WO2021161961A1 - 光学フィルタ及びその製造方法、光センサ並びに固体撮像素子 - Google Patents
光学フィルタ及びその製造方法、光センサ並びに固体撮像素子 Download PDFInfo
- Publication number
- WO2021161961A1 WO2021161961A1 PCT/JP2021/004600 JP2021004600W WO2021161961A1 WO 2021161961 A1 WO2021161961 A1 WO 2021161961A1 JP 2021004600 W JP2021004600 W JP 2021004600W WO 2021161961 A1 WO2021161961 A1 WO 2021161961A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- dielectric
- light
- dielectric layer
- intermediate layer
- layer
- Prior art date
Links
- 230000003287 optical effect Effects 0.000 title claims abstract description 111
- 238000004519 manufacturing process Methods 0.000 title claims description 12
- 238000003384 imaging method Methods 0.000 title abstract description 12
- 239000003989 dielectric material Substances 0.000 claims abstract description 32
- 238000009751 slip forming Methods 0.000 claims abstract description 3
- 238000000034 method Methods 0.000 claims description 7
- 238000010030 laminating Methods 0.000 claims description 3
- 239000000758 substrate Substances 0.000 claims description 3
- 239000005001 laminate film Substances 0.000 abstract 3
- 238000001514 detection method Methods 0.000 description 36
- 238000006243 chemical reaction Methods 0.000 description 17
- 230000005540 biological transmission Effects 0.000 description 11
- 239000000463 material Substances 0.000 description 10
- 238000012986 modification Methods 0.000 description 8
- 230000004048 modification Effects 0.000 description 8
- 230000000694 effects Effects 0.000 description 4
- 238000000059 patterning Methods 0.000 description 3
- 229910004298 SiO 2 Inorganic materials 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 230000002238 attenuated effect Effects 0.000 description 2
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- 230000003595 spectral effect Effects 0.000 description 2
- 238000004611 spectroscopical analysis Methods 0.000 description 2
- 239000004642 Polyimide Substances 0.000 description 1
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- 229910021607 Silver chloride Inorganic materials 0.000 description 1
- 229910010413 TiO 2 Inorganic materials 0.000 description 1
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 229910052732 germanium Inorganic materials 0.000 description 1
- GNPVGFCGXDBREM-UHFFFAOYSA-N germanium atom Chemical compound [Ge] GNPVGFCGXDBREM-UHFFFAOYSA-N 0.000 description 1
- 229920002100 high-refractive-index polymer Polymers 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 229910021421 monocrystalline silicon Inorganic materials 0.000 description 1
- ZKATWMILCYLAPD-UHFFFAOYSA-N niobium pentoxide Inorganic materials O=[Nb](=O)O[Nb](=O)=O ZKATWMILCYLAPD-UHFFFAOYSA-N 0.000 description 1
- URLJKFSTXLNXLG-UHFFFAOYSA-N niobium(5+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Nb+5].[Nb+5] URLJKFSTXLNXLG-UHFFFAOYSA-N 0.000 description 1
- 239000011368 organic material Substances 0.000 description 1
- 229920001721 polyimide Polymers 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 239000002861 polymer material Substances 0.000 description 1
- 229920005591 polysilicon Polymers 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 1
- 229910052814 silicon oxide Inorganic materials 0.000 description 1
- HKZLPVFGJNLROG-UHFFFAOYSA-M silver monochloride Chemical compound [Cl-].[Ag+] HKZLPVFGJNLROG-UHFFFAOYSA-M 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
- G02B1/10—Optical coatings produced by application to, or surface treatment of, optical elements
- G02B1/11—Anti-reflection coatings
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/20—Filters
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/20—Filters
- G02B5/28—Interference filters
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T1/00—General purpose image data processing
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components 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
- H01L27/144—Devices controlled by radiation
- H01L27/146—Imager structures
Definitions
- the present invention relates to an optical filter and a method for manufacturing the same, an optical sensor provided with the optical filter, and a solid-state image sensor. More specifically, the present invention relates to a technique for detecting visible light and near-infrared light having a specific wavelength by using an optical filter having a dielectric laminated structure.
- Patent Document 1 acquires pulse wave information of a subject using green light and infrared light.
- a solid-state image sensor is provided with a bandpass filter that suppresses the transmission of visible light and transmits infrared light, and a color filter that transmits red light, green light, or blue light for each pixel. Is used.
- the ophthalmologic imaging apparatus described in Patent Document 2 photographs the anterior segment of the eye with infrared light and images the fundus with visible light.
- a camera that captures an image by visible light is provided in addition to a solid-state image sensor that captures an image by infrared light.
- Optical sensors and solid-state imaging devices that detect visible light and near-infrared light are equipped with infrared light cut filters that transmit visible light and block infrared light in order to prevent light that is not detected.
- a bandpass filter that suppresses the transmission of light and transmits infrared light is provided.
- an optical filter for example, an interference filter having a dielectric laminated structure in which high refractive index films and low refractive index films are alternately laminated is used (see, for example, Patent Documents 3 and 4).
- the optical sensor described in Patent Document 3 is provided with an infrared light cut filter having a dielectric laminated structure.
- a high refractive index film such as a polysilicon film or a Ta 2 O 5 film is provided between the interference filter and the condenser lens. Has been done.
- an optical sensor capable of integrally forming a plurality of optical filters having different optical characteristics and individually and simultaneously detecting light of a specific wavelength in at least a visible light region and an infrared light region. And a solid-state imaging device.
- the filter region is formed with an intermediate layer located at the center in the thickness direction. It is composed of a dielectric laminated film formed on each of the light incident side and the light emitting side of the intermediate layer, and the dielectric laminated film includes a first dielectric layer made of a dielectric material and the first dielectric.
