KR102506435B1 - Method of manufacturing image sensor including nanostructure color filter - Google Patents

Abstract

An image sensor manufacturing method includes preparing a sensor substrate including a sensor layer including photo-sensing cells and a signal wiring layer on which wires for reading electrical signals from the photo-sensing cells are formed; and forming a nanopattern layer including a plurality of nanostructures made of a high refractive index material on the sensor substrate. According to the above manufacturing method, a thin image sensor having excellent wavelength selectivity and suitable for high resolution is manufactured.

Description

Method of manufacturing image sensor including nanostructure color filter

The present disclosure relates to a method of manufacturing a high-resolution image sensor.

The number of pixels of an image sensor is gradually increasing, and accordingly, pixel miniaturization is required. In order to miniaturize the pixel, securing the amount of light and removing noise are important issues, and recently, a cell-separation type BIS (back illuminated structure) sensor has been introduced and much progress has been made.

However, the structure of an optical component that collects color light toward an optical sensor, such as a color filter or a microlens, is a limiting factor in miniaturizing pixels. For example, a color filter of an absorption type and a microlens guiding light toward the color filter are disposed on the color filter, and the thickness of these two optical components becomes a limiting factor in miniaturizing pixels.

An object of the present disclosure is to provide a method of manufacturing an image sensor employing a color filter having a structure suitable for pixel miniaturization.

According to one type, preparing a sensor substrate including a sensor layer including one or more photo-sensing cells and a signal wiring layer on which wires for reading electrical signals from the photo-sensing cells are formed; forming a first material layer having a first refractive index on the sensor substrate; and forming a nanopattern layer including a plurality of nanostructures made of a material having a second refractive index greater than the first refractive index on the first material layer.

The forming of the nano-pattern layer may include bonding a first substrate having the second refractive index on the first material layer; forming a second material layer having a predetermined thickness by reducing the thickness of the first substrate; Patterning the second material layer; may include.

In the patterning of the second material layer, the second material layer may be patterned in a form including a plurality of regions in which at least one of the plurality of nanostructures has a different shape or a repeatedly arranged period.

The first material layer may be a silicon oxide layer, and the first substrate may be a silicon substrate.

The bonding of the first substrate may use an anodic bonding method.

In order to reduce the thickness of the first substrate, a chemical mechanical polishing (CMP) method may be used.

The method may further include forming a weak region by implanting ions into the first substrate before bonding the first substrate.

In order to reduce the thickness of the first substrate, a layer splitting method may be used.

The first substrate may be a silicon on insulator (SOI) substrate including first and second silicon layers and a silicon oxide layer disposed between the first and second silicon layers.

In order to reduce the thickness of the first substrate, the second silicon layer and the silicon oxide layer may be removed.

In the forming of the nano-pattern layer, a method of forming the plurality of nanostructures on a second substrate and transferring the plurality of nanostructures onto the first material layer may be used.

The manufacturing method may further include forming a plurality of nanoribbons by under-etching a surface of the second substrate at a position in contact with the plurality of nanostructures.

A viscoelastic polymer material may be used to transfer the plurality of nanostructures onto the first material layer.

In addition, according to one type, a silicon on insulator (SOI) substrate including first and second silicon layers and a silicon oxide layer disposed between the first and second silicon layers is prepared, and the second silicon layer processing into a sensor layer having one or more photo-sensing cells; forming wires for reading electrical signals from the photo-sensing cells and a protective layer to protect the wires on the sensor layer; bonding a first substrate on the protective layer; reducing the thickness of the first silicon layer; and patterning the first silicon layer to form a nano-pattern layer including a plurality of nanostructures.

In the forming of the nano-pattern layer, the first silicon layer may be patterned in a form including a plurality of regions in which at least one of the plurality of nanostructures has a different shape or a repeatedly arranged period.

The protective layer may be formed of a silicon oxide material.

A silicon substrate may be used as the first substrate.

The step of bonding the first substrate on the passivation layer may use an anodic bonding method.

In the bonding, a method of polymer bonding the protective layer and the first substrate with a polymer material layer interposed therebetween may be used.

