KR20000041459A - Image sensor and fabrication method thereof - Google Patents
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- 239000010937 tungsten Substances 0.000 claims description 3
- 206010034972 Photosensitivity reaction Diseases 0.000 abstract description 4
- 230000036211 photosensitivity Effects 0.000 abstract description 4
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- 239000010408 film Substances 0.000 description 33
- 239000010410 layer Substances 0.000 description 27
- 206010034960 Photophobia Diseases 0.000 description 10
- 208000013469 light sensitivity Diseases 0.000 description 10
- 239000011229 interlayer Substances 0.000 description 6
- 230000003287 optical effect Effects 0.000 description 5
- 239000000463 material Substances 0.000 description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 239000003990 capacitor Substances 0.000 description 2
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- 239000011347 resin Substances 0.000 description 2
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- 229910052814 silicon oxide Inorganic materials 0.000 description 2
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- 239000012535 impurity Substances 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000000206 photolithography Methods 0.000 description 1
- 229920002120 photoresistant polymer Polymers 0.000 description 1
- 238000002310 reflectometry Methods 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
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- H01L31/08—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors
- H01L31/10—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors characterised by potential barriers, e.g. phototransistors
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Abstract
Description
본 발명은 이미지센서 및 그 제조방법에 관한 것으로, 특히 입사하는 광을 효과적으로 집광할 수 있도록 구현된 이미지센서 및 그 제조방법에 관한 것이다.The present invention relates to an image sensor and a method for manufacturing the same, and more particularly, to an image sensor and a method for manufacturing the same so as to effectively collect incident light.
일반적으로, 이미지센서(image sensor)라 함은 광학 영상(optical image)을 전기 신호로 변환시키는 반도체소자로서, 이중 전하결합소자(charge coupled device: 이하 CCD)는 개개의 MOS(Metal-Oxide-Silicon: 이하 MOS) 커패시터가 서로 매우 근접한 위치에 있으면서 전하 캐리어가 커패시터에 저장되고 이송되는 소자이며, CMOS(Complementary MOS; 이하 CMOS) 이미지센서는 제어회로(control circuit) 및 신호처리회로(signal processing circuit)를 주변회로로 사용하는 CMOS 기술을 이용하여 화소수만큼 MOS트랜지스터를 만들고 이것을 이용하여 차례차례 출력(output)을 검출하는 스위칭 방식을 채용하는 소자이다.In general, an image sensor is a semiconductor device that converts an optical image into an electrical signal, and a charge coupled device (CCD) is an individual metal-oxide-silicon (MOS). Is a device in which charge carriers are stored and transported in a capacitor while the capacitors are in close proximity to each other, and a CMOS (Complementary MOS) image sensor is a control circuit and a signal processing circuit. Is a device that adopts a switching method that makes MOS transistors by the number of pixels by using CMOS technology using peripheral circuits, and sequentially detects the output by using the same.
이러한 다양한 이미지센서를 제조함에 있어서, 이미지센서의 감광도(photo sensitivity)를 증가시키기 위한 노력들이 진행되고 있는바 그 중 하나가 집광기술이다. 예컨대, CMOS 이미지센서는 빛을 감지하는 광감지부분과 감지된 빛을 전기적 신호로 처리하여 데이터화하는 로직회로부분으로 구성되어 있는바, 광감도를 높이기 위해서는 전체 이미지센서 면적에서 광감지부분의 면적이 차지하는 비율(Fill Factor)을 크게 하려는 노력이 진행되고 있지만, 근본적으로 로직회로 부분을 제거할 수 없기 때문에 제한된 면적 하에서 이러한 노력에는 한계가 있다. 따라서 광감도를 높여주기 위하여 광감지부분 이외의 영역으로 입사하는 빛의 경로를 바꿔서 광감지부분으로 모아주는 집광기술이 많이 연구되고 잇다.In manufacturing such various image sensors, efforts are being made to increase the photo sensitivity of the image sensor. For example, the CMOS image sensor is composed of a light sensing portion for detecting light and a logic circuit portion for processing the detected light as an electrical signal to make data. In order to increase the light sensitivity, the area of the light sensing portion occupies the entire area of the image sensor. Efforts have been made to increase the fill factor, but these efforts are limited in a limited area because the logic circuit part cannot be removed fundamentally. Therefore, in order to increase the light sensitivity, a lot of research has focused on the condensing technology that changes the path of light incident to the area other than the light sensing area and collects the light sensing area.
