JP2008177362A - Solid-state imaging apparatus and camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid-state imaging apparatus with a color filter, capable of reducing the influence of interference due to planarizing films or barrier films when a multilayer film interference filter is used as the color filter, and suppressing the dispersion of a spectroscopic characteristic due to variation in the film thickness of the planarizing films. <P>SOLUTION: In the solid-state imaging apparatus 101, unit pixels (1a, 1b, 1c) are two-dimensionally arrayed, respectively including: the color filters 29 for transmitting the prescribed color of light in incident light 35; the planarizing films 28, 30; and the barrier films 26, 32. The color filter 29 is constituted of a λ/4 film composed of a high refractive index material and a low refractive index material. The optical film thickness of the barrier films 26, 32 is substantially equal to λ/2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a solid-state imaging device used for a digital camera or the like, and more particularly to a color filter provided in the solid-state imaging device for spectrally dividing incident light.

  In a solid-state imaging device used for a digital still camera, a digital video camera, or the like, a plurality of unit pixels (also referred to as “light receiving cells”) are two-dimensionally arranged on a semiconductor substrate, and each unit pixel photoelectrically converts incident light. It has a structure including a photoelectric conversion unit for conversion and a color filter for color separation.

  The color filter is made of an organic pigment or dye. Color separation is realized by the color filter, and the photoelectric conversion signals in all unit pixels are collected to capture one image. Data can be generated (see, for example, Patent Documents 1, 2, or 4).

In such a solid-state imaging device, a silicon nitride film is usually formed as a barrier film (also referred to as “protective film”) in order to protect the pixel portion and the circuit portion. For example, the reflection of incident light can be suppressed by configuring the color filter of the solid-state imaging device by laminating a silicon oxynitride film and a silicon nitride film (see, for example, Patent Document 3).
JP-A-7-311310 JP 2000-180621 A JP 2000-252451 A International Publication No. 05/069376 Pamphlet

  However, when a multilayer interference filter having a protective film (see, for example, Patent Document 4) is used as the color filter (generally, the color filter is formed using a laminated film of a low refractive index material and a high refractive index material. However, in addition to the color filter, a protective film such as a barrier film is also formed.) In some cases, the protective film adversely affects the spectral characteristics of the color filter (for example, Patent Document 4).

  In addition, when the set wavelength of the color filter and the film thickness of the barrier film are not appropriate, so-called “interference” occurs, which affects spectral characteristics (also referred to as “transmission characteristics”) with respect to incident light. In addition, the position of the barrier film has a great influence on the spectral characteristics.

  Further, when the planarizing film or the like of the element is formed using CMP (Chemical Mechanical Polishing), there is a problem in that the spectral characteristics vary because the film thickness variation becomes large.

  Therefore, the present invention can reduce the influence of interference due to a planarization film or a barrier film when a multilayer interference filter is used as a color filter, and can further suppress variation in spectral characteristics due to variation in film thickness of the planarization film. An object of the present invention is to provide a solid-state imaging device including a color filter.

  In order to achieve the above object, a solid-state imaging device according to the present invention is a solid-state imaging device in which unit pixels including a color filter having a multilayer film structure having a set wavelength λ and a barrier film are two-dimensionally arranged. The color filter is made of a high refractive index material or a low refractive index material, and its optical film thickness is substantially equal to λ / 4, and the optical film thickness of the barrier film is approximately equal to λ / 2. .

  With the above configuration, the influence of interference caused by a barrier film other than the color filter can be reduced, and when the barrier film is included in addition to the color filter, the camera 100 that is excellent as a total device can be realized.

  The barrier film is adjacent to the color filter. By adopting the above configuration, since the materials having different refractive indexes are adjacent to the color filter, it is possible to eliminate the influence of the planarizing film on the interference generated between the color filter and the barrier film other than the color filter. Excellent spectral characteristics can be realized.

  Further, a reflection suppressing film having an optical film thickness substantially equal to λ / 4 is formed on at least one of the upper surface and the lower surface of the barrier film. With the above structure, variation in transmission characteristics due to variation in film thickness due to a planarization process (CMP process) of an element can be suppressed. Furthermore, the transmittance can be improved by the effect of the antireflection film, and a highly sensitive solid-state imaging device can be realized.

