CN1877867B - Solid-state imaging devices and cameras - Google Patents

Abstract

The object of the present invention is to provide a small-sized solid-state imaging device capable of greatly improving sensitivity, which has: a semiconductor substrate (11) formed with a plurality of photoelectric conversion parts (17); a light-shielding film (19) positioned at the photoelectric conversion part (17) above, there are a plurality of openings (20) corresponding to each photoelectric conversion part (17), formed on the semiconductor substrate (11); and a high refractive index layer (125), formed in the openings (20) ); the opening width of the opening (20) is smaller than the maximum wavelength converted into the wavelength in vacuum of the light entering the photoelectric conversion part (17), and the high refractive index layer (125) is made of a high refractive index material. The refractive index material has a refractive index that allows light of the maximum wavelength to pass through the opening (20).

Description

Solid-state imaging devices and cameras

technical field

The present invention relates to a solid-state imaging device used in a digital camera and the like, and particularly relates to a light receiving unit constituting the solid-state imaging device.

Background technique

A general solid-state imaging device has a structure in which a plurality of light-receiving units are formed on a semiconductor substrate, and each light-receiving unit has a photoelectric conversion part for photoelectrically converting light incident through an opening of a light-shielding film, and The color filter formed on the film for color separation is generally a primary color filter or a complementary color filter. The primary color filter uses red (R), blue (R), and green (G), and in the complementary color filter, the complementary color of red is cyan (C), and the complementary color of green is magenta (M). The complementary color to blue is yellow (Y). In general, signals obtained from the three colors and green (G) are used in solid-state imaging devices using complementary color filters. And, the above-mentioned one color is assigned to each light receiving unit in a certain pattern. In this way, each light receiving unit generates a signal based on the brightness of the color signal separated by the color filter (for example, see Patent Documents 1 and 2).

In addition, in order to amplify the above-mentioned signal and achieve high sensitivity, microlenses are formed on the upper and lower sides of the color filter to achieve a high signal/noise ratio (see, for example, Patent Document 3).

Furthermore, as a method of realizing high sensitivity, the following proposal is proposed: for example, in the opening of the light-shielding film, a high refractive index material and a low refractive index material formed to surround the high refractive index material are placed, and the high refractive index material and the low refractive index material are used. Light is collected by total reflection at the boundary of the low-refractive index material (for example, see Patent Document 4).

FIG. 1 is a diagram showing the configuration of a camera using a solid-state imaging device.

In this camera, incident light 24 reaches the solid-state imaging device 3 placed inside the camera 2 through a camera lens 34 .

FIG. 2 is a diagram showing an arrangement of light receiving cells of a conventional solid-state imaging device.

In this solid-state imaging device, light incident through the camera lens 34 shown in FIG. Photoelectric conversion to obtain images.

FIG. 3 shows cross-sectional views of light receiving units 1a, 1b, and 1c of a conventional solid-state imaging device.

Each light-receiving unit is based on a semiconductor substrate 11 made of silicon added with N-type impurities, and an insulating layer 13 , a metal layer 14 and a color filter layer 15 are formed. At this time, the photoelectric conversion layer 12 is formed in the semiconductor substrate 11 . The photoelectric conversion layer 12 is a layer in which a P-type well 16 is formed by ion-implanting P-type impurities into the semiconductor substrate 11 and has a photoelectric conversion portion 17 which is an N-type region formed by ion-implanting N-type impurities into the P-type well 16 .

The insulating layer 13 is a layer composed of an interlayer film 18 provided on the photoelectric conversion layer 12 to insulate the photoelectric conversion layer 12 and the metal layer 14 .

The metal layer 14 is a layer including a light shielding film 19 and an in-layer lens 30 . In the formation of the metal layer 14 , after the light shielding film 19 is formed, an interlayer film 29 as a planarization layer is formed on the light shielding film 19 . Furthermore, after the interlayer film 29 on the light shielding film 19 is formed, the intralayer lens 30 is formed. The interlayer film 31 is formed on the inner lens 30 so as to cover the surface of the inner lens 30 .

The color filter layer 15 is a layer including a color filter composed of a blue color filter film 21a, a green color filter film 21b, and a red color filter film 21c, and an interlayer film 22 on the color filter.

Incident light 24 enters from above the light receiving units 1a, 1b, 1c, is condensed by the microlens 23 formed on the color filter, and passes through the blue color filter 21a, the green color filter 21b or the red color filter 21c. The light transmitted through the color filter is condensed again by the in-layer lens 30 , passes through the opening 20 , and reaches the photoelectric conversion unit 17 . When the light receiving units 1 a , 1 b , and 1 c are large light receiving units having a square with a side of 5.6 μm as in the past, the width of the opening 20 is as large as 2.0 μm or more. Therefore, for example, visible light with a red wavelength of 650 nm on the long wavelength side can sufficiently pass through the opening without being affected by the width of the opening. In addition, light of a near-infrared wavelength on the long-wavelength side used in a dark-field camera or the like can sufficiently pass through the opening.

Patent Document 1: Japanese Patent Application Laid-Open No. 10-341012

Patent Document 2: Japanese Patent Application Laid-Open No. 5-326902

Patent Document 3: Japanese Patent Laid-Open No. 2000-164837

Patent Document 4: Japanese Patent Application Laid-Open No. 6-224398

However, in order to increase the pixel count of solid-state imaging devices, if the light-receiving unit is miniaturized and shrunk, the width of the opening of the light-shielding film will approach that of visible light such as red (R), green (G) and blue (B) light. wavelength. And, when the width of the opening of the light-shielding film becomes smaller than the wavelength of visible light, among the wavelengths of light transmitted through the color filter, light in a wavelength band above a specific wavelength determined by the width of the opening is blocked. Light having a wavelength equal to or greater than the wavelength cannot pass through the opening, and cannot reach the photoelectric conversion portion. In this case, the transmittance of red (R) color light on the long-wavelength side is significantly lowered. For example, when light with a red wavelength of 650 nm passes through a narrow opening in a vacuum, the light with a wavelength of 650 nm in a vacuum fills the opening with a silicon oxide film (SiO ₂ ) having a refractive index of 1.45. 450nm having a wavelength (650nm/1.45=450nm) of the value of dividing the wavelength by the refractive index. Therefore, the transmittance of light having a wavelength of 650 nm in this vacuum is almost zero when the width of the opening is approximately 450 nm, but actually decreases from around the opening width of 650 nm. Therefore, when the material filling the opening is a low-refractive-index material such as a silicon oxide film (SiO ₂ ), light having a wavelength equal to or greater than the width of the opening cannot be transmitted.

In particular, when the light receiving unit is a small square light receiving unit with one side smaller than 3.2 μm, the width of the opening is 1.0 μm or less. With such a narrow opening width, when the planarization layer filling the opening is made of a low-refractive index material, light with a wavelength on the long-wavelength side, such as long-wavelength red-wavelength visible light and 1.0 to 2.0 μm near-infrared light, , especially impenetrable. For example, when the planarization layer filling the opening is made of a silicon oxide film (SiO ₂ ) with a low refractive index of 1.5 or a low refractive index resin with a refractive index of 1.3 to 1.7, long-wavelength light cannot through the opening.

In addition, when the width of the opening of the light-shielding film is smaller than the wavelength of visible light, it is difficult to gather the light transmitted through each color filter to the opening even with microlenses or in-layer lenses. In particular, long-wavelength red (R) light and short-wavelength green (G) and blue (B) light are more difficult to condense, so it is difficult to pass through the opening to reach the photoelectric conversion unit.

Furthermore, as shown in FIG. 4 showing the state in which light enters the solid-state imaging device (light-receiving unit), the principal ray of light entering through the camera lens 34 enters the light-receiving unit 1 in the central portion A perpendicularly, but Since the light enters the light receiving units 1 of the peripheral portions B and C obliquely, the state of light entering the microlenses of the light receiving units 1 in the solid-state imaging device is different. Therefore, in order to achieve multi-pixel solid-state imaging devices, if the light receiving unit is miniaturized and reduced in size, the width of the opening 20 of the light shielding film 19 becomes extremely narrow. Even when the width of the opening 20 of the light-shielding film 19 is narrowed, as shown in FIG. Since the incident light 24 enters the microlens 23 perpendicularly to the light receiving unit 1, the incident light 24 can be converged to the photoelectric conversion unit 17 in the light receiving unit 1 at the central portion A. However, in the light receiving unit 1 of the peripheral portion C, the incident light 24 enters the microlens 23 obliquely, so even when the light is collected by the microlens 23, the incident light 24 reaches the light-shielding film 19 and cannot enter the opening 20. It is difficult to converge the incident light 24 to the photoelectric conversion part 17 .

Furthermore, in a solid-state imaging device characterized by a wide dynamic range, light-receiving cells are arranged as shown in FIG. 6 . That is, a plurality of light-receiving units A for receiving low-intensity light and light-receiving units B for receiving high-intensity light are arranged in rows and columns. Signals photoelectrically converted by light-receiving unit A receiving low-intensity light and light-receiving unit B receiving high-intensity light are combined inside or outside the solid-state imaging device to obtain an image with a wide dynamic range. In such a solid-state imaging device, as shown in FIG. 7 showing a cross-sectional view (cross-sectional view between M-N in FIG. 6 ) of the light-receiving unit (light-receiving unit A, B in FIG. 6 ), the light-receiving unit A receiving low-intensity light The opening 20A having a large opening width is formed in the center, and the opening 20B having a small opening width is formed in the light receiving unit B for receiving high-intensity light. Then, in order to compensate for the reduction in light concentration efficiency caused by the miniaturization of the light receiving unit, when the light concentration of the microlens 23 is optimized in the wide opening 20A, it is difficult for a part of the incident light 24 to enter the narrow opening. Therefore, the incident light 24 passing through the opening 20B is reduced, and the sensitivity of the light receiving unit B receiving high-brightness light is greatly reduced. And, in the peripheral portion of the solid-state imaging device, the incident angle of the incident light 24 is larger than that of the central portion, so the light transmitted through the opening 20B is more difficult to converge. The sensitivity of the light-receiving unit B decreases greatly, and sensitivity shading and color unevenness occur, so that the quality of the obtained image deteriorates significantly.

Contents of the invention

Therefore, an object of the present invention is to provide a compact solid-state imaging device capable of greatly improving sensitivity by improving the amount of light transmitted when the opening width of the light-shielding film is reduced.

In order to achieve the above object, the solid-state imaging device of the present invention is characterized by comprising: a semiconductor substrate; a photoelectric conversion portion formed on the semiconductor substrate; and a light-shielding film provided with an opening formed above the photoelectric conversion portion. a portion provided on the above-mentioned semiconductor substrate; and a high-refractive-index layer formed in the above-mentioned opening portion, the opening width of the above-mentioned opening portion is larger than the maximum wavelength converted into the wavelength in vacuum of the light incident on the above-mentioned photoelectric conversion portion through the above-mentioned opening portion. The above-mentioned high-refractive-index layer is made of a high-refractive-index material, and the high-refractive-index material has a refractive index that allows the light of the above-mentioned maximum wavelength to pass through the light that enters the photoelectric conversion part through the above-mentioned opening, and the above-mentioned high-refractive index The layer is composed of a high refractive index material having a refractive index of 1.8 or higher. Here, the above-mentioned solid-state imaging device further includes a filter film that is disposed above the opening to transmit light in a specific wavelength band; The aforementioned maximum wavelength is small.

In the solid-state imaging device according to the present invention, the principle that the wavelength of light passing through the opening becomes the value obtained by dividing the wavelength in vacuum by the refractive index (wavelength in vacuum/(refractive index N)), the high refractive index material is used to fill the opening, so that the wavelength of the light passing through the opening is relatively reduced. Therefore, when the maximum wavelength of the transmission wavelength band of the light passing through the opening is converted into the wavelength in vacuum when the refractive index in the opening is N, only the thickness of the high refractive index material filling the opening is increased. Refractive index times (N times). As a result, the width of the opening is narrowed, and even when the width of the opening is equal to or smaller than the wavelength of light to be transmitted in vacuum, light can be transmitted by filling the opening with a high refractive index material. In other words, it is possible to realize a compact solid-state imaging device capable of greatly improving the sensitivity to light on the long-wavelength side and greatly improving the sensitivity.

Furthermore, in order to achieve the above object, the opening may be filled with the high refractive index layer.

By adopting the above-mentioned structure, the high-refractive index material is filled in the entire area of the opening, and the average refractive index of the entire opening can be increased, so that the transmission wavelength band of the light passing through the opening in vacuum can be shifted to the long-wavelength side. Larger shifts can further increase the photosensitivity on the long-wavelength side.