도1은 종래기술에 의한 집광기술을 보여주는 종래의 이미지센서 단면도로서, 도1에는 집광에 관련된 이미지센서의 주요부분만이 개략적으로 도시되어 있다.Figure 1 is a cross-sectional view of a conventional image sensor showing a condensing technique according to the prior art, Figure 1 schematically shows only the main part of the image sensor related to the condensing.
도1을 참조하면, 종래의 이미지센서는 광감지소자(102a, 102b, 102c) 이외의 영역(103)으로 광이 입사되는 것을 방지하기 위하여 층간절연막(105a, 105b) 내에 광차폐층(light shield layer)(104)이 형성되어 있으며, 그 위로 칼라필터(106a, 106b, 106c)가 어레이되어 있고, 칼라필터 위에는 마이크로렌즈(108a, 108b, 108c)가 형성되어 있다. 통상적으로 광감지소자(102a, 102b, 102c)는 포토게이트 또는 포토다이오드 등으로 형성되며 광차폐층(104)은 금속층으로 형성된다. 칼라필터(106a, 106b, 106c)의 재료로는 염료가 첨부된 레지스트가 주로 이용되고 있으며, 마이크로렌즈(108a, 108b, 108c)의 재료로는 레지스트 또는 그와 유사한 수지(resin)가 주로 이용된다. 광감지소자 102a에는 레드(Red)칼라필터 106a를 통과한 빛을 입사받으며, 입사되는 빛은 마이크로렌즈 108a를 통해 광감지소자 102a에 집광된다. 마찬가지로 그린(Green)칼라필터 106b 및 블루(Blue) 칼라필터 106c를 통과하는 빛은 그 상부에 형성된 마이크로렌즈 108b 및 108c에 의해 각각 집광되어 광감지소자 102b 및 102c에 입사된다. 잘 알려진 바와 같이, 층간절연막(105a, 105b)은 투명물질로서 통상 실리콘산화물계 박막이 적용되고, 칼라필터(106a, 106b, 106c) 상부에는 평탄화 또는 광투과도 향상을 목적으로 버퍼층이 형성되는바, 이 역시 통상 실리콘산화물계 물질 또는 포토레지스트가 적용된다.Referring to FIG. 1, a conventional image sensor includes a light shield in an interlayer insulating film 105a, 105b to prevent light from being incident into an area 103 other than the photosensitive devices 102a, 102b, and 102c. layer 104 is formed, and color filters 106a, 106b, and 106c are arrayed thereon, and microlenses 108a, 108b, and 108c are formed on the color filters. Typically, the photosensitive devices 102a, 102b, 102c are formed of a photogate or photodiode, and the light shielding layer 104 is formed of a metal layer. As the material of the color filters 106a, 106b and 106c, a resist with dye is mainly used, and as the material of the microlenses 108a, 108b and 108c, a resist or a similar resin is mainly used. . The light passing through the red color filter 106a is incident on the photosensitive device 102a, and the incident light is focused on the photosensitive device 102a through the microlens 108a. Similarly, light passing through the green color filter 106b and the blue color filter 106c is collected by the microlenses 108b and 108c formed thereon, respectively, and is incident on the photosensitive elements 102b and 102c. As is well known, the interlayer insulating films 105a and 105b are typically transparent silicon oxide based thin films, and a buffer layer is formed on the color filters 106a, 106b, and 106c to improve planarization or light transmittance. This also usually applies to silicon oxide based materials or photoresists.
한편, 마이크로렌즈는 각 광감지소자의 구성 즉, 단위화소의 크기와 위치, 모양, 그리고 광감지소자의 깊이, 그리고 광차폐층의 높이, 위치, 크기 등등에 의해 결정되는 최적의 크기와 두께 그리고 곡률반경으로 형성되어야 한다. 그러나, 점점 이미지센서가 고집적화 되어감에 따라 역시 단위화소의 크기가 축소되면서 마이크로렌즈의 크기도 그에 따라 축소되며 또한 마이크로렌즈로부터 광감지소자까지의 깊이는 깊어지게 되는 바, 이에 의해 마이크로렌즈가 정확한 광집속 기능을 수행하도록, 즉 원하는 광감지소자에 정확히 광을 집속하도록, 그 두께 및 곡률 반경 등을 설정하기가 매우 어렵게 된다.On the other hand, the microlens is an optimal size and thickness determined by the configuration of each photosensitive device, that is, the size and position of the unit pixel, the shape and depth of the photosensitive device, and the height, position, size, etc. of the light shielding layer It should be formed with a radius of curvature. However, as the image sensor becomes more and more highly integrated, the size of the unit pixel is also reduced, and the size of the microlens is also reduced accordingly, and the depth from the microlens to the light sensing element is deepened. It is very difficult to set the thickness, the radius of curvature, and the like so as to perform the light focusing function, that is, to focus the light accurately on the desired light sensing element.