  Further, a reflection suppressing film having an optical film thickness substantially equal to λ / 4 is formed on the color filter side of the barrier film. With the above structure, it is possible to suppress variation in spectral characteristics due to film thickness variation caused by the planarization process of the element. Furthermore, by forming the reflection suppression film only on the filter side, it is possible to further improve the transmittance, and to realize a highly sensitive solid-state imaging device.

  The barrier film includes a first barrier film on the incident light side of the color filter and a second barrier film on the outgoing light side of the color filter, and each film of the first barrier film and the second barrier film. Thickness is equal. With the above configuration, the symmetry of the color filter can be improved, and the light transmittance can be improved. Therefore, a highly sensitive solid-state imaging device can be realized.

  The high refractive index material is titanium dioxide, and the low refractive index material is silicon dioxide. By setting it as the said structure, the refractive index difference of high refractive index material and low refractive index material can be enlarged, and the outstanding spectral characteristic can be implement | achieved.

  The barrier film is a silicon nitride film. With the above configuration, a highly reliable solid-state imaging device can be realized by the barrier effect of the silicon nitride film. Furthermore, a function as an etching stop film at the time of etching can be realized as a barrier film.

  The antireflection film is a silicon oxynitride film. With the above structure, the silicon oxynitride film has a lower refractive index than that of the silicon nitride film and is higher than that of silicon dioxide used in a planarization film and the like, and thus is effective as a reflection suppressing film.

  The barrier film is a silicon oxynitride film. With the above structure, the silicon oxynitride film has a smaller refractive index difference than that of silicon dioxide used for a planarizing film or the like than the silicon nitride film. And the influence of interference can be reduced.

  The color filter according to the present invention includes a λ / 4 film in which two types of dielectric layers having the same optical film thickness are alternately stacked, and an insulating layer having a film thickness other than the λ / 4 film, and transmits light. In the first unit pixel and the second unit pixel having different target colors, the thickness of the insulator layer is different.

  With the above configuration, RGB color separation in each unit pixel can be realized only by changing the film thickness of the insulator layer, and it is possible to reduce the thickness as compared with a general color filter, and solid-state imaging The manufacturing process of the device can be simplified.

  The present invention can also be realized as a camera having the solid-state imaging device.

  In the case of using a multilayer interference filter as a color filter, the solid-state imaging device according to the present invention reduces the influence of interference due to a planarization film or a barrier film by setting the film thickness of the barrier film to λ / 2. Furthermore, it is possible to realize a solid-state imaging device that realizes excellent color separation characteristics that can suppress variations in characteristics due to film thickness variations in the planarization film by forming a reflection suppression film on the barrier film.

  Hereinafter, embodiments of a solid-state imaging device according to the present invention will be 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.

(Embodiment 1)
First, the configuration of the digital still camera according to the present invention will be described. FIG. 1 is a block diagram showing the main functional configuration of a digital still camera 100 according to the present invention.

  As shown in FIG. 1, the digital still camera 100 includes a lens 101, a solid-state imaging device 102, a color signal synthesis unit 103, a video signal creation unit 104, and an element driving unit 105.

  The lens 101 is a condensing element for forming an image of light (incident light 35) incident on the digital still camera 100 on the imaging region of the solid-state imaging device 102. The solid-state imaging device 102 is a unit that photoelectrically converts light collected by the lens 101 to generate a color signal. The element driving unit 105 is a unit that extracts a color signal from the solid-state imaging device 102. The color signal synthesis unit 103 is a unit that performs color shading on the color signal received from the solid-state imaging device 102. The video signal creation unit 104 is a unit that generates a color video signal from the color signal subjected to color shading in the color signal synthesis unit 103. The color video signal is finally recorded as color image data on a recording medium (not shown) such as a RAM or a memory card.

  FIG. 2 is a diagram schematically illustrating the configuration of the solid-state imaging device 102 according to the present embodiment. As shown in FIG. 2, the solid-state imaging device 102 includes a unit pixel 1, a vertical shift register 2, a horizontal shift register 3, and a drive circuit 5. Each column of unit pixels 1 (sixteen unit pixels 1 are schematically shown in FIG. 2) arranged two-dimensionally is selected by the vertical shift register 2, and one row is horizontally shifted. The color signal for each unit pixel 1 is selected from the register 3 and output from the output amplifier 4. Note that the drive circuit 5 drives the vertical shift register 2, the horizontal shift register 3, and the output amplifier 4.

