lens surface on at least one lens surface.

According to one embodiment, the curved lens surface may be any one of a convex lens surface, a concave lens surface, and a composite curved lens surface.

According to one embodiment, the curved lens surface of the first lens may be an aspherical surface.

According to one embodiment, the composite lens module is capable of concentrating far-infrared rays with a wavelength of 8um to 12um.

According to one embodiment, the nanostructure may have a shape dimension smaller than the incident wavelength.

An optical device according to an embodiment for achieving an object of the present invention may include the composite lens module.

According to one embodiment, the optical device may be an infrared camera.

A method of manufacturing a composite lens module according to an embodiment for achieving an object of the present invention includes forming a metalens including at least one metasurface having a plurality of nanostructures on a first substrate; forming a stacked structure by stacking a second substrate on the first substrate on which the metalens is formed; And it may include the step of placing a mold having an engraved structure corresponding to the curved lens surface on the laminated structure and embedding the first substrate in the lower part of the second substrate to bond them.

According to the present invention, it is possible to effectively bond a lens protection window that provides durability and scratch protection for a far-infrared lens.

In addition, according to the present invention, it is possible to provide a thin film chalcogenide lens module, making it possible to manufacture an ultra-small camera module. In addition, it is possible to manufacture a chalcogenide lens composite module with an embedded metalens, which is a lens form combined with a metalens, making it possible to achieve thinning of the lens module and improvement of transmission efficiency at the same time.

However, the effects according to an embodiment of the technology disclosed in this specification are not limited to those mentioned above, and other effects not mentioned may be clearly understood by those skilled in the art from the description below.

In order to more fully understand the drawings cited in this specification, a brief description of each drawing is provided.
Figure 1 shows a cross-section of a composite lens module according to an embodiment of the present invention.
Figure 2 shows a cross section of a composite lens module according to an embodiment of the present invention.
Figure 3 is a diagram schematically showing a method of manufacturing a composite lens module according to an embodiment of the present invention.
FIG. 4(a) shows a plan view (a photo viewed from above) of a composite lens module according to an embodiment of the present invention, and FIG. 4(b) shows a bottom view (a photo viewed from below).
Figure 5 shows a photograph of the surface of a nanostructure metalens according to an embodiment of the present invention.

The technology disclosed in this specification can be subject to various changes and can have various embodiments, and specific embodiments will be illustrated in the drawings and described in detail through detailed description. However, this is not intended to limit the technology disclosed in this specification to specific embodiments, and the technology disclosed in this specification is understood to include all changes, equivalents, and substitutes included in the spirit and scope of the technology disclosed in this specification. It has to be.

In describing the technology disclosed in this specification, if it is determined that a detailed description of related known technology may unnecessarily obscure the gist of the technology disclosed in this specification, the detailed description will be omitted. In addition, numbers (eg, first, second, etc.) used in the description of this specification are merely identifiers to distinguish one component from another component.

In this specification, when a component is referred to as “joined” or “coupled” with another component, the component may be directly bonded or combined with the other component, but no special description to the contrary is used. Unless it exists, it should be understood that it can be joined or combined through another component in the middle.

Expressions such as “first,” “second,” “first,” or “second” used in various embodiments herein may modify various elements regardless of order and/or importance, and It does not limit the components. For example, a first component may be renamed a second component without departing from the scope of the technology disclosed in this specification, and similarly, the second component may also be renamed the first component.

As used herein, the expressions “optional” and “optionally” mean that the subsequently described event or circumstance may or may not occur and that the description includes instances where the event or circumstance occurs and instances where it does not occur.

In the present specification, when a part of a film, layer, region, component, etc. is said to be “on” or “on” another part, it does not only mean that it is directly on top of the other part, but also that it is another film, layer, region, or element in between. This also includes cases where components, etc. are included.

As used herein, a “nano” object refers to an object in which at least one dimension is in the nm range. Nanoscale objects can have any of a wide range of shapes and can be formed from a wide range of materials, including, for example, nanowires, nanotubes, nanoplatelets, nanoparticles, and other nanostructures. .

As used herein, a “micro” object refers to an object in which at least one dimension is in the μm range. Typically, the angular dimensions of micro-sized objects are in or exceed the μm range. Micro-sized objects can have any of a wide range of shapes and can be formed from a wide range of materials, including, for example, microwires, microtubes, microparticles, and other microstructures.

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification may be used with meanings that can be commonly understood by those skilled in the art to which the present invention pertains. Additionally, terms defined in commonly used dictionaries are not interpreted ideally or excessively unless clearly specifically defined.

Hereinafter, a composite lens module according to a preferred embodiment will be described in detail.

According to one embodiment of the present invention, as shown in Figure 1, a first lens 110; And a composite lens module 100 including a lens protection window 120 built into the lower part of the first lens 110 can be provided.