In addition, as shown in Japanese Patent Application Laid-Open No. 6-224398, a low-refractive-index material is disposed in an opening so as to surround a high-refractive-index material, and total reflection at the boundary between the high-refractive-index material and the low-refractive-index material is utilized. In the case of the method of concentrating light, it is necessary to actively introduce a low refractive index material into the opening, so the width of the high refractive index material in the opening is obtained by subtracting the width of the low refractive index material in the opening from the width of the opening. value. Therefore, in this case, the wavelength of light that can be substantially transmitted is determined by the width of the high-refractive index material that must be smaller than the width of the opening. Therefore, the actual aperture width is reduced, and the light of the transmitted wavelength on the long wavelength side is limited, which is disadvantageous in improving the sensitivity. However, by adopting the above structure, the width of the opening is equal to the width of the high refractive index material in the opening, and the substantial opening width can be increased. Therefore, the light of the transmitted wavelength on the long wavelength side is not limited, and the sensitivity can be improved.

As in the above structure, by using a high refractive index material having a refractive index of 1.8 or more as a material constituting the high refractive index layer filling the opening, even when the width of the opening is 1.0 μm or less, it is possible to make the visible light Light with a wavelength near the red wavelength and near-infrared light with a wavelength of 1.0 to 2.0 μm is transmitted therethrough.

Furthermore, in order to achieve the above object, the thickness of the high refractive index layer is substantially the same as the thickness of the light shielding film, or is greater than the thickness of the light shielding film.

By adopting the above-mentioned structure, the thickness of the material with a high refractive index in the opening is equal to or greater than the thickness in the height direction of the opening, and the cut-off wavelength converted into the wavelength in vacuum can be shifted to the long wavelength side. The long-wavelength-side transmission wavelength band of the light transmitted through the opening is widened, and the sensitivity on the long-wavelength side can be improved.

In addition, in order to achieve the above object, the high refractive index layer may have a convex lens shape to converge the light entering the photoelectric conversion portion through the opening.

By adopting the above-mentioned structure, the upper surface of the high-refractive-index material that passes through the opening is formed into a convex lens shape, and light can be collected directly above the opening. Therefore, when the width of the opening is close to the wavelength of visible light, it can be large. Amplitude increases the concentration ratio.

Furthermore, when the light-receiving unit is miniaturized and the unit pitch is reduced in the lateral direction, as shown in FIG. 3 and Japanese Patent Application Laid-Open No. 2000-164837, it is possible to require intralayer lenses and layers above and below the intralayer lenses as in the past. The interlayer film, so the longitudinal dimension on the shading film has not changed from the past. Therefore, although the cell pitch is reduced in the lateral direction, the vertical dimension cannot be reduced, so it is difficult to collect light into the narrow opening, and the light collection efficiency is greatly deteriorated. However, by adopting the above-mentioned structure, the in-layer lens above the light-shielding film, which is necessary in the structure of the conventional solid-state imaging device, can be omitted, and the height of the entire light-receiving unit can be reduced, so the above-mentioned problem does not occur.

Furthermore, in order to achieve the above object, the above-mentioned high refractive index material may also be any one of titanium oxide, tantalum oxide and niobium oxide.

Using high-refractive index materials such as titanium oxide, tantalum oxide, niobium oxide, or hafnium oxide with the above-mentioned structure for the high-refractive index layer, compared with the case of silicon oxide with a refractive index of 1.5, which is generally used as an insulating layer, an extra large opening can be obtained. The refractive index can shift the transmission wavelength band of the light transmitted through the opening in terms of the wavelength in vacuum to the long wavelength side to a large extent, so that the sensitivity on the long wavelength side can be further improved.

Moreover, in order to achieve the above purpose, the opening width may also be less than or equal to 1.0 μm.

By adopting the above-mentioned structure, in the frequency band of 1.0 μm or less in the main absorption region of silicon constituting the photoelectric conversion part, the effect of expanding the transmission wavelength band of the light transmitted through the opening to the long wavelength side is increased, so that a remarkable Improve sensitivity.

As above, in the solid-state imaging device of the present invention, a fine light-receiving unit can be realized without sacrificing sensitivity, and the number of pixels in a specific optical size (for example, 1/4 inch, etc.) of the imaging section can be increased. In the camera of the solid-state imaging device of the invention, it is possible to realize a camera with high sensitivity and high pixel quality and high image quality.

In order to achieve the above object, the method for manufacturing a solid-state imaging device according to the present invention is characterized by comprising: an opening forming step of forming a light-shielding film on a semiconductor substrate on which a photoelectric conversion portion is formed, and forming an opening located in the above-mentioned light-shielding film in the light-shielding film. an opening above the photoelectric conversion part; and a high-refractive-index layer forming step of forming a high-refractive-index layer in the opening and on the light-shielding film; The surface of the above-mentioned high refractive index layer is flat. Here, in the step of forming the high-refractive-index layer, the high-refractive-index layer may be formed to have a film thickness equal to or greater than 1/2 of the width of the opening. The high-refractive-index layer is made of a high-refractive-index material having a refractive index of 1.8 or higher.

By adopting the above structure, a high refractive index layer with a high refractive index is formed in the opening, and a high refractive index layer with a high refractive index is continuously formed on the high refractive index layer in the opening, thereby utilizing the high refractive index layer with a high refractive index. Since the layer flattens the upper part of the opening, the light incident into the opening can be entered into the opening without being diffusely reflected, and a decrease in sensitivity can be prevented.

Furthermore, in order to achieve the above object, the method of manufacturing the solid-state imaging device further includes a planarization step of planarizing the surface of the high refractive index layer.

By adopting the above-mentioned structure, a high-refractive index layer with a high refractive index is formed in the opening, and a high-refractive-index layer with a high refractive index is continuously formed on the high-refractive-index layer in the opening, and then the high-refractive index layer is formed by CMP or the like. The high-refractive-index layer is planarized and etched, so the flatness of the high-refractive-index layer above the opening can be improved, and diffuse reflection of light incident on the opening can be minimized. As a result, it is possible to minimize the unevenness among the light receiving units in the amount of light that can enter the opening, and to significantly improve the unevenness in sensitivity.

Furthermore, in order to achieve the above-mentioned object, the above-mentioned method of manufacturing a solid-state imaging device further includes a lens forming step of processing the above-mentioned high refractive index layer located above the opening into a convex lens shape.

By adopting the above-mentioned structure, a high-refractive index layer with a high refractive index is formed in the opening, and a high-refractive-index layer with a high refractive index is continuously formed on the high-refractive-index layer in the opening, and then the high-refractive index layer with a high refractive index is used. Since the in-layer lens is formed in a single layer, a special film forming process conventionally required for the in-layer lens can be eliminated, and the steps for manufacturing a solid-state imaging device can be reduced. As a result, an inexpensive solid-state imaging device can be provided. In addition, since the in-layer lens is located directly in front of the light-shielding film, light can be collected efficiently even when the opening width is small, and high sensitivity can be realized.

Furthermore, in order to achieve the above object, the solid-state imaging device of the present invention is characterized by comprising: a semiconductor substrate; a plurality of photoelectric conversion parts formed on the semiconductor substrate; a plurality of microlenses provided on the semiconductor substrate. On the bottom, corresponding to each of the above-mentioned photoelectric conversion parts, located above the above-mentioned photoelectric conversion part; The optical film is arranged in a two-dimensional shape; among the above-mentioned plurality of photoelectric conversion parts, there are a first photoelectric conversion part and a second photoelectric conversion part, and the second photoelectric conversion part is located at a position higher than the filter film above the first photoelectric conversion part. Below the filter film for longer wavelength light; the refractive index of the microlens above the second photoelectric conversion part is greater than the refractive index of the microlens above the first photoelectric conversion part.

By adopting the above-mentioned structure, in the solid-state imaging device according to the present invention, the refractive index of the microlens formed on or under the color filter film that transmits long-wavelength light can be made higher than that of the microlens formed on the color filter film that transmits short-wavelength light. The microlenses above or below the film have a large refractive index. As a result, it is possible to increase the condensing efficiency of long-wavelength light that is difficult to condense, and to significantly increase the sensitivity of the photoelectric conversion unit that photoelectrically converts long-wavelength light. As a result, even when the light-receiving unit is miniaturized and the opening width of the light-shielding film is reduced, the light concentrating rate can be improved, and the amount of light passing through the narrow opening of the light-shielding film can be increased, making it possible to make a A compact solid-state imaging device with improved sensitivity.

Furthermore, in order to achieve the above object, the solid-state imaging device of the present invention is characterized by comprising: a semiconductor substrate; a plurality of photoelectric conversion parts formed on the semiconductor substrate; a plurality of microlenses provided on the semiconductor substrate. On the bottom, corresponding to each of the above-mentioned photoelectric conversion parts, located above the above-mentioned photoelectric conversion part; The optical film is arranged in a two-dimensional shape; the above-mentioned microlens is composed of a low-refractive index material and a high-refractive-index material; among the above-mentioned plurality of photoelectric conversion parts, there are a first photoelectric conversion part and a second photoelectric conversion part, and the second photoelectric conversion part The volume of the high refractive index material contained in the above-mentioned microlens located above the second photoelectric conversion part is lower than that of the filter film above the above-mentioned first photoelectric conversion part. The high-refractive-index material contained in the microlens above the first photoelectric conversion portion is bulky, and the high-refractive-index material is a high-refractive-index material having a refractive index of 1.8 or higher.

By adopting the above-mentioned structure, the microlens is composed of multiple materials of low refractive index material and high refractive index material, and by changing the volume ratio, the average value of the microlens above or below the color filter that transmits light in the long wavelength band The refractive index is larger than the average refractive index of the microlens above or below the color filter that transmits light in the short-wavelength band. As a result, it is possible to increase the condensing efficiency of long-wavelength light that is difficult to condense, and to significantly increase the sensitivity of the photoelectric conversion unit that photoelectrically converts long-wavelength light.

Furthermore, in order to achieve the above object, the solid-state imaging device of the present invention is characterized by comprising: a semiconductor substrate; a plurality of photoelectric conversion parts formed on the semiconductor substrate; a plurality of microlenses provided on the semiconductor substrate above, corresponding to each of the above-mentioned photoelectric conversion parts above the above-mentioned photoelectric conversion part; The film is arranged in a two-dimensional shape; among the above-mentioned plurality of photoelectric conversion parts, there are a first photoelectric conversion part and a second photoelectric conversion part, and the second photoelectric conversion part is located above the filter film above the first photoelectric conversion part, and transmits The height of the microlens located above the second photoelectric conversion part under the filter film for longer wavelength light is higher than that of the micro lens located above the first photoelectric conversion part.

By adopting the above structure, the height of the microlenses formed on or under the color filter that transmits long-wavelength light can be made higher than the height of the microlens formed on or under the color filter that transmits short-wavelength light . As a result, it is possible to increase the condensing efficiency of long-wavelength light that is difficult to condense, and to significantly increase the sensitivity of the photoelectric conversion unit that photoelectrically converts long-wavelength light.

Furthermore, in order to achieve the above object, the refractive index of the microlens located above the second photoelectric conversion unit may be larger than the refractive index of the micro lens located above the first photoelectric conversion unit.

By adopting the above-mentioned structure, the refractive index of the microlens formed on or under the color filter that transmits light with a long wavelength is higher than that of the microlens formed on or under the color filter that transmits light with a short wavelength. The rate is high. As a result, in addition to the effect of increasing the lens height, the effect of increasing the refractive index can be further improved, so the light-concentrating ratio of light in the long-wavelength band can be further improved, and therefore the performance of the photoelectric conversion part that performs photoelectric conversion of long-wavelength light can be greatly improved. sensitivity.

Also, in order to achieve the above object, the material constituting the above microlens may be any one of titanium oxide, tantalum oxide, niobium oxide and hafnium oxide.

As in the above structure, microlenses can be made of high-refractive-index materials such as titanium oxide, tantalum oxide, niobium oxide, or hafnium oxide. Compared with silicon oxide films with a refractive index of 1.45, which are generally used as insulating films, they can achieve an extremely large refractive index. . As a result, the concentration ratio of light in the long-wavelength band can be improved, and thus the sensitivity of the photoelectric conversion portion that photoelectrically converts long-wavelength light can be greatly improved.

Furthermore, in order to achieve the above object, the solid-state imaging device of the present invention is characterized by comprising: a semiconductor substrate; a plurality of photoelectric conversion parts formed on the semiconductor substrate; a high refractive index film provided on the semiconductor substrate. and a color filter arranged on the above-mentioned semiconductor substrate, corresponding to each of the above-mentioned photoelectric conversion parts above the above-mentioned photoelectric conversion part, and the filter films with different transmission wavelength bands are arranged in a 2-dimensional shape; in the above-mentioned multiple photoelectric conversion parts There are a first photoelectric conversion part and a second photoelectric conversion part in the part, and the second photoelectric conversion part is located below the filter film above the first photoelectric conversion part and the filter film that transmits light with a longer wavelength; The high refractive index film above the second photoelectric conversion part has a higher refractive index than the high refractive index film above the first photoelectric conversion part. Made of high refractive index material.