Alternatively, a method of forming the protective layer with a polymer material and polymer bonding the protective layer and the first substrate may be used.

In the bonding, a method of metal bonding the passivation layer and the first substrate with a metal material layer interposed therebetween may be used.

According to the above-described manufacturing method, an image sensor having a nanostructured color filter is manufactured.

According to the above-described manufacturing method, since the optical properties are determined by the period, shape, arrangement, etc. of the nanostructure, a nanostructured color filter having excellent wavelength selectivity and easy color bandwidth control is manufactured. , a high resolution, thin image sensor can be implemented.

According to the above-described manufacturing method, since the microlens can be omitted by designing the nanostructure so that the thickness is very short compared to the visible light wavelength band and has the function of a microlens, a thin image sensor can be implemented.

According to the above-described manufacturing method, since a silicon single crystal layer can be used as a material of a nanostructure by utilizing a silicon substrate or an SOI substrate, an image sensor having excellent wavelength selectivity can be more easily manufactured.

1 is a cross-sectional view showing a schematic structure of an image sensor according to an exemplary embodiment.
FIG. 2 is a perspective view showing a schematic structure of a nanostructured color filter employed in the image sensor of FIG. 1 .
3A to 3E are views illustrating a method of manufacturing an image sensor according to an embodiment.
4A to 4E are views illustrating a method of manufacturing an image sensor according to another embodiment.
5A to 5H are views illustrating a method of manufacturing an image sensor according to another embodiment.
6A to 6G are views illustrating a method of manufacturing an image sensor according to another embodiment.
7A to 7G are views illustrating a method of manufacturing an image sensor according to another embodiment.
8A to 8G are views illustrating a method of manufacturing an image sensor according to another embodiment.

Since the present invention can apply various transformations and have various embodiments, specific embodiments will be illustrated in the drawings and described in detail in the detailed description. Effects and features of the present invention, and methods for achieving them will become clear with reference to the embodiments described later in detail together with the drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various forms.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, and when describing with reference to the drawings, the same components are given the same reference numerals, and overlapping descriptions thereof will be omitted.

In the following embodiments, terms such as first and second are used for the purpose of distinguishing one component from another component without limiting meaning.

In the following examples, expressions in the singular number include plural expressions unless the context clearly dictates otherwise.

In the following embodiments, terms such as include or have mean that features or components described in the specification exist, and do not preclude the possibility that one or more other features or components may be added.

In the following embodiments, when a part such as a film, region, component, etc. is said to be on or on another part, not only when it is directly above the other part, but also when another film, region, component, etc. is interposed therebetween. Including if there is

In the drawings, the size of components may be exaggerated or reduced for convenience of explanation. For example, since the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of description, the present invention is not necessarily limited to the illustrated bar.

1 is a cross-sectional view showing a schematic structure of an image sensor 100 to be manufactured according to a manufacturing method according to an embodiment. FIG. 2 is a perspective view showing a schematic structure of a nanostructured color filter 150 employed in the image sensor 100 of FIG. 1 .

The image sensor 100 includes a sensor layer 130 that senses light and generates an electrical signal, and a nanostructured color filter 150 formed on the sensor layer 130 . The sensor layer 130 includes one or more light-sensing cells, for example, light-sensing cells 131, 132, and 133.

The image sensor 100 according to the embodiment employs the nanostructured color filter 150 to realize high resolution and minimize the overall thickness. The nanostructured color filter 150 includes a nanostructured pattern in which two materials having different refractive indices are repeatedly arranged at a predetermined period, and a plurality of color filter areas are implemented by adjusting the shape and period of the pattern.

The nanostructured color filter 150 includes a first material layer 151 made of a material having a first refractive index, and a plurality of nanoparticles formed on the first material layer 151 and made of a material having a second refractive index greater than the first refractive index. The structure 153 includes an array of nanopatterned layers.

The high refractive index materials constituting the nanostructure 153 include monocrystalline silicon, polycrystalline silicon (Poly Si), amorphous silicon (amorphous Si), Si ₃ N ₄ , GaP, TiO ₂ , AlSb, AlAs, AlGaAs, AlGaInP, BP, ZnGeP Either of _{the two} may be employed.

