WO2010122719A1 - Solid-state imaging element - Google Patents

Solid-state imaging element Download PDF

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Publication number
WO2010122719A1
WO2010122719A1 PCT/JP2010/002530 JP2010002530W WO2010122719A1 WO 2010122719 A1 WO2010122719 A1 WO 2010122719A1 JP 2010002530 W JP2010002530 W JP 2010002530W WO 2010122719 A1 WO2010122719 A1 WO 2010122719A1
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Prior art keywords
color filter
color
filter
solid
state imaging
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PCT/JP2010/002530
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French (fr)
Japanese (ja)
Inventor
齋藤繁
香山信三
薄田学
六車充
廣瀬裕
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パナソニック株式会社
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Publication of WO2010122719A1 publication Critical patent/WO2010122719A1/en

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/20—Filters
    • G02B5/201—Filters in the form of arrays
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N2209/00—Details of colour television systems
    • H04N2209/04—Picture signal generators
    • H04N2209/041—Picture signal generators using solid-state devices
    • H04N2209/042—Picture signal generators using solid-state devices having a single pick-up sensor
    • H04N2209/045—Picture signal generators using solid-state devices having a single pick-up sensor using mosaic colour filter

Definitions

  • the present invention relates to a solid-state image sensor, and more particularly to a filtering technique for a solid-state image sensor used for a digital camera or the like.
  • color filters for transmitting the three primary colors of RGB are laminated (for example, refer to Patent Document 1), and it is possible to express almost all colors.
  • the conventional method of expressing colors using RGB as primary colors is not sufficient for expressing natural colors as perceived by human eyes. In particular, a color that cannot be expressed in a part of blue-green color is generated.
  • the X filter of the XYZ color system has transmission center wavelengths in red and blue.
  • the filter characteristics approximate to the X filter of the XYZ color system cannot be obtained. This is because when two color filters are overlapped, the filter characteristics are multiplied and light is not transmitted.
  • a reflective color filter has been proposed as a color filter applicable to the XYZ color system (see, for example, Patent Document 2).
  • the reflective color filter uses an inorganic dielectric multilayer filter, and the dielectric multilayer filter is formed by alternately laminating a high refractive index film and a low refractive index film alternately.
  • the color filter transmits light of a specific wavelength under a certain film thickness condition.
  • a dielectric multilayer filter it is possible to generate a light forbidden band in which light in a certain wavelength region cannot be transmitted. Therefore, by stacking a plurality of dielectric multilayer filters having different film configurations, a color filter that can transmit only light of a specific wavelength can be realized. When such a color filter is used, it is possible to realize three types of color filters that transmit light of desired three primary colors.
  • B, G, and R represent a blue signal, a green signal, and a red signal, respectively.
  • a pixel arrangement having four units of RGGB pixels called “Bayer array” as unit cells in order to obtain a large luminance can most efficiently acquire a luminance signal. Therefore, it is conceivable to use one G pixel of the RGGB pixels instead of the emerald pixel as a pixel arrangement when the emerald filter is used.
  • the green signal having the largest proportion of the luminance is reduced by half (that is, the pixel is changed from 2 pixels to 1 pixel). It cannot be acquired efficiently.
  • a thin-film color filter having a filter characteristic that has a negative sensitivity to light having a wavelength near 500 nm, particularly a red visual sensitivity, while obtaining a luminance signal efficiently is still Absent.
  • an object of the present invention is to provide a solid-state imaging device capable of realizing a thin-film color filter that realizes a filter characteristic of human visibility without reducing a luminance signal.
  • a solid-state imaging device includes a plurality of light receiving units arranged two-dimensionally and a color filter disposed on each of the plurality of light receiving units and having different light absorption characteristics.
  • the plurality of color filters include a first color filter having a transmission center wavelength in a blue region, a second color filter having a transmission center wavelength in a green region, and a first color filter having a transmission center wavelength in a red region.
  • a third color filter having a transmission band of 1 and a second transmission band having a transmission center wavelength in a blue region, wherein the third color filter includes a medium having a dielectric constant larger than 1 and smaller than 5.
  • metal fine particles having an average particle diameter of 100 nm or less dispersed in the medium.
  • the third color filter has both plasmon absorption and interband absorption, and its spectral characteristics are very close to the transmission characteristics of the XYZ color system X filter. Therefore, it is possible to realize a color filter that realizes a filter characteristic of human visibility without using a reflective color filter and an emerald filter. As a result, it is possible to realize a thin film color filter that realizes a filter characteristic of human visibility without reducing the luminance signal.
  • the solid-state imaging device of the present invention is characterized in that the maximum transmittance of the second transmission band is 10 to 50% with respect to the maximum transmittance of the first transmission band.
  • the solid-state imaging device of the present invention is characterized in that the medium contains silicon and oxygen.
  • Such a configuration makes it possible to uniformly disperse the metal fine particles in the medium, so that it is possible to realize a color filter that realizes the filter characteristic of human visibility with high accuracy.
  • the first color filter is composed of a pigment or dye-based color resist containing a blue pigment
  • the second color filter is composed of a green pigment. It is comprised from the pigment or dye-type color resist to contain.
  • the first color filter and the first color filter can be easily formed even by using the current process, and the development cost is reduced.
  • the first color filter has a refractive index higher than that of a medium around the first color filter, and the first color filter has a blue region of the first color filter.
  • the first color filter is composed of a first material that transmits 50% or more of light having a transmission center wavelength, the refractive index of the first material is n1, the refractive index of the medium around the first color filter is n2, and the first color filter And ⁇ 1 ⁇ cos ⁇ 1 (n2 / n1), where ⁇ 1 is the angle formed by the incident light on the light and the normal to the light incident surface of the first color filter.
  • the second color filter has a refractive index higher than that of the medium around the second color filter, and is made of a second material that transmits 50% or more of light having a transmission center wavelength in the green region of the second color filter.
  • the refractive index of the second material is n3, the refractive index of the medium around the second color filter is n4, and the incident light to the second color filter is incident on the light incident surface of the second color filter.
  • the angle formed with the normal is ⁇ 2
  • the following equation is satisfied: ⁇ 2 ⁇ cos ⁇ 1 (n4 / n3)
  • the third color filter has a refractive index higher than that of the medium around the third color filter, and emits light having a transmission center wavelength of the first transmission band and the second transmission band of the third color filter.
  • the refractive index of the third material is n5
  • the refractive index of the medium around the third color filter is n6
  • the incident light to the third color filter is the first material.
  • the color filter functions as an optical waveguide that guides incident light to the light receiving unit, so that the sensitivity of the solid-state imaging device is improved.
  • the solid-state imaging device further includes a wiring layer disposed above a surface opposite to the light incident surface of the light-receiving unit, The color filter, the second color filter, and the third color filter are arranged above the light incident surface of the light receiving unit.
  • the solid-state imaging device of the present invention is characterized in that the metal fine particles are composed of at least one of gold, silver, copper, chromium, and iron chromium oxide.
  • an X filter having excellent heat resistance, light resistance, and environmental resistance can be realized.
  • the solid-state imaging device is characterized in that spectral characteristics obtained by the first color filter, the second color filter, and the third color filter satisfy a color matching condition. To do.
  • the present invention it is possible to realize a solid-state imaging device including a thin-film color filter that realizes a filter characteristic of human visibility without reducing a luminance signal. It becomes possible to improve.
  • FIG. 1 is a graph showing the transmission characteristics of Au fine particles (the dielectric constant dependence of the surrounding medium).
  • FIG. 2 is a cross-sectional view showing the structure of the solid-state imaging device according to the embodiment of the present invention.
  • FIG. 3 is a diagram showing the transmission characteristics of the third color filter according to the embodiment.
  • FIG. 4A is a diagram illustrating spectral characteristics obtained by the first color filter, the second color filter, and the third color filter according to the embodiment.
  • FIG. 4B is a diagram showing a color gamut possessed by a filter characteristic of xy chromaticity distribution and human visibility obtained by the color filter according to the embodiment.
  • FIG. 5A is a diagram illustrating spectral characteristics obtained by a conventional RGB filter.
  • FIG. 5B is a diagram showing a color gamut having a filter characteristic of xy chromaticity distribution and human visibility obtained by a conventional RGB filter.
  • FIG. 6A is a cross-sectional view for explaining the method for manufacturing the solid-state imaging element according to the embodiment.
  • FIG. 6B is a cross-sectional view for illustrating the method for manufacturing the solid-state imaging element according to the embodiment.
  • FIG. 6C is a cross-sectional view for illustrating the method for manufacturing the solid-state imaging element according to the embodiment.
  • FIG. 6D is a cross-sectional view for illustrating the method for manufacturing the solid-state imaging element according to the embodiment.
  • FIG. 7 is a cross-sectional view illustrating the structure of the solid-state imaging device according to the first modification.
  • FIG. 8 is a cross-sectional view illustrating a structure of a solid-state imaging device according to the second modification.
  • Non-patent Document 1 “Functional Pigments and Nanotechnology”. "Issued in October 2006, CMC Publishing Co., Ltd.). The plasmon absorption of such metal fine particles greatly depends on the surrounding medium of the metal fine particles, and the absorption characteristics differ greatly depending on the surrounding medium.
  • FIG. 1 is a graph showing the transmission characteristics of Au fine particles (dependence on the dielectric constant of the surrounding medium).
  • the graph of FIG. 1 represents the transmission characteristics when the dielectric constant ⁇ m of the surrounding medium of the Au fine particles is different.
  • the graph of FIG. 1 is derived from an absorption coefficient equation based on the Mie theory shown in the following equation (1).
  • ⁇ ( ⁇ ) is the absorption coefficient
  • ⁇ is the angular frequency
  • c is the speed of light
  • q is the volume of the Au fine particle
  • ⁇ 1 ( ⁇ ) is the real part of the complex dielectric constant of the Au fine particle
  • ⁇ 2 ( ⁇ ) Is the imaginary part of the complex dielectric constant of the Au fine particles.
  • Numerous models have been proposed for the complex permittivity of Au fine particles, but in the derivation of the graph of FIG. 1, we calculated using the Drude-Lorentz model (Non-patent Document 2: AppliedAppOptics Vol.37 No. .22 “Optical properties of metallic films for vertical-cavity optoelectronic devices”).
  • FIG. 1 shows that the plasmon absorption edge shifts to the short wavelength side as ⁇ m decreases, and to the long wavelength side as ⁇ m increases.
  • FIG. 2 is a cross-sectional view showing the structure of the solid-state imaging device 100 according to the present embodiment.