By adopting the above-mentioned structure, the refractive index of the high-refractive-index film positioned on or under the color filter that transmits light in the long-wavelength band is higher than that of the high-refractive film positioned on or under the color filter that transmits light in the short-wavelength band. The refractive index of the rate film is large. As a result, when the light in the long wavelength band, which is difficult to condense, enters the light-receiving unit at a relatively large incident angle, the light incident at a large incident angle tends to be bent and incident toward the photoelectric conversion part by the high-refractive index film, Therefore, the sensitivity of the photoelectric conversion portion for photoelectrically converting light in a long wavelength band can be greatly improved.

Furthermore, in order to achieve the above object, the solid-state imaging device of the present invention is characterized by comprising: a semiconductor substrate; a plurality of photoelectric conversion parts formed on the semiconductor substrate; a high refractive index film provided on the semiconductor substrate. and a color filter arranged on the above-mentioned semiconductor substrate, corresponding to each of the above-mentioned photoelectric conversion parts above the above-mentioned photoelectric conversion part, and the filter films with different transmission wavelength bands are arranged in a 2-dimensional shape; in the above-mentioned multiple photoelectric conversion parts There are a first photoelectric conversion part and a second photoelectric conversion part in the part, and the second photoelectric conversion part is located below the filter film above the first photoelectric conversion part and the filter film that transmits light with a longer wavelength; The high refractive index film above the second photoelectric conversion part is thicker than the high refractive index film above the first photoelectric conversion part.

By adopting the above-mentioned structure, the film thickness of the high-refractive index layer located above or below the color filter that transmits light in the long-wavelength band is higher than that of the film located above or below the color filter that transmits light in the short-wavelength band. The film thickness of the refractive index film is large. As a result, when light in the long-wavelength band that is difficult to condense enters the light-receiving unit at a large incident angle, the light incident at a large incident angle is easily bent in the direction of the photoelectric conversion part by the thick high-refractive index film. Therefore, the sensitivity of the photoelectric conversion part that photoelectrically converts long-wavelength light can be greatly improved.

Also, in order to achieve the above object, the material constituting the above high refractive index film may contain any one of phthalein oxide, tantalum oxide, niobium oxide and hafnium oxide.

With the above structure, high refractive index materials such as titanium oxide, tantalum oxide, niobium oxide, or hafnium oxide are used for the high refractive index film. Compared with the case of silicon oxide film with a refractive index of 1.45, which is generally used as an insulating layer, it is possible to achieve extra large refractive index. As a result, the condensing rate of light in the long wavelength band can be improved, and thus the sensitivity of the photoelectric conversion unit that photoelectrically converts light in the long wavelength band can be greatly improved.

In order to achieve the above object, the solid-state imaging device of the present invention is characterized in that it has: a semiconductor substrate; a plurality of photoelectric conversion parts, and a plurality of microlenses, which are arranged on the above-mentioned semiconductor substrate and correspond to each of the above-mentioned photoelectric conversion parts Located above the photoelectric conversion part; among the above-mentioned plurality of photoelectric conversion parts, there are a first photoelectric conversion part and a second photoelectric conversion part, and the second photoelectric conversion part is larger than the incident angle of light entering the first photoelectric conversion part The incident light is incident at an angle of incidence; the refractive index of the microlens located above the second photoelectric conversion part is larger than the refractive index of the microlens located above the first photoelectric conversion part.

By adopting the above structure, in the solid-state imaging device according to the present invention, the refractive index of the microlens of the light receiving unit having a large light incident angle is larger than the refractive index of the microlens of the light receiving unit having a small light incident angle, so the light incident can be improved. The light-gathering ratio of the light-receiving unit with a large angle greatly improves the sensitivity. As a result, even when the light-receiving unit is miniaturized and the opening width of the light-shielding film is reduced, the light concentrating rate can be increased, and the amount of light passing through the narrow opening of the light-shielding film can be increased, and the sensitivity can be greatly improved. small solid-state imaging devices.

Furthermore, in order to achieve the above object, the solid-state imaging device of the present invention is characterized by comprising: a semiconductor substrate; a plurality of photoelectric conversion parts formed on the semiconductor substrate; and a plurality of microlenses provided on the semiconductor substrate. On the substrate, corresponding to each of the above-mentioned photoelectric conversion parts is located above the above-mentioned photoelectric conversion part; the above-mentioned microlens is made of low refractive index material and high refractive index material; a photoelectric conversion part, the second photoelectric conversion part is incident with an incident angle larger than the incident angle of light incident on the first photoelectric conversion part; The volume of the index material is larger than the volume of the high-refractive-index material contained in the microlens located above the first photoelectric conversion part, and the high-refractive-index material is a high-refractive-index material having a refractive index of 1.8 or more.

By adopting the above-mentioned structure, the microlens is composed of multiple materials of low refractive index material and high refractive index material, and its volume ratio is changed, so that the average refractive index of the microlens of the light receiving unit with a large light incident angle can be made smaller than the light incident angle. The average refractive index of the microlens of the light receiving unit is large. As a result, it is possible to increase the condensing rate of the light-receiving unit having a large incident angle of light which is difficult to condense, and it is possible to significantly improve the sensitivity.

Furthermore, in order to achieve the above object, the solid-state imaging device of the present invention is characterized by comprising: a semiconductor substrate; a plurality of photoelectric conversion parts formed on the semiconductor substrate; and a plurality of microlenses provided on the semiconductor substrate. On the substrate, corresponding to each of the above-mentioned photoelectric conversion parts is located above the above-mentioned photoelectric conversion part; there are a first photoelectric conversion part and a second photoelectric conversion part in the above-mentioned plurality of photoelectric conversion parts, and the second photoelectric conversion part is incident on the above-mentioned Light is incident at a larger incident angle of light to the first photoelectric conversion unit; the height of the microlens above the second photoelectric conversion unit is higher than that of the microlens above the first photoelectric conversion unit.

With the above structure, the height of the microlenses of the light-receiving unit with a large light incident angle is higher than the average height of the microlenses of the light-receiving unit with a small light incident angle, so the sensitivity of the light-receiving unit with a large light incident angle can be greatly improved.

Furthermore, in order to achieve the above object, the refractive index of the microlens located above the second photoelectric conversion part may be larger than the refractive index of the microlens above the first photoelectric conversion part.

By adopting the above structure, the refractive index of the microlens of the light receiving unit having a large light incident angle is larger than the refractive index of the microlens of the light receiving unit having a small light incident angle, so that the sensitivity of the light receiving unit having a large light incident angle can be greatly improved. .

Furthermore, in order to achieve the above object, the material constituting the above microlens may also contain any one of titanium oxide, tantalum oxide, niobium oxide and hafnium oxide.

As in the above-mentioned structure, high refractive index materials such as titanium oxide, tantalum oxide, niobium oxide, and hafnium oxide are used for the microlenses, so that, compared with the case of a silicon oxide film with a refractive index of 1.45, which is generally used as an insulating film, it is possible to realize The extremely large refractive index can greatly improve the sensitivity of the light-receiving unit with a large light incident angle.

Furthermore, in order to achieve the above object, the solid-state imaging device of the present invention is characterized by comprising: a semiconductor substrate; a plurality of photoelectric conversion parts formed on the semiconductor substrate; and a high refractive index film provided on the semiconductor substrate. On the substrate; among the above-mentioned plurality of photoelectric conversion parts, there are a first photoelectric conversion part and a second photoelectric conversion part, and the second photoelectric conversion part has a larger incident angle than the incident angle of light incident on the first photoelectric conversion part. Incident light: The refractive index of the above-mentioned high-refractive index film positioned above the above-mentioned second photoelectric conversion part is larger than the refractive index of the above-mentioned high-refractive index film positioned above the above-mentioned first photoelectric conversion part, and the above-mentioned high-refractive index film has 1.8 The above refractive index is made of high refractive index material.

By adopting the above-mentioned structure, the refractive index of the high-refractive index film in the light-receiving unit with a large light-incident angle is larger than the refractive index of the high-refractive-index film in the light-receiving unit with a small light-incident angle. The high-refractive-index film inside the cell can bend the light incident at a relatively large incident angle toward the direction of the photoelectric conversion unit, so the sensitivity of the light-receiving unit with a large incident angle of light can be greatly improved.

Furthermore, in order to achieve the above object, the solid-state imaging device of the present invention is characterized by comprising: a semiconductor substrate; a plurality of photoelectric conversion parts formed on the semiconductor substrate; and a high refractive index film provided on the semiconductor substrate. On the substrate; among the above-mentioned plurality of photoelectric conversion parts, there are a first photoelectric conversion part and a second photoelectric conversion part, and the second photoelectric conversion part has a larger incident angle than the incident angle of light incident on the first photoelectric conversion part. Incident light: the high refractive index film located above the second photoelectric conversion part is thicker than the high refractive index film located above the first photoelectric conversion part.

By adopting the above-mentioned structure, the film thickness of the high-refractive index film in the light-receiving unit with a large light incident angle is thicker than the film thickness of the high-refractive-index film in the light-receiving unit with a small light incident angle. The high-refractive index film of the light-receiving unit can bend the light incident at a relatively large incident angle toward the direction of the photoelectric conversion part, so the sensitivity of the light-receiving unit having a large incident angle can be greatly improved.

Furthermore, in order to achieve the above object, the material constituting the high refractive index layer may contain any one of titanium oxide, tantalum oxide, niobium oxide, and hafnium oxide.

As in the above-mentioned structure, high-refractive-index materials such as titanium oxide, tantalum oxide, niobium oxide, and hafnium oxide are used for the high-refractive index film, so that compared with the case of a silicon oxide film with a refractive index of 1.45 that is generally used as an insulating film, Realizing a super large refractive index can greatly improve the sensitivity of the light receiving unit with a large light incident angle.

In order to achieve the above object, a solid-state imaging device according to the present invention is characterized in that a plurality of light-receiving units having a photoelectric conversion portion for generating signal charges according to the brightness of incident light are formed on a semiconductor substrate, and a photoelectric conversion portion has a The microlens includes a first light receiving unit having a first opening width and a second light receiving unit having a second opening width larger than the first opening width among the plurality of light receiving units, and the microlens of the first light receiving unit The refractive index is larger than the refractive index of the microlens of the second light receiving unit.

As described above, in the solid-state imaging device of the present invention, the refractive index of the microlens of the light receiving unit having a small opening width is set higher than the refractive index of the microlens of the light receiving unit having a large opening width. As a result, it is possible to simultaneously optimize the light collection efficiency of the light-receiving unit having a small opening width and the light-receiving unit having a large opening width, and greatly improve the sensitivity of the light-receiving unit having two opening widths. As a result, even when the light-receiving unit is miniaturized and the opening width of the light-shielding film is reduced, the light-concentrating rate can be increased, and the amount of light passing through the narrow opening of the light-shielding film can be increased, and the sensitivity can be greatly improved. Small solid-state imaging device.

In order to achieve the above object, a solid-state imaging device according to the present invention is characterized in that a plurality of light-receiving units having a photoelectric conversion portion for generating signal charges according to the brightness of incident light are formed on a semiconductor substrate, and a photoelectric conversion portion has a The microlens includes a first light receiving unit having a first opening width and a second light receiving unit having a second opening width larger than the first opening width among the plurality of light receiving units, and the microlens of the first light receiving unit and the microlens of the second light receiving unit are formed of at least a low refractive index material and a high refractive index material respectively, and the volume of the high refractive index material contained in the microlens of the first light receiving unit is higher than that of the microlens of the second light receiving unit The volume of the high-refractive-index material contained in is large, and the above-mentioned high-refractive-index material is a high-refractive-index material having a refractive index of 1.8 or more.

Like this, under the situation that microlens is made of low-refractive-index material and high-refractive-index material, make the volume of the high-refractive-index material contained in the microlens of light-receiving unit with opening width smaller than the microlens of light-receiving unit with opening width be larger. The high refractive index material contained in the lens has a large volume, so that the average refractive index of the microlenses of the light receiving unit with a small opening width is larger than that of the microlenses of the light receiving unit with a large opening width. As a result, it is possible to simultaneously optimize the light collection efficiency of the light-receiving unit having a small aperture width and the light-receiving unit having a large aperture width, and greatly improve the sensitivity of a light-receiving unit having two aperture widths.