  FIG. 3 is a cross-sectional view of the substrate showing the structure of a part (specifically, three unit pixels 1a, 1b and 1c) of the solid-state imaging device 102 according to the present embodiment. Each unit pixel 1a to 1c is formed on the basis of a substrate 11 made of silicon to which an N-type impurity is added, and has the following layers.

  The photoelectric conversion layer 12 includes a P-type well 21 formed by ion-implanting P-type impurities into the substrate 11 and an N-type region formed by ion-implanting N-type impurities into the P-type well 21. 22 is included.

  The metal layer 13 is a layer in which wiring from the vertical shift register 2 and wiring for transferring signal charges to the horizontal shift register 3 are formed by a CVD (Chemical Vapor Deposition) method or the like. Further, the light shielding film 24 is also formed by using the CVD method, and the silicon dioxide 23 is also formed in the opening portion of the light shielding film 24 for planarizing the element by the CVD method or the like. The light shielding film 24 has an opening for guiding light to the unit pixel.

  The filter layer 14 includes a silicon nitride film 26 as a barrier film, silicon dioxide 28 for flattening the element, a color filter 29 formed of a multilayer interference filter, silicon dioxide 30 for flattening a step of the color filter 29, And a silicon nitride film 32 which is a barrier film at the time of etch back when the microlens 34 is formed.

  The incident light 35 is light incident from above the unit pixel, is collected by the microlens 34, and reaches the photoelectric conversion unit 22 through the filter layer 14 and the metal layer 13.

Next, spectral characteristics of the solid-state imaging device 102 according to the present embodiment will be described.
4A to 4D are diagrams illustrating spectral characteristics of the unit pixels 1a to 1c in the solid-state imaging device 102 according to the present embodiment. In FIG. 4A, the first barrier film 26 and the second barrier film 32 have the same film thickness, and the thickness of the λ / 2 film with respect to 530 nm, which is the set wavelength (λ) of the color filter 29. This is the spectral characteristic of the solid-state imaging device 102 when is set to 133 nm.

In the color filter 29, the setting wavelength is 530 nm, the film thickness of titanium dioxide as a λ / 4 film is 52 nm, and the film thickness of silicon dioxide as a λ / 4 film is 91 nm. As the configuration of the multilayer interference filter corresponding to the light of each color of R (Red), G (Green) and B (Blue) after the spectroscopy, in the case of the unit pixel 1b corresponding to the R light, TiO ₂ (52 nm) / a _{SiO 2 (91nm) / TiO 2} (52nm) / SiO 2 (30nm) / TiO 2 (52nm) / SiO 2 (91nm) / TiO 2 (52nm). In the case of the unit pixel 1c corresponding to the G _{light, TiO 2 (52nm) / SiO} 2 (91nm) / TiO 2 (52nm) / SiO 2 (0nm) / TiO 2 (52nm) / SiO 2 (91nm) / TiO ₂ (52 nm). Furthermore, in the case of the unit pixel 1a corresponding to the B light, TiO ₂ (52 nm) / SiO ₂ (91 nm) / TiO ₂ (52 nm) / SiO ₂ (133 nm) / TiO ₂ (52 nm) / SiO ₂ (91 nm) / TiO ₂ (52 nm).

RGB color separation is realized by changing the film thickness of only one layer of SiO ₂ as a spacer layer (133 nm in the unit pixel 1a (B), 30 nm in the unit pixel 1b (R), and 0 nm in the unit pixel 1c (G)). be able to.

  FIGS. 4B to 4D are flat views of the B light unit pixel 1a, the R light unit pixel 1b, and the G light unit pixel 1c in the solid-state imaging device 102 according to the present embodiment. The spectral characteristics are shown when the film thickness (500 nm) of silicon dioxide 30 that is a chemical layer is changed by −200 nm, −100 nm, 0 nm, +100 nm, and +200 nm, respectively.