  • the solid-state imaging device 100 includes a p-type Si substrate 101, a plurality of light receiving portions 102, an interlayer insulating film 103, a wiring layer 104 corresponding to a signal line, a plurality of color filters, a planarizing film 106, and a light collecting element (on-chip). Microlens) 107.
  • the solid-state imaging device 100 may include a p-type semiconductor layer instead of the p-type Si substrate 101, or may further include a p-type semiconductor layer formed on the p-type Si substrate 101. In this case, the light receiving portion 102 is formed in the semiconductor layer.
  • the p-type Si substrate 101 is provided with a reading unit (not shown) such as a transistor for reading an electric signal generated by light incident on each light receiving unit 102.
  • the light receiving unit 102 is an n-type region and is two-dimensionally arranged on the surface of the p-type Si substrate 101. Note that the thickness of the p-type Si substrate 101 varies depending on the solid-state imaging device 100, but is, for example, 5 to 10 ⁇ m.
  • the color filter is disposed on each of the plurality of light receiving units 102.
  • the plurality of color filters include three types of color filters having different light absorption characteristics in the visible light range, that is, an XYZ color system X filter, Y filter, and Z filter.
  • the plurality of color filters includes a first color filter (blue filter having a transmission center wavelength (having a transmission peak with a transmittance of 50% or more)) in a blue region (wavelength region of 410 to 510 nm) as a Z filter.
  • a second color filter (green filter) 109 having a transmission center wavelength in a green region (wavelength region of 470 to 650 nm) as a Y filter, and a red region (wavelength region of 520 to 670 nm) as an X filter
  • a third color filter 110 having a first transmission band having a transmission center wavelength and a second transmission band having a transmission center wavelength in the blue region.
  • the XYZ color system is a color system approved as a standard color system by the CIE (International Lighting Commission) in 1931.
  • the first color filter 108, the second color filter 109, and the third color filter 110 include one first color filter 108, one second color filter 109, and two third color filters 110. Two unit dimensions are arranged as one unit cell.
  • the first color filter 108 has a pigment containing a blue pigment dispersed therein
  • the second color filter 109 has a pigment containing a green pigment dispersed therein.
  • the first color filter 108 and the second color filter 109 may be made of a dye-based color resist instead of a pigment.
  • the third color filter 110 includes a medium having a dielectric constant larger than 1 and smaller than 5, and metal fine particles composed of nano-order gold, silver, copper, chromium, iron chromium oxide and the like dispersed in the medium. Composed. At this time, if the average particle diameter of the metal fine particles is about the same as or larger than the wavelength of the incident light, the light incident on the metal fine particles will be reflected. Therefore, the average particle diameter of the metal fine particles is smaller than the incident wavelength. , 100 nm or less is desirable.
  • the third color filter 110 is composed of SOG containing silicon and oxygen and Au fine particles having a particle size distribution of 5 to 50 nm dispersed in the SOG.
  • FIG. 3 is a diagram showing measured values of the transmission characteristics of the third color filter 110 mounted on the solid-state imaging device 100 according to the present embodiment.
  • the third color filter 110 a filter in which Au fine particles having a particle size distribution of 5 to 50 nm (median value 15 nm) are dispersed in SOG is used.
  • the third color filter 110 has a transmission characteristic that is in good agreement with the calculation result.
  • the maximum transmittance of the second transmission band is 10 to 50% with respect to the maximum transmittance of the first transmission band. Therefore, the transmission characteristics of the XYZ color system X filter can be realized by the third color filter 110.
  • FIG. 4A is a diagram showing spectral sensitivity characteristics obtained by the first color filter 108, the second color filter 109, and the third color filter 110 of the solid-state imaging device 100 according to the present embodiment.
  • FIG. 4B shows an xy chromaticity distribution (a region indicated by a diagonal line surrounded by a dotted line in FIG. 4B) obtained by the color filter of the solid-state imaging device 100 according to the present embodiment and a filter characteristic of human visibility. It is a figure which shows the color gamut (area
  • FIG. 5A is a diagram showing spectral sensitivity characteristics obtained by a conventional general RGB filter.
  • FIG. 5A is a diagram showing spectral sensitivity characteristics obtained by a conventional general RGB filter.
  • FIG. 5B shows an xy chromaticity distribution of a conventional general RGB filter (a region indicated by diagonal lines surrounded by a dotted line in FIG. 5B) and a color gamut having a filter characteristic of human visibility (FIG. 5B). It is a figure which shows the area
  • the spectral characteristics obtained by the first color filter 108, the second color filter 109, and the third color filter 110 satisfy the color matching condition.
  • a color filter having a filter characteristic of human visibility can be realized.
  • the spectral sensitivity characteristic and the xy chromaticity distribution of a conventional general RGB filter are only a very narrow region with respect to human visual sensitivity. .
  • 6A to 6D are cross-sectional views for explaining a method for manufacturing a color filter of the solid-state imaging device 100 according to the present embodiment.
  • the light receiving portion 102, the interlayer insulating film 103, and the wiring layer 104 are formed on the p-type Si substrate 101 using a normal semiconductor process.
  • a solution 152 having a dielectric constant larger than 1 and smaller than 5 in which metal fine particles having a particle size distribution of 5 to 50 nm are dispersed by spin-on method is applied to the surface of the interlayer insulating film 103, and about 400 Sintered at °C.
  • a resist 153 is applied, and lithography and etching 155 such as dry etching and wet etching are performed on the solution 152 to form the third color filter 110.
  • a solution 156 in which a negative pigment containing a green dye is dispersed by spin-on is applied to the surface of the interlayer insulating film 103, and only a desired region of the solution 156 is cured by lithography 154.
  • the solution 156 is wet-etched with a TMAH (tetramethylammonium hydroxide) solution or the like to form the second color filter 109.
  • TMAH tetramethylammonium hydroxide
  • a solution 157 in which a negative pigment containing a blue pigment is dispersed is applied to the surface of the interlayer insulating film 103 by a spin-on method, and only a desired region of the solution 157 is cured by lithography 154.
  • the solution 157 is wet-etched with a TMAH solution or the like to form the first color filter 108.
  • the second color filter 109 formed in the process of FIG. 6B has already been thermally sintered, it is not affected by wet etching.
  • a flattening film 106 is formed on the color filter by using the CVD method, and a condensing element 107 is formed on the flattening film 106.
  • a negative pigment color resist is assumed as a material constituting the color filter, but a positive pigment color resist may be used.
  • metal fine particles having an average particle diameter of 100 nm or less are dispersed in a medium having a dielectric constant larger than 1 and smaller than 5 without using a reflective color filter and an emerald filter.
  • a reflective color filter and an emerald filter are used to improve the quality of the X filter of the XYZ color system. Therefore, it is possible to realize a thin film color filter that realizes the filter characteristic of human visibility without reducing the luminance signal.
  • Modification 1 in the present embodiment will be described.
  • the wiring layer 104 is disposed above the light incident surface of the light receiving unit 102 together with the first color filter 108, the second color filter 109, and the third color filter 110.
  • the wiring layer 104 is disposed above the surface of the light receiving unit 102 opposite to the light incident surface. That is, the wiring layer 104 is disposed on the surface side opposite to the surface on which the light receiving portion 102 of the p-type Si substrate 101 is formed.
  • FIG. 7 is a cross-sectional view showing the structure of the solid-state imaging device 200 according to this modification.
  • the solid-state imaging device 200 includes a p-type Si substrate 101, a plurality of light receiving units 102, an interlayer insulating film 103, a wiring layer 104, a plurality of color filters, a planarizing film 106, a light collecting element 107, and a support substrate 202. ing.
  • the plurality of color filters include a first color filter 108, a second color filter 109, and a third color filter 110.
  • the support substrate 202 is a substrate for reinforcing the strength of the p-type Si substrate 101, and is formed of, for example, a Si substrate made of the same material as the p-type Si substrate 101.
  • the wiring layer 104 is formed above one surface of the p-type Si substrate 101 (above the surface opposite to the light incident surface). Over the other surface of the p-type Si substrate 101 (above the light incident surface), an interlayer insulating film 103, a color filter, a planarizing film 106, and a light collecting element 107 are formed.
  • the solid-state imaging device 200 of the present modification it is possible to prevent the incident light to the light receiving unit 102 from being reflected by the wiring layer 104 and to prevent a decrease in sensitivity due to the wiring layer 104.
  • FIG. 8 is a cross-sectional view showing the structure of the solid-state imaging device 300 according to this modification.
  • the solid-state imaging device 300 includes a p-type Si substrate 101, a plurality of light receiving portions 102, an interlayer insulating film 103, a wiring layer 104, a plurality of color filters, a planarizing film 106, and a light collecting element 107.
  • the plurality of color filters include a first color filter 108, a second color filter 109, and a third color filter 110.
  • the first color filter 108 has a refractive index higher than that of the medium (interlayer insulating film 103) around the first color filter 108, and transmits 50% or more of light having a transmission center wavelength in the blue region of the first color filter 108.
  • the refractive index of the first material is n1
  • the refractive index of the medium (interlayer insulating film 103) around the first color filter is n2
  • the incident light to the first color filter is When the angle formed with the normal line of the light incident surface of the first color filter 108 is ⁇ 1, ⁇ 1 ⁇ cos ⁇ 1 (n2 / n1) is satisfied.
  • the second color filter 109 has a higher refractive index than the medium (interlayer insulating film 103) around the second color filter 109, and transmits 50% or more of light having a transmission center wavelength in the green region of the second color filter 109.
  • the refractive index of the second material is n3
  • the refractive index of the medium (interlayer insulating film 103) around the second color filter 109 is n4
  • the incident light to the second color filter 109 is When the angle formed with the normal line of the light incident surface of the second color filter 109 is ⁇ 2, ⁇ 2 ⁇ cos ⁇ 1 (n4 / n3) is satisfied.
  • the third color filter 110 has a higher refractive index than the medium (interlayer insulating film 103) around the third color filter 110, and transmits the first transmission band and the second transmission band of the third color filter 110.
  • the third material is made of a third material that transmits 50% or more of light having a center wavelength.
  • the refractive index of the third material is n5
  • the refractive index of the medium (interlayer insulating film 103) around the third color filter 110 is n6, and the third ⁇ 3 ⁇ cos ⁇ 1 (n6 / n5) is satisfied, where ⁇ 3 is an angle formed by the light incident on the color filter 110 and the normal line of the light incident surface of the third color filter 110.
  • an insulating film mainly composed of SiO 2 having a refractive index of 1.45 is used as the interlayer insulating film 103, and a refractive index of 1 is used as the first color filter 108, the second color filter 109, and the third color filter 110.
  • a filter containing .85 polybenzoxazole is used.
  • the color filter functions as an optical waveguide, and incident light can be guided to the light receiving unit 102 by the waveguide structure, thereby improving the sensitivity of the solid-state imaging device. be able to.
  • the present invention can be used for solid-state imaging devices, and in particular, can be used for digital cameras, mobile phones, single-lens reflex cameras, scanners, and the like.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Solid State Image Pick-Up Elements (AREA)
  • Optical Filters (AREA)
  • Color Television Image Signal Generators (AREA)