The first material layer 151 may be a support for forming a nanostructure. The first material layer 151 may be made of a material having a lower refractive index than the nanostructure 153 . For example, any one of PC, PS, polymer such as PMMA, and SiO ₂ may be employed.

The nanopattern layer formed by the plurality of nanostructures 150 includes a plurality of color filter regions CF1 , CF2 , and CF3 . The plurality of color filter regions CF1 , CF2 , and CF3 are disposed to face each of the light sensing cells 131 , 132 , and 133 . The plurality of color filter areas CF1 , CF2 , and CF3 may be configured to transmit light of the first color, light of the second color, and light of the third color, and reflect or absorb the rest. For example, the first color, the second color, and the third color may be red, green, and blue, respectively. Although three color filter regions CF1, CF2, and CF3 are shown in the figure, this is an example, and the color filter regions CF1, CF2, and CF3 are repeatedly arranged as many pixels as necessary. In this case, the color filters may be repeatedly arranged in a form in which two green color filters, one blue color filter, and one red color filter form four pixels. Alternatively, cyan, yellow, green, and magenta color filters may be repeatedly arranged. Alternatively, the color filters may be repeatedly arranged in a form in which two white, one blue, and one red pixels form four pixels.

As shown in FIG. 2 , the nanostructured color filter 150 includes a plurality of nanostructures 153 repeatedly arranged at a predetermined period T on the first material layer 151 . Although the nanostructure 153 is shown in the form of a hexahedral block, it is not limited thereto and may have various shapes such as a polyhedral column or a cylinder. In addition, although the nanostructures 153 are illustrated as two-dimensionally arranged in rows and columns, the nanostructures 153 in each row or column may be alternately arranged.

A region between the nanostructures 153 may be an empty space, for example, a region in which air exists, and thus, a structure in which the nanostructure 153 and the low refractive index material, that is, air are alternately disposed is formed A region between the nanostructures 153 may be filled with a material having a refractive index smaller than that of the nanostructures 153 .

The nanostructured color filter 150 has a predetermined wavelength determined by the difference in refractive index between the high refractive index material and the low refractive index material constituting the nanostructure 153, period (T), shape, thickness (Th) of the nanostructure 153, and the like. transmits light and reflects others. The period (T) is a value smaller than the wavelength (λ), and may be, for example, less than 3/4 of the wavelength or less than half of the wavelength. The thickness (th) of the nanostructure 153 is a value smaller than the wavelength (λ), and may be, for example, less than half of the wavelength. Here, the wavelength means the center wavelength of a selected wavelength band to be transmitted.

At least one of the details such as period, material, shape, and thickness of the color filter regions CF1, CF2, and CF3 may be determined differently so as to transmit light of a desired wavelength and reflect or absorb the rest. can The material and shape of the nanostructure 153 are the same for each of the color filters CF1, CF2, and CF3, and the period or thickness of the repeated arrangement of the nanostructure 153 is the color filter CF1, CF2, and CF3. ), the selected wavelength band can be adjusted by adjusting differently in each. For example, the color filter area CF1 may have a period T1 and a thickness t1, the color filter area CF2 may have a period T2 and a thickness t2, and the color filter area ( CF3) may have a period T3 and a thickness t3.

In addition, the shape and arrangement of the nanostructures 153 in each of the color filter regions CF1, CF2, and CF3 may be designed to collect incident light. In addition, in order to derive a structure suitable for the incident angle, the shape and arrangement of the nanostructure 153 may be determined. In this case, even in the case of the same color filter area, detailed design details may be different according to the relative position within the image sensor 100 .

A plurality of photo-sensing cells 131, 132, and 133 constituting the sensor layer 130 are independently driven and generate electrical signals proportional to the intensity of light incident on the corresponding device. The photo-sensing cells 131, 132, and 133 may include, for example, a photodiode, a complementary metal-oxide semiconductor (CMOS) sensor, or a charge-coupled device (CCD) sensor. In addition, barrier ribs 135 partitioning the plurality of light sensing cells 131, 132, and 133 may be further provided. The barrier rib 135 obliquely passes through the color filters CF1, CF2, and CF3 and transmits light obliquely incident to the photo-sensing cells 131, 132, and 133, not the cell, but adjacent photo-sensing cells ( It serves to prevent progression to 131) (132) (133). To this end, the barrier rib 135 may be made of a material that absorbs or reflects light. A material having a lower refractive index than that of the photo-sensing cells 131, 132, and 133 may be used as a material for the barrier rib 135.

