KR102327503B1 - Image sensor, method for fabricating the same and electronic device having the same - Google Patents

Abstract

An image sensor, a manufacturing method thereof, and an electronic device having the same are provided. An image sensor according to an embodiment includes a photoelectric conversion element; and a pixel lens formed on the photoelectric conversion element, the upper layer having a smaller area than the lower layer, and comprising a plurality of light collecting layers including a color filter material.

Description

Image sensor, manufacturing method thereof, and electronic device having the same

The present invention relates to a semiconductor device manufacturing technology, and more particularly, to an image sensor including a light collecting member having a multi-layered step shape, a manufacturing method thereof, and an electronic device having the same.

An image sensor is a device that converts an optical image into an electrical signal. Recently, with the development of the computer industry and the communication industry, the demand for image sensors with improved performance in various fields such as digital cameras, camcorders, PCS (Personal Communication System), game devices, security cameras, medical micro cameras, and robots is increasing. have.

An embodiment of the present invention provides an image sensor with improved performance, a manufacturing method thereof, and an electronic device having the same.

An image sensor according to an embodiment of the present invention includes a photoelectric conversion element; and a pixel lens formed on the photoelectric conversion element, the upper layer having a smaller area than the lower layer, and comprising a plurality of light collecting layers including a color filter material.

In addition, the image sensor according to the embodiment may further include a focusing layer inserted between the photoelectric conversion element and the pixel lens. The focusing layer may have a refractive index greater than that of the pixel lens. The focusing layer may have a larger area than the pixel lens. In addition, the image sensor according to the embodiment may further include an anti-reflection layer disposed between the photoelectric conversion element and the pixel lens or between the photoelectric conversion element and the focusing layer. In addition, the image sensor according to the embodiment includes a planarization layer covering the pixel lens and having a flat upper surface; and a hemispherical lens formed on the planarization layer.

The pixel lens may have a multi-layered step shape. The pixel lens may be an integrated structure in which the plurality of light collecting layers are formed of a single color filter material. The thickness of the lowermost light collecting layer in the pixel lens may be proportional to the wavelength length of the incident light separated by color. In the pixel lens, the line width of the lower layer exposed by the upper layer may be smaller than the wavelength of the incident light. In the pixel lens, each of the plurality of light collecting layers may have the same shape and may be disposed parallel to each other. In the pixel lens, the thickness of the upper layer may be the same as or thinner than the thickness of the lower layer. In the pixel lens, the plurality of light collecting layers may have the same refractive index.

An image sensor manufacturing method according to an embodiment of the present invention includes: forming a transfer layer including a color filter material on a substrate on which a photoelectric conversion element is formed; Preparing a stamp in which the shape of the pixel lens to be formed is engraved; pressing the stamp toward the transfer layer to imprint a shape engraved on the stamp with the transfer layer; curing the imprinted transfer layer; and removing the stamp to form a pixel lens including a plurality of light collecting layers in which the upper layer has a smaller area than the lower layer.

An electronic device according to an embodiment of the present invention includes an optical system; an image sensor receiving light from the optical system and outputting a predetermined signal in response to the received light; and a signal processing unit configured to perform a signal processing operation on the signal output from the image sensor, wherein the image sensor includes: a photoelectric conversion element; and a pixel lens formed on the photoelectric conversion element, the upper layer having a smaller area than the lower layer, and comprising a plurality of light collecting layers including a color filter material.

In addition, in the electronic device according to the embodiment, the image sensor may further include a focusing layer interposed between the photoelectric conversion element and the pixel lens. In addition, in the electronic device according to the embodiment, the image sensor may further include an anti-reflection layer disposed between the photoelectric conversion element and the pixel lens or between the photoelectric conversion element and the focusing layer. In addition, in the electronic device according to the embodiment, the image sensor may include a planarization layer covering the pixel lens and having a flat upper surface; and a hemispherical lens formed on the planarization layer.

The pixel lens may have a multi-layered step shape. The pixel lens may be an integrated structure in which the plurality of light collecting layers are formed of a single color filter material.

The present technology based on the means for solving the above problems can improve the light collecting efficiency in a unit pixel by providing a pixel lens having a multi-layered step shape. In addition, as the pixel lens acts as a color filter, it is possible to further improve light collection efficiency in a unit pixel and reduce the size (or height) of the image sensor.