또한, 원하는 광감지소자에 정확히 광이 집속되지 않고 벗어나므로써 어레이된 광감지소자들끼리의 광감도가 균일하지 않게 된다. 즉, 각 단위화소에 형성되는 마이크로렌즈는 각 단위화소의 광감지소자에 일정하게 정렬되기 때문에 가운데와 외곽 단위화소의 광감지소자에 도달하는 광의 양이 다르게되어 광감도의 불 균일도를 가져온다.In addition, since light is not focused on the desired photosensitive device without being focused, the photosensitivity between the arrayed photosensitive elements is not uniform. That is, since the microlenses formed in each unit pixel are constantly aligned with the light sensing elements of each unit pixel, the amount of light reaching the light sensing elements of the center and outer unit pixels is different, resulting in unevenness of light sensitivity.
또한, 볼록렌즈 형상의 마이크로렌즈를 형성하는 방법은, 포토리소그라피 공정에 의해 레지스트 패턴을 형성하고 열처리에 의해 레지스트를 플로우시킨 다음, 베이킹(baking)을 실시하여 경화시키는 방법이 사용되고 있으나, 레지스트 물질 자체가 고온에 약하기 때문에 소자의 내열성이 떨어지는 문제점이 있다.In addition, as a method of forming a convex lens-shaped microlens, a resist pattern is formed by a photolithography process, a resist is flowed by heat treatment, and then a baking is performed to harden the resist material itself. Has a problem in that the heat resistance of the device is inferior because it is weak to high temperature.
본 발명의 목적은 상기 문제점을 해결하기 위하여 안출된 것으로써, 광집속력이 증대되어 광감도를 향상시키는 이미지센서 및 그 제조방법을 제공하는데 있다.SUMMARY OF THE INVENTION An object of the present invention is to provide an image sensor and a method for manufacturing the same, which are devised to solve the above problems, and thus improve light sensitivity by increasing light focusing power.
본 발명의 다른 목적은 단위화소들 간의 광감도 균일도를 개선하기 위한 이미지센서 및 그 제조방법을 제공하는데 있다.Another object of the present invention is to provide an image sensor and a manufacturing method for improving the light sensitivity uniformity between unit pixels.
본 발명의 또 다른 목적은 내열성이 우수한 이미지센서 및 그 제조방법을 제공하는데 있다.Still another object of the present invention is to provide an image sensor excellent in heat resistance and a method of manufacturing the same.
도1은 종래기술에 의한 집광기술을 보여주는 종래의 이미지센서 단면도,1 is a cross-sectional view of a conventional image sensor showing a light collecting technique according to the prior art;
도2a 내지 도2e는 본 발명의 일 실시예에 따른 이미지센서 제조 공정도,2a to 2e is a manufacturing process of the image sensor according to an embodiment of the present invention,
도3a 내지 도3e는 본 발명의 다른 실시예에 따른 이미지센서 제조 공정도.3a to 3e is a manufacturing process of the image sensor according to another embodiment of the present invention.
* 도면의 주요부분에 대한 부호의 설명* Explanation of symbols for main parts of the drawings
202 : 광감지소자 204 : 광차폐층202: photosensitive device 204: light shielding layer
205, 209 : 절연막 206 : 버퍼절연막205 and 209 insulating film 206 buffer insulating film
207 : 쐐기형 홈 208 : 반사층207: wedge groove 208: reflective layer
210 : 칼라필터210: color filter
상기 목적을 달성하기 위한 본 발명의 이미지센서는, 광감지소자; 상기 광감지소자 상부에서 그 하부로 갈수록 폭이 좁아지는 홈을 갖는 제1광투과절연막; 상기 홈의 측벽에 형성되어 외부로부터 입사되는 광을 상기 광감지소자로 집속하는 반사층; 상기 반사층이 형성된 기판 전면에 형성되어 평탄화된 제2광투과절연막; 및 상기 제2광투과절연막 상에 형성된 칼라필터를 포함하여 이루어진다.The image sensor of the present invention for achieving the above object, the optical sensing element; A first light transmissive insulating film having a groove that becomes narrower from the upper portion of the photosensitive device toward the lower portion thereof; A reflective layer formed on the sidewall of the groove to focus light incident from the outside onto the photosensitive device; A second light transmission insulating layer formed on the entire surface of the substrate on which the reflective layer is formed and planarized; And a color filter formed on the second light transmitting insulating film.