In order to achieve the above object, a solid-state imaging device according to the present invention is characterized in that a plurality of light-receiving units having a photoelectric conversion portion for generating signal charges according to the brightness of incident light are formed on a semiconductor substrate, and a photoelectric conversion portion has a The microlens includes a first light receiving unit having a first opening width and a second light receiving unit having a second opening width larger than the first opening width among the plurality of light receiving units, and has a light receiving unit disposed on the first light receiving unit. The first high refractive index interlayer film on the unit, and the second high refractive index interlayer film disposed on the second light receiving unit, the refractive index of the first high refractive index interlayer film is higher than that of the second high refractive index The interlayer film has a high refractive index, and the first high-refractive-index interlayer film and the second high-refractive-index interlayer film are made of a high-refractive-index material having a refractive index of 1.8 or higher.

In this way, the refractive index of the high-refractive-index interlayer film on the light-receiving unit with a small opening width is larger than that of the high-refractive-index interlayer film on the light-receiving unit with a large opening width. The high-refractive-index interlayer film on the light-receiving unit can bend light incident at a relatively large incident angle toward the direction of the photoelectric conversion unit. As a result, it is possible to simultaneously optimize the light collection efficiency of the light-receiving unit having a small aperture width and the light-receiving unit having a large aperture width, and greatly improve the sensitivity of a light-receiving unit having two aperture widths.

In order to achieve the above object, a solid-state imaging device according to the present invention is characterized in that a plurality of light-receiving units having a photoelectric conversion portion for generating signal charges according to the brightness of incident light are formed on a semiconductor substrate, and a photoelectric conversion portion has a The microlens includes a first light receiving unit having a first opening width and a second light receiving unit having a second opening width larger than the first opening width among the plurality of light receiving units, and has a light receiving unit disposed on the first light receiving unit. The first high-refractive-index interlayer film on the unit, and the second high-refractive-index interlayer film disposed on the second light-receiving unit, the film thickness of the first high-refractive-index interlayer film is greater than that of the second high-refractive-index interlayer film The film thickness of the interlayer film is thick.

In this way, the film thickness of the high-refractive-index interlayer film on the light-receiving unit with a small opening width is thicker than the film thickness of the high-refractive-index interlayer film on the light-receiving unit with a large opening width. The high-refractive-index interlayer film on the light-receiving unit can bend light incident at a relatively large incident angle toward the direction of the photoelectric conversion unit. As a result, it is possible to simultaneously optimize the light collection efficiency of the light-receiving unit having a small aperture width and the light-receiving unit having a large aperture width, and greatly improve the sensitivity of a light-receiving unit having two aperture widths.

In order to achieve the above object, it is characterized in that a plurality of light-receiving units having photoelectric conversion sections that generate signal charges according to the brightness of incident light are formed on a semiconductor substrate, microlenses are provided on the above-mentioned photoelectric conversion sections, There are a first light receiving unit with a first opening width and a second light receiving unit with a second opening width larger than the first opening width in the unit, and the height of the microlens of the first light receiving unit is higher than that of the second light receiving unit. The height of the microlens is high.

In this way, the height of the microlens on the light receiving unit with a small opening width is higher than the height of the microlens on the light receiving unit with a large opening width. As a result, it is possible to simultaneously optimize the light collection efficiency of the light-receiving unit having a small aperture width and the light-receiving unit having a large aperture width, and greatly improve the sensitivity of a light-receiving unit having two aperture widths.

Furthermore, it is characterized in that the refractive index of the microlens of the second light receiving unit is larger than the refractive index of the microlens of the first light receiving unit. In this way, the refractive index of the microlenses on the light receiving unit with a smaller opening width is made larger than the refractive index of the microlenses on the light receiving unit with a larger opening width. As a result, it is possible to simultaneously optimize the condensing efficiency of the light receiving unit having a small opening width and the light receiving unit having a large opening width, and greatly improve the sensitivity of the light receiving unit having two opening widths.

It is characterized in that the material of the microlens or the interlayer film at least contains titanium oxide, tantalum oxide, niobium oxide and hafnium oxide. In this way, by using high-refractive index materials such as titanium oxide, tantalum oxide, niobium oxide, and hafnium oxide, a particularly large refractive index can be obtained compared with the case of a silicon oxide film with a refractive index of 1.45 that is generally used as an insulating film. Therefore, The light gathering ratio of the light receiving unit with small opening width and the light receiving unit with large opening width can be optimized at the same time, and the sensitivity of the light receiving unit with two opening widths can be greatly improved.

Invention effect

In the solid-state imaging device of the present invention, a high-refractive-index material with a high refractive index is used for the opening of the light-shielding film formed on the photoelectric conversion part, and even when the width of the opening is narrowed, the light transmitted through the opening can be kept. The transmission wavelength band is relatively large. In this way, even when the size of the light receiving unit and the aperture of the solid-state imaging device are reduced, it is possible to prevent a significant decrease in sensitivity on the long-wavelength side, and achieve miniaturization and high sensitivity. Furthermore, the high-refractive-index material that fills the opening is also formed continuously above the opening for flattening, thereby reducing the diffuse reflection of light above the opening, and suppressing sensitivity unevenness among light-receiving units while preventing a decrease in sensitivity. , capable of achieving high image quality. In addition, after the high-refractive-index material filling the opening is continuously formed on the opening, microlenses are formed using the high-refractive-index material to realize a high-sensitivity, high-signal-to-noise ratio solid-state imaging device. A camera that achieves high image quality.

In the solid-state imaging device of the present invention, the refractive index of the microlens, the volume of the high-refractive-index material constituting the microlens or the height of the microlens, or the high-refractive-index The refractive index of the material or the film thickness of the high refractive index material, the refractive index of the microlens formed above or below the color filter that transmits short-wavelength light, the volume of the high refractive index material constituting the microlens, or the volume of the microlens The height, or the refractive index of the high-refractive index material or the film thickness of the high-refractive index material is different, and the light-concentrating rate of light in the long-wavelength band can be improved, and the photoelectric conversion part for photoelectrically converting long-wavelength light can be greatly improved. sensitivity. In this way, a solid-state imaging device with high sensitivity and high S/N ratio can be realized, and it can be said that the present invention is effective for realizing a camera with high image quality.

In the solid-state imaging device of the present invention, the refractive index of the microlens, the volume of the high refractive index material constituting the microlens or the height of the microlens, or the refractive index of the high refractive index material formed in the light receiving unit with a large incident angle of light Or the film thickness of the high refractive index material, the refractive index of the microlens formed by the light receiving unit with a small incident angle of light, the volume of the high refractive index material constituting the microlens or the height of the microlens, or the height of the high refractive index material The film thickness of the refractive index or the high-refractive index material is different, and the sensitivity of the light-receiving unit with a large incident angle of light can be greatly improved. In this way, a solid-state imaging device with high sensitivity and a high signal-to-noise ratio can be realized. Therefore, it can be said that the present invention is effective for realizing a camera with high image quality.

In the solid-state imaging device of the present invention, the refractive index of the microlens, the volume of the high refractive index material of the microlens, the height of the microlens, the refractive index of the high refractive index material, or The film thickness of the high refractive index material is related to the refractive index of the microlens formed on the light receiving unit with a large opening width, the volume of the high refractive index material of the microlens, the height of the microlens, the refractive index of the high refractive index material, Alternatively, the film thickness of the high-refractive-index material is different, and the sensitivity of the light-receiving unit with a large incident angle of light can be greatly improved. In this way, a solid-state imaging device with high sensitivity and high S/N ratio can be realized, and it can be said that the solid-state imaging device of the present invention is effective for realizing a camera with high image quality.

Description of drawings

FIG. 1 is a diagram showing a camera using a solid-state imaging device.

FIG. 2 is a diagram showing an arrangement of light receiving cells of a conventional solid-state imaging device.

3 is a cross-sectional view showing a light receiving unit of a conventional solid-state imaging device.

FIG. 4 is a diagram showing how light enters a conventional solid-state imaging device (light receiving unit).

5 is a cross-sectional view showing a light-receiving unit of a conventional solid-state imaging device (a light-receiving unit located at a central portion A and a peripheral portion C).

FIG. 6 is a diagram showing an arrangement of light-receiving cells of a solid-state imaging device featuring a wide dynamic range.

7 is a cross-sectional view showing light receiving units A and B of a conventional solid-state imaging device characterized by a wide dynamic range.

8 is a cross-sectional view of a light receiving unit of the solid-state imaging device according to Embodiment 1 of the present invention.

FIG. 9 is a graph showing transmission characteristics of a color filter layer and openings.

10 is a cross-sectional view showing a method of forming a structure on a light-shielding film in the light-receiving unit of the solid-state imaging device according to Embodiment 1 of the present invention.

11 is a cross-sectional view showing a light receiving unit of a solid-state imaging device according to Embodiment 2 of the present invention.

12 is a cross-sectional view showing a method of forming a structure on a light-shielding film in a light-receiving unit of a solid-state imaging device according to Embodiment 2 of the present invention.

13 is a cross-sectional view of a light receiving unit of a solid-state imaging device according to Embodiment 3 of the present invention.

14 is a cross-sectional view of a light receiving unit of a solid-state imaging device according to Embodiment 4 of the present invention.

15 is a cross-sectional view of a light receiving unit of a solid-state imaging device according to Embodiment 5 of the present invention.

16 is a cross-sectional view of a light receiving unit of a solid-state imaging device according to Embodiment 6 of the present invention.

17 is a cross-sectional view of a light receiving unit of a solid-state imaging device according to Embodiment 7 of the present invention.

18 is a cross-sectional view of a light receiving unit of a solid-state imaging device according to Embodiment 8 of the present invention.

19 is a cross-sectional view of a light receiving unit of a solid-state imaging device according to Embodiment 9 of the present invention.

20 is a diagram showing how light enters the solid-state imaging device (light receiving unit) according to Embodiment 10 of the present invention.

21 is a cross-sectional view of a light-receiving unit (a light-receiving unit located at a central portion A and a peripheral portion C) of a solid-state imaging device according to Embodiment 10 of the present invention.

22 is a cross-sectional view of a light-receiving unit (light-receiving unit located at a central portion A and a peripheral portion C) of a solid-state imaging device according to Embodiment 11 of the present invention.

23 is a cross-sectional view of a light-receiving unit (a light-receiving unit located at a central portion A and a peripheral portion C) of a solid-state imaging device according to Embodiment 12 of the present invention.

24 is a cross-sectional view of a light-receiving unit (light-receiving unit located at the central portion A and peripheral portion C) of the solid-state imaging device according to Embodiment 13 of the present invention.

25 is a cross-sectional view of a light-receiving unit (light-receiving unit located at the central portion A and peripheral portion C) of the solid-state imaging device according to Embodiment 14 of the present invention.

26 is a cross-sectional view of a light-receiving unit (light-receiving unit located at the central portion A and peripheral portion C) of the solid-state imaging device according to Embodiment 15 of the present invention.

27 is a cross-sectional view of light receiving units A and B of the solid-state imaging device according to Embodiment 16. FIG.

28 is a cross-sectional view of light receiving units A and B of the solid-state imaging device according to Embodiment 17. FIG.

29 is a cross-sectional view of light receiving units A and B of the solid-state imaging device according to Embodiment 18. FIG.

30 is a cross-sectional view of light receiving units A and B of the solid-state imaging device according to Embodiment 19. FIG.

31 is a cross-sectional view of light receiving units A and B of the solid-state imaging device according to Embodiment 20. FIG.

32 is a cross-sectional view of light receiving units A and B of the solid-state imaging device according to Embodiment 21. FIG.

Detailed ways

The solid-state imaging device according to the embodiment of the present invention will be described in detail below with reference to the drawings. In addition, the following embodiments do not limit the present invention.

(Embodiment 1)

8 is a cross-sectional view of light receiving units 111a, 111b, and 111c of the solid-state imaging device according to Embodiment 1 of the present invention. The semiconductor substrate 11, photoelectric conversion layer 12, and insulating layer 13 of each light receiving unit have the same structure as that of the conventional light receiving unit shown in FIG. 3 .

The metal layer 114 is a layer including the light-shielding film 19 and the in-layer lens 30 as in the conventional solid-state imaging device, but in the solid-state imaging device according to Embodiment 1 of the present invention, the metal layer 114 is embedded in the Form the opening 20 of the light-shielding film 19 in the same way as the high-refractive-index layer 125 made of a high-refractive-index material. The inner lens 30 has an interlayer film 31 formed on the inner lens 30 . Also, the color filter layer 15 including the interlayer film 22 is formed on the metal layer 114 , and the microlens 23 is formed on the color filter layer 15 .