As such, as the light collection efficiency in the unit pixel is improved, the quantum efficiency in the photoelectric conversion device may also be improved. As a result, the performance of the image sensor can be improved.

1 is a block diagram schematically showing an image sensor according to an embodiment of the present invention;
2 is a view showing a unit pixel of the image sensor according to the first embodiment of the present invention.
3 is a perspective view illustrating a pixel lens in a unit pixel of the image sensor according to the first embodiment;
4 is a diagram illustrating a unit pixel of an image sensor according to a second embodiment of the present invention.
5A to 5D are cross-sectional views illustrating a method of manufacturing an image sensor according to an embodiment of the present invention.
6 is a diagram schematically illustrating an electronic device having an image sensor according to an embodiment of the present invention.

Hereinafter, the most preferred embodiment of the present invention will be described with reference to the drawings in order to describe in detail enough that a person skilled in the art can easily implement the technical idea of the present invention. The drawings are not necessarily drawn to scale, and in some examples, the proportions of at least some of the structures illustrated in the drawings may be exaggerated in order to clearly show the features of the embodiments. When a multi-layer structure having two or more layers is disclosed in the drawings or detailed description, the relative positional relationship or arrangement order of the layers as shown only reflects a specific embodiment, and thus the present invention is not limited thereto, and the relative positions of the layers The relationship or arrangement order may be different. Further, the drawings or detailed description of a multi-layer structure may not reflect all layers present in a particular multi-layer structure (eg, one or more additional layers may be present between the two layers shown). For example, in the multilayer structure of the drawings or detailed description, where a first layer is on a second layer or on a substrate, it indicates that the first layer can be formed directly on the second layer or directly on the substrate. Furthermore, it may also indicate that one or more other layers are present between the first layer and the second layer or between the first layer and the substrate.

An embodiment of the present invention, which will be described later, provides an image sensor with improved performance, a manufacturing method thereof, and an electronic device having the same. Here, the image sensor with improved performance may mean that light collection efficiency in a unit pixel is improved. In general, an image sensor has a plurality of unit pixels, and a micro lens (ML) of a semi-spherical type to correspond to each of the plurality of unit pixels is disposed on an upper portion of a photoelectric conversion element. is formed The incident light is condensed to the photoelectric conversion element through the micro lens, and the light collection efficiency in the unit pixel is determined by the micro lens.

However, the known microlens has disadvantages in that the process is complicated and expensive because it is formed by a method of reflowing a lens forming material, for example, a resist. In addition, only a hemispherical shape can be realized by the reflow method, and it is difficult to form a microlens having a symmetrical and uniform shape. This also acts as a cause of increasing crosstalk. In addition, it is difficult to reduce the height (or thickness) of the image sensor because the distance required for condensing the incident light to the light receiving unit, that is, the focal length is long. Due to this, there is a disadvantage in that it is also difficult to miniaturize the electronic device including the image sensor.

Accordingly, an embodiment to be described below provides a method capable of improving light collection efficiency in a unit pixel by overcoming the disadvantages of the microlens described above. To this end, each of the plurality of unit pixels may include a pixel lens formed on the photoelectric conversion element and configured with a plurality of light collecting layers having a lower area or line width greater than an upper layer. Accordingly, the pixel lens may have a multi-layered step shape. A pixel lens having a multi-layered step shape can collect incident light like a hemispherical micro lens according to sub-wavelength optics or sub-wavelength effect. In addition, effective light collection is possible even within a limited area in response to an increase in the degree of integration of the image sensor. For reference, sub-wavelength optics is a study of optical effects at a spatial scale smaller than a wavelength, and it is known that the minimum spatial scale at which an optical effect can be obtained corresponds to half the wavelength (λ/2), but sub-wavelength optics According to wavelength optics, optical effects can be obtained even at spatial scales smaller than half a wavelength.

1 is a block diagram schematically illustrating an image sensor according to an embodiment of the present invention.

1, the image sensor according to the embodiment includes a pixel array 100 in which a plurality of unit pixels 110 are arranged in a matrix structure, correlated double sampling (CDS, 120), Analog-to-digital converter (ADC, 130), buffer (Buffer, 140), row driver (150), timing generator (160), control register (170) and ramp signal A generator (ramp signal generator, 180) may be included.