In addition, the image sensor 100 includes a signal wiring layer 110 for reading electrical signals from the sensor layer 130 . The signal wiring layer 110 may include a plurality of metal wires 112 and a protective layer 114 protecting the metal wires 112 .

The nanostructured color filter 150 is disposed on the upper surface of the sensor layer 130 , that is, on the surface opposite to the surface on which the signal wiring layer 110 is formed on the sensor layer 130 . In this way, a structure in which light enters the sensor layer 130 immediately after passing through the nanostructured color filter 150 is referred to as Back Side Illumination (BSI). Unlike this, the signal wiring layer 110 is provided on top of the sensor layer 130, that is, the structure in which light is incident on the sensor layer 130 via the signal wiring layer 110 is referred to as Front Side Illumination (FSI). do. In the case of the backside illumination type, since there is no interference by the signal wiring layer 110 in the process of light reaching the sensor layer 130, the efficiency of the light incident on the sensor layer 130 is higher than that of the front illumination type.

Hereinafter, various methods of manufacturing the above-described image sensor 100 or an image sensor having a structure capable of performing substantially the same function as the above image sensor 100 will be described.

3A to 3E are views illustrating a method of manufacturing an image sensor according to an embodiment.

As shown in FIG. 3A , a sensor substrate including a sensor layer 130 and a signal wiring layer 110 on which wires for reading electrical signals from the sensor layer 130 are formed is prepared.

The sensor layer 130 may be made of a semiconductor material and may include a detailed structure capable of sensing light and generating an electrical signal, for example, a diode structure. Although not shown, the sensor layer 130 may include a plurality of photo-sensing cells and may include a barrier rib structure partitioning the plurality of photo-sensing cells.

The sensor substrate including the signal wiring layer 110 and the sensor layer 130 may be supported by the substrate S1. The substrate S1 may serve as a handling substrate for forming an additional structure on the back side of the sensor substrate, ie, the upper surface of the sensor layer 130, or may be omitted.

Next, as shown in FIG. 3B, a first material layer 151 having a first refractive index is formed. The first material layer 151 may have a thickness smaller than a wavelength range of visible light, for example, about 50 nm to about 200 nm. The first material layer 151 may be formed of SiO ₂ or various polymer materials such as HSQ or SU8. Depending on the material of the first material layer 1510, a manufacturing method such as deposition or spin coating may be used.

Next, as shown in FIG. 3C , a substrate S2 is disposed on the first material layer 151 . The substrate S2 may be bonded to the first material layer 151 .

The substrate S2 includes a material having a higher refractive index than the refractive index of the first material layer 151, and the above-described nanostructure may be formed therefrom. The substrate S2 may be a silicon substrate and may be made of a single crystal silicon material.

Before bonding the substrate S2 to the first material layer 151, a weak area WA may be previously formed inside the substrate S2. The weak area WA may be formed by, for example, ion implantation. For example, in the case of implanting a plurality of H+ ions into a predetermined depth position inside the substrate S2, the depth position may become a relatively soft region compared to other positions due to the implanted ions. In the next step, the weak area WA may be used when reducing the thickness of the substrate S2 by layer splitting.

When bonding the substrate S2 to the first material layer 151, an anodic bonding method may be used. Anodic bonding is also called field-assisted sealing, and is a method mainly used for bonding glass and silicon wafers. When the substrate S2 is a silicon substrate and the first material layer 151 is formed of SiO ₂ , an anodic bonding method may be used. A brief description of the anodic bonding process is as follows. A voltage of hundreds of volts is applied between the substrate S2 and the first material layer 151 so that the substrate S2 becomes relatively positive, and then the temperature is raised to several hundred degrees Celsius. Positive ions of the first material layer 151 have increased motility due to a rise in temperature, and move toward the surface of the first material layer 151 that becomes a cathode and disappear. Anions that are relatively more strongly confined in the first material layer 151 form a space charge layer near the interface with the substrate S2, and positive ions in the first material layer 151 move toward the opposite side of the interface. Accordingly, the potential drop at the interface between the substrate S2 and the first material layer 151 increases, and the two interfaces are bonded by this electric field.