In the solid-state imaging device according to Embodiment 1, the light condensed by the microlens 23 and passed through the color filter layer 15 is condensed by the in-layer lens 30 again, passes through the opening 20 in which the high refractive index layer 125 is formed, and reaches the photoelectric sensor. Transformation section 17.

Here, the opening 20 has an opening width smaller than the maximum wavelength of the light incident on the photoelectric conversion unit 17 converted into a wavelength in vacuum. That is, it has an aperture width smaller than the maximum wavelength of red (R) color light in vacuum. Furthermore, the high-refractive-index material has a refractive index such that light having a maximum wavelength converted into a wavelength in vacuum transmits light entering the photoelectric conversion portion 17 through the opening 20 . That is, it has a refractive index capable of transmitting red (R) light that enters the photoelectric conversion portion 17 through the opening portion 20 .

FIG. 9 is a graph showing the transmission characteristics of the color filter layer 15 and the opening 20 .

It is well known that light having a wavelength equal to or greater than the wavelength close to the width of the opening 20 among the light incident on the opening 20 hardly passes through the opening 20 and is blocked. When the width of the opening 20 is wide (for example, 2 μm or more), since the width of the opening 20 is large, the cutoff wavelength 101 is on the longer wavelength side than the red spectrum. Therefore, light transmitted through the color filters of red (R), green (G), and blue (B) spectrums can be transmitted through the openings 20 , respectively. However, when the width of the opening 20 is narrowed as the light receiving elements 111a, 111b, and 111c are miniaturized, the cutoff wavelength 102 becomes the transmission wavelength of the red (R) color filter 21c due to the narrowing of the opening 20. the following. As a result, in the opening 20 under the red (R) color filter 21c, the transmittance of red light may be extremely small, and the amount of light reaching the photoelectric conversion portion 17 may decrease, possibly causing a decrease in sensitivity. In the solid-state imaging device of the present invention, the high-refractive-index layer 125 is formed in the opening 20 in order to solve this problem. By using the high-refractive-index layer 125 in the opening 20, the wavelength of light passing through the opening 20 can be reduced to one-half of the refractive index (1/(refractive index=N) relative to the wavelength in vacuum. ). For example, when titanium oxide (TiO ₂ ) with a refractive index of 2.5 is used as the high refractive index layer 125, the wavelength of light transmitted through the opening 20 is 1/2.5 of the wavelength in vacuum, and is 650 nm in vacuum. The wavelength of the red light becomes 260 nm in the opening 20 . Therefore, for example, in the opening 20 having an opening width of 650 nm, the wavelength of red light of 650 nm in vacuum becomes a wavelength of 260 nm. As a result, the wavelength of red light in the opening 20 is 260 nm (650 nm in vacuum), which is very small relative to the opening width of 650 nm, and the red light can sufficiently pass through the opening 20 .

In the case of considering the cut-off wavelength, the refractive index in the opening 20 is 1. For example, the cut-off wavelength is converted into the wavelength in vacuum, and the cut-off wavelength of the opening 20 with an aperture width of 650 nm is obtained by using titanium oxide (TiO) with a high refractive index of 2.5. ₂ ) The inside of the opening 20 is filled so that the refractive index inside the opening 20 is 2.5, which is 1625nm which is 2.5 times the cutoff wavelength of 650nm in terms of vacuum. Therefore, filling the opening 20 with a high-refractive-index material with a refractive index of N can expand the cut-off wavelength in a vacuum that can pass through the opening 20 by N times. As shown in FIG. 9 , the cutoff wavelength 103 is made larger than that of visible light. That is to say, even when the width of the opening 20 is reduced, by using a material with a high refractive index as the material filling the opening 20, the cutoff wavelength can be shifted to the long wavelength side, so it is possible to expand the wavelength on the long wavelength side. The transmission band can improve the sensitivity on the long wavelength side.

Furthermore, since the width of the high-refractive-index material located in the opening 20 is made the same as the width of the opening 20 , the maximum cutoff wavelength can be realized.

Furthermore, titanium oxide having a refractive index of 2.5 is exemplified as a high-refractive-index material constituting the above-mentioned high-refractive-index layer 125 . However, by setting the refractive index in the opening 20 to 1.8 or more, even in the case where the width of the opening 20 is 1.0 μm or less, it is possible to make visible light with a wavelength near red and a long wavelength near 1.0 to 2.0 μm. Light of longer wavelengths such as infrared light is transmitted, so the high refractive index material filling the opening 20 is not limited to titanium oxide if it has a refractive index of 1.8 or higher, especially 2.2 or higher.

In addition, the thickness 28 of the high refractive index material shown in FIG. 8 is approximately the same as the thickness 27 of the opening 20, that is, the thickness of the light shielding film 19, or is larger than the thickness 27 of the opening 20, and the opening 20 is completely filled with the high refractive index material. buried. In this way, the cut-off wavelength of the opening 20 converted into the wavelength in vacuum can be shifted to the long-wavelength side to the maximum, so the transmission wavelength band on the long-wavelength side can be expanded, and the sensitivity on the long-wavelength side can be improved.

Furthermore, the high refractive index material filling the opening 20 is compared with the refractive index (about 1.5) of silicon oxide, which is generally used as an insulating layer, by using silicon nitride, titanium oxide, tantalum oxide, niobium oxide, etc. In particular, the refractive index can be increased, the cut-off wavelength of the opening 20 converted into the wavelength in vacuum can be shifted to the long-wavelength side to the maximum, the transmission wavelength band on the long-wavelength side can be further expanded, and the sensitivity on the long-wavelength side can be further improved.

In addition, in the solid-state imaging device according to Embodiment 1, visible light is exemplified as incident light, but the same effect can be confirmed for the wavelength of near-infrared light, so the photoelectric conversion of silicon is equivalent to the wavelength of near-infrared light. Light in a frequency band of 1.0 μm or less also has a large effect of expanding the transmission band of the wavelength to the long wavelength side, and can achieve a significant improvement in sensitivity.

10 is a cross-sectional view showing a method of forming the structure on the light-shielding film 19 in the light-receiving units 111a, 111b, and 111c of the solid-state imaging device according to Embodiment 1 of the present invention. 10 shows the steps from the step of forming the opening 20 to the step of forming the interlayer film 29 above the light shielding film 19 in the light receiving units 111 a , 111 b , and 111 c of the solid-state imaging device according to the first embodiment.

In this formation method, first, a patterned resist is formed on the light shielding film 19 . That is, a resist is formed on the light-shielding film 19, and the resist is removed in the region where the opening 20 is formed. Then, a part of light-shielding film 19 is removed using a resist as a mask by dry etching, and a first step of forming opening 20 above photoelectric conversion portion 17 is performed ( FIG. 10( a )).

Then, the following steps are continuously performed: the second step ( FIG. 10 ( b )) of forming a high refractive index layer 125 that transmits light in the opening 20 and on the light shielding film 19 ; The third step of forming the high refractive index layer 125 on the surface (FIG. 10(c)). In this manner, by continuously performing the second step and the third step, the step of planarizing the high refractive index layer 125 on the opening 20 using the high refractive index layer 125 itself can be completed.

Finally, a fourth step of forming an interlayer film 29 on the light shielding film 19 having a lower refractive index than the high refractive index layer 125 is performed ( FIG. 10( d )).

By performing the first to fourth steps above, the structure on the light-shielding film 19 of the light-receiving units 111 a , 111 b , and 111 c of the solid-state imaging device according to Embodiment 1 can be formed. Like the solid-state imaging device of the present invention, especially when the width of the opening 20 is small, after the second step of filling the opening 20 with a high-refractive-index material, if the high-refractive-index material is continuously formed, a gap is formed in the opening 20. For the concave high refractive index material, as the film thickness increases, the width of the concave portion decreases, and finally the left and right side walls of the concave portion contact, and the high refractive index layer 125 can be formed with a flat surface structure. At this time, when the high refractive index material is uniformly attached to the plane and side surfaces of the light-shielding film 19, the film thickness of the high refractive index layer 125 can be made 1/2 or more of the width (d) of the opening 20, so that The recess is flat. The high-refractive-index layer 125 is planarized, so the surface of the interlayer film 29 above the light-shielding film 19 on the high-refractive-index layer 125 can be formed flat, and it is possible to omit cleaning the interlayer film with CMP (Chemical Mechanical Polishing) or the like. 29 The process of planarization can be performed, or the amount and time of polishing such as CMP can be reduced.

When this formation method is applied to a solid-state imaging device having a structure in which the width (d) of the opening 20 is large as in the past, the film thickness (d/2) of the high-refractive index layer 125 for eliminating the above-mentioned concave portion is equivalent to Therefore, the film thickness of the high-refractive index layer 125 increases when planarization is performed by the above-mentioned formation method, and there arises a problem that it is difficult to gather light. Therefore, this forming method is practically effective particularly in the case of a narrow opening 20 in which the width (d) of the opening 20 is 1.5 μm or less.

When the above formation method is used, in terms of the characteristics of the solid-state imaging device, the high refractive index layer 125 on the opening 20 can be easily planarized, so the interlayer film 29 above the high refractive index layer 125 and the light shielding film 19 The unevenness of the interface between them disappears, and the light can be incident on the opening 20 without randomly reflecting light at the interface, so that the decrease in sensitivity can be greatly improved.

In the formation method of FIG. 10, after forming the high refractive index layer 125 to make the surface flattened, the interlayer film 29 on the light shielding film 19 is formed immediately, but it may also be formed after the third step of forming the high refractive index material. A fifth step of planarizing the high refractive index layer 125 by CMP or the like is added. In this way, diffuse reflection of light at the interface between the high-refractive index layer 125 and the interlayer film 29 above the light-shielding film 19 can be further reduced, and the decrease in sensitivity can be greatly improved. In addition, it is possible to minimize the unevenness in the amount of light incident on the opening 20 of each light receiving unit, and it is also possible to greatly improve the unevenness in sensitivity.

(Embodiment 2)

11 is a cross-sectional view of light receiving units 211a, 211b, and 211c of the solid-state imaging device according to Embodiment 2 of the present invention. The semiconductor substrate 11, photoelectric conversion layer 12, and insulating layer 13 of each light receiving unit have the same structure as that of the conventional light receiving unit shown in FIG. 3 .

The metal layer 214 is a layer including the light shielding film 19 as in conventional solid-state imaging devices. However, in the solid-state imaging device according to Embodiment 2 of the present invention, the metal layer 214 has a high-refractive index layer 225 formed to fill the opening 20 of the light-shielding film 19 after forming the light-shielding film 19 . Constructed of high refractive index material. At this time, the high refractive index layer 225 is processed into the shape of a convex in-layer lens. In this way, the interlayer film 29 and the in-layer lens 30 above the light shielding film 19 required in the structure of the conventional solid-state imaging device can be omitted, and the height of the entire light receiving unit can be reduced.

In the solid-state imaging device of Embodiment 2, the incident light 24 passes through the microlens 23 and the color filter layer 15, does not pass through the in-layer lens 30 of the conventional solid-state imaging device, and directly utilizes the high refractive index layer 225. The in-layer lens condenses the light to reach the photoelectric conversion unit 17 . In this way, the high refractive index layer 225 located in the opening 20 has a convex intralayer lens shape, and can collect light directly above the opening 20. Therefore, when the width of the opening 20 is close to the wavelength of visible light, it can Significantly increase the concentration rate.

12 is a cross-sectional view showing a method of forming the structure on the light-shielding film 19 in the light-receiving units 211a, 211b, and 211c of the solid-state imaging device according to Embodiment 2 of the present invention. 12 shows the steps from the manufacturing process of the opening 20 to the forming process of the interlayer film 31 on the light shielding film 19 in the light receiving units 211 a , 211 b , and 211 c of the solid-state imaging device according to the second embodiment.

In this manufacturing method, the first to third steps of forming the high refractive index layer 225 are performed by the same method as the method for forming the solid-state imaging device in Embodiment 1 shown in FIG. c) Afterwards, the fourth to seventh steps of forming intralayer lenses using the formed high refractive index layer 225 itself are additionally performed, and then the eighth step of forming the interlayer film 31 on the light shielding film 19 is performed. The fourth to eighth steps will be described in detail below.

First, a fourth step of applying a resist 32 on the high refractive index layer 225 is performed ( FIG. 12( d )).

Then, the fifth step of exposure and development is performed to leave the resist 32 in the area where the lens is not formed ( FIG. 12( e )).

Next, a sixth step of shaping the remaining resist 32 into a lens shape by heating is performed ( FIG. 12( f )).

Then, a seventh step of forming an in-layer lens using the high refractive index layer 225 by uniformly etching the lens-shaped resist 32 and the high refractive index layer 225 is performed ( FIG. 12( g )).