- It has a structure in which second dielectric layers made of a dielectric material having a higher refractive index than the layers are alternately laminated, and the thickness of the intermediate layer differs for each filter region, and at least the dielectric laminated film on the light emitting side is ,
- the first dielectric layer and the second dielectric layer are continuously formed over the entire area without being separated for each filter region.
- the dielectric laminated film on the light incident side is also formed continuously over the entire area without the first dielectric layer and the second dielectric layer being separated for each filter region. You may be.
- an infrared light cut filter region that attenuates infrared light and selectively transmits only visible light and a near-infrared light of a specific wavelength that attenuates visible light and selectively transmits the visible light are transmitted.
- a bandpass filter area can also be provided. In that case, two or more bandpass filter regions having different wavelengths of near-infrared light to be selectively transmitted may be provided.
- the intermediate layer in the optical filter of the present invention can be formed of the same dielectric material as the first dielectric layer or the second dielectric layer.
- the optical filter of the present invention may be provided with an antireflection film on the outermost layer on the light emitting side. In that case, the outermost layer on the light incident side may be provided with a low refractive index dielectric layer made of a dielectric material having a lower refractive index than the second dielectric layer.
- a first dielectric layer made of a dielectric material and a second dielectric layer made of a dielectric material having a higher refractive index than the first dielectric layer are formed on the entire surface of the substrate.
- the optical sensor according to the present invention includes the above-mentioned optical filter.
- the solid-state image sensor according to the present invention includes the above-mentioned optical filter.
- the solid-state image sensor may be provided with a color filter that transmits only visible light having a specific wavelength on the light incident side or the light emitting side of the optical filter.
- a plurality of optical filters having different optical characteristics can be integrally formed, and light of a specific wavelength can be detected individually and simultaneously from at least the visible light region to the infrared light region.
- An optical sensor and a solid-state image sensor can be realized.
- FIG. 5 is a cross-sectional view taken along the line aa shown in FIG. It is sectional drawing which shows the other structural example of the optical filter of 1st Embodiment of this invention.
- a to F are schematic cross-sectional views showing the manufacturing method of the optical filter shown in FIG. 3 in the order of the steps. It is sectional drawing which shows the structural example of the optical sensor of the 2nd Embodiment of this invention.
- a to C are plan views showing an example of pixel arrangement of the optical sensor shown in FIG.
- A is a plan view showing a pixel arrangement example of the solid-state image sensor according to the third embodiment of the present invention
- B is a plan view showing a configuration example of an optical filter.
- It is a cross-sectional view which shows the schematic structure of the solid-state image sensor of the 3rd Embodiment of this invention, A is a cross section by line bb shown in FIG. 7A, and B is a cross section by line cc shown in FIG. 7A.
- A is a plan view showing an example of pixel arrangement of the solid-state image sensor according to the fourth embodiment of the present invention
- B is a plan view showing the configuration of an optical filter.
- a and B are cross-sectional views showing a schematic configuration of a solid-state image sensor according to a fourth embodiment of the present invention
- A is a cross-sectional view taken along the line dd shown in FIG. 9A
- B is an e-e shown in FIG. 9A. It is a cross section by a line.
- FIG. 1 is a plan view
- FIG. 2 is a cross-sectional view taken along the line aa shown in FIG.
- a first bandpass filter region 11 that selectively transmits only light of a specific wavelength and attenuates light of other wavelengths to suppress transmission, and a first bandpass.
- Second bandpass filter regions 12 that selectively transmit light having a wavelength different from that of the filter regions 11 are alternately formed.
- the arrangement and area of the first bandpass filter area 11 and the second bandpass filter area 12 are not limited to the configuration shown in FIG. 1, and the number of either one may be increased or the area may be increased. Or it can be arranged in a biased manner. Further, the number of bandpass filter regions is not limited to two, and other bandpass filter regions having different transmission wavelengths or attenuation wavelengths may be provided.
- the first bandpass filter region 11 and the second bandpass filter region 12 are formed on the intermediate layer 13 and the dielectric laminated films 14 formed on both sides (light incident side and light emitting side) of the intermediate layer 13. It is composed of 15.
- the first dielectric layer 10L made of a dielectric material and the second dielectric layer 10H made of a dielectric material having a refractive index higher than that of the first dielectric layer 10L are alternately laminated. It has a structure.
- the thickness of the intermediate layer 13 is different between the first bandpass filter region 11 and the second bandpass filter region 12, but the thickness of the other layers, that is, the first dielectric having a low refractive index.
- the thickness of the body layer 10L and the thickness of the second dielectric layer 10H having a high refractive index are common to the bandpass filter regions 11 and 12.
- At least the first dielectric layer 10L and the second dielectric layer 10H are integrally formed over the entire optical filter, and are integrally formed with the first bandpass filter region 11 and the second bandpass filter region 12. No light-shielding wall is provided at the boundary, and it is not physically or optically separated.
- the thicknesses of the first dielectric layer 10L, the second dielectric layer 10H, and the intermediate layer 13 are not particularly limited, and depend on the performance required for the bandpass filter and the wavelength of transmitted light or attenuated light. Can be set as appropriate.
- the reference wavelength is ⁇ 0
- the refractive index of the dielectric material forming the first dielectric layer 10L is n L
- the refractive index of the dielectric material forming the second dielectric layer 10H is n H
- the first band The thickness of the first dielectric layer 10L in the pass filter region 11 and the second band pass filter region 12 is ⁇ 0 / (4 ⁇ n L )
- the thickness of the second dielectric layer 10H is ⁇ 0 / (4). ⁇ n H ).
- the reference wavelength ⁇ 0 is the central wavelength of the light to be selectively transmitted in the bandpass filter regions 11 and 12.