The timing generator 160 may generate one or more control signals for controlling the operation of each of the row driver 150 , the correlated double sampling 120 , the analog-to-digital converter 130 , and the ramp signal generator 180 . The control register 170 may generate one or more control signals for controlling operations of the ramp signal generator 180 , the timing generator 160 , and the buffer 140 , respectively.

The row driver 150 may drive the pixel array 100 in a row line unit. For example, the row driver 150 may generate a selection signal for selecting one row line from among a plurality of row lines. Each of the plurality of unit pixels 110 may sense incident light and output an image reset signal and an image signal as the correlated double sampling 120 through a column line. The correlated double sampling 120 may perform sampling on each of the received image reset signal and the image signal.

The analog-to-digital converter 130 may compare the ramp signal output from the ramp signal generator 180 and the sampling signal output from the correlated double sampling 120 with each other to output a comparison signal. A level transition time of the comparison signal may be counted according to the clock signal provided from the timing generator 160 , and the count value may be output to the buffer 140 . The ramp signal generator 180 may operate under the control of the timing generator 160 .

The buffer 140 may store each of a plurality of digital signals output from the analog-to-digital converter 130 , and then sense and amplify each of them to output them. Accordingly, the buffer 140 may include a memory (not shown) and a sense amplifier (not shown). The memory is for storing a count value, and the count value means a count value associated with signals output from the plurality of unit pixels 110 . The sense amplifier may sense and amplify each count value output from the memory.

In the above-described image sensor, the plurality of unit pixels may include a pixel lens capable of improving light collection efficiency. Hereinafter, a unit pixel including a pixel lens will be described in detail with reference to the drawings.

2 is a cross-sectional view illustrating a unit pixel of an image sensor according to a first embodiment of the present invention, and FIG. 3 is a perspective view illustrating a pixel lens in a unit pixel of the image sensor according to the first embodiment.

2 and 3, the image sensor according to the first embodiment includes a substrate 210 including a photoelectric conversion element 220 formed to correspond to each of a plurality of unit pixels 110, a photoelectric conversion element ( 220), the pixel lens 230 is formed on the substrate 210 to overlap the upper layer, has a smaller area (or line width) than the lower layer, and is composed of a plurality of light collecting layers 231, 232, and 233 including a color filter material. and an anti-reflection layer 240 disposed between the substrate 210 and the pixel lens 230 . In the present embodiment, as the pixel lens 230 in which a plurality of light collecting layers 231 , 232 , and 233 are stacked, the first light collecting layer 231 , the second light collecting layer 232 , and the third light collecting layer 233 are sequentially formed. was exemplified in a laminated form. Specifically, the first light collecting layer 231 is the lowermost light collecting layer, and the third light collecting layer 233 is the uppermost light collecting layer. An area of each of the plurality of light collecting layers 231 , 232 , and 233 may gradually decrease from the lowermost light collecting layer to the uppermost light collecting layer.

The substrate 210 may include a semiconductor substrate. The semiconductor substrate may be in a single crystal state and may include a silicon-containing material. That is, the substrate 210 may include a single-crystal silicon-containing material.

The photoelectric conversion device 220 may include a photo diode. For example, the photoelectric conversion device 220 formed on the substrate 210 may include a plurality of vertically overlapping photoelectric conversion layers (not shown), and each of the plurality of photoelectric conversion layers includes an N-type impurity region and a P-type impurity region. It may be a photodiode including an impurity region.

The anti-reflection layer 240 is to prevent diffuse reflection between the pixel lens 230 and the substrate 210 having different refractive indices. may include

The pixel lens 230 may serve as a light collecting member for condensing incident light. In order to improve the light collecting efficiency, the pixel lens 230 may be a multilayer in which two or more light collecting layers having an area or line width smaller than that of the lower layer are stacked on the pixel lens 230 . Accordingly, the pixel lens 230 may have a multi-layered step shape. As the pixel lens 230 has a multi-layered step shape, line widths W1 , W2 , W3 , and W4 of the lower layer exposed by the upper layer may be smaller than the wavelength of the incident light. Specifically, the line widths W1 and W2 of the second light collecting layer 232 exposed by the third light collecting layer 233 and the line widths of the first light collecting layer 231 exposed by the second light collecting layer 232 ( W3 and W4) may be smaller than the wavelength of the incident light. As such, since the line width of the lower layer exposed by the upper layer in the pixel lens 230 having a multi-layer step shape is smaller than the wavelength of incident light, the pixel lens 230 having a multi-layer step shape according to sub-wavelength optics is also a hemispherical lens. (270) is possible. Line widths W1, W2, W3, and W4 of the lower layer exposed by the upper layer in the pixel lens 230 may be the same (W1=W2, W3=W4) or different from each other (W1≠W2, W3≠) W4). The plurality of light collecting layers 231 , 232 , and 233 may have the same shape as each other, and each of the plurality of light collecting layers 231 , 232 , and 233 may be disposed parallel to each other. The plurality of light collecting layers 231 , 232 , and 233 may have a polygonal shape or a circular shape (see FIG. 3 ).