Finally, an eighth step of forming an interlayer film 31 on the light shielding film 19 is performed ( FIG. 12( h )).

As described above, since the fourth to seventh steps of forming the in-layer lens using the high-refractive index layer 225 are performed, it is possible to eliminate the special film-forming process required for the conventional in-layer lens and reduce the number of steps for manufacturing a solid-state imaging device. Therefore, a low-cost solid-state imaging device can be provided. Furthermore, since the in-layer lens is located directly in front of the light shielding film 19, even when the width of the opening 20 is small, light can be collected efficiently and high sensitivity can be realized.

(Embodiment 3)

13 is a cross-sectional view of light receiving units 311a, 311b, and 311c of the solid-state imaging device according to Embodiment 3 of the present invention.

The solid-state imaging device of Embodiment 3 is different from the solid-state imaging device of Embodiment 1 in that the insulating layer 13 , the insulating layer among the metal layer 114 , and the microlens 23 have the same refractive index.

In the solid-state imaging device according to Embodiment 3, the light-receiving unit having a longer transmission wavelength of the optical filter has a larger refractive index of the insulating layer 13 and the metal layer 114 and the microlens 23, and the higher the refractive index of the insulating layer in the filter is. In light-receiving units having different transmission wavelengths of the light sheet, the insulating layer 13 , the insulating layer in the metal layer 114 , and the microlens 23 have different refractive indices. For example, in the long-wavelength light-receiving unit of the optical filter, a material with a large refractive index is used to form the insulating layer 13, the insulating layer in the metal layer 114 and the microlens 23, so that their refractive indices are equal; In the light-receiving unit with a short transmission wavelength of the light sheet, the insulating layer 13, the insulating layer in the metal layer 114, and the microlens 23 are made of a material with a small refractive index, so that their refractive indices are equal. As a result, manufacturing cost can be suppressed. In addition, since long-wavelength light can be collected in the narrow opening, the concentration ratio of long-wavelength light can be increased, and the sensitivity of the photoelectric conversion portion for photoelectrically converting long-wavelength light can be greatly improved.

(Embodiment 4)

14 is a cross-sectional view of light receiving units 411a, 411b, and 411c of the solid-state imaging device according to Embodiment 4 of the present invention. The semiconductor substrate 11, the photoelectric conversion layer 12, the insulating layer 13, the metal layer 14 and the color filter layer 15 of each light receiving unit have the same structure as that shown in FIG. The structure of the solid-state imaging device is substantially the same.

The solid-state imaging device according to Embodiment 4 is configured such that the refractive index of the material constituting the microlens 423 formed on the color filter layer 15 differs depending on the transmission wavelength band of the color filter.

As the miniaturization of the light receiving unit progresses, the width of the opening 20 becomes narrower. For example, when the width of the opening 20 is 2 μm or less, it is difficult to collect light on the opening 20 . In particular, it is well known that it is difficult to condense light when it passes through the red (R) color filter 21 c having a long-wavelength transmission wavelength band. Therefore, in the solid-state imaging device of Embodiment 4, in order to solve this problem, the refractive index of the microlens 423 is increased as the transmission wavelength band of the color filter increases. For example, a silicon oxide film with a refractive index of 1.5 is utilized in the microlens 423 on the blue (B) color filter film 21a with a transmission wavelength band of a short wavelength; A silicon nitride film with a refractive index of 2.0 is utilized in the microlens 423; a titanium oxide film with a refractive index of 2.5 is utilized in the microlens 423 on the red (R) color filter film 21c with a long-wavelength transmission wavelength band to realize A structure in which the refractive index increases as the wavelength becomes longer. In this way, the concentration ratio of long-wavelength light can be improved, and the sensitivity of the photoelectric conversion unit that photoelectrically converts long-wavelength light can be greatly improved.

(Embodiment 5)

15 is a cross-sectional view of light receiving units 511a, 511b, and 511c of the solid-state imaging device according to Embodiment 5 of the present invention.

Each light receiving unit has a semiconductor substrate 11 , a photoelectric conversion layer 12 , an insulating layer 13 , a metal layer 14 and a color filter layer 15 having approximately the same structure as the conventional light receiving unit shown in FIG. 3 .

The solid-state imaging device of Embodiment 5 has the following structure: the microlens 523 formed on the color filter layer 15 of each light-receiving unit is made of a low-refractive-index material 526 (for example, silicon oxide with a refractive index of 1.5), and a low-refractive-index material with a lower refractive index ratio. The high refractive index material 525 (such as silicon nitride with a refractive index of 2.0) is composed of two materials.

In this solid-state imaging device, the constituent ratios of the low-refractive-index material 526 and the high-refractive-index material 525 in the microlenses 523 formed on the color filter layer 15 differ depending on the transmission wavelength band of the color filter. That is, as the transmission wavelength band of the color filter becomes longer, the volume ratio of the high refractive index material 525 of the microlens 523 increases. For example, in the microlens 523 on the blue (B) color filter film 21a with a short-wavelength transmission wavelength band, the volume ratio of the low-refractive index material 526 and the high-refractive index material 525 is set to 9:1; In the microlens 523 on the green (G) color filter film 21b of the transmission wavelength band, the volume ratio of the low refractive index material 526 and the high refractive index material 525 is set to 4:6; R) In the microlens 523 on the color filter film 21c, the volume ratio of the low-refractive-index material 526 and the high-refractive-index material 525 is set to 1:9, so that the volume ratio of the high-refractive-index material 525 becomes longer with the transmission wavelength band. structure that increases with wavelength. In this way, the average refractive index of the microlens above or below the color filter that transmits light in the long wavelength band can be made larger than the average refractive index of the microlens above or below the color filter that transmits light in the short wavelength band. . As a result, it is possible to increase the concentration rate of light in the long wavelength band where light collection is difficult, and to significantly increase the sensitivity of the photoelectric conversion unit that photoelectrically converts light in the long wavelength band.

(Embodiment 6)

16 is a cross-sectional view of light receiving units 611a, 611b, and 611c of the solid-state imaging device according to Embodiment 6 of the present invention.

Each light receiving unit has a semiconductor substrate 11 , a photoelectric conversion layer 12 , an insulating layer 13 , and a color filter layer 15 having approximately the same structure as the conventional light receiving unit shown in FIG. 3 .

The solid-state imaging device of Embodiment 6 has a structure in which a light-shielding film 19 having an opening 20, interlayer films 13, 632, and high Refractive index interlayer film 727 .

In this solid-state imaging device, when the transmission wavelength bands of the color filters are different, the refractive index of the high-refractive-index interlayer film 727 formed under the color filter layer 15 is different. That is, it has a structure in which the refractive index of the high-refractive-index interlayer film 727 increases as the transmission wavelength band of the color filter becomes longer. For example, a silicon oxide film with a refractive index of 1.5 is used in the high-refractive index interlayer film 727 under the blue (B) color filter film 21a having a short-wavelength transmission wavelength band; ) a silicon nitride film with a refractive index of 2.0 in the high-refractive-index interlayer film 727 under the color filter film 21b; a high-refractive-index interlayer film under the red (R) color filter film 21c having a transmission wavelength band of long wavelength In 727, a titanium oxide film with a refractive index of 2.5 is used; thereby realizing a structure in which the refractive index increases as the transmission wavelength band becomes longer wavelength.

By adopting the above-mentioned structure, the refractive index of the high-refractive-index interlayer film 727 located under the color filter that transmits light in the long-wavelength band is higher than the high-refractive index under the color filter that transmits light in the short-wavelength band. The interlayer film 727 has a large refractive index. Therefore, even when the long-wavelength light that is difficult to collect light enters the light-receiving unit at a relatively large incident angle, the high-refractive index interlayer film 727 can be used to achieve a large The light incident at the incident angle bends and enters the photoelectric conversion unit. As a result, the sensitivity of the photoelectric conversion portion for photoelectrically converting light in the long wavelength band can be greatly improved.

Furthermore, in the solid-state imaging device according to Embodiment 6, the high-refractive-index interlayer film 727 is located under the color filter, but the same effect can be obtained when the high-refractive-index interlayer film 727 is located on the color filter. .

(Embodiment 7)

17 is a cross-sectional view of light receiving units 711a, 711b, and 711c of the solid-state imaging device according to Embodiment 7 of the present invention.

The solid-state imaging device of Embodiment 7 differs from the solid-state imaging device of Embodiment 6 in that the film thickness of the high-refractive index interlayer film 727 varies depending on the light receiving unit.

In this solid-state imaging device, when the transmission wavelength bands of the color filters are different, the film thickness of the high-refractive index interlayer film 727 increases as the transmission wavelength band of the color filters becomes longer. For example, the film thickness of the high-refractive index interlayer film 727 under the blue (B) color filter film 21a having a short-wavelength transmission wavelength band is set to 300nm; The film thickness of the high-refractive index interlayer film 727 is set to 500 nm; the film thickness of the high-refractive index interlayer film 727 under the red (R) color filter film 21c having a long-wavelength transmission wavelength band is set to 700 nm. The transmission wavelength band becomes long, and the film thickness of the high-refractive-index interlayer film 727 is increased.

By adopting the above-mentioned structure, the film thickness of the high-refractive index interlayer film 727 located under the color filter that transmits light in the long-wavelength band is larger than that of the high-refractive-index interlayer film 727 under the color filter that transmits light in the short-wavelength band. The film thickness of the film 727 is large, so even when the light of the long-wavelength band that is difficult to condense enters the light-receiving unit at a large incident angle, since the high-refractive index interlayer film 727 is thick, it is easy to make the light with a large The light entering at the incident angle bends and enters the photoelectric conversion unit. As a result, the sensitivity of the photoelectric conversion portion for photoelectrically converting light in the long wavelength band can be greatly improved.

Furthermore, in the solid-state imaging device according to Embodiment 7, when the transmission wavelength band of the color filter is different for each light receiving unit, the high refractive index interlayer film 727 is formed as the transmission wavelength band of the color filter becomes longer. However, even a structure in which the film thickness of the high-refractive-index interlayer film 727 is increased at the same refractive index has the same effect.

Furthermore, in the solid-state imaging device of Embodiment 7, the high-refractive-index interlayer film 727 is located under the color filter, but the same effect can be obtained when the high-refractive-index interlayer film 727 is located on the color filter.

(Embodiment 8)

18 is a cross-sectional view of light receiving units 811a, 811b, and 811c of a solid-state imaging device according to Embodiment 8 of the present invention.

The solid-state imaging device of the eighth embodiment differs from the solid-state imaging device of the fourth embodiment in that the height of the microlens 423 varies depending on the light receiving unit.

In the solid-state imaging device according to the eighth embodiment, when the transmission wavelength bands of the color filters are different, the height of the microlenses 423 on the color filter layer 15 is configured to be different. The height of the microlens 423 increases as the color filter transmission wavelength band becomes longer. For example, the height of the microlens 423 on the blue (B) color filter film 21a with a short-wavelength transmission wavelength band is set to 1.0 μm; The height of the microlens 423 is set to 1.2 μm; the height of the microlens 423 on the red (R) color filter film 21c with a long-wavelength transmission wavelength band is set to 1.4 μm, thereby realizing that the height of the microlens 423 varies with the transmission wavelength band It becomes a structure that increases with a long wavelength. In this way, the concentration ratio of long-wavelength light can be improved, and the sensitivity of the photoelectric conversion unit that photoelectrically converts long-wavelength light can be greatly improved.

Furthermore, in the solid-state imaging device according to Embodiment 8, the microlens 423 has a structure in which the height of the microlens 423 increases and the refractive index increases as the incident angle of light to the light receiving unit increases. The same effect is also obtained in the configuration in which only the height of the microlens 423 is increased.

(Embodiment 9)

19 is a cross-sectional view of light receiving units 911a, 911b, and 911c of the solid-state imaging device according to Embodiment 9 of the present invention.

The solid-state imaging device of Embodiment 9 is similar to the solid-state imaging device of Embodiment 4 in that the insulating layer 13, the insulating layer in the metal layer 14, and the microlens 423 have the same refractive index for light-receiving elements having color filters in the same transmission wavelength band. Cameras are different. For example, for light-receiving units with filter films having the same transmission wavelength band, one material is used to form the insulating layer 13, the insulating layer in the metal layer 14, and the microlens 423, so that their refractive indices are equal. As a result, manufacturing cost can be suppressed.

In addition, the light-gathering efficiency of each microlens 423 can be represented by the following formula (Formula 1).