Abstract

Provided is a solid-state imaging element capable of implementing a thin-film color filter which implements the filter characteristics of human visual sensitivity without reducing luminance signals, and the solid-state imaging element is provided with a plurality of two-dimensionally arranged light receiving portions (102), and color filters which are arranged on the respective plurality of light receiving portions (102), and which have different light absorption characteristics from one another, wherein a plurality of the color filters include a first color filter (108) having a transmission center wavelength in a blue color region, a second color filter (109) having the transmission center wavelength in a green color region, and a third color filter (110) comprising a first transmission band having the transmission center wavelength in a red color region, and a second transmission band having the transmission center wavelength in the blue color region, and wherein the third color filter (110) is configured from a medium, the permittivity of which is greater than 1 but lower than 5, and metallic fine particles having an average particle diameter of not more than 100 nm, which are dispersed in the medium.

Description

固体撮像素子Solid-state image sensor
　本発明は、固体撮像素子に関し、特にデジタルカメラ等に使用される固体撮像素子のフィルタリング技術に関する。 The present invention relates to a solid-state image sensor, and more particularly to a filtering technique for a solid-state image sensor used for a digital camera or the like.
　従来、固体撮像素子においては、ＲＧＢ三原色を透過させるための色フィルタが積層されており（例えば、特許文献１参照）、殆どの色についての表現を可能にしている。しかし、従来のＲＧＢを原色として色を表す方式では、人間の目に感じるような自然な色を表現することについては十分とは云えない。特に、青緑色の一部に表現できない色が生じてしまう。 Conventionally, in a solid-state imaging device, color filters for transmitting the three primary colors of RGB are laminated (for example, refer to Patent Document 1), and it is possible to express almost all colors. However, the conventional method of expressing colors using RGB as primary colors is not sufficient for expressing natural colors as perceived by human eyes. In particular, a color that cannot be expressed in a part of blue-green color is generated.
　そこで、ＸＹＺ表色系という概念の色フィルタ特性が提案されている。これは、人間の目の赤色を感じる視神経が青緑色に対して負の感度を持つことを考慮した色フィルタ特性である。このようなフィルタ特性を持つ色フィルタを固体撮像素子に採用することで、より人間の目に近い撮像をすることができる。 Therefore, a color filter characteristic of the concept of XYZ color system has been proposed. This is a color filter characteristic considering that the optic nerve that senses the red color of the human eye has a negative sensitivity to blue-green. By adopting a color filter having such filter characteristics in a solid-state imaging device, it is possible to perform imaging closer to human eyes.
　このとき、ＸＹＺ表色系のＸフィルタは、赤色及び青色に透過中心波長を有する。しかし、単純に赤色透過フィルタと青色透過フィルタとを重ね合わせてもＸＹＺ表色系のＸフィルタに近似したフィルタ特性は得られない。というのは、２つの色フィルタを重ね合わせるとフィルタ特性が掛け合わされ、光が透過しなくなるからである。 At this time, the X filter of the XYZ color system has transmission center wavelengths in red and blue. However, even if the red transmission filter and the blue transmission filter are simply overlapped, the filter characteristics approximate to the X filter of the XYZ color system cannot be obtained. This is because when two color filters are overlapped, the filter characteristics are multiplied and light is not transmitted.
　そこで、ＸＹＺ表色系に適用可能な色フィルタとして反射型色フィルタが提案されている（例えば、特許文献２参照）。この反射型色フィルタは具体的には無機の誘電体多層膜フィルタを用いるものであり、誘電体多層膜フィルタは周期的に高屈折率の膜と低屈折率の膜とを交互に積層してなり、ある膜厚条件で特定の波長の光が透過する色フィルタである。このような誘電体多層膜フィルタを用いることで、ある波長領域の光が透過できない、光の禁止帯を生じさせることができる。従って、膜の構成を変えた誘電体多層膜フィルタを複数重ねることで、ある特定波長の光だけが透過できるような色フィルタを実現できる。このような色フィルタを用いると、所望の三原色の光を透過させる３種類の色フィルタを実現することが可能になる。 Therefore, a reflective color filter has been proposed as a color filter applicable to the XYZ color system (see, for example, Patent Document 2). Specifically, the reflective color filter uses an inorganic dielectric multilayer filter, and the dielectric multilayer filter is formed by alternately laminating a high refractive index film and a low refractive index film alternately. Thus, the color filter transmits light of a specific wavelength under a certain film thickness condition. By using such a dielectric multilayer filter, it is possible to generate a light forbidden band in which light in a certain wavelength region cannot be transmitted. Therefore, by stacking a plurality of dielectric multilayer filters having different film configurations, a color filter that can transmit only light of a specific wavelength can be realized. When such a color filter is used, it is possible to realize three types of color filters that transmit light of desired three primary colors.
　しかし、反射型色フィルタでＸＹＺ表色系に適用可能な色フィルタを実現しようとした場合、複数の誘電体多層膜フィルタを重ねる必要等があり、色フィルタの膜厚が４μｍ程度と非常に厚くなるため、固体撮像素子のアスペクト比が高くなり、集光効率が低下してしまうという課題が生じる。さらに、反射型色フィルタが所望の光以外を全て反射することによりフレアが引き起こされるという課題も生じる。 However, when it is intended to realize a color filter applicable to the XYZ color system with a reflective color filter, it is necessary to overlap a plurality of dielectric multilayer filters, and the thickness of the color filter is as extremely thick as about 4 μm. As a result, the aspect ratio of the solid-state imaging device is increased, resulting in a problem that the light collection efficiency is reduced. Further, there is a problem that flare is caused when the reflective color filter reflects all light other than desired light.
　そこで、負の視感度となる青緑色の光だけを透過する吸収型のエメラルドフィルタを用い、このエメラルドフィルタに対応するエメラルド画素で得られる信号成分を赤色の信号成分から差分することで、赤色フィルタの負の視感度を実現する方法が提案されている（例えば、特許文献３参照）。 Therefore, by using an absorption type emerald filter that transmits only blue-green light with negative visual sensitivity, the signal component obtained by the emerald pixel corresponding to this emerald filter is subtracted from the red signal component, so that the red filter Have been proposed (see, for example, Patent Document 3).
米国特許第３９７１０６５号明細書US Pat. No. 3,971,065 米国特許第７１３２６４４号明細書US Pat. No. 7,132,644 特開２００４－２００３５７号公報JP 2004-200377 A
　ところで、一般に、輝度信号は、「Ｙ＝０．１１Ｂ＋０．５９Ｇ＋０．３０Ｒ」で表わされる。ここで、Ｂ、Ｇ及びＲは、それぞれ青色信号、緑色信号及び赤色信号を表わす。これに関し、輝度を大きく取るために「ベイヤー配列」と呼ばれるＲＧＧＢ画素から成る４画素を単位セルとした画素配置が最も輝度信号を効率よく取得できることが知られている。従って、エメラルドフィルタを用いた場合の画素配置としては、ＲＧＧＢ画素の１つのＧ画素をエメラルド画素に代えて用いることが考え得る。 Incidentally, in general, the luminance signal is represented by “Y = 0.11B + 0.59G + 0.30R”. Here, B, G, and R represent a blue signal, a green signal, and a red signal, respectively. In this regard, it is known that a pixel arrangement having four units of RGGB pixels called “Bayer array” as unit cells in order to obtain a large luminance can most efficiently acquire a luminance signal. Therefore, it is conceivable to use one G pixel of the RGGB pixels instead of the emerald pixel as a pixel arrangement when the emerald filter is used.
　しかしながら、ＲＧＧＢ画素の１つのＧ画素をエメラルド画素に代えて用いると、輝度に最も占める割合が大きい緑色信号が半減してしまう（即ち、２画素から１画素になってしまう）ため、輝度信号を効率よく取得できない。その結果、輝度信号を効率よく取得しつつ、人間の視感度の特に赤色の視感度が５００ｎｍ付近の波長の光に対して負の感度を持つようなフィルタ特性を有する薄膜の色フィルタは、まだない。 However, if one G pixel of the RGGB pixels is used instead of the emerald pixel, the green signal having the largest proportion of the luminance is reduced by half (that is, the pixel is changed from 2 pixels to 1 pixel). It cannot be acquired efficiently. As a result, a thin-film color filter having a filter characteristic that has a negative sensitivity to light having a wavelength near 500 nm, particularly a red visual sensitivity, while obtaining a luminance signal efficiently, is still Absent.
　そこで本発明は、上記課題に鑑み、輝度信号を減らすことなく人間の視感度のフィルタ特性を実現する薄膜の色フィルタを実現可能な固体撮像素子を提供することを目的とする。 In view of the above problems, an object of the present invention is to provide a solid-state imaging device capable of realizing a thin-film color filter that realizes a filter characteristic of human visibility without reducing a luminance signal.
　上記課題を解決するため、本発明の固体撮像素子は、２次元状に配置された複数の受光部と、前記複数の受光部のそれぞれの上に配置され、互いに異なる光吸収特性を有する色フィルタとを備え、複数の前記色フィルタは、青色領域に透過中心波長を有する第１の色フィルタと、緑色領域に透過中心波長を有する第２の色フィルタと、赤色領域に透過中心波長を有する第１の透過帯と、青色領域に透過中心波長を有する第２の透過帯とを持つ第３の色フィルタとを含み、前記第３の色フィルタは、誘電率が１より大きく５より小さい媒質と、前記媒質中に分散された平均粒径１００ｎｍ以下の金属微粒子とから構成されることを特徴とする。 In order to solve the above-described problems, a solid-state imaging device according to the present invention includes a plurality of light receiving units arranged two-dimensionally and a color filter disposed on each of the plurality of light receiving units and having different light absorption characteristics. The plurality of color filters include a first color filter having a transmission center wavelength in a blue region, a second color filter having a transmission center wavelength in a green region, and a first color filter having a transmission center wavelength in a red region. A third color filter having a transmission band of 1 and a second transmission band having a transmission center wavelength in a blue region, wherein the third color filter includes a medium having a dielectric constant larger than 1 and smaller than 5. And metal fine particles having an average particle diameter of 100 nm or less dispersed in the medium.
　このような構成とすることにより、第３の色フィルタはプラズモン吸収とバンド間吸収との双方を有し、その分光特性がＸＹＺ表色系のＸフィルタの透過特性に非常に近い特性となる。従って、反射型色フィルタ及びエメラルドフィルタを用いることなく、人間の視感度のフィルタ特性を実現する色フィルタを実現することができる。その結果、輝度信号を減らすことなく人間の視感度のフィルタ特性を実現する薄膜の色フィルタを実現することができる。 By adopting such a configuration, the third color filter has both plasmon absorption and interband absorption, and its spectral characteristics are very close to the transmission characteristics of the XYZ color system X filter. Therefore, it is possible to realize a color filter that realizes a filter characteristic of human visibility without using a reflective color filter and an emerald filter. As a result, it is possible to realize a thin film color filter that realizes a filter characteristic of human visibility without reducing the luminance signal.
　さらに上記課題を解決するため、本発明の固体撮像素子は、前記第２の透過帯の最大透過率は、前記第１の透過帯の最大透過率に対し、１０～５０％であることを特徴とする。 Furthermore, in order to solve the above-described problem, the solid-state imaging device of the present invention is characterized in that the maximum transmittance of the second transmission band is 10 to 50% with respect to the maximum transmittance of the first transmission band. And
　このような構成とすることにより、人間の視感度のフィルタ特性を高精度で実現する色フィルタが実現可能となる。 By adopting such a configuration, it is possible to realize a color filter that realizes a filter characteristic of human visibility with high accuracy.
　さらに上記課題を解決するため、本発明の固体撮像素子は、前記媒質は、シリコン及び酸素を含むことを特徴とする。 Furthermore, in order to solve the above-mentioned problem, the solid-state imaging device of the present invention is characterized in that the medium contains silicon and oxygen.
　このような構成とすることにより、金属微粒子を媒質中に均一に分散させることが可能となるため、人間の視感度のフィルタ特性を高精度で実現する色フィルタが実現可能となる。 Such a configuration makes it possible to uniformly disperse the metal fine particles in the medium, so that it is possible to realize a color filter that realizes the filter characteristic of human visibility with high accuracy.