- the thickness of the intermediate layer 13 is, for example, 0.15 ⁇ ⁇ 0 in the first bandpass filter region 11. / (4 ⁇ n L ), and the second bandpass filter region 12 is 0.29 ⁇ ⁇ 0 / (4 ⁇ n L ).
- the intermediate layer 13 is made of a high-dielectric material, the thickness thereof is, for example, 1.74 ⁇ ⁇ 0 / (4 ⁇ n H ) in the first bandpass filter region 11 and the second band.
- the path filter region 12 is 2.21 ⁇ ⁇ 0 / (4 ⁇ n H ).
- the thickness of the intermediate layer 13 may be 0 depending on the wavelength of the light to be selectively transmitted.
- the number of layers of the first dielectric layer 10L and the second dielectric layer 10H is also not particularly limited, but the second dielectric layer 10H having a high refractive index is three or more layers, and a total of five or more layers are laminated. It is preferable, more preferably 5 layers or more of each layer, and further preferably 10 or more layers of each layer. As a result, the frequency characteristics of the bandpass filter regions 11 and 12 can be made steep.
- the first dielectric layer 10L having a low refractive index can be formed of, for example, silicon dioxide (SiO 2 ), and the second dielectric layer 10H having a higher refractive index can be formed of, for example, titanium oxide (SiO 2). It can be formed of TiO 2 ), niobium pentoxide (Nb 2 O 5 ), silicon nitride (Si 3 N 4 ), single crystal silicon, polycrystalline silicon and the like.
- the intermediate layer 13 includes a high refractive index polymer material such as polyimide and a light transmissive polymer having a low refractive index, in addition to the inorganic dielectric material used in the first dielectric layer 10L or the second dielectric layer 10H described above. It can be formed from a material. Note that FIG. 2 shows an example formed of the same material as the first dielectric layer 10L.
- the wavelength of the light selectively transmitted in the first bandpass filter region 11 and the second bandpass filter 12 can be arbitrarily set in the range from the visible light region to the infrared light region, for example.
- the first bandpass filter region 11 is an "infrared cut filter” that cuts infrared light and transmits only visible light
- the second bandpass filter region 12 is specified by cutting visible light. It is also possible to have a configuration in which only the near-infrared light of the above is transmitted.
- the light separated by the optical filter of the present embodiment is not limited to visible light and infrared light, and terahertz waves, microwaves, and millimeter waves can also be targeted.
- FIG. 3 is a cross-sectional view showing a configuration example of another optical filter of the present embodiment
- FIGS. 4A to 4F are schematic cross-sectional views showing the manufacturing method of the optical filter shown in FIG. 3 in the order of the steps.
- the first dielectric layer 10L and the second dielectric layer 10H are alternately laminated on the entire surface of the pixel, and the dielectric laminated film on the light emitting side is laminated. 14 is formed.
- the same material as the first dielectric layer 10L or the second dielectric layer 10H or an organic or inorganic dielectric material different from the dielectric layers 10L and 10H is placed on the dielectric laminated film 14.
- the first intermediate layer 13a is formed.
- the first intermediate layer 13a formed in the region directly above the pixel 3 is removed by patterning.
- a second intermediate layer 13b for the pixel 3 is formed as a whole with the same dielectric material as the first intermediate layer 13a, and then as shown in FIG. 4E, on the first intermediate layer 13a.
- the second intermediate layer 13b formed in the above is removed by patterning. After that, the first dielectric layer 10L and the second dielectric layer 10H are alternately laminated on the first intermediate layer 13a and the second intermediate layer 13b to form the dielectric laminated film 15 on the light incident side.
- the optical filter of the present embodiment uses the principle of the Fabry-Perot interferometer, and since the dielectric laminated films formed on both sides of the intermediate layer function as semi-transmissive films, it is selected by changing the thickness of the intermediate layer. The wavelength of the light to be transmitted can be changed. Further, since the optical filter of the present embodiment can integrally form a plurality of filter regions having different optical characteristics, light of a specific wavelength can be detected individually and simultaneously from at least the visible light region to the infrared light region. It becomes possible to do.
- the layers other than the intermediate layer are common and integrally formed between the bandpass filter regions, so that the etching and patterning steps are significantly larger than those of the conventional interference film filter. It can be reduced to and the manufacturing process can be simplified.
- the conventional optical filter attenuates light by all layers, the wavelength of selective transmission is determined by the thickness of the entire filter, but in the optical filter of the present embodiment, the wavelength of selective transmission is determined by the intermediate layer. Since the thickness of the intermediate layer is about 1/100 of the total thickness of the conventional optical filter, as shown in Table 1 below, the incident angle is higher than that of the conventional color filter using an organic material. The dependence is low, and the color mixing ratio can be suppressed to about 1% even for light having an incident angle of 25 °.
- the optical filter of the present invention may have a structure in which dielectric laminated films 14 and 15 are formed on at least both sides of the intermediate layer 13 shown in FIG. 2, and is on the light incident side surface and / or the light emitting side. Other layers may be laminated on the surface.
- an antireflection film is provided on the light emitting side.
- the antireflection film can be formed of, for example, a material having a refractive index in the range of 1.5 to 2.5, preferably 1.9 to 2.1, and specifically, SiN, C, SiON, Ni or It can be formed of silver chloride or the like.
- the material for forming the antireflection film is not limited to these, and may be formed of other materials as long as the refractive index is within the above-mentioned range.
- the thickness of the antireflection film can be arbitrarily set in the range of 5 to 1000 nm, but is preferably ⁇ 0 / (4 ⁇ n R).
- ⁇ 0 is a reference wavelength
- n R is the refractive index of the dielectric material forming the antireflection film.