According to one embodiment, the first lens 110 may be made of chalcogenide material. Chalcogenide is a material composed of binary or more compounds containing one or more chalcogen elements such as sulfur (S), selenium (Se), and telenium (Te) excluding oxygen (O) in group 6 of the periodic table. represents. Chalcogenide has the characteristic of quickly changing between crystalline and amorphous states as heat is applied. In the crystalline state, optical reflectivity is high and electrical resistance is low, while in the amorphous state, reflectivity is low and electrical resistance is high.

According to one embodiment, the chalcogenide material includes at least one element selected from the group consisting of sulfur (S), selenium (Se), and telenium (Te); and arsenic (As), boron (B), aluminum (Al), gallium (Ga), indium (In), silicon (Si), germanium (Ge), tin (Sn), antimony (Sb), and bismuth (Bi). , it may contain at least one element selected from the group consisting of silver (Ag), cadmium (Cd), zinc (Zn), and thallium (Tl). For example, the chalcogenide material includes germanium (Ge), gallium (Ga), antimony (Sb), and selenium (Se), but on a mol% basis, 5≤germanium≤25, 2≤gallium≤20, It may have a content of 5≤antimony≤25 and 55≤selenium≤70.

According to one embodiment, the lens protection window 120 is built-in and bonded to the lower part of the first lens 110 to physically/chemically protect the first lens 110 from the external environment. In other words, since the lens protection window goes into the first lens and is mechanically interlocked by pressure at the corner, the bonding force is strong and there is also an effect of reducing the thickness of the entire module. Additionally, since a separate adhesive is not used, there is an advantage in that there is no loss of IR transparency due to the bonding layer. Furthermore, during high-temperature chalcogenide lens molding, an additional bonding process is not required because the lens protection window is placed on the lower surface and molded at the same time.

Therefore, the chalcogenide lens and silicon substrate composite module according to the present invention can implement a (far) infrared camera module with strong durability and small volume.

According to one embodiment, the lens protection window 120 may be made of a material that is resistant to scratches and has high infrared transparency. For example, the lens protection window 120 may be made of silicon (Si). The lens protection window 120 may be made of silicon, preferably having a minimum infrared transmittance of 40% or more, more preferably having a minimum infrared transmittance of 50% or more.

According to one embodiment, the first lens 110 may have a curved lens surface on at least one lens surface. The curved lens surface may be any one of a convex lens surface, a concave lens surface, and a composite curved lens surface. The curved lens surface of the first lens 110 may be an aspherical surface.

According to one embodiment of the present invention, as shown in Figure 2, a first lens 110; A lens protection window 120 built into the lower part of the first lens 110; A composite lens module 200 can be provided, including a meta-lens 130 including at least one meta-surface including a plurality of nanostructures disposed on the lens protection window 120.

According to one embodiment, the metalens 130 has at least one metasurface including a plurality of nanostructures having a shape dimension smaller than the incident wavelength of the composite lens module.

The incident wavelength of the composite lens module may be in the far-infrared region. The far-infrared incident wavelength band may be in the range of about 8um to 12um, and the dimensions of the nanostructure may be configured to have a wavelength smaller than this. That is, the array pitch and width of the nanostructure may be smaller than the far-infrared ray incident wavelength. For example, the size of the nanostructure may be about 100nm to 10um, but is not limited thereto. Therefore, a metalens containing a metasurface with nano/micro structures of the size of the incident wavelength or less is capable of optical phase modulation, and the flat microstructure acts as a lens to collect light. Therefore, it has the advantage of minimizing the thickness compared to general lenses.

According to one embodiment, the nanostructure may be composed of nano lines, mesh, nano holes, nano polygons, nano networks, or nanoparticles that are arranged regularly or irregularly. The nanostructure may be a pillar-shaped structure. For example, it may have a square pillar shape or a cylindrical shape. In addition, various pillar shapes having a rectangular, cross-shaped, polygonal, or elliptical cross-sectional shape can be applied to the nanostructure.

The nanostructure may be made of germanium, lead telluride (PbTe), silicon, or a combination thereof. Preferably, the nanostructure may be made of the same material as the lens protection window.

A composite lens module using the metalens can be mounted and used in an electronic device (optical device, etc.). For example, infrared cameras, smartphones, wearable devices, Internet of Things (IoT) devices, home appliances, tablet PCs (personal computers), PDAs (personal digital assistants), PMPs (portable multimedia players), and navigation. It can be installed in electronic devices such as navigation, drones, robots, driverless cars, self-driving cars, and advanced driver assistance systems (ADAS).