　さらに上記課題を解決するため、本発明の固体撮像素子は、前記第１の色フィルタは、青色素を含む顔料又は染料系のカラーレジストから構成され、前記第２の色フィルタは、緑色素を含む顔料又は染料系のカラーレジストから構成されることを特徴とする。 Furthermore, in order to solve the above-described problem, in the solid-state imaging device of the present invention, the first color filter is composed of a pigment or dye-based color resist containing a blue pigment, and the second color filter is composed of a green pigment. It is comprised from the pigment or dye-type color resist to contain.
　このような構成とすることにより、現行プロセスを用いても容易に第１の色フィルタ及び第１の色フィルタを形成することが可能となり、開発コストが低下する。 By adopting such a configuration, the first color filter and the first color filter can be easily formed even by using the current process, and the development cost is reduced.
　さらに上記課題を解決するため、本発明の固体撮像素子は、前記第１の色フィルタは、該第１の色フィルタの周囲の媒質より屈折率が高く、該第１の色フィルタの青色領域の透過中心波長の光を５０％以上透過する第１材料から構成され、前記第１材料の屈折率をｎ１、該第１の色フィルタの周囲の媒質の屈折率をｎ２、該第１の色フィルタへの入射光が該第１の色フィルタの光入射面の法線となす角度をθ１とするとき、下記の式を満足し、θ１＜ｃｏｓ－１（ｎ２／ｎ１）
　前記第２の色フィルタは、該第２の色フィルタの周囲の媒質より屈折率が高く、該第２の色フィルタの緑色領域の透過中心波長の光を５０％以上透過する第２材料から構成され、前記第２材料の屈折率をｎ３、該第２の色フィルタの周囲の媒質の屈折率をｎ４、該第２の色フィルタへの入射光が該第２の色フィルタの光入射面の法線となす角度をθ２とするとき、下記の式を満足し、
θ２＜ｃｏｓ－１（ｎ４／ｎ３）
　前記第３の色フィルタは、該第３の色フィルタの周囲の媒質より屈折率が高く、該第３の色フィルタの第１の透過帯及び第２の透過帯の透過中心波長の光を５０％以上透過する第３材料から構成され、前記第３材料の屈折率をｎ５、該第３の色フィルタの周囲の媒質の屈折率をｎ６、該第３の色フィルタへの入射光が該第３の色フィルタの光入射面の法線となす角度をθ３とするとき、下記の式を満足する
θ３＜ｃｏｓ－１（ｎ６／ｎ５）
　ことを特徴とする。 Furthermore, in order to solve the above-described problem, in the solid-state imaging device of the present invention, the first color filter has a refractive index higher than that of a medium around the first color filter, and the first color filter has a blue region of the first color filter. The first color filter is composed of a first material that transmits 50% or more of light having a transmission center wavelength, the refractive index of the first material is n1, the refractive index of the medium around the first color filter is n2, and the first color filter And θ1 <cos −1 (n2 / n1), where θ1 is the angle formed by the incident light on the light and the normal to the light incident surface of the first color filter.
The second color filter has a refractive index higher than that of the medium around the second color filter, and is made of a second material that transmits 50% or more of light having a transmission center wavelength in the green region of the second color filter. The refractive index of the second material is n3, the refractive index of the medium around the second color filter is n4, and the incident light to the second color filter is incident on the light incident surface of the second color filter. When the angle formed with the normal is θ2, the following equation is satisfied:
θ2 <cos −1 (n4 / n3)
The third color filter has a refractive index higher than that of the medium around the third color filter, and emits light having a transmission center wavelength of the first transmission band and the second transmission band of the third color filter. % Of the third material that transmits at least%, the refractive index of the third material is n5, the refractive index of the medium around the third color filter is n6, and the incident light to the third color filter is the first material. Θ3 <cos −1 (n6 / n5) satisfying the following expression, where θ3 is an angle formed with the normal line of the light incident surface of the color filter 3
It is characterized by that.
　このような構成とすることにより、色フィルタが入射光を受光部に導く光導波路として機能するため、固体撮像素子の感度が向上する。 By adopting such a configuration, the color filter functions as an optical waveguide that guides incident light to the light receiving unit, so that the sensitivity of the solid-state imaging device is improved.
　さらに上記課題を解決するため、本発明の固体撮像素子は、前記固体撮像素子は、さらに、前記受光部の光入射面と反対側の面上方に配置された配線層を備え、前記第１の色フィルタ、第２の色フィルタ及び第３の色フィルタは、前記受光部の光入射面上方に配置されることを特徴とする。 Furthermore, in order to solve the above-described problem, the solid-state imaging device according to the present invention further includes a wiring layer disposed above a surface opposite to the light incident surface of the light-receiving unit, The color filter, the second color filter, and the third color filter are arranged above the light incident surface of the light receiving unit.
　このような構成とすることにより、入射光が配線層に遮られることなく受光部に届くため、固体撮像素子の感度が向上する。 By adopting such a configuration, incident light reaches the light receiving unit without being blocked by the wiring layer, so that the sensitivity of the solid-state imaging device is improved.
　さらに上記課題を解決するため、本発明の固体撮像素子は、前記金属微粒子は、金、銀、銅、クロム及び鉄クロム酸化物の少なくとも１つから構成されることを特徴とする。 Further, in order to solve the above-mentioned problems, the solid-state imaging device of the present invention is characterized in that the metal fine particles are composed of at least one of gold, silver, copper, chromium, and iron chromium oxide.
　このような構成とすることにより、耐熱性、耐光性及び耐環境性に優れたＸフィルタが実現可能となる。 By adopting such a configuration, an X filter having excellent heat resistance, light resistance, and environmental resistance can be realized.
　さらに上記課題を解決するため、本発明の固体撮像素子は、前記第１の色フィルタ、第２の色フィルタ及び第３の色フィルタにより得られる分光特性は、等色条件を満たすことを特徴とする。 Furthermore, in order to solve the above-described problem, the solid-state imaging device according to the present invention is characterized in that spectral characteristics obtained by the first color filter, the second color filter, and the third color filter satisfy a color matching condition. To do.
　このような構成とすることにより、人間の視感度のフィルタ特性を高精度で実現する色フィルタが実現可能となる。 By adopting such a configuration, it is possible to realize a color filter that realizes a filter characteristic of human visibility with high accuracy.
　以上のように本発明によれば、輝度信号を減らすことなく人間の視感度のフィルタ特性を実現する薄膜の色フィルタを備えた固体撮像素子を実現できるので、撮像画像の色再現性及び画質を向上させることが可能となる。 As described above, according to the present invention, it is possible to realize a solid-state imaging device including a thin-film color filter that realizes a filter characteristic of human visibility without reducing a luminance signal. It becomes possible to improve.
図１は、Ａｕ微粒子の透過特性（周囲媒質の誘電率依存性）を示すグラフである。FIG. 1 is a graph showing the transmission characteristics of Au fine particles (the dielectric constant dependence of the surrounding medium). 図２は、本発明の実施の形態に係る固体撮像素子の構造を示す断面図である。FIG. 2 is a cross-sectional view showing the structure of the solid-state imaging device according to the embodiment of the present invention. 図３は、同実施の形態に係る第３の色フィルタの透過特性を示す図である。FIG. 3 is a diagram showing the transmission characteristics of the third color filter according to the embodiment. 図４Ａは、同実施の形態に係る第１の色フィルタ、第２の色フィルタ及び第３の色フィルタによって得られる分光特性を示す図である。FIG. 4A is a diagram illustrating spectral characteristics obtained by the first color filter, the second color filter, and the third color filter according to the embodiment. 図４Ｂは、同実施の形態に係る色フィルタによって得られるｘ－ｙ色度分布及び人間の視感度のフィルタ特性が有する色域を示す図である。FIG. 4B is a diagram showing a color gamut possessed by a filter characteristic of xy chromaticity distribution and human visibility obtained by the color filter according to the embodiment. 図５Ａは、従来のＲＧＢフィルタによって得られる分光特性を示す図である。FIG. 5A is a diagram illustrating spectral characteristics obtained by a conventional RGB filter. 図５Ｂは、従来のＲＧＢフィルタによって得られるｘ－ｙ色度分布及び人間の視感度のフィルタ特性が有する色域を示す図である。FIG. 5B is a diagram showing a color gamut having a filter characteristic of xy chromaticity distribution and human visibility obtained by a conventional RGB filter. 図６Ａは、同実施の形態に係る固体撮像素子の製造方法を説明するための断面図である。FIG. 6A is a cross-sectional view for explaining the method for manufacturing the solid-state imaging element according to the embodiment. 図６Ｂは、同実施の形態に係る固体撮像素子の製造方法を説明するための断面図である。FIG. 6B is a cross-sectional view for illustrating the method for manufacturing the solid-state imaging element according to the embodiment. 図６Ｃは、同実施の形態に係る固体撮像素子の製造方法を説明するための断面図である。FIG. 6C is a cross-sectional view for illustrating the method for manufacturing the solid-state imaging element according to the embodiment. 図６Ｄは、同実施の形態に係る固体撮像素子の製造方法を説明するための断面図である。FIG. 6D is a cross-sectional view for illustrating the method for manufacturing the solid-state imaging element according to the embodiment. 図７は、変形例１に係る固体撮像素子の構造を示す断面図である。FIG. 7 is a cross-sectional view illustrating the structure of the solid-state imaging device according to the first modification. 図８は、変形例２に係る固体撮像素子の構造を示す断面図である。FIG. 8 is a cross-sectional view illustrating a structure of a solid-state imaging device according to the second modification.
　以下、本発明の実施の形態における固体撮像素子について、図面を参照しながら具体的に説明する。なお、本発明について、以下の実施の形態及び添付の図面を用いて説明を行うが、これは例示を目的としており、本発明はこれらに限定されることを意図しない。 Hereinafter, a solid-state imaging device according to an embodiment of the present invention will be specifically described with reference to the drawings. In addition, although this invention is demonstrated using the following embodiment and attached drawing, this is for the purpose of illustration and this invention is not intended to be limited to these.
　金属微粒子は、外部電場と自由電子の集団運動との共鳴現象により金属固有のプラズマ周波数に対応した波長の光を吸収することが知られている（非特許文献１：「機能性顔料とナノテクノロジー」、２００６年１０月発行、（株）シーエムシー出版）。このような金属微粒子のプラズモン吸収は金属微粒子の周囲媒質に大きく依存し、周囲媒質によって吸収特性が大きく異なる。 Metal fine particles are known to absorb light having a wavelength corresponding to the plasma frequency unique to the metal due to a resonance phenomenon between an external electric field and collective motion of free electrons (Non-patent Document 1: “Functional Pigments and Nanotechnology”). "Issued in October 2006, CMC Publishing Co., Ltd.). The plasmon absorption of such metal fine particles greatly depends on the surrounding medium of the metal fine particles, and the absorption characteristics differ greatly depending on the surrounding medium.
　図１は、Ａｕ微粒子の透過特性（周囲媒質の誘電率依存性）を示すグラフである。 FIG. 1 is a graph showing the transmission characteristics of Au fine particles (dependence on the dielectric constant of the surrounding medium).
　なお、図１のグラフはＡｕ微粒子の周囲媒質の誘電率εｍが異なる場合の透過特性を表している。また、図１のグラフは下記の式（１）に示すＭｉｅ理論による吸収係数の式から導かれている。式（１）において、α（ω）は吸収係数、ωは角振動数、ｃは光速、ｑはＡｕ微粒子の体積、ε１（ω）はＡｕ微粒子の複素誘電率の実部、ε２（ω）はＡｕ微粒子の複素誘電率の虚部である。Ａｕ微粒子の複素誘電率については数々のモデルが提案されているが、図１のグラフの導出において我々はドルーデ・ローレンツモデルを用いて計算を行った（非特許文献２：Applied Optics Vol.37 No.22“Optical properties of metallic films for vertical-cavity optoelectronic devices”）。 The graph of FIG. 1 represents the transmission characteristics when the dielectric constant εm of the surrounding medium of the Au fine particles is different. The graph of FIG. 1 is derived from an absorption coefficient equation based on the Mie theory shown in the following equation (1). In equation (1), α (ω) is the absorption coefficient, ω is the angular frequency, c is the speed of light, q is the volume of the Au fine particle, ε1 (ω) is the real part of the complex dielectric constant of the Au fine particle, ε2 (ω) Is the imaginary part of the complex dielectric constant of the Au fine particles. Numerous models have been proposed for the complex permittivity of Au fine particles, but in the derivation of the graph of FIG. 1, we calculated using the Drude-Lorentz model (Non-patent Document 2: AppliedAppOptics Vol.37 No. .22 “Optical properties of metallic films for vertical-cavity optoelectronic devices”).