In order to further improve the light collecting efficiency of the pixel lens 230 , in the plurality of light collecting layers 231 , 232 , and 233 , the thickness of the upper layer may be the same as or thinner than the thickness of the lower layer. Specifically, the thickness t3 of the third light collecting layer 233 may be the same as the thickness t2 of the second light collecting layer 232 (t2=t3), or may be thinner (t2>t3). In addition, the thickness t2 of the second light collecting layer 232 may be the same as the thickness t1 of the first light collecting layer 231 (t2 = t1), or may be thinner (t1 > t2). In addition, in order to further improve the light collecting efficiency of the pixel lens 230 , the plurality of light collecting layers 231 , 232 , and 233 may have the same refractive index.

The pixel lens 230 may act as a condensing member for condensing incident light and also act as a color filter for color separation of incident light. To this end, the plurality of light collecting layers 231 , 232 , and 233 constituting the pixel lens 230 may include a color filter material. That is, the plurality of light collecting layers 231 , 232 , and 233 constituting the pixel lens 230 may all include the same color filter material. Accordingly, the plurality of light collecting layers 231 , 232 , and 233 constituting the pixel lens 230 may be a one-body structure formed of one color filter material.

For effective color separation of incident light, the first light collecting layer 231 , which is the lowermost light collecting layer in the pixel lens 230 , may have a shape that covers the entire unit pixel 110 , that is, an area corresponding to the unit pixel 110 .

In consideration of a focal length according to chromatic aberration for each color, the thickness t1 of the light collecting layer of the lowermost layer of the pixel lens 230 may be proportional to the wavelength length of the color-separated incident light. That is, as the wavelength length of the color-separated incident light increases, the thickness t1 of the first light collecting layer 231 may also increase. For example, when the pixel lens 230 is made of a green filter material, when the pixel lens 230 is made of a blue filter material based on the thickness t1 of the first light collecting layer 231 , the first light collecting layer 231 is may decrease, and when the pixel lens 230 is made of a red filter material, the thickness t1 of the first light collecting layer 231 may increase. For reference, the focal length refers to a distance at which incident light focused from the pixel lens 230 reaches the photoelectric conversion element 220 .

The image sensor according to the above-described first embodiment includes the pixel lens 230 having a multi-layered step shape, so that the light collecting efficiency in the unit pixel 110 can be improved. In addition, as the pixel lens 230 acts as a color filter, the light collection efficiency in the unit pixel 110 can be further improved and the size (or height) of the image sensor can be reduced.

As such, as the light collection efficiency of the unit pixel 110 is improved, the quantum efficiency of the photoelectric conversion device 220 may also be improved. As a result, the performance of the image sensor can be improved.

4 is a cross-sectional view illustrating a unit pixel of an image sensor according to a second embodiment of the present invention. Here, the same reference numerals are used for the same components as those of the first embodiment, and detailed descriptions thereof will be omitted.

As shown in FIG. 4 , the image sensor according to the second embodiment includes a substrate 210 including a photoelectric conversion element 220 formed to correspond to each of a plurality of unit pixels 110 , and formed on the substrate 210 . The focusing layer 250 , the anti-reflection layer 240 disposed between the substrate 210 and the focusing layer 250 , and the photoelectric conversion device 220 are formed on the focusing layer 250 to overlap the upper layer with a smaller area than the lower layer A pixel lens 230 having a (or line width) and a plurality of light collecting layers 231 , 232 , and 233 including a color filter material, a planarization layer 260 covering the pixel lens 230 and having a flat top surface and a hemispherical lens 270 formed on the planarization layer 260 . In the present embodiment, as the pixel lens 230 in which a plurality of light collecting layers 231 , 232 , and 233 are stacked, the first light collecting layer 231 , the second light collecting layer 232 , and the third light collecting layer 233 are sequentially formed. was exemplified in a laminated form. Specifically, the first light collecting layer 231 is the lowermost light collecting layer, and the third light collecting layer 233 is the uppermost light collecting layer. An area of each of the plurality of light collecting layers 231 , 232 , and 233 may gradually decrease from the lowermost light collecting layer to the uppermost light collecting layer. For reference, since the substrate 210 , the photoelectric conversion element 220 , the antireflection layer 240 , and the pixel lens 230 in the second embodiment are the same as in the first embodiment, a detailed description thereof will be omitted.