- the optical filter of this modification is provided with an antireflection film on the outermost layer on the light emitting side, the transmission wavelength intensity disturbance due to the reflection of light in each wavelength range is suppressed, and the variation in spectral characteristics is reduced.
- the transmission characteristics can be sharpened. As a result, it is possible to suppress the occurrence of a phenomenon called spectral ripple in which the sensitivity of light fluctuates up and down.
- the configurations and effects other than the above in this modification are the same as those in the first embodiment described above.
- the optical filter according to the second modification of the first embodiment of the present invention has a low refractive index dielectric material on the light emitting side surface of the dielectric laminated film 14 and / or the light incident side surface of the dielectric laminated film 15.
- a refractive index dielectric layer is laminated, and an antireflection film is laminated on the outermost layer on the light emitting side. That is, when the low refractive index dielectric layer is laminated on the light emitting side surface of the dielectric laminated film 14, the antireflection film is further laminated on the light emitting side surface, and the low refractive index dielectric layer is laminated. If not, an antireflection film is laminated on the light emitting side surface of the dielectric laminated film 14.
- This low refractive index dielectric layer can be formed of, for example, the same material as the above-mentioned dielectric layer 10L.
- the thickness of the low refractive index dielectric layer provided on the light emitting side surface of the dielectric laminated film 14 may be 100 nm or more, and the thickness of the low refractive index dielectric layer provided on the light incident side surface of the dielectric laminated film 15. Is, for example, 0.5 ⁇ ⁇ 0 / (4 ⁇ n L ).
- ⁇ 0 is a reference wavelength
- n L is the refractive index of the dielectric material forming the low refractive index dielectric layer.
- the refractive index, material, thickness, etc. of the antireflection film are the same as those of the first modification described above.
- an antireflection film is provided on the outermost layer on the light emitting side, and a low refractive index dielectric is provided between the outermost layer on the light incident side and / or the dielectric laminated film on the light emitting side. Since the layer is provided, the transmission characteristics can be significantly improved especially in the visible light region.
- the configurations and effects other than the above in this modification are the same as those in the first embodiment described above.
- the optical sensor of the present embodiment includes the optical filter of the first embodiment described above, and simultaneously detects two or more lights having different wavelengths.
- FIG. 5 is a cross-sectional view showing a configuration example of the optical sensor of the present embodiment
- FIGS. 6A to 6C are plan views showing a pixel arrangement example of the optical sensor shown in FIG.
- the optical sensor 1 of the present embodiment has two types of pixels (first near-infrared pixel IR1, second near-red) that detect near-infrared light having different wavelengths from each other. It is provided with an outer pixel IR2).
- an optical filter 10 is provided on the photoelectric conversion layer 20.
- the optical filter 10 has a first band path that attenuates visible light and near-infrared light that is not to be detected at a position corresponding to the first near-infrared pixel IR1 and transmits only the near-infrared light that is to be detected.
- a second filter region 11 is provided, and visible light and near-infrared light not to be detected are attenuated at a position corresponding to the second near-infrared pixel IR2, and only the near-infrared light to be detected is transmitted.
- a band path filter region 12 is provided.
- an on-chip lens 30 is provided for each pixel on the bandpass filter regions 11 and 12 of the optical filter 10.
- the photoelectric conversion layer 20 detects the incident light as an electric signal, and has a configuration in which a plurality of photoelectric conversion portions are formed on a semiconductor substrate such as silicon or germanium or an organic photoelectric conversion film.
- the structure of the photoelectric conversion layer 20 is not particularly limited, and a CCD (Charge Coupled Device) structure, a CMOS (Complementary Metal Oxide Semiconductor) structure, or the like can be adopted.
- the pixel arrangement in the optical sensor 1 of the present embodiment is not particularly limited, but for example, as shown in FIG. 6A, the first near-infrared pixel IR1 and the second near-infrared pixel IR2 are alternately arranged in a grid pattern. Can be placed in.
- the near-infrared light detection region 71 composed of the plurality of first near-infrared pixels IR1 and the near-infrared light detection region 72 composed of the plurality of second near-infrared pixels IR2 are arranged in a grid pattern (FIG. 6B) or. It may be arranged in a strip shape (FIG. 6C).
- the optical sensor 1 of the present embodiment is not limited to the one that detects two types of near-infrared light, and may detect visible light and near-infrared light, and has different wavelengths 3 It can also detect more than a species of light. Further, the wavelength region of the optical sensor 1 of the present embodiment is not limited to near-infrared light, but includes all wavelength regions corresponding to the signal region converted by the photoelectric conversion layer 20, and includes wavelength spectroscopy thereof.
- the optical sensor of this embodiment uses an optical filter in which a plurality of filter regions having different optical characteristics are integrated, two or more types of light can be detected simultaneously and individually, and measurement can be performed in a short time. , It is possible to acquire multiple pieces of information. As a result, the optical sensor of the present embodiment is expected to be applied not only to the sensing field but also to various applications such as the medical field and the security field.
- the solid-state image sensor of the present embodiment includes the optical filter of the first embodiment described above, and simultaneously and individually detects one or two or more visible lights and one or two or more near-infrared lights. ..
- FIG. 7A is a plan view showing an example of pixel arrangement of the solid-state image sensor of the present embodiment
- FIG. 7B is a plan view showing a configuration example of an optical filter.
- 8A and 8B are cross-sectional views showing a schematic configuration of the solid-state image sensor of the present embodiment
- FIG. 8A is a cross-sectional view taken along the line bb shown in FIG. 7A
- FIG. 8B is taken along the line cc shown in FIG. 7A. It is a cross section.
- the solid-state image sensor 2 of the present embodiment includes a visible light detection region composed of pixels R, G, and B for detecting visible light, and pixels IR1 and IR2 for detecting near-infrared light.