Figure JPOXMLDOC01-appb-M000001
Figure JPOXMLDOC01-appb-M000001
　図１から、εｍが小さいほど短波長側へ、またεｍが大きいほど長波長側へプラズモン吸収端がシフトすることがわかる。 FIG. 1 shows that the plasmon absorption edge shifts to the short wavelength side as εm decreases, and to the long wavelength side as εm increases.
　以上より、εｍを任意の値に設定することで金属微粒子に対しさまざまな分光特性をもたせることが可能であるのがわかる。特に、Ａｕ微粒子のεｍ＝２．１付近で得られる分光特性は、ＸＹＺ表色系のＸフィルタの透過特性に非常に近い特性となっている。従って、εｍ＝２．１付近の媒質（例えば、ＳＯＧ（Ｓｐｉｎ－Ｏｎ－Ｇｌａｓｓ））にＡｕ微粒子を分散させれば、Ｘフィルタの分光特性を実現可能である。 From the above, it can be seen that various spectral characteristics can be imparted to the metal fine particles by setting εm to an arbitrary value. In particular, the spectral characteristics obtained near εm = 2.1 of the Au fine particles are very close to the transmission characteristics of the X filter of the XYZ color system. Therefore, if the Au fine particles are dispersed in a medium around εm = 2.1 (for example, SOG (Spin-On-Glass)), the spectral characteristics of the X filter can be realized.
　このとき、εｍ＝１以下では、２つの吸収ピークを持つ透過特性が得られなないためＸフィルタとしての機能を十分満足することが困難である。また、εｍ＝５以上では、波長６００ｎｍ付近まで吸収ピークがシフトするためＸフィルタとしての機能を十分満足することが困難である。従って、Ｘフィルタとしての機能を十分満足可能なεｍとしては１より大きく５より小さいことが望ましい。 At this time, if εm = 1 or less, it is difficult to sufficiently satisfy the function as an X filter because a transmission characteristic having two absorption peaks cannot be obtained. Further, when εm = 5 or more, the absorption peak shifts to a wavelength near 600 nm, so that it is difficult to sufficiently satisfy the function as an X filter. Therefore, it is desirable that εm sufficiently satisfying the function as the X filter is larger than 1 and smaller than 5.
　図２は、本実施の形態に係る固体撮像素子１００の構造を示す断面図である。 FIG. 2 is a cross-sectional view showing the structure of the solid-state imaging device 100 according to the present embodiment.
　この固体撮像素子１００は、ｐ型Ｓｉ基板１０１、複数の受光部１０２、層間絶縁膜１０３、信号線に相当する配線層１０４、複数の色フィルタ、平坦化膜１０６、及び集光素子（オンチップマイクロレンズ）１０７より構成されている。なお、固体撮像素子１００は、ｐ型Ｓｉ基板１０１の代わりにｐ型半導体層を備えてもよいし、又はｐ型Ｓｉ基板１０１の上に形成されたｐ型半導体層を更に備えてもよい。この場合には、受光部１０２は半導体層に形成される。 The solid-state imaging device 100 includes a p-type Si substrate 101, a plurality of light receiving portions 102, an interlayer insulating film 103, a wiring layer 104 corresponding to a signal line, a plurality of color filters, a planarizing film 106, and a light collecting element (on-chip). Microlens) 107. The solid-state imaging device 100 may include a p-type semiconductor layer instead of the p-type Si substrate 101, or may further include a p-type semiconductor layer formed on the p-type Si substrate 101. In this case, the light receiving portion 102 is formed in the semiconductor layer.
　ｐ型Ｓｉ基板１０１には、各受光部１０２に入射した光によって発生した電気信号を読み出すトランジスタ等の読出し部（図外）が設けられている。受光部１０２は、ｎ型領域であり、ｐ型Ｓｉ基板１０１表面に２次元状に配置されている。なお、ｐ型Ｓｉ基板１０１の厚さは、固体撮像素子１００によって異なるが、例えば５～１０μｍとされる。 The p-type Si substrate 101 is provided with a reading unit (not shown) such as a transistor for reading an electric signal generated by light incident on each light receiving unit 102. The light receiving unit 102 is an n-type region and is two-dimensionally arranged on the surface of the p-type Si substrate 101. Note that the thickness of the p-type Si substrate 101 varies depending on the solid-state imaging device 100, but is, for example, 5 to 10 μm.
　色フィルタは、複数の受光部１０２のそれぞれの上に配置されている。複数の色フィルタは、可視光域において異なる光吸収特性を有する３種類の色フィルタ、つまりＸＹＺ表色系のＸフィルタ、Ｙフィルタ及びＺフィルタを含む。具体的に、複数の色フィルタは、Ｚフィルタとしての青色領域（４１０～５１０ｎｍの波長域）に透過中心波長を有する（透過率５０％以上の透過ピークを有する）第１の色フィルタ（青色フィルタ）１０８と、Ｙフィルタとしての緑色領域（４７０～６５０ｎｍの波長域）に透過中心波長を有する第２の色フィルタ（緑色フィルタ）１０９と、Ｘフィルタとしての赤色領域（５２０～６７０ｎｍの波長域）に透過中心波長を有する第１の透過帯と、青色領域に透過中心波長を有する第２の透過帯とを持つ第３の色フィルタ１１０とを含む。なお、ＸＹＺ表色系とは、１９３１年にＣＩＥ（国際照明委員会）で標準表色系として承認された表色系である。 The color filter is disposed on each of the plurality of light receiving units 102. The plurality of color filters include three types of color filters having different light absorption characteristics in the visible light range, that is, an XYZ color system X filter, Y filter, and Z filter. Specifically, the plurality of color filters includes a first color filter (blue filter having a transmission center wavelength (having a transmission peak with a transmittance of 50% or more)) in a blue region (wavelength region of 410 to 510 nm) as a Z filter. ) 108, a second color filter (green filter) 109 having a transmission center wavelength in a green region (wavelength region of 470 to 650 nm) as a Y filter, and a red region (wavelength region of 520 to 670 nm) as an X filter And a third color filter 110 having a first transmission band having a transmission center wavelength and a second transmission band having a transmission center wavelength in the blue region. The XYZ color system is a color system approved as a standard color system by the CIE (International Lighting Commission) in 1931.
　第１の色フィルタ１０８、第２の色フィルタ１０９及び第３の色フィルタ１１０は、１つの第１の色フィルタ１０８、１つの第２の色フィルタ１０９、及び２つの第３の色フィルタ１１０を１つの単位セルとして２次元状に配置される。 The first color filter 108, the second color filter 109, and the third color filter 110 include one first color filter 108, one second color filter 109, and two third color filters 110. Two unit dimensions are arranged as one unit cell.
　第１の色フィルタ１０８は青色素を含む顔料が分散されてなり、第２の色フィルタ１０９は緑色素を含む顔料が分散されてなる。なお、第１の色フィルタ１０８及び第２の色フィルタ１０９は、顔料ではなく染料系のカラーレジストで構成されても構わない。 The first color filter 108 has a pigment containing a blue pigment dispersed therein, and the second color filter 109 has a pigment containing a green pigment dispersed therein. Note that the first color filter 108 and the second color filter 109 may be made of a dye-based color resist instead of a pigment.
　第３の色フィルタ１１０は、誘電率が１より大きく５より小さい媒質と、この媒質中に分散されたナノオーダの金、銀、銅、クロム及び鉄クロム酸化物等から構成される金属微粒子とから構成される。このとき、金属微粒子の平均粒径が入射した光の波長と同程度かそれよりも大きくなると、金属微粒子に入射した光が反射してしまうため、金属微粒子の平均粒径は入射波長よりも小さく、１００ｎｍ以下であることが望ましい。例えば、第３の色フィルタ１１０は、シリコン及び酸素を含むＳＯＧと、ＳＯＧに分散された粒径分布が５～５０ｎｍのＡｕ微粒子とにより構成されている。 The third color filter 110 includes a medium having a dielectric constant larger than 1 and smaller than 5, and metal fine particles composed of nano-order gold, silver, copper, chromium, iron chromium oxide and the like dispersed in the medium. Composed. At this time, if the average particle diameter of the metal fine particles is about the same as or larger than the wavelength of the incident light, the light incident on the metal fine particles will be reflected. Therefore, the average particle diameter of the metal fine particles is smaller than the incident wavelength. , 100 nm or less is desirable. For example, the third color filter 110 is composed of SOG containing silicon and oxygen and Au fine particles having a particle size distribution of 5 to 50 nm dispersed in the SOG.
　図３は、本実施の形態に係る固体撮像素子１００に搭載された第３の色フィルタ１１０の透過特性の実測値を示す図である。なお、第３の色フィルタ１１０としては、粒径分布が５～５０ｎｍ（メジアン値１５ｎｍ）のＡｕ微粒子がＳＯＧに分散されてなるフィルタが用いられている。 FIG. 3 is a diagram showing measured values of the transmission characteristics of the third color filter 110 mounted on the solid-state imaging device 100 according to the present embodiment. As the third color filter 110, a filter in which Au fine particles having a particle size distribution of 5 to 50 nm (median value 15 nm) are dispersed in SOG is used.
　第３の色フィルタ１１０については、図３からもわかるように、計算結果と良く一致した透過特性が得られている。そして、第３の色フィルタ１１０において第２の透過帯の最大透過率が第１の透過帯の最大透過率に対し１０～５０％となっている。従って、第３の色フィルタ１１０によりＸＹＺ表色系のＸフィルタの透過特性を実現することができる。 As can be seen from FIG. 3, the third color filter 110 has a transmission characteristic that is in good agreement with the calculation result. In the third color filter 110, the maximum transmittance of the second transmission band is 10 to 50% with respect to the maximum transmittance of the first transmission band. Therefore, the transmission characteristics of the XYZ color system X filter can be realized by the third color filter 110.
　図４Ａは本実施の形態に係る固体撮像素子１００の第１の色フィルタ１０８、第２の色フィルタ１０９及び第３の色フィルタ１１０によって得られる分光感度特性を示す図である。また、図４Ｂは本実施の形態に係る固体撮像素子１００の色フィルタによって得られるｘ－ｙ色度分布（図４Ｂの点線で囲まれた斜線で示した領域）及び人間の視感度のフィルタ特性が有する色域（図４Ｂの実線で囲まれた領域）を示す図である。また、図５Ａは従来の一般的なＲＧＢフィルタによって得られる分光感度特性を示す図である。また、図５Ｂは従来の一般的なＲＧＢフィルタのｘ－ｙ色度分布（図５Ｂの点線で囲まれた斜線で示した領域）及び人間の視感度のフィルタ特性が有する色域（図５Ｂの実線で囲まれた領域）を示す図である。 FIG. 4A is a diagram showing spectral sensitivity characteristics obtained by the first color filter 108, the second color filter 109, and the third color filter 110 of the solid-state imaging device 100 according to the present embodiment. FIG. 4B shows an xy chromaticity distribution (a region indicated by a diagonal line surrounded by a dotted line in FIG. 4B) obtained by the color filter of the solid-state imaging device 100 according to the present embodiment and a filter characteristic of human visibility. It is a figure which shows the color gamut (area | region enclosed with the continuous line of FIG. 4B) which has. FIG. 5A is a diagram showing spectral sensitivity characteristics obtained by a conventional general RGB filter. FIG. 5B shows an xy chromaticity distribution of a conventional general RGB filter (a region indicated by diagonal lines surrounded by a dotted line in FIG. 5B) and a color gamut having a filter characteristic of human visibility (FIG. 5B). It is a figure which shows the area | region enclosed with the continuous line.
　図４Ａ及び図４Ｂからわかるように、第１の色フィルタ１０８、第２の色フィルタ１０９及び第３の色フィルタ１１０により得られる分光特性は等色条件を満たすので、固体撮像素子１００の色フィルタによって人間の視感度のフィルタ特性を有する色フィルタを実現することができる。これに対して、図５Ａ及び図５Ｂに示されるように、従来の一般的なＲＧＢフィルタの分光感度特性及びｘ－ｙ色度分布は、人間の視感度に対し、非常に狭い領域でしかない。 As can be seen from FIGS. 4A and 4B, the spectral characteristics obtained by the first color filter 108, the second color filter 109, and the third color filter 110 satisfy the color matching condition. Thus, a color filter having a filter characteristic of human visibility can be realized. On the other hand, as shown in FIGS. 5A and 5B, the spectral sensitivity characteristic and the xy chromaticity distribution of a conventional general RGB filter are only a very narrow region with respect to human visual sensitivity. .
　図６Ａ～図６Ｄは本実施の形態に係る固体撮像素子１００の色フィルタの製造方法を説明するための断面図である。 6A to 6D are cross-sectional views for explaining a method for manufacturing a color filter of the solid-state imaging device 100 according to the present embodiment.
　まず、通常の半導体プロセスを用いて、ｐ型Ｓｉ基板１０１に、受光部１０２、層間絶縁膜１０３及び配線層１０４が形成される。 First, the light receiving portion 102, the interlayer insulating film 103, and the wiring layer 104 are formed on the p-type Si substrate 101 using a normal semiconductor process.
　次に、図６Ａに示すように、スピンオン法で粒径分布が５～５０ｎｍの金属微粒子が分散された誘電率が１より大きく５より小さい溶液１５２が層間絶縁膜１０３表面に塗布され、約４００℃で焼結される。その後、レジスト１５３が塗布され、溶液１５２に対してリソグラフィーとドライエッチング及びウェットエッチング等のエッチング１５５とが行われ、第３の色フィルタ１１０が形成される。 Next, as shown in FIG. 6A, a solution 152 having a dielectric constant larger than 1 and smaller than 5 in which metal fine particles having a particle size distribution of 5 to 50 nm are dispersed by spin-on method is applied to the surface of the interlayer insulating film 103, and about 400 Sintered at ℃. Thereafter, a resist 153 is applied, and lithography and etching 155 such as dry etching and wet etching are performed on the solution 152 to form the third color filter 110.