The focusing layer 250 serves to adjust the distance at which the incident light focused through the pixel lens 230 reaches the photoelectric conversion element 220 , that is, a focal length. By providing the focusing layer 250 , it is possible to implement a focal length shorter than that of a general micro lens. Here, the focal length may be controlled by adjusting the thickness T1 of the focusing layer 250 according to the thickness T2 of the pixel lens 230 . For example, when the thickness T1 of the focusing layer 250 is thinner than the thickness T2 of the pixel lens 230 , the focal length may be shortened (T1 < T2), and the thickness T1 of the focusing layer 250 . ) becomes thicker, the focal length may be longer (T1>T2).

In order to effectively transmit the incident light focused through the pixel lens 230 to the photoelectric conversion device 220 , the focusing layer 250 may have a larger area than the pixel lens 230 . The focusing layer 250 may have a shape corresponding to each unit pixel 110 . Accordingly, the focusing layer 250 may have the same area as the lowermost light collecting layer of the pixel lens 230 , that is, the first light collecting layer 231 , and the focusing layer 250 may be in contact with each other between adjacent unit pixels 110 . can For example, the focusing layer 250 may have a rectangular shape.

In order to more effectively transmit the incident light collected through the pixel lens 230 to the photoelectric conversion device 220 , the focusing layer 250 may have a refractive index greater than that of the pixel lens 230 . As the focusing layer 250 , any light-transmitting material having a refractive index greater than that of the pixel lens 230 may be applied. The focusing layer 250 may be a single layer or a multi-layer in which light-transmitting materials having different refractive indices are stacked. When the focusing layer 250 is multi-layered, the refractive index of the focusing layer 250 may have a slope. The refractive index may increase.

The hemispherical lens 270 may perform a function of condensing incident light to the pixel lens 230 as well as a function of preventing reflection of the incident light. The planarization layer 260 is for forming the hemispherical lens 270 on the pixel lens 230 having a multi-layered step shape, and may be formed through a low-temperature process to prevent damage to the pixel lens 230 . For example, the planarization layer 260 may include a low-temperature oxide layer (ULTO).

The image sensor according to the above-described second embodiment includes the pixel lens 230 having a multi-layered step shape, so that light collection efficiency in the unit pixel 110 can be improved. In addition, as the pixel lens 230 acts as a color filter, the light collection efficiency in the unit pixel 110 can be further improved and the size (or height) of the image sensor can be reduced. In addition, by providing the focusing layer 250 and the hemispherical lens, the light collecting efficiency in the unit pixel 110 can be more effectively improved.

As such, as the light collection efficiency of the unit pixel 110 is improved, the quantum efficiency of the photoelectric conversion device 220 may also be improved. As a result, the performance of the image sensor can be improved.

Hereinafter, a method of manufacturing an image sensor according to the above-described embodiments of the present invention will be described with reference to the drawings. Here, in the image sensor according to embodiments of the present invention, the pixel lens may include a color filter material, and a plurality of light collecting layers constituting the pixel lens may be an integrated structure composed of a single color filter material. Accordingly, a method of forming a pixel lens through an imprinting process is exemplified in a manufacturing method to be described later.

5A to 5D are cross-sectional views illustrating a method of manufacturing an image sensor according to an embodiment of the present invention. Here, a method of manufacturing the image sensor shown in FIG. 2 will be described by way of example.

As shown in FIG. 5A , a photoelectric conversion device 11 is formed on a substrate 10 . The substrate 10 may include a single-crystal silicon-containing material, and the photoelectric conversion device 11 may include a photodiode. The photoelectric conversion device 11 may include a plurality of vertically overlapping photoelectric conversion layers (not shown), and each of the plurality of photoelectric conversion layers may include an N-type impurity region and a P-type impurity region. The N-type impurity region and the P-type impurity region may be formed through an ion implantation process.