  FIG. 5A shows the case where the thickness of the silicon nitride film 32 as the first barrier film is changed from 133 nm to 50 nm in the solid-state imaging device 102 of FIG. 3 (the silicon nitride film as the second barrier film). The film thickness of 26 is 133 nm and has no change.). In this case, ripples affect the spectrum due to the interference of the silicon nitride film, and excellent spectral characteristics cannot be realized. 5B to 5D, as in FIG. 5A, the B light unit pixel 1a and the R light when the thickness of the silicon nitride film 32 is changed from 133 nm to 50 nm. Spectral characteristics when the film thickness (500 nm) of the silicon dioxide 30 that is the respective flattening layer in the unit pixel 1b and the G light unit pixel 1c is changed by −200 nm, −100 nm, 0 nm, +100 nm, and +200 nm, respectively. Show.

  As described above, by configuring the color filter according to the present embodiment, it is possible to reduce the influence of interference particularly in the spectral characteristics of G light, and to realize a solid-state imaging device having excellent spectral characteristics. it can.

(Embodiment 2)
FIG. 6 is a cross-sectional view of the substrate showing the structure of the unit pixels (1a, 1b, 1c) of the solid-state imaging device 202 according to the present embodiment. The unit pixels 1a to 1c according to the present embodiment include silicon oxynitride films 25 and 27 and silicon oxynitride films 31 and 33, which are reflection suppression films, in the second barrier film 26 and the first barrier film 32. The unit pixels 1a to 1c according to the first embodiment are different in that they are formed on the upper and lower surfaces of each barrier film. Since the other components are the same as those in the first embodiment, description thereof is omitted.

  Here, the refractive indexes of the silicon oxynitride films 25, 27, 31, and 33 are “1.56”. These film thicknesses are all the same, and are 85 nm, which is the film thickness of the λ / 4 film having the set wavelength 530 nm of the color filter 29.

  7A to 7D are diagrams showing the spectral characteristics of the unit pixels (1a, 1b, 1c) in the solid-state imaging device 202 according to the present embodiment.

  When FIG. 7A is compared with FIG. 4A which is the spectral characteristic shown in the first embodiment, the spectral characteristic of the solid-state imaging device 202 according to the present invention is Further, it can be seen that the influence of interference can be reduced.

  7B to 7D show the respective flattening layers in the unit pixel 1a for B light, the unit pixel 1b for R light, and the unit pixel 1c for G light in the configuration of FIG. 7A. The spectral characteristics when the film thickness (500 nm) of silicon dioxide 30 is changed by −200 nm, −100 nm, 0 nm, +100 nm, and +200 nm, respectively.

  Here, the silicon dioxide 30 is a layer for flattening the color filter 29 and is generally formed using CMP. The film thickness variation of the CMP technique is generally about ± 200 nm, and as can be seen by comparing these FIGS. 7B to 7D, it is a case where the film thickness of the silicon dioxide 30 changes. In addition, the solid-state imaging device 202 in the present embodiment can reduce the influence of film thickness variation. Similarly, the silicon dioxide 28 is a layer for flattening the level difference caused by the light shielding film 24. Similarly, by forming a reflection suppressing film, the influence of film thickness variation can be reduced.

(Embodiment 3)
FIG. 8 is a cross-sectional view of the substrate showing the structure of the unit pixels (1a, 1b, 1c) of the solid-state imaging device 302 according to the present embodiment. The unit pixels 1a to 1c according to the present embodiment are different from the first embodiment in that the silicon nitride film 26 as the second barrier film is adjacent to the color filter 29. The other components are the same as those in the first embodiment, and a description thereof will be omitted.

  FIG. 9A is a diagram showing the spectral characteristics of each unit pixel (1a, 1b, 1c) in the solid-state imaging device 302 according to the present embodiment. FIGS. 9B to 9D are graphs showing the respective planarization layers of the B light unit pixel 1a, the R light unit pixel 1b, and the G light unit pixel 1c in the configuration of FIG. The spectral characteristics when the film thickness (500 nm) of silicon 30 is changed by −200 nm, −100 nm, 0 nm, +100 nm, and +200 nm, respectively.