The substrate S2 may be bonded to the first material layer 151 using a polymer bonding method. In this case, the first material layer 151 may be formed of a polymer material capable of polymer bonding. The substrate S2 may be bonded to the first material layer 151 by disposing the substrate S2 on the first material layer 151 and heating, cooling, or pressurizing the substrate S2 .

Next, as shown in FIG. 3D, a second material layer 154 having a second refractive index is formed. The second material layer 154 represents a layer processed to a desired thickness by removing most of the area of the substrate S2. A chemical mechanical polishing (CMP) method may be used, and an additional etching process may be further performed to finely adjust the thickness.

Alternatively, as described in FIG. 3C , when the weak area WA is formed in advance by ion implantation inside the substrate S2, a layer splitting method may be performed using this area. For example, if another substrate is bonded to the substrate S2 on which the weak area WA is formed and the bonded substrate is peeled off, layer splitting occurs with the weak area WA of the substrate S2 as a boundary. It is done. Even in this case, an additional etching process may be further performed to finely adjust the thickness.

Next, the second material layer 154 is patterned to form a nanopatterned layer including a plurality of nanostructures 153 as shown in FIG. 3E. To form the nanopattern layer, a photolithography process may be used, and a mask prepared to vary the cycle in which the nanostructures 153 are arranged may be used according to regions. According to the method described above, the image sensor 101 having the nanostructured color filter 150 is manufactured.

According to the above-described manufacturing method, since a pre-manufactured silicon substrate including a single-crystal silicon layer is used, the nanostructure 153 can be easily formed with a single-crystal silicon material, and a nanostructured color filter having better wavelength selectivity is provided. An image sensor that does can be manufactured.

4A to 4E are views illustrating a method of manufacturing an image sensor according to another embodiment.

In the manufacturing method of this embodiment, in that a silicon on insulator (SOI) substrate is used as a material for forming the plurality of nanostructures 153 included in the nanostructured color filter 150, the manufacturing method described in FIGS. 3A to 3E There is a difference between the method and

As shown in FIGS. 4A and 4B, a sensor substrate including a sensor layer 130 and a signal wiring layer 110 on which wires for reading electrical signals from the sensor layer 130 are formed is prepared, and the sensor layer 130 A first material layer 151 having a first refractive index is formed thereon.

Next, as shown in FIG. 4C , a substrate S3 is disposed on the first material layer 151 . The substrate S3 may be bonded to the first material layer 151 .

The substrate S3 is a silicon on insulator (SOI) substrate including a first silicon layer 155 , a silicon oxide layer 156 , and a second silicon layer 157 . The first silicon layer 155 may be made of a single crystal silicon material, and has a higher refractive index than the refractive index of the first material layer 151 made of SiO ₂ or a polymer material. The aforementioned nanostructure may be formed from the first silicon layer 155 .

When bonding the third substrate S2 to the first material layer 151, as described above, an anodic bonding method or a polymer bonding method may be used.

Next, as shown in FIG. 4D, a second material layer 154 having a second refractive index is formed. The second material layer 154 represents a layer processed to a desired thickness by removing most of the substrate S3. In order to remove the silicon oxide layer 156 and the second silicon layer 157 of the substrate S3, a chemical mechanical polishing (CMP) method may be used, and the remaining first silicon layer 155 may have a fine thickness. To adjust, an additional etching process may be further performed.

Next, the second material layer 154 is patterned to form a plurality of nanostructures 153 as shown in FIG. 3E. To form the nanostructures 153, a photolithography process may be used, and a mask prepared to vary a cycle in which the nanostructures 153 are arranged may be used according to regions. According to the method described above, the image sensor 102 having the nanostructured color filter 150 is manufactured.

5A to 5H are views illustrating a method of manufacturing an image sensor according to another embodiment.