Next, an anti-reflection layer 12 is formed on the substrate 10 . The anti-reflection layer 12 may be formed by alternately stacking two or more material layers having different refractive indices at least once.

Next, a transfer layer 13 is formed on the anti-reflection layer 12 . The transfer layer 13 may include a color filter material. The color filter material used as the transfer layer 13 may be based on a thermoplastic polymer material, for example, PMMA (Polymethly Methacrylate), or a material that causes polymerization by ultraviolet rays, for example, resin.

As shown in FIG. 5B , a stamp 20 in which the shape of the pixel lens 14 to be formed is engraved is prepared. The stamp 20 is also referred to as a mold, and includes a semiconductor material such as silicon or silicon oxide, a metal material such as nickel (Ni), quartz, pyrex, and soda lime glass. , may be formed using any one selected from the group consisting of a light-transmitting material such as alumina or sapphire and a plastic material.

Next, the stamp 20 is aligned on the substrate 10 on which the transfer layer 13 is formed.

As shown in FIG. 5C , the stamp 20 is pressed toward the transfer layer 13 to imprint the pattern engraved on the stamp 20 on the transfer layer 13A. In this case, when the transfer layer 13A is based on a thermoplastic polymer material, the imprinted transfer layer 13A may be cured through heat treatment. On the other hand, when the transfer layer 13A is based on a material that causes a polymerization reaction by ultraviolet rays, the imprinted transfer layer 13A can be cured by irradiating ultraviolet rays.

As shown in FIG. 5D , after the imprinted transfer layer 13A is cured, the stamp 20 is removed, and a post-treatment is performed to remove residues remaining on the surface of the transfer layer 13A. As the post-treatment, any one or more of a front etching process, an oxygen plasma treatment, or a cleaning process may be performed.

Thereby, the plurality of light collecting layers 14A, 14B, 14C are formed on the substrate 10 to overlap the photoelectric conversion element 11, the upper layer has a smaller area (or line width) than the lower layer, and includes a color filter material. The configured pixel lens 14 may be formed.

Thereafter, the image sensor may be completed through a known manufacturing technique.

The image sensor according to the above-described embodiment may be used in various electronic devices or systems. Hereinafter, a case in which an image sensor according to an embodiment of the present invention is applied to a camera will be described with reference to FIG. 6 .

6 is a diagram schematically illustrating an electronic device having an image sensor according to an embodiment of the present invention.

Referring to FIG. 6 , an electronic device having an image sensor according to an embodiment may be a camera capable of capturing a still image or a moving image. The electronic device may include an optical system 310 or an optical lens, a shutter unit 311 , an image sensor 300 , and a driving unit 313 and a signal processing unit 312 for controlling/driving the shutter unit 311 . have.

The optical system 310 guides image light (incident light) from the subject to the pixel array of the image sensor 300 (refer to reference numeral '100' in FIG. 1 ). The optical system 310 may include a plurality of optical lenses. The shutter unit 311 controls a light irradiation period and a shielding period for the image sensor 300 . The driving unit 313 controls a transmission operation of the image sensor 300 and a shutter operation of the shutter unit 311 . The signal processing unit 312 performs various types of signal processing on the signal output from the image sensor 300 . The image signal Dout after signal processing is stored in a storage medium such as a memory or output to a monitor or the like.

Although the technical spirit of the present invention has been specifically described according to the above preferred embodiments, it should be noted that the above embodiments are for explanation only and not for limitation. In addition, those skilled in the art will understand that various embodiments within the scope of the technical spirit of the present invention are possible.