- a near-infrared light detection region composed of IR3 is provided.
- the solid-state imaging device 2 has an infrared light cut filter region that transmits visible light and attenuates infrared light on a photoelectric conversion layer 21 that detects incident light as an electric signal. 44.
- An optical filter 40 having three types of bandpass filter regions 41, 42, and 43 that selectively transmit near-infrared light of a specific wavelength, and selectively transmit red light R, blue light B, and green light R.
- Three types of color filters 50 and an on-chip lens 30 are provided.
- the visible light detection region In the visible light detection region, three types of pixels having different detection wavelengths are provided.
- the three types of pixels provided in the visible light detection region are defined as "first visible light pixel”, “second visible light pixel”, and “third visible light pixel”, for example, the first visible light pixel is red light. R can be detected, green light G can be detected by the second visible light pixel, and blue light B can be detected by the third visible light pixel.
- the infrared light cut filter region 44 of the optical filter 40 is formed at a position corresponding to the first to third visible light pixels, and further, visible light other than the red light R is formed on the infrared light cut filter region 44.
- a red light filter 51 that reflects and / or absorbs visible light, a green light filter 53 that reflects and / or absorbs visible light other than green light G, and a blue light filter that reflects and / or absorbs visible light other than blue light B. 52 may be provided, and the on-chip lens 30 may be provided on the 52.
- the position of the on-chip lens 30 differs between the visible light detection region and the near-infrared light detection region depending on the presence or absence of the color filters 51 to 53.
- This can be solved by providing a flattening layer after forming the color filter 50 and forming an on-chip lens 30 on the flattening layer.
- the transmission wavelengths of the color filters 51 to 53 provided on the photoelectric conversion layer 11 are not limited to the red light R, the green light G, and the blue light B described above, and are not limited to the specifications of the solid-state image sensor 2 and the like. It can be appropriately selected accordingly.
- the material forming each of the color filters 51 to 53 is not particularly limited, and a known material can be used.
- the near-infrared light detection region is also provided with three types of pixels having different detection wavelengths.
- first near-infrared pixel IR1 “second near-infrared pixel IR2” and “third near-infrared pixel IR3”, for example.
- the first near-infrared pixel IR1 detects light of an arbitrary wavelength in the range of 700 to 830 nm
- the second near-infrared pixel IR2 detects light of an arbitrary wavelength in the range of 830 to 880 nm
- the outer pixel IR3 can be configured to detect light of an arbitrary wavelength in the range of 880 to 1200 nm.
- the bandpass filter region 41 is located at a position corresponding to the first near-infrared pixel IR1 and the bandpass filter region 42 is located at a position corresponding to the second near-infrared pixel IR2.
- An optical filter 40 in which a bandpass filter region 43 is formed at a position corresponding to the near-infrared pixel IR3 may be used.
- the bandpass filter region 41 of the optical filter 40 selectively transmits the light to be detected in the range of 700 to 830 nm
- the bandpass filter region 42 selectively transmits the light to be detected in the range of 830 to 880 nm. It is transmitted, and the bandpass filter region 43 selectively transmits the light to be detected in the range of 880 to 1200 nm.
- an on-chip lens 30 is provided for each pixel on the optical filter 40 or on the flattening layer formed on the optical filter 40.
- the color filter 50 is provided on the optical filter 40, but the optical filter 40 may be provided on the color filter 50 by turning it upside down. As a result, it is possible to suppress color mixing in which light from an oblique direction is incident on other pixels.
- the solid-state image sensor 2 of the present embodiment detects visible light in each pixel of the visible light detection region and detects near-infrared light in each pixel of the near-infrared light detection region. Specifically, visible light (R, G, B) in a specific wavelength band transmitted through the color filters 51 to 53 arranged on the photoelectric conversion layer 21 in the visible light detection region is incident on the photoelectric conversion layer 21. Then, an electric signal corresponding to the intensity of visible light (R, G, B) in the wavelength band transmitted through the color filters 51 to 53 is output from the photoelectric conversion layer 21. Thereby, for example, a color image derived from visible light can be obtained.
- the photoelectric conversion layer 21 in the near-infrared light detection region near-infrared light in a specific wavelength band transmitted through the first to third bandpass filter regions 41 to 43 of the optical filter 40 arranged on the photoelectric conversion layer 21 is transmitted. Incident. Then, an electric signal corresponding to the intensity of near-infrared light in the wavelength band transmitted through the first to third bandpass filter regions 41 to 43 is output from the photoelectric conversion layer 21.
- the solid-state image sensor of the present embodiment does not always need to detect and image using all six types of pixels, and detects only in either the visible light detection region or the near-infrared light detection region.
- detection / imaging may be performed using one or two of the three types of pixels. For example, in the daytime, only each pixel in the visible light detection region is operated or only the signal from each photoelectric conversion unit in the visible light detection region is used to detect visible light, and in the nighttime, each of the near infrared light detection regions is detected. It is also possible to detect near-infrared light by operating only the pixels or by using only the signals from each photoelectric conversion unit in the near-infrared light detection region.
- the signals of the near-infrared light detected in the near-infrared light detection region are used to correct the red light R, green light G, and blue light B signals detected in the visible light detection region.
- the influence of the near-infrared light component can be removed.
- the signals of the near-infrared light IR1, IR2, and IR3 detected in the near-infrared detection region 3 are used by using the red light R, green light G, and blue light B signals detected in the visible light detection region. Can be corrected to eliminate the influence of visible light components contained in ambient light such as headlights. As a result, the detection accuracy of visible light and near-infrared light is improved, and the color reproducibility in color photography can be improved.