The manufacturing method of the image sensor according to the embodiment is different from the manufacturing method of the above-described embodiments in that it uses a method of separately manufacturing a plurality of nanostructures on a separate substrate and then transferring them onto the sensor layer.

First, referring to FIG. 5A , a second material layer 154 is formed on a substrate S4. The second material layer 154 may be formed of a material having a high refractive index suitable for a material of a nanostructure constituting a nanostructured color filter.

The substrate S4 is a silicon substrate, and the second material layer 154 may be made of a single crystal silicon material. Alternatively, the entirety of the substrate S4 and the second material layer 154 may be a silicon on insulator (SOI) substrate. That is, the second material layer 154 may be an upper silicon layer of the SOI substrate, and the substrate S4 may include a silicon oxide layer and a lower silicon layer.

Next, as shown in FIG. 5B , the second material layer 154 is patterned to include a plurality of nanostructures 153 .

Next, as shown in FIG. 5C , the surface of the substrate S4 at a position in contact with the plurality of nanostructures 153 is under-etched. For this under-etching, an etching method using an etchant having different etching rates between the material of the nanostructure 153 and the material of the substrate S4 may be used. For example, the etching rate of the substrate S4 may be significantly faster than the etching rate of the nanostructure 153 by using a specific etchant. In this case, the substrate S4 under the nanostructure 153 may also be isotropically etched to form an under-etched pattern.

As shown, the nanostructure 153 is supported on the substrate S4 by the nanoribbons nr, and thus can be easily separated from the substrate S4.

Next, as shown in FIG. 5D , a viscoelastic material layer 170 covering the nanostructure 153 is formed. The viscoelastic material layer 170 is a material having viscosity, elasticity, and releasability that facilitates separation of the nanostructure 153 from the substrate S4 , and may be a polymer material. Polydimethylsiloxane (PDMS) may be used as the viscoelastic material layer 170 .

Next, as shown in FIG. 5E, the viscoelastic polymer layer 170 is separated from the substrate S4. Since the support force due to the viscosity of the viscoelastic polymer layer 170 is stronger than the support force of the nanoribbons nr on the substrate S4, the plurality of nanostructures 153 are easily separated from the substrate S4.

As shown in FIGS. 5F and 5G, a sensor substrate including a sensor layer 130 and a signal wiring layer 110 on which wires for reading electrical signals from the sensor layer 130 are formed is prepared, and the sensor layer 130 A first material layer 151 having a first refractive index is formed thereon. The first material layer 151 may be made of SiO ₂ , HSQ, or SU8. The first material layer 151 may be formed of the same material as that of the aforementioned viscoelastic polymer layer 170 .

Next, as shown in FIG. 5H, by disposing the viscoelastic polymer layer 170 in which the plurality of nanostructures 153 are embedded is disposed on the first material layer 151, the image sensor equipped with the nanostructured color filter 150' ( 103) is prepared.

6A to 6G are views illustrating a method of manufacturing an image sensor according to another embodiment.

In the method of manufacturing an image sensor according to the present embodiment, a silicon layer of a silicon on insulator (SOI) substrate is used to form a sensor layer, and a silicon oxide layer and another silicon layer provided on the SOI substrate are respectively formed to form a nanostructured color filter. It is used as a low refractive index material and a high refractive index material for

First, as shown in FIG. 6A, an SOI substrate S5 including a first silicon layer 165, a silicon oxide layer 161, and a second silicon layer 141 is prepared. The first silicon layer 165 may be a single crystal silicon layer.

Next, as shown in FIG. 6B , a sensor layer 140 is formed and a wire 112 is formed on the sensor layer 140 . The sensor layer 140 represents a layer processed into a form including a plurality of photo-sensing cells by further performing an additional process including doping and barrier rib formation on the second silicon layer 141 of FIG. 6A.

Next, as shown in FIG. 6C, a protective layer 114 for protecting the wirings 112 is further formed. The protective layer 114 may be formed of SiO ₂ .

As shown in FIG. 6D, the substrate S6 is disposed on the protective layer 114. The substrate S6 is used as a handling substrate for a process of forming a nanostructure from the first silicon layer 165 . The substrate S6 may be a silicon substrate and may be bonded to the protective layer 114 using an anode bonding method.