210: substrate 220: photoelectric conversion element
230: pixel lens 240: anti-reflection layer
250: focusing layer 260: planarization layer
270: hemispherical lens

Claims (20)

photoelectric conversion element;
a pixel lens formed on the photoelectric conversion element and including a plurality of light collecting layers; and
a focusing layer inserted between the photoelectric conversion element and the pixel lens;
The focusing layer has a refractive index greater than that of the pixel lens,
An upper layer of the plurality of light collecting layers has a smaller area than a lower layer,
each of the plurality of light collecting layers of the pixel lens has a color filter material and has a flat surface, and
The line width of the lower layer exposed by the upper layer is smaller than the wavelength of the incident light.
◈Claim 2 was abandoned when paying the registration fee.◈ According to claim 1,
and the focusing layer has a larger area than the pixel lens.
◈Claim 3 was abandoned when paying the registration fee.◈ According to claim 1,
The image sensor further comprising an anti-reflection layer inserted between the photoelectric conversion element and the pixel lens or between the photoelectric conversion element and the focusing layer.
◈Claim 4 was abandoned when paying the registration fee.◈ According to claim 1,
a planarization layer covering the pixel lens and having a planar ring top surface; and
The image sensor further comprising a hemispherical lens formed on the planarization layer.
◈Claim 5 was abandoned when paying the registration fee.◈ According to claim 1,
The pixel lens is an image sensor having a multi-layered step shape.
◈Claim 6 was abandoned when paying the registration fee.◈ According to claim 1,
The pixel lens is an integral structure, and
The plurality of light collecting layers include the same color filter material.
◈Claim 7 was abandoned when paying the registration fee.◈ According to claim 1,
In the pixel lens, the thickness of the lowermost light collecting layer is proportional to the wavelength of the color-separated incident light.
◈Claim 8 was abandoned when paying the registration fee.◈ According to claim 1,
The plurality of light collecting layers of the pixel lens have the same shape, have different sizes, and are disposed parallel to each other.
◈Claim 9 was abandoned at the time of payment of the registration fee.◈ According to claim 1,
The thickness of the upper layer is equal to or smaller than the thickness of the lower layer.
◈Claim 10 was abandoned when paying the registration fee.◈ According to claim 1,
The plurality of light collecting layers of the pixel lens have the same refractive index.
forming a transfer layer including a color filter material on the substrate on which the photoelectric conversion element is formed;
Preparing a stamp engraved with a multi-layered step shape;
pressing the stamp toward the transfer layer to imprint a shape engraved on the stamp with the transfer layer; and
and curing the transfer layer to form a pixel lens,
The pixel lens has a multi-layered step shape and includes a plurality of light collecting layers, and
An upper layer of the plurality of light collecting layers has a smaller area than a lower layer.
optical system;
an image sensor receiving light from the optical system and outputting a predetermined signal in response to the received light; and
A signal processing unit for processing the signal output from the image sensor,
The image sensor is
photoelectric conversion element;
a pixel lens formed on the photoelectric conversion element and including a plurality of light collecting layers; and
a focusing layer inserted between the photoelectric conversion element and the pixel lens;
The focusing layer has a refractive index greater than that of the pixel lens,
An upper layer of the plurality of light collecting layers has a smaller area than a lower layer,
each of the plurality of light collecting layers includes a color filter material and has a flat surface, and
The line width of the lower layer exposed by the upper layer is smaller than the wavelength of the incident light.
◈Claim 13 was abandoned when paying the registration fee.◈ 13. The method of claim 12,
The electronic device further comprising an anti-reflection layer inserted between the photoelectric conversion element and the pixel lens or between the photoelectric conversion element and the focusing layer.
◈Claim 14 was abandoned at the time of payment of the registration fee.◈ 13. The method of claim 12,
a planarization layer covering the pixel lens and having a flat top surface; and
The electronic device further comprising a hemispherical lens formed on the planarization layer.
◈Claim 15 was abandoned when paying the registration fee.◈ 13. The method of claim 12,
The pixel lens is an electronic device having a multi-layered step shape.
◈Claim 16 was abandoned at the time of payment of the registration fee.◈ 13. The method of claim 12,
The pixel lens is an integral structure, and
The plurality of light collecting layers include the same color filter material.
photoelectric conversion element;
a pixel lens formed on the photoelectric conversion element and including a plurality of light collecting layers; and
a focusing layer inserted between the photoelectric conversion element and the pixel lens;
The focusing layer has a larger area than the pixel lens,
The upper layer of the plurality of light collecting layers has a smaller area than the lower layer,
each of the plurality of light collecting layers of the pixel lens comprises a color filter material and has a planar surface, and
The line width of the lower layer exposed by the upper layer is smaller than the wavelength of the incident light.
◈Claim 18 was abandoned when paying the registration fee.◈ 18. The method of claim 17,
The focusing layer has the same area as a lowermost layer of the plurality of light collection layers.
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