이하, 본 발명이 속하는 기술분야에서 통상의 지식을 가진자가 본 발명의 기술적 사상을 용이하게 실시할 수 있을 정도로 상세히 설명하기 위하여, 본 발명의 가장 바람직한 실시예를 첨부된 도면을 참조하여 설명하기로 한다.DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art may easily implement the technical idea of the present invention. do.
도2a 내지 도2e는 본 발명의 일 실시예에 따른 이미지센서 제조 공정도이다.2a to 2e is a manufacturing process of the image sensor according to an embodiment of the present invention.
도2a에는 통상적인 방법으로 광감지소자(202) 형성, 절연막(205) 형성, 광차폐층(204) 형성 등의 공정을 실시하여, 칼라필터가 형성되기 직전까지 공정이 완료된 상태이다.In FIG. 2A, the photosensitive device 202 is formed, the insulating film 205 is formed, the light shielding layer 204 is formed, and the like is completed until the color filter is formed.
이어서 본 실시예에서는, 도2b에 도시된 바와 같이, 버퍼절연막(206)을 소정두께로 증착하는 바, 이 버퍼절연막(206)은 평탄화 및 기판의 높이를 높이기 위한 목적으로 형성되는 것이다. 한편, 제품 및 그 설계에 따라 버퍼절연막(206)의 형성은 생략 가능하다.Subsequently, in this embodiment, as shown in Fig. 2B, a buffer insulating film 206 is deposited to a predetermined thickness, and the buffer insulating film 206 is formed for the purpose of planarization and height of the substrate. On the other hand, the formation of the buffer insulating film 206 can be omitted depending on the product and its design.
이어서, 도2c에 도시된 바와 같이, 광감지소자(202) 상부의 절연막(205, 206)을 선택적으로 식각하여 하부로 갈수록 그 오픈 폭이 좁아지도록 경사진 쐐기형 홈(207)을 형성한다. 이때, 광감지소자(202)와 홈(207)의 저부가 서로 맞닿지 않도록 식각정도를 조절한다. 쐐기 형상으로 홈(207)을 형성하는 방법, 즉 경사지게 절연막을 식각하는 기술은 당업자라면 용이하게 실시할 수 있으므로 여기서 그 설명은 생략하기로 한다.Subsequently, as shown in FIG. 2C, the insulating films 205 and 206 on the photosensitive device 202 are selectively etched to form a wedge-shaped groove 207 that is inclined so that the open width thereof becomes narrower toward the lower portion. At this time, the degree of etching is adjusted so that the bottoms of the light sensing element 202 and the groove 207 do not contact each other. A method of forming the groove 207 in a wedge shape, that is, a technique of etching the insulating film inclinedly can be easily performed by those skilled in the art, and the description thereof will be omitted herein.
이어서, 도2d에 도시된 바와 같이, 기판 전면에 반사층을 증착한 후 다시 비등방성 식각하여 홈의 측벽에 스페이서 형상의 반사층(208)을 형성한다. 반사층(208)은 실리콘(Si)층, 티타늄(Ti)층, 티타늄나이트라이드(TiN), 알루미늄(Al)층, 구리(Cu)층 및 텅스텐(W)층 등 광에 대해 고반사율을 갖는 박막은 모두 적용될 수 있다.Subsequently, as shown in FIG. 2D, the reflective layer is deposited on the entire surface of the substrate and then anisotropically etched to form a spacer-shaped reflective layer 208 on the sidewall of the groove. The reflective layer 208 is a thin film having high reflectivity for light such as a silicon (Si) layer, a titanium (Ti) layer, a titanium nitride (TiN), an aluminum (Al) layer, a copper (Cu) layer, and a tungsten (W) layer. Are all applicable.