- a near-infrared light cut filter and a plurality of bandpass filters that selectively transmit light of a specific wavelength are integrally formed with continuity. It is possible to simultaneously and individually detect a wide range of light from visible light to infrared light and capture an unprecedented image. Further, since the solid-state image sensor of the present embodiment detects with different pixels for each wavelength, the design of each pixel is easy and the film configuration can be simplified, so that it can be manufactured more easily than the conventional product. It will be possible.
- the configuration of the solid-state image sensor of the present embodiment can be applied to both the back-illuminated type and the front-illuminated type, but the back-illuminated type, which is less affected by the reflected light, is preferable.
- the configurations and effects of the solid-state image sensor of the present embodiment other than the above are the same as those of the optical sensor of the second embodiment described above.
- the solid-state image sensor of the present embodiment includes the optical filter of the first embodiment described above, and detects both visible light and near-infrared light in some pixels.
- FIG. 9A is a plan view showing an example of pixel arrangement of the solid-state image sensor of the present embodiment
- FIG. 9B is a plan view showing the configuration of an optical filter.
- 10A and 10B are cross-sectional views showing a schematic configuration of the solid-state image sensor of the present embodiment
- FIG. 10A is a cross-sectional view taken along the line dd shown in FIG. 9A
- FIG. 10B is an e-e shown in FIG. 9A. It is a cross section by a line.
- the solid-state image sensor 3 of the present embodiment is provided with pixels for detecting visible light and near-infrared light in addition to pixels R, G, and B for detecting only visible light. ..
- the solid-state imaging device 3 has a band path that transmits visible light of a specific wavelength and near-infrared light of a specific wavelength on a photoelectric conversion layer 21 that detects incident light as an electric signal.
- An optical filter 60 provided with filter regions 61, 62, 63 and an infrared light cut filter region that attenuates near-infrared light and transmits only visible light, and a color filter 50 that transmits only visible light of a specific wavelength are provided.
- an on-chip lens 30 is provided for each pixel.
- the positions of the optical filter 60 and the color filter 50 may be opposite to each other, and the optical filter 60 may be formed on the color filter 50.
- the color information of visible light is mainly used in an environment where the amount of visible light is small.
- the signal-to-noise ratio S / N ratio
- visible light is detected as in the conventional case. It is not necessary to take the image by the image and the image by the near-infrared light separately, and it is possible to obtain the image by the visible light and one or more near-infrared light by one imaging.
- both near-infrared light and visible light can be used by using invisible near-infrared illumination even in a dark environment where there is little visible light such as at night.
- a clear image can be obtained by using.
- near-infrared light information can be determined from the image by multi-spectroscopy using near-infrared light on the color image by visible light.
- Optical sensor 2 3 Solid-state image sensor 10, 40, 60 Optical filter 10L 1st dielectric layer (low refractive index layer) 10H second dielectric layer (high refractive index layer) 11, 12, 41 to 43, 61 to 63 Bandpass filter area 13, 13a, 13b Intermediate layer 14, 15 Dielectric laminated film 20 to 22 Photoconverted layer 30 Lens 44, 64 Infrared light cut filter area 50 to 53 Color Filter 71, 72 Near infrared light detection region