According to one embodiment of the present invention, as shown in FIG. 3, forming a stacked structure by stacking a second substrate 320 on a first substrate 310; And placing a mold 340 having an engraved structure corresponding to the curved lens surface on the laminated structure and heating and pressing the mold 340 to embed the first substrate 310 in the lower part of the second substrate 320 and bond it. A method for manufacturing a composite lens module is provided.

According to one embodiment, the first substrate 310 may be a lens protection window. Additionally, the second substrate 320 may be made of a chalcogenide material. The description of the lens protection window and chalcogenide material is the same as described above.

According to one embodiment, the composite lens module manufacturing method further includes forming a metalens including at least one metasurface having a plurality of nanostructures on the first substrate before forming the layered structure. can do.

According to one embodiment, a lens protection window is placed on the bottom surface when forming a lens by pressing at a temperature above the chalcogenide molding temperature using a mold, so that a lens is formed on the top surface and a lens protection window is simultaneously embedded on the bottom surface. By molding it so well, a composite lens module can be formed in a single process. Therefore, since the present invention can be processed into a lens shape by molding using a mold, the manufacturing process price can be lowered compared to the prior art. In addition, since there is no need to use an adhesive, it is possible to implement a module with strong durability and a small volume while preventing loss of transmittance due to IR absorption loss by the adhesive bonding layer.

According to one embodiment, the metasurface can be manufactured using processing processes such as photoetching process, electron beam lithography, imprint process grinding, dry polishing, CMP (chemical mechanical polishing), reactive ion etching, wet etching, and dry etching. there is. For example, after the initial lithography process, Si (silicon) can be manufactured using dry etching (Deep RIE, reactive ion etching).

Example

When pressurized at a process temperature of 190 degrees, process pressure of 4 bar, and 1 hour, a composite lens module was manufactured in which a lens protection window containing a silicon nanostructure that functions as a metalens was embedded and bonded into a chalcogenide lens. FIG. 4(a) shows a top view (a photo viewed from above) of a composite lens module manufactured according to an example, and FIG. 4(b) shows a bottom view (a photo viewed from below). Additionally, Figure 5 shows a photograph of the surface of a nanostructured metalens.

As described above, although the embodiments have been described with limited examples and drawings, various modifications and variations can be made by those skilled in the art from the above description. For example, the described techniques may be performed in a different order than the described method, and/or components of the described structure, device, etc. may be combined or combined in a form different from the described method, or may be used with other components or equivalents. Appropriate results can be achieved even if replaced or substituted by .

Therefore, other implementations, other embodiments, and equivalents of the claims also fall within the scope of the following claims.

Claims (14)

first lens; and
It includes a lens protection window embedded in the lower part of the first lens,
A composite lens module wherein the first lens is made of a chalcogenide material. According to claim 1,
A composite lens module comprising a metalens including at least one metasurface having a plurality of nanostructures disposed on an upper portion of the lens protection window. According to claim 1,
A composite lens module wherein the lens protection window is made of silicon. According to claim 2,
A composite lens module wherein the nanostructure is made of germanium, lead telluride (PbTe), silicon, or a combination thereof. According to claim 1,
The chalcogenide material is,
At least one element selected from the group consisting of sulfur (S), selenium (Se), and telenium (Te); and
Arsenic (As), boron (B), aluminum (Al), gallium (Ga), indium (In), silicon (Si), germanium (Ge), tin (Sn), antimony (Sb), bismuth (Bi) , a composite lens module comprising at least one element selected from the group consisting of silver (Ag), cadmium (Cd), zinc (Zn), and thallium (Tl). According to claim 1,
A composite lens module, wherein the first lens has a curved lens surface on at least one lens surface. According to claim 1,
The curved lens surface is one of a convex lens surface, a concave lens surface, and a composite curved lens surface. According to claim 1,
A composite lens module, wherein the curved lens surface of the first lens is aspherical. According to claim 2,
A composite lens module that focuses far-infrared rays with a wavelength of 8um to 12um. According to clause 9,
A composite lens module, wherein the nanostructure has a shape dimension smaller than the wavelength. An optical device comprising the composite lens module of any one of claims 1 to 10. According to claim 11,
An optical device, wherein the optical device is an infrared camera. forming a stacked structure by stacking a second substrate on a first substrate; and
A step of placing a mold having an engraved structure corresponding to a curved lens surface on the laminated structure and bonding the first substrate to a lower portion of the second substrate,
The first substrate is made of silicon,
A method of manufacturing a composite lens module, wherein the second substrate is made of a chalcogenide material. Forming a metalens including at least one metasurface having a plurality of nanostructures on a first substrate;
forming a stacked structure by stacking a second substrate on the first substrate on which the metalens is formed; and
A composite lens module manufacturing method comprising the step of placing a mold having an engraved structure corresponding to a curved lens surface on the laminated structure and embedding the first substrate in a lower part of the second substrate to bond them.