　次に、図６Ｂに示すように、スピンオン法で緑色素を含むネガ型の顔料が分散された溶液１５６が層間絶縁膜１０３表面に塗布され、リソグラフィー１５４により溶液１５６の所望の領域のみが硬化される。その後、溶液１５６に対してＴＭＡＨ（水酸化テトラメチルアンモニウム）溶液等でウェットエッチングが行われ、第２の色フィルタ１０９が形成される。ここで、図６Ａの工程で形成されている第３の色フィルタ１１０は既に熱焼結しているため、ウェットエッチングの影響を受けない。 Next, as shown in FIG. 6B, a solution 156 in which a negative pigment containing a green dye is dispersed by spin-on is applied to the surface of the interlayer insulating film 103, and only a desired region of the solution 156 is cured by lithography 154. The Thereafter, the solution 156 is wet-etched with a TMAH (tetramethylammonium hydroxide) solution or the like to form the second color filter 109. Here, since the third color filter 110 formed in the process of FIG. 6A has already been thermally sintered, it is not affected by wet etching.
　次に、図６Ｃに示すように、スピンオン法で青色素を含むネガ型の顔料が分散された溶液１５７が層間絶縁膜１０３表面に塗布され、リソグラフィー１５４により溶液１５７の所望の領域のみが硬化される。その後、溶液１５７に対してＴＭＡＨ溶液等でウェットエッチングが行われ、第１の色フィルタ１０８が形成される。ここで、図６Ｂの工程で形成されている第２の色フィルタ１０９は既に熱焼結しているため、ウェットエッチングの影響を受けない。 Next, as shown in FIG. 6C, a solution 157 in which a negative pigment containing a blue pigment is dispersed is applied to the surface of the interlayer insulating film 103 by a spin-on method, and only a desired region of the solution 157 is cured by lithography 154. The Thereafter, the solution 157 is wet-etched with a TMAH solution or the like to form the first color filter 108. Here, since the second color filter 109 formed in the process of FIG. 6B has already been thermally sintered, it is not affected by wet etching.
　最後に、図６Ｄに示すように、ＣＶＤ法を用いて色フィルタ上に平坦化膜１０６が成膜され、平坦化膜１０６上に集光素子１０７が形成される。 Finally, as shown in FIG. 6D, a flattening film 106 is formed on the color filter by using the CVD method, and a condensing element 107 is formed on the flattening film 106.
　なお、本実施の形態に係る固体撮像素子１００の製造工程では、色フィルタを構成する材料としてネガ型の顔料カラーレジストを仮定しているが、ポジ型の顔料カラーレジストでも構わない。また、第１の色フィルタ１０８、第２の色フィルタ１０９及び第３の色フィルタ１１０の形成工程の順番を変更されても問題ない。 In the manufacturing process of the solid-state imaging device 100 according to the present embodiment, a negative pigment color resist is assumed as a material constituting the color filter, but a positive pigment color resist may be used. In addition, there is no problem even if the order of forming the first color filter 108, the second color filter 109, and the third color filter 110 is changed.
　以上のように本実施の形態の固体撮像素子１００は、反射型色フィルタ及びエメラルドフィルタを用いることなく、誘電率が１より大きく５より小さい媒質に平均粒径１００ｎｍ以下の金属微粒子が分散されてなる第３の色フィルタ１１０を用いてＸＹＺ表色系のＸフィルタに対応する分光特性を実現している。従って、輝度信号を減らすことなく人間の視感度のフィルタ特性を実現する薄膜の色フィルタを実現することができる。 As described above, in the solid-state imaging device 100 according to the present embodiment, metal fine particles having an average particle diameter of 100 nm or less are dispersed in a medium having a dielectric constant larger than 1 and smaller than 5 without using a reflective color filter and an emerald filter. Using the third color filter 110, spectral characteristics corresponding to the X filter of the XYZ color system are realized. Therefore, it is possible to realize a thin film color filter that realizes the filter characteristic of human visibility without reducing the luminance signal.
　（変形例１）
　ここで、本実施の形態における変形例１について説明する。上記実施の形態では、配線層１０４は第１の色フィルタ１０８、第２の色フィルタ１０９及び第３の色フィルタ１１０と共に受光部１０２の光入射面の上方に配置されるとした。しかし、本変形例では、配線層１０４が受光部１０２の光入射面と反対側の面の上方に配置される。つまり、配線層１０４がｐ型Ｓｉ基板１０１の受光部１０２が形成された面とは反対側の面側に配置される。 (Modification 1)
Here, Modification 1 in the present embodiment will be described. In the above embodiment, the wiring layer 104 is disposed above the light incident surface of the light receiving unit 102 together with the first color filter 108, the second color filter 109, and the third color filter 110. However, in the present modification, the wiring layer 104 is disposed above the surface of the light receiving unit 102 opposite to the light incident surface. That is, the wiring layer 104 is disposed on the surface side opposite to the surface on which the light receiving portion 102 of the p-type Si substrate 101 is formed.
　図７は、本変形例に係る固体撮像素子２００の構造を示す断面図である。 FIG. 7 is a cross-sectional view showing the structure of the solid-state imaging device 200 according to this modification.
　この固体撮像素子２００は、ｐ型Ｓｉ基板１０１、複数の受光部１０２、層間絶縁膜１０３、配線層１０４、複数の色フィルタ、平坦化膜１０６、集光素子１０７、及び支持基板２０２より構成されている。複数の色フィルタは、第１の色フィルタ１０８、第２の色フィルタ１０９及び第３の色フィルタ１１０を含む。 The solid-state imaging device 200 includes a p-type Si substrate 101, a plurality of light receiving units 102, an interlayer insulating film 103, a wiring layer 104, a plurality of color filters, a planarizing film 106, a light collecting element 107, and a support substrate 202. ing. The plurality of color filters include a first color filter 108, a second color filter 109, and a third color filter 110.
　支持基板２０２は、ｐ型Ｓｉ基板１０１の強度を補強するための基板であり、例えば、ｐ型Ｓｉ基板１０１と同じ材料のＳｉ基板により形成される。 The support substrate 202 is a substrate for reinforcing the strength of the p-type Si substrate 101, and is formed of, for example, a Si substrate made of the same material as the p-type Si substrate 101.
　配線層１０４はｐ型Ｓｉ基板１０１の一方面上方（光入射面と反対側の面上方）に形成されている。ｐ型Ｓｉ基板１０１の他方面上方（光入射面上方）には、層間絶縁膜１０３、色フィルタ、平坦化膜１０６及び集光素子１０７が形成されている。 The wiring layer 104 is formed above one surface of the p-type Si substrate 101 (above the surface opposite to the light incident surface). Over the other surface of the p-type Si substrate 101 (above the light incident surface), an interlayer insulating film 103, a color filter, a planarizing film 106, and a light collecting element 107 are formed.
　以上のように本変形例の固体撮像素子２００によれば、配線層１０４により受光部１０２への入射光が反射されるのを防止し、配線層１０４による感度低下を防止することができる。 As described above, according to the solid-state imaging device 200 of the present modification, it is possible to prevent the incident light to the light receiving unit 102 from being reflected by the wiring layer 104 and to prevent a decrease in sensitivity due to the wiring layer 104.
　（変形例２）
　また、本実施の形態における変形例２について説明する。本変形例では、色フィルタが光導波路として機能する。 (Modification 2)
Also, a second modification of the present embodiment will be described. In this modification, the color filter functions as an optical waveguide.
　図８は、本変形例に係る固体撮像素子３００の構造を示す断面図である。 FIG. 8 is a cross-sectional view showing the structure of the solid-state imaging device 300 according to this modification.
　この固体撮像素子３００は、ｐ型Ｓｉ基板１０１、複数の受光部１０２、層間絶縁膜１０３、配線層１０４、複数の色フィルタ、平坦化膜１０６、及び集光素子１０７より構成されている。複数の色フィルタは、第１の色フィルタ１０８、第２の色フィルタ１０９及び第３の色フィルタ１１０を含む。 The solid-state imaging device 300 includes a p-type Si substrate 101, a plurality of light receiving portions 102, an interlayer insulating film 103, a wiring layer 104, a plurality of color filters, a planarizing film 106, and a light collecting element 107. The plurality of color filters include a first color filter 108, a second color filter 109, and a third color filter 110.
　第１の色フィルタ１０８は、第１の色フィルタ１０８の周囲の媒質（層間絶縁膜１０３）より屈折率が高く、第１の色フィルタ１０８の青色領域の透過中心波長の光を５０％以上透過する第１材料から構成され、第１材料の屈折率をｎ１、第１の色フィルタ１０８の周囲の媒質（層間絶縁膜１０３）の屈折率をｎ２、第１の色フィルタ１０８への入射光が第１の色フィルタ１０８の光入射面の法線となす角度をθ１とするとき、θ１＜ｃｏｓ－１（ｎ２／ｎ１)を満足する。 The first color filter 108 has a refractive index higher than that of the medium (interlayer insulating film 103) around the first color filter 108, and transmits 50% or more of light having a transmission center wavelength in the blue region of the first color filter 108. The refractive index of the first material is n1, the refractive index of the medium (interlayer insulating film 103) around the first color filter is n2, and the incident light to the first color filter is When the angle formed with the normal line of the light incident surface of the first color filter 108 is θ1, θ1 <cos −1 (n2 / n1) is satisfied.
　第２の色フィルタ１０９は、第２の色フィルタ１０９の周囲の媒質（層間絶縁膜１０３）より屈折率が高く、第２の色フィルタ１０９の緑色領域の透過中心波長の光を５０％以上透過する第２材料から構成され、第２材料の屈折率をｎ３、第２の色フィルタ１０９の周囲の媒質（層間絶縁膜１０３）の屈折率をｎ４、第２の色フィルタ１０９への入射光が第２の色フィルタ１０９の光入射面の法線となす角度をθ２とするとき、θ２＜ｃｏｓ－１（ｎ４／ｎ３）を満足する。 The second color filter 109 has a higher refractive index than the medium (interlayer insulating film 103) around the second color filter 109, and transmits 50% or more of light having a transmission center wavelength in the green region of the second color filter 109. The refractive index of the second material is n3, the refractive index of the medium (interlayer insulating film 103) around the second color filter 109 is n4, and the incident light to the second color filter 109 is When the angle formed with the normal line of the light incident surface of the second color filter 109 is θ2, θ2 <cos −1 (n4 / n3) is satisfied.
　第３の色フィルタ１１０は、第３の色フィルタ１１０の周囲の媒質（層間絶縁膜１０３）より屈折率が高く、第３の色フィルタ１１０の第１の透過帯及び第２の透過帯の透過中心波長の光を５０％以上透過する第３材料から構成され、第３材料の屈折率をｎ５、第３の色フィルタ１１０の周囲の媒質（層間絶縁膜１０３）の屈折率をｎ６、第３の色フィルタ１１０への入射光が第３の色フィルタ１１０の光入射面の法線となす角度をθ３とするとき、θ３＜ｃｏｓ－１（ｎ６／ｎ５）を満足する。 The third color filter 110 has a higher refractive index than the medium (interlayer insulating film 103) around the third color filter 110, and transmits the first transmission band and the second transmission band of the third color filter 110. The third material is made of a third material that transmits 50% or more of light having a center wavelength. The refractive index of the third material is n5, the refractive index of the medium (interlayer insulating film 103) around the third color filter 110 is n6, and the third Θ3 <cos −1 (n6 / n5) is satisfied, where θ3 is an angle formed by the light incident on the color filter 110 and the normal line of the light incident surface of the third color filter 110.
　例えば、層間絶縁膜１０３として屈折率１．４５のＳｉＯ２を主成分とする絶縁膜が用いられ、第１の色フィルタ１０８、第２の色フィルタ１０９及び第３の色フィルタ１１０として屈折率１．８５のポリベンゾオキサゾールを含むフィルタが用いられる。 For example, an insulating film mainly composed of SiO 2 having a refractive index of 1.45 is used as the interlayer insulating film 103, and a refractive index of 1 is used as the first color filter 108, the second color filter 109, and the third color filter 110. A filter containing .85 polybenzoxazole is used.
　以上のように本変形例の固体撮像素子３００によれば、色フィルタが光導波路として機能し、導波路構造により入射光を受光部１０２に導くことができるので、固体撮像素子の感度を向上させることができる。 As described above, according to the solid-state imaging device 300 of the present modification, the color filter functions as an optical waveguide, and incident light can be guided to the light receiving unit 102 by the waveguide structure, thereby improving the sensitivity of the solid-state imaging device. be able to.
　本発明は、固体撮像素子に利用可能であり、特にデジタルカメラ、携帯電話、一眼レフカメラ及びスキャナ等に利用可能である。 The present invention can be used for solid-state imaging devices, and in particular, can be used for digital cameras, mobile phones, single-lens reflex cameras, scanners, and the like.
　　１００、２００、３００　　固体撮像素子
　　１０１　　Ｓｉ基板
　　１０２　　受光部
　　１０３　　層間絶縁膜
　　１０４　　配線層
　　１０６　　平坦化膜
　　１０７　　集光素子
　　１０８　　第１の色フィルタ
　　１０９　　第２の色フィルタ
　　１１０　　第３の色フィルタ
　　１５２、１５６、１５７　　溶液
　　１５３　　レジスト
　　１５４　　リソグラフィー
　　１５５　　エッチング
　　２０２　　支持基板 DESCRIPTION OF SYMBOLS 100, 200, 300 Solid-state image sensor 101 Si substrate 102 Light-receiving part 103 Interlayer insulation film 104 Wiring layer 106 Flattening film 107 Condensing element 108 1st color filter 109 2nd color filter 110 3rd color filter 152, 156 157 Solution 153 Resist 154 Lithography 155 Etching 202 Support substrate