(Formula 1)

s=k×λ/NA (NA=n sinθ)

s: Expanded diameter of the focal spot

k: Coefficient determined by imaging conditions

λ: wavelength

n: Refractive index of the medium under the microlens

θ: Stretched fillet of the microlens (θ in Figure 19)

According to the above formula (Formula 1), if the coefficient k and the tensile fillet angle θ of the microlens are constant, the expanded diameter s of the focal spot is proportional to the wavelength λ and inversely proportional to the refractive index n. Therefore, if the refractive index n of the microlens 423 is changed according to the wavelength λ of the light to be condensed, the expanded diameter s of the condensed spot can be kept constant regardless of the wavelength λ of the light to be condensed.

For example, look at red light and blue light. Here, the wavelength of red light is expressed as "λ _R ", the wavelength of blue light is expressed as "λ _B ", the refractive index of the microlens 423 of the unit to condense red light is expressed as "n R ", and the wavelength of blue light to be condensed is expressed as "n _R ". The microlens 423 of the unit has a refractive index "n _B ". Since the wavelength λ _R of red light is larger than the wavelength λ _B of blue light, by making n _R larger than n _B , the expansion diameter s of the red light and blue condensing spots can be kept constant.

Furthermore, according to the above formula (Formula 1), the expanded diameter s of the focal spot decreases as the stretching fillet angle θ of the microlens increases. Therefore, as the stretched fillet angle θ of the microlens increases, if the refractive index n is reduced, the expanded diameter s of light convergence can be kept constant regardless of the stretched fillet angle θ of the microlens.

(Embodiment 10)

FIG. 20 shows how light enters the solid-state imaging device (light receiving unit) according to Embodiment 10 of the present invention.

As shown in FIG. 20 , the principal ray of light entering through the camera lens 34 enters the light receiving unit 1011 in the central portion A vertically, but enters the light receiving units 1011 in the peripheral portions B and C obliquely.

At this time, in the solid-state imaging device according to Embodiment 10, the refractive index of the microlens 1023 of the light receiving unit 1011 varies depending on the position of the light receiving unit 1011, and the microlenses 1023 of the light receiving unit 1011 at the peripheral portions B and C where oblique light enters are different. The refractive index of the lens 1023 is larger than the refractive index of the microlens 1023 of the light receiving unit 1011 in the central portion A.

21 is a cross-sectional view of a light-receiving unit (a light-receiving unit located at a central portion A and a peripheral portion C) of a solid-state imaging device according to Embodiment 10 of the present invention.

Each light receiving unit has a semiconductor substrate 11 , a photoelectric conversion layer 12 , an insulating layer 13 , a metal layer 14 and a color filter layer 15 having the same structure as the conventional light receiving unit shown in FIG. 5 .

The solid-state imaging device according to Embodiment 10 has a structure in which the refractive index of the material constituting the microlenses 1023 formed on the color filter layer 15 differs depending on the incident angle of light.

As the miniaturization of the light receiving unit progresses, the width of the opening 20 becomes narrower. For example, when the width of the opening 20 is 1 μm or less, it is known that it is difficult to collect light on the opening 20 , especially when the light incident angle 33 to the photoelectric conversion part 17 is large. Therefore, in the solid-state imaging device according to Embodiment 10, in order to eliminate this problem, the refractive index of the microlens 1023 of the light receiving unit is increased as the incident angle 33 increases. For example, for the microlens 1023 of the light-receiving unit in the central part A where the incident angle 33 is 0 degrees, silicon oxide with a refractive index of 1.5 is used; Silicon nitride with a ratio of 2.0; a structure in which the refractive index increases with the increase of the incident angle 33 is realized. In this way, it is possible to increase the condensing efficiency of light in the light receiving unit having a large incident angle 33 , and to significantly increase the sensitivity of the light receiving unit having a large incident angle 33 .

(Embodiment 11)

22 is a cross-sectional view of a light-receiving unit (light-receiving unit located at a central portion A and a peripheral portion C) of a solid-state imaging device according to Embodiment 11 of the present invention.

Each light receiving unit has a semiconductor substrate 11 , a photoelectric conversion layer 12 , an insulating layer 13 , a metal layer 14 and a color filter layer 15 having the same structure as the conventional light receiving unit shown in FIG. 5 .

The structure of the solid-state imaging device in Embodiment 11 is that the microlens 1123 of each light receiving unit is made of a low-refractive-index material 1126 (for example, silicon oxide with a refractive index of 1.5), and a high-refractive-index material 1125 with a higher refractive index than the low-refractive-index material 1126. (such as silicon nitride with a refractive index of 2.0) composed of two materials.

In this solid-state imaging device, the volume ratio of the low-refractive-index material 1126 and the high-refractive-index material 1125 in the microlens 1123 differs depending on the incident angle 33 to the light receiving unit. That is, in the light-receiving unit whose incident angle 33 is increased, the composition ratio of the low-refractive-index material 1126 and the high-refractive-index material 1125 of the microlens 1123 is changed, and the volume ratio of the high-refractive-index material 1125 is increased. For example, in the microlens 1123 of the light-receiving unit (the light-receiving unit located in the central part A) whose incident angle is 0 degrees, the volume ratio of the low-refractive-index material 1126 and the high-refractive-index material 1125 is 9:1; In the microlens 1123 of the 30-degree light-receiving unit (the light-receiving unit located in the peripheral portion C), the volume ratio of the low-refractive-index material 1126 and the high-refractive-index material 1125 is 1:9. In this way, the average refractive index of the microlenses 1123 in the light receiving unit with a large incident angle can be made larger than the average refractive index of the microlenses 1123 in the light receiving unit with a small incident angle 33 . As a result, it is possible to increase the light collecting efficiency of the light-receiving unit having a large incident angle 33 , which is difficult to collect light, and to significantly increase the sensitivity of the light-receiving unit having a large incident angle 33 .

(Embodiment 12)

23 is a cross-sectional view of a light-receiving unit (a light-receiving unit located at a central portion A and a peripheral portion C) of a solid-state imaging device according to Embodiment 12 of the present invention.

Each light receiving unit has a semiconductor substrate 11 , a photoelectric conversion layer 12 , an insulating layer 13 , and a color filter layer 15 having substantially the same structure as the conventional light receiving unit shown in FIG. 5 .

In the solid-state imaging device of the twelfth embodiment, the light-shielding film 19 having the opening 20, the interlayer films 31 and 1232, and the high-refractive index layer are formed in the metal layer 1214 under the color filter layer 15 of each light-receiving unit. The structure of the intermembrane 1227.

In this solid-state imaging device, the refractive index of the high-refractive-index interlayer film 1227 of the light-receiving unit is configured to be different when the light incident angle 33 to the light-receiving unit is different. That is, it is configured such that the refractive index of the high-refractive-index interlayer film 1227 increases as the incident angle 33 of light to the light-receiving unit increases. For example, a silicon oxide film with a refractive index of 1.5 is used for the high refractive index interlayer film 1227 of the light receiving unit whose light incident angle 33 to the light receiving unit is 0 degree; The silicon nitride film with a refractive index of 2.0 is used for the high-index interlayer film 1227; therefore, a structure in which the refractive index of the high-refractive index interlayer film 1227 increases as the light incident angle 33 increases can be realized.

Since such a structure is adopted, the refractive index of the high-refractive-index interlayer film 1227 of the light-receiving unit located at a large light-incident angle 33 is larger than the refractive index of the high-refractive-index interlayer film 1227 of the light-receiving unit at a small light-incident angle 33, so it is possible to The sensitivity of the light-receiving unit with a large light incident angle 33 is greatly improved.

Furthermore, in the solid-state imaging device according to Embodiment 12, the high-refractive-index interlayer film 1227 is located under the color filter, but the same effect can be obtained when the high-refractive-index interlayer film 1227 is located on the color filter.

Furthermore, in the solid-state imaging device of Embodiment 12, the high-refractive-index interlayer film 1227 is located on the light-shielding film 19 , but the same effect can be obtained when the high-refractive-index interlayer film 1227 is located under the light-shielding film 19 .

(Embodiment 13)

24 is a cross-sectional view of a light-receiving unit (light-receiving unit located at the central portion A and peripheral portion C) of the solid-state imaging device according to Embodiment 13 of the present invention.

The solid-state imaging device of the thirteenth embodiment differs from the solid-state imaging device of the twelfth embodiment in that the film thickness of the high-refractive index interlayer film 1227 varies depending on the light receiving unit.

In this solid-state imaging device, the film thickness of the high-refractive-index interlayer film 1227 on the light-receiving unit is different when the light incident angle 33 to the light-receiving unit is different. That is, as the light incident angle 33 to the light receiving unit increases, the film thickness of the high refractive index interlayer film 1227 increases. For example, the film thickness of the high-refractive-index interlayer film 1227 of the light-receiving unit whose light incident angle 33 is 0 degrees to the light-receiving unit is 300 nm; The film thickness of the film 1227 is 500 nm, thereby realizing a structure in which the film thickness of the high-refractive-index interlayer film 1227 increases as the light incident angle 33 increases.

By adopting the above structure, the film thickness of the high-refractive-index interlayer film 1227 of the light-receiving unit located at the light incident angle 33 is larger, and the film thickness of the high-refractive-index interlayer film 1227 of the light-receiving unit smaller than the light incident angle 33 is larger, so it is possible to The sensitivity of the light-receiving unit with a large light incident angle 33 is greatly improved.

Furthermore, in the solid-state imaging device according to the thirteenth embodiment, when the light incident angle 33 differs for each light receiving unit, the high refractive index interlayer film is made to decrease as the light incident angle 33 to the light receiving unit increases. The structure in which the film thickness of 1227 is increased and the refractive index is also increased, but the structure in which only the film thickness of the high-refractive index interlayer film 1227 is increased also has the same effect.

Furthermore, in the solid-state imaging device of Embodiment 13, the high-refractive-index interlayer film 1227 is located under the color filter, but the same effect can be obtained when the high-refractive-index interlayer film 1227 is located on the color filter.

In addition, in the solid-state imaging device of Embodiment 13, the high-refractive-index interlayer film 1227 is located on the light-shielding film 19 , but the same effect can be obtained when the high-refractive-index interlayer film 1227 is located under the light-shielding film 19 .

(Embodiment 14)

25 is a cross-sectional view of a light-receiving unit (light-receiving unit located at the central portion A and peripheral portion C) of the solid-state imaging device according to Embodiment 14 of the present invention.

The solid-state imaging device of Embodiment 14 is different from the solid-state imaging device of Embodiment 10 in that the height of the microlens 1023 varies depending on the light receiving unit.

In the solid-state imaging device according to the fourteenth embodiment, the height of the microlens 1023 is different when the light incident angle 33 to the light receiving unit is different. The height of the microlens 1023 increases as the light incident angle 33 increases. For example, the height of the microlens 1023 whose light incident angle 33 is 0 degree to the light receiving unit is set as 1.0 μm; the height of the microlens 1023 of the light receiving unit whose light incident angle 33 is 30 degrees to the light receiving unit is set as 1.2 μm; thereby realizing The height of the microlens 1023 increases as the light incident angle 33 increases.

By adopting the above-mentioned structure, the height of the microlens 1023 positioned at the light-receiving unit with a large light incident angle 33 is higher than the height of the microlens 1023 at the light-receiving unit with a small light incident angle 33. The sensitivity of the light receiving unit.

Furthermore, in the solid-state imaging device according to the fourteenth embodiment, the height of the microlens 1023 increases as the light incident angle 33 to the light receiving unit increases, and the refractive index also increases. The structure of the height of the large microlenses 1023 also has the same effect.

(Embodiment 15)

26 is a cross-sectional view of a light-receiving unit (light-receiving unit located at the central portion A and peripheral portion C) of the solid-state imaging device according to Embodiment 15 of the present invention.

The solid-state imaging device of Embodiment 15 differs from the solid-state imaging device of Embodiment 10 in that the insulating layer 13 , the insulating layer in the metal layer 14 , and the microlens 1023 have the same refractive index for light-receiving cells at the same incident angle. For example, for light-receiving units with the same incident angle, the insulating layer 13, the insulating layer in the metal layer 14, and the microlens 1023 are made of one material, so that their refractive indices are equal. As a result, manufacturing cost can be suppressed.

Furthermore, the light collection efficiency of each microlens 1023 can be represented by the following formula (Formula 2).

(Formula 2)

s=k×λ/NA (NA=n sinθ)

s: Expanded diameter of the focal point

k: Coefficient determined by imaging conditions

λ: wavelength

n: Refractive index of the medium under the microlens

θ: Stretched fillet of the microlens (θ in Figure 26)

In the case where the condensed spot diameter s is the same, it is difficult for light to enter the opening in the photoelectric conversion portion having a large incident angle of incident light.