FIG. 6E shows an inverted form of the laminated structure of FIG. 6D. That is, the substrate S6 is located at the bottom and the second silicon layer 165 is located at the top. The second material layer 164 is formed by reducing the thickness of the second silicon layer 165 to a desired thickness, as shown in FIG. 6F. The second material layer 164 represents a layer in which the thickness of the second silicon layer 165 is adjusted to a thickness suitable for forming nanostructures. For the thickness control, a CMP process may be used, and an additional etching process may be further performed.

Next, the second material layer 164 is patterned to form a plurality of nanostructures 163 as shown in FIG. 3E. To form the nanostructure 163, a photolithography process may be used. In the photolithography process, a mask prepared to differently form a period in which the nanostructures 163 are disposed according to regions may be used. According to the method described above, the image sensor 102 having the nanostructured color filter 160 is manufactured.

7A to 7G are views illustrating a method of manufacturing an image sensor according to another embodiment.

The manufacturing method of this embodiment is different from the manufacturing method described in FIGS. 6A to 6G in a method of bonding the substrate S7 used as a handling substrate to the protective layer 114 .

Processes of FIGS. 7A to 7C are substantially the same as those of FIGS. 6A to 6C. Next, as shown in FIG. 7D, the substrate S7 is placed on the protective layer 114, and a polymer layer 180 is further formed on the protective layer 114, and the polymer layer 180 is used as a bonding material, The substrate S7 and the protective layer 114 are polymer bonded. Alternatively, when the protective layer 114 is formed of a polymer material, since the polymer material serves as a bonding material, a separate polymer layer 180 is not formed and the substrate S7 and the protective layer 114 are bonded with the polymer. It can be.

FIG. 7e shows an inverted form of the laminated structure of FIG. 7d. That is, the substrate S7 is located at the bottom and the second silicon layer 165 is located at the top. As shown in FIG. 7F by reducing the thickness of the second silicon layer 165 to a desired thickness, the second material layer 164 is formed, and the second material layer 164 is patterned to form a plurality of nanostructures as shown in FIG. 7G. (163). According to the method described above, the image sensor 105 having the nanostructured color filter 160 is manufactured.

8A to 8G are views illustrating a method of manufacturing an image sensor according to another embodiment.

The manufacturing method of this embodiment is different from the manufacturing method described in FIGS. 6A to 6G in a method of bonding the substrate S8 used as a handling substrate to the protective layer 114 .

Processes of FIGS. 8A to 8C are substantially the same as those of FIGS. 6A to 6C. Next, as shown in FIG. 8D, the substrate S7 is disposed on the protective layer 114, and a metal layer 180 is further formed on the protective layer 114 so that the substrate S7 and the protective layer 114 are formed with metal. bonded

FIG. 8e shows an inverted form of the laminated structure of FIG. 8d. That is, the substrate S8 is located at the bottom and the second silicon layer 165 is located at the top. By reducing the thickness of the second silicon layer 165 to a desired thickness, as shown in FIG. 8F, a second material layer 164 is formed, and the second material layer 164 is patterned to form a plurality of nanostructures as shown in FIG. 8G. (163). According to the method described above, the image sensor 106 having the nanostructured color filter 160 is fabricated.

So far, exemplary embodiments have been described and shown in the accompanying drawings in order to facilitate the understanding of the present invention. However, it should be understood that these examples are merely illustrative of the invention and not limiting thereof. And it should be understood that the present invention is not limited to the description shown and described. This is because various other variations may occur to those skilled in the art.