이어서, 도2e에 도시된 바와 같이, 절연막(209)을 증착하여 기판을 평탄화시킨 다음, 이 절연막(209) 위에 칼라필터(210)를 어레이한다. 물론 칼라필터는 흑백이미지센서일 경우 필요가 없을 것이다.Subsequently, as shown in FIG. 2E, an insulating film 209 is deposited to planarize the substrate, and then the color filter 210 is arrayed on the insulating film 209. Of course, the color filter would not need to be a monochrome image sensor.
결국, 도2e를 참조하면, 본 실시예에 따른 이미지센서는 광감지소자(202) 상부에서 하부로 갈수록 좁아지는 쐐기형 반사층(208)이 형성되어 있기 때문에, 빛이 다소 경사져서 입사되더라도 그 빛이 일단 반사층(208)과 만나게 되면 광감지소자(202) 쪽으로 집광되기 때문에 광감도를 향상시킬 수 있다. 또한, 도2에서는 하나의 광감지소자에 대응되는 반사층만을 도시하였으나, 모든 광감지소자 상부에도 이러한 반사층이 형성되므로, 각 단위화소 들간의 광감지 균일도가 개선되게 된다. 그리고, 고온에 약한 레지스트 계열의 수지를 사용하는 마이크로렌즈가 필요 없기 때문에 이미지센서의 내열성을 개선할 수 있다.2E, since the wedge-shaped reflective layer 208 narrows from the upper part of the light sensing element 202 to the lower part of the image sensor according to the present embodiment, even if the light is slightly inclined, Once it meets the reflective layer 208, the light is condensed toward the photosensitive device 202, it is possible to improve the light sensitivity. In addition, although only the reflective layer corresponding to one optical sensing element is illustrated in FIG. 2, since the reflective layer is formed on all the optical sensing elements, the uniformity of the optical sensing between the unit pixels is improved. In addition, since a microlens using a resist-type resin that is weak at high temperatures is not required, heat resistance of the image sensor can be improved.
도3a 내지 도3e는 본 발명의 다른 실시예에 따른 이미지센서 제조 공정도이다.3A to 3E are flowcharts illustrating an image sensor manufacturing process according to another exemplary embodiment of the present invention.
먼저, 도 3a는 소자분리절연막(322), 포토다이오드(323), 층간절연막(324)이 형성된 반도체기판(321) 상에 포토다이오드(323)의 상부가 오픈되도록 금속막패턴(325)을 형성하고, 평탄화된 층간절연막(326) 및 절연막(327)을 적층한 상태를 나타내고 있다. 여기서, 상기 반도체기판(321)은 에피택셜실리콘층 또는 반도체층이 될 수도 있다. 포토다이오드(323)는 광감지소자로서 불순물확산에 의해 형성되는 베리드(buried) 포토다이오드로 도시되어 있다. 금속막패턴(325)은 광차폐(photo-shield) 역할을 하는데, 단위 포토다이오드(323)의 상부에서 그 주변을 에워싸는 막대 형태의 패턴으로 형성되어 있다. 물론 층간절연막(326)이 충분한 두께로 형성되어 절연 효과가 충분하다면, 상기 절연막(327)은 형성하지 않을 수도 있다.First, FIG. 3A illustrates a metal film pattern 325 formed on the semiconductor substrate 321 on which the device isolation insulating film 322, the photodiode 323, and the interlayer insulating film 324 are formed so as to open the upper portion of the photodiode 323. The planarized interlayer insulating film 326 and the insulating film 327 are stacked. The semiconductor substrate 321 may be an epitaxial silicon layer or a semiconductor layer. Photodiode 323 is shown as a buried photodiode formed by diffusion of impurities as a photosensitive device. The metal film pattern 325 serves as a photo-shield, and is formed in a rod-shaped pattern surrounding the periphery of the unit photodiode 323. Of course, if the interlayer insulating film 326 is formed to a sufficient thickness and the insulating effect is sufficient, the insulating film 327 may not be formed.