  In the first embodiment, since the silicon dioxide 28 exists between the color filter 29 and the silicon nitride film 26, there is an influence of film thickness variation. However, the structure shown in FIG. The planarization film 28 is formed immediately after the formation of the light shielding film 24, and the barrier film 26 and the color filter 29 are formed adjacent to each other. Therefore, it is possible to eliminate the influence of the variation in film thickness due to CMP on the spectral characteristics. Become. Therefore, excellent spectral characteristics can be realized.

(Embodiment 4)
FIG. 10 is a cross-sectional view of the substrate showing the structure of the unit pixels (1a, 1b, 1c) of the solid-state imaging device 402 according to the fourth embodiment. The unit pixels 1a to 1c according to the present embodiment include silicon oxynitride films 25 and 27 and silicon oxynitride films 31 and 33 as reflection suppression films in the second barrier film 26 and the first barrier film 32, respectively. The difference from Embodiment 3 is that the barrier film is formed on the upper surface and the lower surface. Since other components are the same as those in the third embodiment, the description thereof is omitted.

  FIG. 11A is a diagram showing the spectral characteristics of each unit pixel (1a, 1b, 1c) in the solid-state imaging device 402 according to the present embodiment. Even with the configuration shown in FIG. 10, the influence of interference can be further reduced, and excellent spectral characteristics can be realized.

  FIGS. 11B to 11D show the flat portions of the B light unit pixel 1a, the R light unit pixel 1b, and the G light unit pixel 1c in the solid-state imaging device 402 according to the present embodiment. The spectral characteristics are shown when the film thickness (500 nm) of silicon dioxide 30 that is a chemical layer is changed by −200 nm, −100 nm, 0 nm, +100 nm, and +200 nm, respectively.

  When FIGS. 9B to 9D and FIGS. 11B to 11D according to the third embodiment are compared, the film thickness of the silicon dioxide 30 is obtained by using the solid-state imaging device 402 in the present embodiment. It can be seen that the influence of the variation on the spectral characteristics can be reduced.

(Embodiment 5)
FIG. 12 is a cross-sectional view of the substrate showing the structure of the unit pixels (1a, 1b, 1c) of the solid-state imaging device 502 according to the fifth embodiment. The unit pixels 1a to 1c according to the present embodiment differ from the fourth embodiment in that the silicon oxynitride film 25 is removed as a reflection suppression film in the second barrier film 26. Since the other components are the same as those in the fourth embodiment, description thereof is omitted.

  FIG. 13A is a diagram showing the spectral characteristics of each unit pixel (1a, 1b, 1c) in the solid-state imaging device 502 according to the present embodiment. When the configuration shown in FIG. 12 is used, it can be seen that the width of the transmission band can be widened when compared with FIG. 11A, which is the spectral characteristic in the case of the fourth embodiment. FIGS. 13B to 13D show the flattening of the B light unit pixel 1a, the R light unit pixel 1b, and the G light unit pixel 1c in the solid-state imaging device 502 according to the present embodiment. The spectral characteristics when the film thickness (500 nm) of the silicon dioxide layer 30 is changed to −200 nm, −100 nm, 0 nm, +100 nm, and +200 nm, respectively.

  Reflection suppression films 31 and 33 are formed on the second barrier film 32 of the solid-state imaging device 502 shown in FIG. 12, and the reflection suppression film 27 and the barrier film 26 are adjacent to the color filter 29. Therefore, it is possible to eliminate the influence of the variation in the thickness of the planarizing layer on the spectral characteristics.

  Therefore, by using the solid-state imaging device 502 according to this embodiment, high sensitivity and excellent spectral characteristics can be realized.

  Further, as a modification of the solid-state imaging device 502 shown in FIG. 12, solid-state imaging having a structure in which the antireflection film 27 is removed from the structure of FIG. 10 in the fourth embodiment (that is, when only the antireflection film 25 is formed). FIG. 14A shows the spectral characteristics of each unit pixel (1a, 1b, 1c) in the apparatus. FIGS. 14B to 14D show a film of silicon dioxide 30 which is a flattening layer in the unit pixel 1a for B light, the unit pixel 1b for R light, and the unit pixel 1c for G light in this case. The spectral characteristics when the thickness (500 nm) is changed by −200 nm, −100 nm, 0 nm, +100 nm, and +200 nm, respectively.