100, 101, 102, 103, 104, 105, 106.. image sensor
110.. Signal wiring layer
112.. Wiring
114.. protective layer
130, 140.. sensor layer
131, 132, 133.. light detection cell
135..Bulkhead
150, 160.. Nanostructured color filters
CF1, CF2, CF3.. color filter area
S1, S2, S3, S4, S5, S6, S8, S8.. boards
151.. First material layer
153, 163.. Nanostructures
154. Second material layer
155, 165.. 1st silicon layer
156, 161.. silicon oxide layer
157, 141.. Second silicon layer

Claims (21)

preparing a sensor substrate including a sensor layer including one or more photo-sensing cells and a signal wiring layer on which wires for reading electrical signals from the photo-sensing cells are formed;
forming a first material layer having a first refractive index on the sensor substrate; and
Forming a nanopattern layer including a plurality of nanostructures made of a material having a second refractive index greater than the first refractive index on the first material layer,
The step of forming the nanopattern layer is
bonding a first substrate having the second refractive index on the first material layer;
forming a second material layer having a predetermined thickness by reducing the thickness of the first substrate;
Patterning the second material layer; including, image sensor manufacturing method. delete According to claim 1,
Patterning the second material layer
The method of manufacturing an image sensor, wherein the second material layer is patterned in a form including a plurality of regions in which at least one of the plurality of nanostructures has a different shape or a repeatedly arranged period. According to claim 1,
The first material layer is a silicon oxide layer,
The first substrate is a silicon substrate, an image sensor manufacturing method. According to claim 4,
The bonding of the first substrate is an image sensor manufacturing method using an anodic bonding method. According to claim 1,
An image sensor manufacturing method using a chemical mechanical polishing (CMP) method to reduce the thickness of the first substrate. According to claim 1,
Prior to bonding the first substrate,
Forming a weak region by implanting ions into the first substrate; further comprising the image sensor manufacturing method. According to claim 7,
An image sensor manufacturing method using a layer splitting method to reduce the thickness of the first substrate. According to claim 1,
The first substrate is a silicon on insulator (SOI) substrate including first and second silicon layers and a silicon oxide layer disposed between the first and second silicon layers. According to claim 9,
In order to reduce the thickness of the first substrate, removing the second silicon layer and the silicon oxide layer, the image sensor manufacturing method. preparing a sensor substrate including a sensor layer including one or more photo-sensing cells and a signal wiring layer on which wires for reading electrical signals from the photo-sensing cells are formed;
forming a first material layer having a first refractive index on the sensor substrate; and
Forming a nanopattern layer including a plurality of nanostructures made of a material having a second refractive index greater than the first refractive index on the first material layer,
The step of forming the nanopattern layer is
A method of manufacturing an image sensor using a method of forming the plurality of nanostructures on a second substrate and transferring the plurality of nanostructures onto the first material layer. According to claim 11,
The method of manufacturing an image sensor further comprising forming a plurality of nanoribbons by under-etching a surface of the second substrate at a position in contact with the plurality of nanostructures. According to claim 12,
An image sensor manufacturing method using a viscoelastic polymer material to transfer the plurality of nanostructures onto the first material layer. A silicon on insulator (SOI) substrate including first and second silicon layers and a silicon oxide layer disposed between the first and second silicon layers is prepared, and the second silicon layer is used to form one or more photo-sensing cells. processing into a sensor layer having;
forming wires for reading electrical signals from the photo-sensing cells and a protective layer to protect the wires on the sensor layer;
bonding a first substrate on the protective layer;
reducing the thickness of the first silicon layer; and
Forming a nano-pattern layer including a plurality of nanostructures by patterning the first silicon layer; According to claim 14,
The step of forming the nanopattern layer is
The method of manufacturing an image sensor, wherein the first silicon layer is patterned in a form including a plurality of regions in which at least one of the plurality of nanostructures has a different shape or a repeatedly arranged period. According to claim 14,
Forming the protective layer with a silicon oxide material, an image sensor manufacturing method. According to claim 16,
An image sensor manufacturing method using a silicon substrate as the first substrate. According to claim 17,
The bonding of the first substrate on the protective layer uses an anodic bonding method, an image sensor manufacturing method. According to claim 14,
In the bonding step,
A method of manufacturing an image sensor using a method of polymer bonding the protective layer and the first substrate with a polymer material layer interposed therebetween. According to claim 14,
Forming the protective layer of a polymer material,
The bonding step uses a method of polymer bonding the protective layer and the first substrate, an image sensor manufacturing method. According to claim 14,
In the bonding step,
An image sensor manufacturing method using a method of metal bonding the protective layer and the first substrate with a metal material layer interposed therebetween.

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