그 다음에, 도3b에 도시된 바와 같이, 상기 절연막(327) 및 층간절연막(326)을 선택적으로 식각하여, 상기 포토다이오드(323) 상부가 오픈되는 홈(328)을 형성하되, 홈의 저부로 갈수록 그 폭이 좁아지도록 측벽(329)이 경사지도록 형성한다. 그리고 그 저부는 상기 금속막패턴(25)과 맞닿도록 금속막패턴(25)이 노출될때까지 식각을 수행한다.Next, as shown in FIG. 3B, the insulating film 327 and the interlayer insulating film 326 are selectively etched to form a groove 328 in which the upper portion of the photodiode 323 is opened, and the bottom of the groove is formed. The side wall 329 is formed to be inclined so that the width thereof becomes narrower. The bottom portion is etched until the metal film pattern 25 is exposed to contact the metal film pattern 25.
이어서, 도3c에 도시된 바와 같이, 전체구조의 상부의 타포로지를 따라 일정두께의 금속막(330)을 증착한다. 이때 상기 금속막(330)은 고반사율을 갖는 알루미늄(Al) 합금막을 사용한다.Subsequently, as shown in FIG. 3C, a metal film 330 having a predetermined thickness is deposited along the tarpology on the top of the overall structure. In this case, the metal film 330 uses an aluminum (Al) alloy film having a high reflectance.
이어서, 도3d에 도시된 바와 같이, 선택적 식각 공정으로 홈(328)의 저면에 증착된 금속막(330a)만을 식각하여 포토다이오드(323) 상부에는 금속막이 오버랩되어 존재하지 않도록 한다.Subsequently, as shown in FIG. 3D, only the metal film 330a deposited on the bottom of the groove 328 is etched by a selective etching process so that the metal film is not overlapped on the photodiode 323.
이어서, 도3e와 같이, 전면에 평탄화된 절연막(332)을 증착하여 기판을 평탄화시킨 다음, 이 절연막(332) 위에 칼라필터(333)를 어레이한다. 물론 칼라필터는 흑백이미지센서일 경우 필요가 없을 것이다.Subsequently, as shown in FIG. 3E, the planarized insulating film 332 is deposited on the entire surface to planarize the substrate, and then the color filter 333 is arrayed on the insulating film 332. Of course, the color filter would not need to be a monochrome image sensor.
결국, 도3e를 참조하면, 본 실시예에 따른 이미지센서는 광감지소자 상부에 하부로 갈수록 좁아지는 경사진 반사층이 형성되어 있기 때문에, 빛이 다소 경사져서 입사되더라도 그 빛이 일단 반사층과 만나게 되면 광감지소자 쪽으로 집광되기 때문에 광감도를 향상시킬 수 있다. 그리고, 단위화소들간의 광감도 균일도를 향상시킬 수 있으며, 레지스트를 사용하는 마이크로렌즈와 달리 상대적으로 내열성이 증대되어 소자의 신뢰성이 향상되는 또 다른 이점이 있다.Finally, referring to FIG. 3E, since the image sensor according to the present exemplary embodiment has an inclined reflective layer formed on the upper portion of the photosensitive device, the inclined reflective layer becomes narrower toward the lower side. Since the light is focused toward the photosensitive device, the light sensitivity can be improved. In addition, it is possible to improve the light sensitivity uniformity between unit pixels, and unlike the microlens using a resist, there is another advantage in that the heat resistance is increased to improve the reliability of the device.
본 발명의 기술 사상은 상기 바람직한 실시예에 따라 구체적으로 기술되었으나, 상기한 실시예는 그 설명을 위한 것이며 그 제한을 위한 것이 아님을 주의하여야 한다. 또한, 본 발명의 기술 분야의 통상의 전문가라면 본 발명의 기술 사상의 범위내에서 다양한 실시예가 가능함을 이해할 수 있을 것이다.Although the technical idea of the present invention has been described in detail according to the above preferred embodiment, it should be noted that the above-described embodiment is for the purpose of description and not of limitation. In addition, those skilled in the art will understand that various embodiments are possible within the scope of the technical idea of the present invention.
상술한 바와 같이, 본 발명에 따른 이미지센서는 광집속력이 증대되어 광감도가 향상되고, 단위화소들 간의 광감도 균일도를 개선할 수 있으며, 또한 내열성이 우수하기 때문에 이미지센서의 성능 및 신뢰성을 크게 향상시키는 탁월한 효과가 있다.As described above, the image sensor according to the present invention can increase the light focusing power to improve the light sensitivity, improve the light sensitivity uniformity between the unit pixels, and because of excellent heat resistance, greatly improving the performance and reliability of the image sensor. Excellent effect
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