  Similarly, as a modification of the solid-state imaging device 502 shown in FIG. 12, in the structure of FIG. 10 in the fourth embodiment, the structure in which both the reflection suppression films 25 and 27 are removed (that is, only the second barrier film 26). FIG. 15A shows the spectral characteristics of the unit pixels (1a, 1b, 1c) in the solid-state imaging device in the case of forming (a). FIGS. 15B to 15D show a film of silicon dioxide 30 which is a flattening layer in the unit pixel 1a for B light, the unit pixel 1b for R light, and the unit pixel 1c for G light in this case. The spectral characteristics when the thickness (500 nm) is changed by −200 nm, −100 nm, 0 nm, +100 nm, and +200 nm, respectively.

  In both structures of the above-described modified examples, the width of the transmission band is small, but it can be seen that the film thickness variation of the silicon dioxide 30 hardly affects the spectral characteristics.

  Therefore, the structure having the spectral characteristics shown in FIGS. 11 and 13 may be employed for applications in which sensitivity is important, and the structure having the spectral characteristics shown in FIGS. 14 and 15 may be employed for applications requiring monochromaticity. I understand.

  As described above, it can be seen that the influence of the variation in the thickness of the silicon dioxide 30 on the spectral characteristics is reduced in any structure.

(Embodiment 6)
FIG. 16 is a substrate cross-sectional view illustrating the structure of the unit pixels (1a, 1b, 1c) of the solid-state imaging device 602 according to the sixth embodiment. In the unit pixels 1a to 1c according to the present embodiment, the barrier film at the time of lens etch-back is composed of the first barrier film 32 and the silicon oxynitride films 31 and 33 that are reflection suppression films. The second embodiment is different from the fourth embodiment in that the film for stopping etching is composed of only the silicon oxynitride film 37. Since the other components are the same as those in the fourth embodiment, description thereof is omitted.

  Here, the film thickness of the silicon oxynitride film 37 is 170 nm which is a λ / 2 film of 530 nm which is the set wavelength of the color filter 29.

  FIG. 17A is a diagram showing the spectral characteristics of each unit pixel (1a, 1b, 1c) in the solid-state imaging device 602 according to the present embodiment. FIGS. 17B to 17D show the flattening of the B light unit pixel 1a, the R light unit pixel 1b, and the G light unit pixel 1c in the solid-state imaging device 602 according to the present embodiment. The spectral characteristics when the film thickness (500 nm) of the silicon dioxide layer 30 is changed to −200 nm, −100 nm, 0 nm, +100 nm, and +200 nm, respectively.

  With the configuration of FIG. 16, the refractive index difference between the silicon dioxide 30 (n = 1.46) and the silicon oxynitride film 37 (n = 1.56) becomes “0.10”, and the silicon dioxide 30 (n = 1.46) and the silicon nitride film (n = 2.0) which is the barrier film are smaller than the refractive index difference “0.54”, so the reflectance is small. Therefore, the influence of the film thickness variation in the silicon dioxide 30 on the spectral characteristics is reduced.

  Therefore, by using the structure in this embodiment, a solid-state imaging device with high sensitivity and excellent spectral characteristics can be realized.

  Although not shown in FIG. 16, the antireflection films 25 and 27 made of a silicon oxynitride film may or may not be provided in the same manner as shown in the fifth embodiment.

  The present invention can be used for solid-state imaging devices such as digital cameras and digital video cameras.