At this time, according to (Formula 2), if the refractive index n is increased, the spread diameter s of the dots can be reduced. Therefore, even in the photoelectric conversion part where the incident angle of the incident light is large, light can enter the photoelectric conversion part by increasing the refractive index n.

(Embodiment 16)

FIG. 27 shows cross-sections of light receiving units A and B (light receiving units A and B in FIG. 6 ) of the solid-state imaging device according to Embodiment 16 of the present invention. Each light receiving unit has a substrate 11 including a photoelectric conversion layer 12, an insulating layer 13, a metal layer 14, and a color filter layer 15, and these are the same as the conventional structure shown in FIG. 7 .

In Embodiment 16, when the opening width of the light receiving unit 1 is different, the refractive indices of the microlenses 123A and 123B formed on the color filter layer 15 are different. In the case of realizing a wide dynamic range by using solid-state imaging devices with different aperture widths, in order to simultaneously optimize the light collection efficiency of the light-receiving unit B with the small aperture width and the light-receiving unit A with the large aperture width, the light-receiving unit formed at the small aperture width The refractive index of the microlens 123B on B is larger than that of the microlens 123A formed on the light receiving unit A having a large opening width. For example, for the microlens 123A of the light receiving unit A whose opening 20A has a width of 2.5 μm, silicon oxide with a refractive index of 1.5 is used; of silicon nitride.

In this way, since the light collection efficiency of the light receiving unit B with a small opening width and the light receiving unit A with a large opening width can be optimized at the same time, the sensitivity of the light receiving unit with two opening widths can be greatly improved. In addition, since the structure in which the refractive index increases as the incident angle of the incident light increases, the light-gathering ratio can be further improved, which has the effect of further improving the sensitivity.

(Embodiment 17)

FIG. 28 shows cross-sections of light receiving units A and B of the solid-state imaging device according to Embodiment 17 of the present invention. Each light receiving unit has a substrate 11 including a photoelectric conversion layer 12, an insulating layer 13, a metal layer 14, and a color filter layer 15, and these are the same as the conventional structure shown in FIG. 7 .

In the seventeenth embodiment, the microlenses 223A and 223B of each light receiving unit are made of two kinds of low refractive index material (such as silicon oxide with a refractive index of 1.5) 1326 and high refractive index material (such as silicon nitride with a refractive index of 2.0) 1325 Material composition.

When the opening width of the light receiving unit 1 is different, the composition of the low refractive index material 1326 and the high refractive index material 1325 of the microlenses 223A and 223B is changed in the light receiving unit B with a small opening width and the light receiving unit A with a large opening width As for the ratio, in the light receiving unit B, the volume ratio of the high refractive index material 1325 is larger than that of the light receiving unit A. For example, in the microlens 223A of the light-receiving unit A with a large opening width, the volume ratio of the low-refractive-index material 1326 and the high-refractive-index material 1325 is 9:1; in the microlens 223B of the light-receiving unit B with a small opening width, The volume ratio of the low-refractive-index material 1326 and the high-refractive-index material 1325 was 1:9.

As a result, it is possible to simultaneously optimize the light collection efficiency of the light receiving unit B having a small opening width and the light receiving unit A having a large opening width, so that the sensitivity of the light receiving unit having two opening widths can be greatly improved.

Furthermore, the average refractive index of the microlens 223B for light with a large incident angle is set to be larger than the average refractive index of the microlens 223A for light with a small incident angle. In this way, regardless of the incident angle of light, the light collecting ratio of each light receiving unit can be made equal.

(Embodiment 18)

FIG. 29 shows cross-sections of light receiving units A and B of the solid-state imaging device according to Embodiment 18 of the present invention. Each light receiving unit has a substrate 11 including a photoelectric conversion layer 12, an insulating layer 13, and a color filter layer 15, and these are the same as the conventional structure shown in FIG. 7 .

In this eighteenth embodiment, the high refractive index interlayer films 27A and 27B and the interlayer film 1332 are provided in the metal layer 1440 under the color filter layer 15 of each light receiving unit 1 .

It has a structure in which the refractive indices of the high-refractive-index interlayer films 27A and 27B on the light-receiving unit 1 are different when the opening width of the light-receiving unit 1 is different. Compared with the large light receiving unit A, the refractive index of the high refractive index interlayer film 27B is increased. For example, for the high-refractive-index interlayer film 27A of the light-receiving unit A with a large opening width, use a silicon oxide film with a refractive index of 1.5; Silicon nitride film. Also, a structure in which the refractive index increases as the light incident angle 1333 increases is employed.

As a result, since the light collection efficiency of the light receiving unit B having a small aperture width and the light receiving unit A having a large opening width can be optimized at the same time, the sensitivity of the light receiving unit having two opening widths can be greatly improved.

In Embodiment Mode 18, an example was shown in which the high-refractive-index interlayer films 27A, 27B are located under the color filter layer 15, but the high-refractive-index interlayer films 27A, 27B may be located on the color filter layer 15. to get the same effect.

Furthermore, in Embodiment Mode 18, an example was shown in which the high-refractive-index interlayer films 27A, 27B are positioned on the light-shielding film 19, but the high-refractive-index interlayer films 27A, 27B may be positioned under the light-shielding film 19. can achieve the same effect.

(Embodiment 19)

FIG. 30 shows cross-sections of light receiving units A and B of the solid-state imaging device according to Embodiment 19 of the present invention. The difference between the nineteenth embodiment and the eighteenth embodiment is that in the nineteenth embodiment, the film thickness of the high-refractive index interlayer films 270A and 270B of the metal layer 1541 under the color filter layer 15 differs depending on the light receiving unit.

When the opening width of the light receiving unit 1 is different, the film thicknesses of the high refractive index interlayer films 270A and 270B on the light receiving unit 1 are different, so that the high refractive index interlayer film 270B of the light receiving unit B with a smaller opening width The film thickness of the high-refractive-index interlayer film 270A of the light receiving unit A larger than the opening width is thicker. For example, the film thickness of the high-refractive index interlayer film 270A of the light receiving unit A having a large opening width is set to 300 nm; the film thickness of the high refractive index interlayer film 270B of the light receiving unit B having a small opening width is set to 500 nm. Furthermore, a structure is adopted in which the film thickness of the high-refractive-index interlayer films 270A and 270B increases as the light incident angle 1333 increases.

As a result, it is possible to simultaneously optimize the light collection efficiency of the light receiving unit B having a small opening width and the light receiving unit A having a large opening width, so that the sensitivity of the light receiving unit having two opening widths can be greatly improved.

In Embodiment 19, when the light incident angle 1333 is different, as the incident angle 1333 increases, the film thickness of the high-refractive-index interlayer films 270A and 270B is increased, and the refractive index is also increased. However, the refractive index may be the same, and only the film thicknesses of the high-refractive index interlayer films 270A and 270B may be changed. In this case, the same effect can also be obtained.

Furthermore, in Embodiment Mode 19, an example was shown in which the high-refractive index interlayer films 270A and 270B are located under the color filter layer 15, but the high-refractive index interlayer films 270A and 270B may be located on the color filter layer 15. In this case The same effect can also be obtained below.

Furthermore, in Embodiment Mode 19, an example in which the high-refractive-index interlayer films 270A and 270B are located on the light-shielding film 19 is shown, but the high-refractive-index interlayer films 270A and 270B may be located under the light-shielding film 19. can achieve the same effect.

(Embodiment 20)

FIG. 31 shows cross-sections of light receiving units A and B of the solid-state imaging device according to Embodiment 20 of the present invention. Each light receiving unit has a substrate 11 including a photoelectric conversion layer 12, an insulating layer 13, a metal layer 14, and a color filter layer 15, and these are the same as the conventional structure shown in FIG. 7 .

In Embodiment 20, when the opening widths are different, the heights of the microlenses 523A and 523B are different. 523A high. For example, the height of the microlens 523A of the light receiving unit A having a large opening width is set to 1.0 μm; the height of the microlens 523B of the light receiving unit B having a small opening width is set to 1.2 μm.

As a result, it is possible to simultaneously optimize the light collection efficiency of the light receiving unit B having a small opening width and the light receiving unit A having a large opening width, so that the sensitivity of the light receiving unit having two opening widths can be greatly improved.

(Embodiment 21)

FIG. 32 shows cross-sections of light receiving units A and B of the solid-state imaging device according to Embodiment 21 of the present invention. Each light receiving unit has a substrate 11 including a photoelectric conversion layer 12 , an insulating layer 13 , an insulating layer in a metal layer 14 , and a color filter layer 15 , which are the same as the conventional structure shown in FIG. 7 .

In Embodiment 21, light receiving unit B having a small opening width and light receiving unit A having a large opening width respectively have a structure in which the insulating layer 13 , the insulating layer in the metal layer 14 , and the microlenses 623A, 623B have the same refractive index. For example, the insulating layer 13 , the insulating layer in the metal layer 14 , and the microlenses 623A and 623B are made of one material for each light receiving unit so that their refractive indices are equal.

Furthermore, the light-gathering efficiency of each microlens can be represented by the following (Formula 3).

(Formula 3)

s=k×λ/NA (NA=n sinθ)

s: Expanded diameter of the focal point

k: Coefficient determined by imaging conditions

λ: wavelength

n: Refractive index of the medium under the microlens

θ: Stretched fillet of the microlens (θ in Figure 32)

According to the above (Formula 3), the expanded diameter s of the light-converging point is inversely proportional to the refractive index n. Since the opening width of the light receiving unit B is smaller than that of the light receiving unit A, it is necessary to reduce the spread diameter s of the spot where the light collects in the light receiving unit B as compared with the light receiving unit A. By increasing the refractive index n of the microlenses of the light receiving unit B compared to the light receiving unit A, the extended diameter s of the condensing point of the light receiving unit B can be made smaller than that of the light receiving unit A.

As above, the solid-state imaging device of the present invention has been described based on the embodiment, but the present invention is not limited to the embodiment. It is also included in the scope of the present invention that those skilled in the art try to implement various modifications without departing from the gist of the present invention.

For example, it is also possible to configure a camera using the solid-state imaging device of the above-described embodiments.

Also, although silicon oxide or the like is used as the material constituting the microlens or the high-refractive-index interlayer film, it is not limited thereto if the material has a higher refractive index than that of a silicon oxide film generally used as an insulating layer. It can be titanium oxide, tantalum oxide, niobium oxide or hafnium oxide, etc.

Industrial availability

The present invention can be used in solid-state imaging devices and the like, and particularly can be used in solid-state imaging devices used in digital still cameras, digital video cameras, and the like.

Claims (8)

1. A solid-state imaging device, characterized in that it has: semiconductor substrate; a photoelectric conversion part formed on the above-mentioned semiconductor substrate; a light-shielding film provided with an opening formed above the photoelectric conversion part, and provided on the semiconductor substrate; and a high-refractive-index layer formed in the aforementioned opening, The high-refractive-index layer is made of a high-refractive-index material having a refractive index that transmits light having a maximum wavelength of light entering the photoelectric conversion portion through the opening, The above-mentioned high-refractive-index layer is made of a high-refractive-index material having a refractive index of 1.8 or higher, An opening width of the opening is smaller than a maximum wavelength of light entering the photoelectric conversion portion through the opening in terms of a wavelength in vacuum. 2. The solid-state imaging device according to claim 1, wherein The opening is filled with the high refractive index layer. 3. The solid-state imaging device according to claim 1, wherein The thickness of the high refractive index layer is equal to or thicker than the thickness of the light shielding film. 4. The solid-state imaging device according to claim 1, wherein The high-refractive-index layer has a convex lens shape, and converges light entering the photoelectric conversion portion through the opening. 5. The solid-state imaging device according to claim 1, wherein The above-mentioned high refractive index material is any one of titanium oxide, tantalum oxide and niobium oxide. 6. The solid-state imaging device according to claim 1, wherein The aforementioned opening width is less than or equal to 1.0 μm. 7. The solid-state imaging device according to claim 1, wherein The solid-state imaging device further includes a filter film provided on the light-shielding film so as to be located above the opening, and to transmit light in a specific wavelength band. 8. A video camera having a solid-state imaging device, characterized in that, The above-mentioned solid-state imaging device has: semiconductor substrate; a photoelectric conversion part formed on the above-mentioned semiconductor substrate; a light-shielding film provided with an opening formed above the photoelectric conversion part, and provided on the semiconductor substrate; and a high refractive index layer formed in the opening; The opening width of the opening is smaller than the maximum wavelength of the light entering the photoelectric conversion part through the opening, converted into a wavelength in vacuum, The high-refractive-index layer is made of a high-refractive-index material having a refractive index that transmits light of the maximum wavelength of light entering the photoelectric conversion portion through the opening, The high-refractive-index layer is made of a high-refractive-index material having a refractive index of 1.8 or higher.

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