Abstract
Description
本発明の光学フィルタは、前記光入射側の誘電体積層膜も、前記第1誘電体層及び前記第2誘電体層がフィルタ領域毎に分離されることなく全域に亘って連続して形成されていてもよい。
また、前記フィルタ領域として、赤外光を減衰させて可視光のみを選択的に透過させる赤外光カットフィルタ領域と、可視光を減衰させて特定波長の近赤外光を選択的に透過させるバンドパスフィルタ領域を設けることもできる。
その場合、選択的に透過させる近赤外光の波長が異なる2以上のバンドパスフィルタ領域が設けられていてもよい。
本発明の光学フィルタにおける前記中間層は、前記第1誘電体層又は第2誘電体層と同じ誘電材料で形成することができる。
また、本発明の光学フィルタは、光出射側最外層に反射防止膜が設けられていてもよい。
その場合、光入射側最外層には前記第2誘電体層よりも低屈折率の誘電材料からなる低屈折率誘電体層が設けられていてもよい。
この固体撮像素子は、前記光学フィルタの光入射側又は光出射側に特定波長の可視光のみ透過するカラーフィルタが設けられていてもよい。
先ず、本発明の第1の実施形態に係る光学フィルタについて説明する。本実施形態の光学フィルタは、相互に異なる波長の光を選択的に透過する2以上のバンドパスフィルタ領域が、同一面上に一体的に形成されている。図1及び図2は本実施形態の光学フィルタの構成例を示す図であり、図1は平面図、図2は図1に示すa-a線による断面図である。
次に、本実施形態の光学フィルタの製造方法について、3種類の画素に対応し、透過波長が異なる3つのバンドパスフィルタ領域を備える光学フィルタを製造する場合を例に説明する。図3は本実施形態の他の光学フィルタの構成例を示す断面図であり、図4A~Fは図3に示す光学フィルタの製造方法をその工程順に示す模式的断面図である。
本発明の光学フィルタは、少なくとも図2に示す中間層13の両側に誘電体積層膜14,15が形成された構造を有していればよく、光入射側の面及び/又は光出射側の面にその他の層が積層されていてもよい。例えば、本発明の第1の実施形態の第1変形例に係る光学フィルタでは、光出射側に反射防止膜が設けられている。
本発明の第1の実施形態の第2変形例に係る光学フィルタは、誘電体積層膜14の光出射側面及び/又は誘電体積層膜15の光入射側面に、低屈折率誘電材料からなる低屈折率誘電体層が積層されており、光出射側最外層に反射防止膜が積層されている。即ち、誘電体積層膜14の光出射側面に低屈折率誘電体層が積層されている場合は、更にその光出射側面に反射防止膜が積層されており、低屈折率誘電体層が積層されていない場合は、誘電体積層膜14の光出射側面に反射防止膜が積層されている。
次に、本発明の第2の実施形態に係る光センサについて説明する。本実施形態の光センサは、前述した第1の実施形態の光学フィルタを備えるものであり、波長が異なる2以上の光を同時に検出する。図5は本実施形態の光センサの構成例を示す断面図であり、図6A~Cは図5に示す光センサの画素配置例を示す平面図である。図5及び図6A~Cに示すように、本実施形態の光センサ1は、相互に異なる波長の近赤外光を検出する2種類の画素(第1近赤外画素IR1,第2近赤外画素IR2)を備える。
次に、本発明の第3の実施形態に係る固体撮像素子について説明する。本実施形態の固体撮像素子は、前述した第1の実施形態の光学フィルタを備え、1又は2以上の可視光と1又は2以上の近赤外光を、同時かつ個別に検出するものである。図7Aは本実施形態の固体撮像素子の画素配置例を示す平面図であり、図7Bは光学フィルタの構成例を示す平面図である。また、図8は本実施形態の固体撮像素子の概略構成を示す断面図であり、図8Aは図7Aに示すb-b線による断面であり、図8Bは図7Aに示すc-c線による断面である。
可視光検出領域には、検出波長が異なる3種類の画素が設けられている。可視光検出領域に設けられた3種の画素をそれぞれ「第1可視光画素」、「第2可視光画素」及び「第3可視光画素」とした場合、例えば第1可視光画素で赤色光Rを検出し、第2可視光画素で緑色光Gを検出し、第3可視光画素で青色光Bを検出する構成とすることができる
近赤外光検出領域にも、検出波長が異なる3種類の画素が設けられている。近赤外光検出領域に設けられた3種の画素をそれぞれ「第1近赤外画素IR1」、「第2近赤外画素IR2」及び「第3近赤外画素IR3」とした場合、例えば第1近赤外画素IR1では700~830nmの範囲で任意の波長の光を検出し、第2近赤外画素IR2では830~880nmの範囲で任意の波長の光を検出し、第3近赤外画素IR3では880~1200nmの範囲で任意の波長の光を検出する構成とすることができる。
次に、本実施形態の固体撮像素子2の動作について説明する。本実施形態の固体撮像素子2は、可視光検出領域の各画素で可視光を検出し、近赤外光検出領域の各画素で近赤外光を検出する。具体的には、可視光検出領域の光電変換層21には、その上に配置されたカラーフィルタ51~53を透過した特定波長帯域の可視光(R,G,B)が入射する。そして、光電変換層21からは、カラーフィルタ51~53を透過した波長帯域の可視光(R,G,B)の強度に対応する電気信号が出力される。これにより、例えば可視光に由来するカラー画像を得ることができる。
次に、本発明の第4の実施形態に係る固体撮像素子について説明する。本実施形態の固体撮像素子は、前述した第1の実施形態の光学フィルタを備え、一部の画素で可視光と近赤外光の両方を検出する。図9Aは本実施形態の固体撮像素子の画素配置例を示す平面図であり、図9Bは光学フィルタの構成を示す平面図である。また、図10A,Bは本実施形態の固体撮像素子の概略構成を示す断面図であり、図10Aは図9Aに示すd-d線による断面であり、図10Bは図9Aに示すe-e線による断面である。
2、3 固体撮像素子
10、40、60 光学フィルタ
10L 第1誘電体層(低屈折率層)
10H 第2誘電体層(高屈折率層)
11、12、41~43、61~63 バンドパスフィルタ領域
13、13a、13b 中間層
14、15 誘電体積層膜
20~22 光電変換層
30 レンズ
44、64 赤外光カットフィルタ領域
50~53 カラーフィルタ
71、72 近赤外光検出領域
Claims (11)
- 相互に異なる波長の光を選択的に透過する2以上のフィルタ領域が同一面上に形成されており、
前記フィルタ領域は、厚さ方向中央に位置する中間層と、前記中間層の光入射側及び光出射側にそれぞれ形成された誘電体積層膜により構成されており、
前記誘電体積層膜は、誘電材料からなる第1誘電体層と、前記第1誘電体層よりも屈折率が高い誘電材料からなる第2誘電体層が交互に積層された構造であり、
前記中間層の厚さはフィルタ領域毎に異なり、
少なくとも前記光出射側の誘電体積層膜は、前記第1誘電体層及び前記第2誘電体層がフィルタ領域毎に分離されることなく全域に亘って連続して形成されている光学フィルタ。 - 前記光入射側の誘電体積層膜も、前記第1誘電体層及び前記第2誘電体層がフィルタ領域毎に分離されることなく全域に亘って連続して形成されている請求項1に記載の光学フィルタ。
- 前記フィルタ領域として、
赤外光を減衰させて可視光のみを選択的に透過させる赤外光カットフィルタ領域と、
可視光を減衰させて特定波長の近赤外光を選択的に透過させるバンドパスフィルタ領域が設けられている請求項1又は2に記載の光学フィルタ。 - 選択的に透過する近赤外光の波長が異なる2以上のバンドパスフィルタ領域が設けられている請求項3に記載の光学フィルタ。
- 前記中間層は、前記第1誘電体層又は第2誘電体層と同じ誘電材料で形成されている請求項1~4のいずれか1項に記載の光学フィルタ。
- 光出射側最外層に反射防止膜が設けられている請求項1~5のいずれか1項に記載の光学フィルタ。
- 更に、光入射側最外層に前記第2誘電体層よりも低屈折率の誘電材料からなる低屈折率誘電体層が設けられている請求項6に記載の光学フィルタ。
- 基板の全面に、誘電材料からなる第1誘電体層と、前記第1誘電体層よりも高屈折率の誘電材料からなる第2誘電体層とを交互に積層して誘電体積層膜を形成する工程と、
前記誘電体積層膜上に、前記第1誘電体層と同じ誘電材料又は前記第2誘電体層と同じ誘電材料で第1中間層を形成する工程と、
任意の画素の直上域の前記中間層を除去する工程と、
前記第1中間層と同じ誘電材料第2中間層を形成した後、前記第1中間層上に形成された第2中間層を除去する工程と、
前記第1中間層及び第2中間層上に、前記第1誘電体層及び前記第2誘電体層を交互に積層して、誘電体積層膜を形成する工程を有する光学フィルタの製造方法。 - 請求項1~7のいずれか1項に記載の光学フィルタを備える光センサ。