Claims (9)

  1. 　２次元状に配置された複数の受光部と、
    　前記複数の受光部のそれぞれの上に配置され、互いに異なる光吸収特性を有する色フィルタとを備え、
    　複数の前記色フィルタは、
    　青色領域に透過中心波長を有する第１の色フィルタと、
    　緑色領域に透過中心波長を有する第２の色フィルタと、
    　赤色領域に透過中心波長を有する第１の透過帯と、青色領域に透過中心波長を有する第２の透過帯とを持つ第３の色フィルタとを含み、
    　前記第３の色フィルタは、誘電率が１より大きく５より小さい媒質と、前記媒質中に分散された平均粒径１００ｎｍ以下の金属微粒子とから構成される
    　固体撮像素子。     A plurality of light receiving portions arranged two-dimensionally;
    A color filter disposed on each of the plurality of light receiving parts and having different light absorption characteristics;
    The plurality of color filters are
    A first color filter having a transmission center wavelength in the blue region;
    A second color filter having a transmission center wavelength in the green region;
    A third color filter having a first transmission band having a transmission center wavelength in the red region and a second transmission band having a transmission center wavelength in the blue region;
    The third color filter includes a medium having a dielectric constant larger than 1 and smaller than 5, and metal fine particles having an average particle diameter of 100 nm or less dispersed in the medium.
  2. 　前記第２の透過帯の最大透過率は、前記第１の透過帯の最大透過率に対し、１０～５０％である
    　請求項１に記載の固体撮像素子。     The solid-state imaging device according to claim 1, wherein the maximum transmittance of the second transmission band is 10 to 50% with respect to the maximum transmittance of the first transmission band.
  3. 　前記媒質は、シリコン及び酸素を含む
    　請求項１又は２に記載の固体撮像素子。     The solid-state imaging device according to claim 1, wherein the medium includes silicon and oxygen.
  4. 　前記第１の色フィルタは、青色素を含む顔料又は染料系のカラーレジストから構成され、
    　前記第２の色フィルタは、緑色素を含む顔料又は染料系のカラーレジストから構成される
    　請求項１～３のいずれか１項に記載の固体撮像素子。     The first color filter is composed of a pigment or dye-based color resist containing a blue pigment,
    The solid-state imaging device according to any one of claims 1 to 3, wherein the second color filter includes a pigment containing a green pigment or a dye-based color resist.
  5. 　前記第１の色フィルタは、該第１の色フィルタの周囲の媒質より屈折率が高く、該第１の色フィルタの青色領域の透過中心波長の光を５０％以上透過する第１材料から構成され、前記第１材料の屈折率をｎ１、該第１の色フィルタの周囲の媒質の屈折率をｎ２、該第１の色フィルタへの入射光が該第１の色フィルタの光入射面の法線となす角度をθ１とするとき、下記の式を満足し、
    θ１＜ｃｏｓ－１（ｎ２／ｎ１）
    　前記第２の色フィルタは、該第２の色フィルタの周囲の媒質より屈折率が高く、該第２の色フィルタの緑色領域の透過中心波長の光を５０％以上透過する第２材料から構成され、前記第２材料の屈折率をｎ３、該第２の色フィルタの周囲の媒質の屈折率をｎ４、該第２の色フィルタへの入射光が該第２の色フィルタの光入射面の法線となす角度をθ２とするとき、下記の式を満足し、
    θ２＜ｃｏｓ－１（ｎ４／ｎ３）
    　前記第３の色フィルタは、該第３の色フィルタの周囲の媒質より屈折率が高く、該第３の色フィルタの第１の透過帯及び第２の透過帯の透過中心波長の光を５０％以上透過する第３材料から構成され、前記第３材料の屈折率をｎ５、該第３の色フィルタの周囲の媒質の屈折率をｎ６、該第３の色フィルタへの入射光が該第３の色フィルタの光入射面の法線となす角度をθ３とするとき、下記の式を満足する
    θ３＜ｃｏｓ－１（ｎ６／ｎ５）
    　請求項１～４のいずれか１項に記載の固体撮像素子。     The first color filter is made of a first material having a refractive index higher than that of the medium around the first color filter and transmitting light having a transmission center wavelength in the blue region of the first color filter by 50% or more. The refractive index of the first material is n1, the refractive index of the medium around the first color filter is n2, and the light incident on the first color filter is incident on the light incident surface of the first color filter. When the angle formed with the normal is θ1, the following formula is satisfied,
    θ1 <cos −1 (n2 / n1)
    The second color filter has a refractive index higher than that of the medium around the second color filter, and is made of a second material that transmits 50% or more of light having a transmission center wavelength in the green region of the second color filter. The refractive index of the second material is n3, the refractive index of the medium surrounding the second color filter is n4, and the incident light to the second color filter is incident on the light incident surface of the second color filter. When the angle formed with the normal is θ2, the following equation is satisfied:
    θ2 <cos −1 (n4 / n3)
    The third color filter has a refractive index higher than that of the medium around the third color filter, and emits light having a transmission center wavelength of the first transmission band and the second transmission band of the third color filter. % Of the third material that transmits at least%, the refractive index of the third material is n5, the refractive index of the medium around the third color filter is n6, and the incident light to the third color filter is the first material. Θ3 <cos −1 (n6 / n5) satisfying the following expression, where θ3 is an angle formed with the normal line of the light incident surface of the color filter 3
    The solid-state imaging device according to any one of claims 1 to 4.
  6. 　前記固体撮像素子は、さらに、前記受光部の光入射面と反対側の面上方に配置された配線層を備え、
    　前記第１の色フィルタ、第２の色フィルタ及び第３の色フィルタは、前記受光部の光入射面上方に配置される
    　請求項１～５のいずれか１項に記載の固体撮像素子。     The solid-state imaging device further includes a wiring layer disposed above a surface opposite to the light incident surface of the light receiving unit,
    The solid-state imaging device according to any one of claims 1 to 5, wherein the first color filter, the second color filter, and the third color filter are disposed above a light incident surface of the light receiving unit.
  7. 　前記金属微粒子は、金、銀、銅、クロム及び鉄クロム酸化物の少なくとも１つから構成される
    　請求項１～６のいずれか１項に記載の固体撮像素子。     The solid-state imaging device according to any one of claims 1 to 6, wherein the metal fine particles are made of at least one of gold, silver, copper, chromium, and iron-chromium oxide.
  8. 　前記第１の色フィルタ、第２の色フィルタ及び第３の色フィルタにより得られる分光特性は、等色条件を満たす
    　請求項１～７のいずれか１項に記載の固体撮像素子。     The solid-state imaging device according to claim 1, wherein spectral characteristics obtained by the first color filter, the second color filter, and the third color filter satisfy a color matching condition.
  9. 　前記第１の色フィルタ、第２の色フィルタ及び第３の色フィルタは、それぞれＸＹＺ表色系のＺフィルタ、Ｙフィルタ及びＸフィルタである
    　請求項１～８のいずれか１項に記載の固体撮像素子。     9. The solid according to claim 1, wherein the first color filter, the second color filter, and the third color filter are an XYZ color system Z filter, a Y filter, and an X filter, respectively. Image sensor.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012073402A1 (en) * 2010-12-01 2012-06-07 パナソニック株式会社 Solid-state imaging element and method for manufacturing same