It is a block diagram which shows the main function structures of the digital still camera concerning this invention. 1 is a diagram illustrating an outline of a configuration of a solid-state imaging apparatus according to Embodiment 1. FIG. 2 is a cross-sectional view of a substrate showing a structure of a unit pixel according to Embodiment 1. FIG. (A)-(d) is a figure which shows the spectral characteristics in the unit pixel which concerns on Embodiment 1. FIG. (A)-(d) is a figure which shows the spectral characteristics when the film thickness of a silicon nitride film is changed in Embodiment 1. FIG. FIG. 5 is a cross-sectional view of a substrate showing a structure of a unit pixel according to a second embodiment. (A)-(d) is a figure which shows the spectral characteristic in the unit pixel which concerns on Embodiment 2. FIG. 6 is a substrate cross-sectional view illustrating a structure of a unit pixel according to Embodiment 3. FIG. (A)-(d) is a figure which shows the spectral characteristics in the unit pixel which concerns on Embodiment 3. FIG. FIG. 6 is a substrate cross-sectional view illustrating a structure of a unit pixel according to a fourth embodiment. (A)-(d) is a figure which shows the spectral characteristics in the unit pixel which concerns on Embodiment 4. FIG. FIG. 10 is a substrate cross-sectional view illustrating a structure of a unit pixel according to a fifth embodiment. (A)-(d) is a figure which shows the spectral characteristics in the unit pixel which concerns on Embodiment 5. FIG. (A)-(d) is a figure which shows the spectral characteristic of the modification in the unit pixel which concerns on Embodiment 5. FIG. (A)-(d) is a figure which shows the spectral characteristic of the other modification in the unit pixel which concerns on Embodiment 5. FIG. FIG. 10 is a cross-sectional view of a substrate showing a structure of a unit pixel according to a sixth embodiment. (A)-(d) is a figure which shows the spectral characteristics in the unit pixel which concerns on Embodiment 6. FIG.

Explanation of symbols

1a, 1b, 1c Unit pixel 2 Vertical shift register 3 Horizontal shift register 4 Amplifier 5 Drive circuit 11 Substrate 12 Photoelectric conversion layer 13 Metal layer 14 Filter layer 15 Lens layer 16 P-type well 21 P-type well 22 Photoelectric conversion unit 23 Silicon dioxide 24 light shielding film 25 silicon oxynitride film (film thickness: 85 nm)
26 Silicon nitride film (film thickness: 133 nm)
27 Silicon oxynitride film (film thickness: 85 nm)
28 Silicon dioxide (flattened film: 500 nm)
29 Color filter 30 Silicon dioxide (flattened film: 500 nm)
31 Silicon oxynitride film (film thickness: 85 nm)
32 Silicon nitride film (thickness: 133 nm)
33 Silicon oxynitride film (film thickness: 85 nm)
34 Microlens 35 Incident light 37 Silicon oxynitride film (film thickness: 170 nm)
DESCRIPTION OF SYMBOLS 100 Digital still camera 102,202,302 Solid-state imaging device 402,502,602 Solid-state imaging device

Claims (11)

A solid-state imaging device in which unit pixels including a color filter having a multilayer film structure having a set wavelength λ and a barrier film are two-dimensionally arranged,
The color filter is composed of a high refractive index material or a low refractive index material, and its optical film thickness is substantially equal to λ / 4.
An optical film thickness of the barrier film is substantially equal to λ / 2. The solid-state imaging device according to claim 1, wherein the barrier film is adjacent to the color filter. 2. The solid-state imaging device according to claim 1, wherein an antireflection film having an optical film thickness substantially equal to λ / 4 is formed on at least one of the upper surface and the lower surface of the barrier film. 2. The solid-state imaging device according to claim 1, wherein a reflection suppressing film having an optical film thickness substantially equal to λ / 4 is formed on the color filter side of the barrier film. The barrier film is
A first barrier film on an incident light side of the color filter;
A second barrier film on the output light side of the color filter;
The solid-state imaging device according to claim 1, wherein the film thicknesses of the first barrier film and the second barrier film are equal. The high refractive index material is titanium dioxide;
The solid-state imaging device according to claim 1, wherein the low refractive index material is silicon dioxide. The solid-state imaging device according to claim 1, wherein the barrier film is a silicon nitride film. The solid-state imaging device according to claim 3, wherein the reflection suppression film is a silicon oxynitride film. The solid-state imaging device according to claim 1, wherein the barrier film is a silicon oxynitride film. The color filter includes a λ / 4 film in which two types of dielectric layers having the same optical film thickness are alternately stacked, and an insulating layer having a film thickness other than the λ / 4 film,
2. The solid-state imaging device according to claim 1, wherein the thickness of the insulator layer is different between the first unit pixel and the second unit pixel having different colors to be transmitted. A camera having a solid-state imaging device in which unit pixels including a color filter that transmits light of a predetermined color of incident light and a barrier film are two-dimensionally arranged,
The color filter is composed of a high refractive index material or a low refractive index material, and its optical film thickness is substantially equal to λ / 4.
An optical film thickness of the barrier film is approximately equal to λ / 2.

Images