- 請求項1~7のいずれか1項に記載の光学フィルタを備える固体撮像素子。
- 前記光学フィルタの光入射側又は光出射側に特定波長の可視光のみ透過するカラーフィルタが設けられている請求項10に記載の固体撮像素子。
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2022500401A JPWO2021161961A1 (ja) | 2020-02-10 | 2021-02-08 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2020-021034 | 2020-02-10 | ||
JP2020021034 | 2020-02-10 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2021161961A1 true WO2021161961A1 (ja) | 2021-08-19 |
Family
ID=77292288
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2021/004600 WO2021161961A1 (ja) | 2020-02-10 | 2021-02-08 | 光学フィルタ及びその製造方法、光センサ並びに固体撮像素子 |
Country Status (2)
Country | Link |
---|---|
JP (1) | JPWO2021161961A1 (ja) |
WO (1) | WO2021161961A1 (ja) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2023095827A1 (ja) * | 2021-11-25 | 2023-06-01 | 三菱ケミカル株式会社 | 構造体及び固体撮像素子 |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2005069376A1 (ja) * | 2004-01-15 | 2005-07-28 | Matsushita Electric Industrial Co.,Ltd. | 固体撮像装置、固体撮像装置の製造方法及びこれを用いたカメラ |
WO2018155486A1 (ja) * | 2017-02-21 | 2018-08-30 | 株式会社ナノルクス | 固体撮像素子及び撮像装置 |
-
2021
- 2021-02-08 JP JP2022500401A patent/JPWO2021161961A1/ja active Pending
- 2021-02-08 WO PCT/JP2021/004600 patent/WO2021161961A1/ja active Application Filing
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2005069376A1 (ja) * | 2004-01-15 | 2005-07-28 | Matsushita Electric Industrial Co.,Ltd. | 固体撮像装置、固体撮像装置の製造方法及びこれを用いたカメラ |
WO2018155486A1 (ja) * | 2017-02-21 | 2018-08-30 | 株式会社ナノルクス | 固体撮像素子及び撮像装置 |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2023095827A1 (ja) * | 2021-11-25 | 2023-06-01 | 三菱ケミカル株式会社 | 構造体及び固体撮像素子 |
Also Published As
Publication number | Publication date |
---|---|
JPWO2021161961A1 (ja) | 2021-08-19 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP6448842B2 (ja) | 固体撮像素子及び撮像装置 | |
US7531781B2 (en) | Imager with image-taking portions optimized to detect separated wavelength components | |
JP7281681B2 (ja) | 撮像システム | |
JP4899008B2 (ja) | 改良型カラーフォトディテクタアレイ及びその製造方法 | |
TWI770168B (zh) | 誘發透射濾光片 | |
US7858921B2 (en) | Guided-mode-resonance transmission color filters for color generation in CMOS image sensors | |
US8227883B2 (en) | Solid-state imaging device and camera | |
US8134191B2 (en) | Solid-state imaging device, signal processing method, and camera | |
JP2007501391A5 (ja) | ||
EP3112828B1 (en) | Integrated circuit and method for manufacturing integrated circuit | |
WO2018150801A1 (ja) | センサ、固体撮像装置及び電子装置 | |
WO2008085385A2 (en) | Plasmonic fabry-perot filter | |
KR20110003696A (ko) | 단일 칩 입체 영상 센서용 광학 필터 배열 및 그 필터 제조 방법 | |
US20180084167A1 (en) | Stacked-filter image-sensor spectrometer and associated stacked-filter pixels | |
US20130181113A1 (en) | Solid-state imaging equipment | |
WO2016158128A1 (ja) | 光検出装置および撮像装置 | |
WO2021161961A1 (ja) | 光学フィルタ及びその製造方法、光センサ並びに固体撮像素子 | |
JP2000180621A (ja) | オンチップカラーフィルタ及びこれを用いた固体撮像素子 | |
JP2008244246A (ja) | 固体撮像装置、カメラ、車両及び監視装置 | |
CN109429025B (zh) | 图像传感器和成像装置 | |
WO2007094092A1 (ja) | 固体撮像装置及びカメラ | |
JP2005266811A (ja) | カラーフィルタ及びその製造方法 | |
US20230280498A1 (en) | Plasmonic metasurface light filter and Imaging Sensor including light filter | |
US10425597B2 (en) | Combined visible and infrared image sensor incorporating selective infrared optical filter | |
WO2015056584A1 (ja) | 光電変換装置 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 21754239 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2022500401 Country of ref document: JP Kind code of ref document: A |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
32PN | Ep: public notification in the ep bulletin as address of the adressee cannot be established |
Free format text: NOTING OF LOSS OF RIGHTS PURSUANT TO RULE 112(1) EPC (EPO FORM 1205A DATED 29.11.2022) |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 21754239 Country of ref document: EP Kind code of ref document: A1 |