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113748518B (en) * 2020-03-27 2023-04-18 京东方科技集团股份有限公司 Display substrate, manufacturing method thereof and display device

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62111204A (en) * 1985-11-08 1987-05-22 Matsushita Electronics Corp Color separating filter
JPH09321262A (en) * 1996-05-27 1997-12-12 Sharp Corp Solid-state image pickup device and method of fabricating the same
JP2003008997A (en) * 2001-06-27 2003-01-10 Konica Corp Image pickup element and digital still camera employing the image pickup element
WO2007046371A1 (en) * 2005-10-19 2007-04-26 Fujifilm Corporation Method for producing metal particle dispersion, metal particle dispersion, and colored composition, photosensitive transfer material, substrate with light-blocking image, color filter and liquid crystal display each using such metal particle dispersion
JP2007329380A (en) * 2006-06-09 2007-12-20 Sony Corp Method and apparatus for acquiring physical information, semiconductor device, signal processor

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62111204A (en) * 1985-11-08 1987-05-22 Matsushita Electronics Corp Color separating filter
JPH09321262A (en) * 1996-05-27 1997-12-12 Sharp Corp Solid-state image pickup device and method of fabricating the same
JP2003008997A (en) * 2001-06-27 2003-01-10 Konica Corp Image pickup element and digital still camera employing the image pickup element
WO2007046371A1 (en) * 2005-10-19 2007-04-26 Fujifilm Corporation Method for producing metal particle dispersion, metal particle dispersion, and colored composition, photosensitive transfer material, substrate with light-blocking image, color filter and liquid crystal display each using such metal particle dispersion
JP2007329380A (en) * 2006-06-09 2007-12-20 Sony Corp Method and apparatus for acquiring physical information, semiconductor device, signal processor

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012073402A1 (en) * 2010-12-01 2012-06-07 パナソニック株式会社 Solid-state imaging element and method for manufacturing same

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