JP4997794B2 - Solid-state image sensor - Google Patents

Description

  The present invention relates to a solid-state imaging device capable of receiving and detecting not only visible light but also infrared light.

In a solid-state imaging device, as the number of pixels increases, the pixel size is reduced, and the area of the photodiode (PD) per pixel decreases.
When the area of the photodiode is reduced, the amount of light reaching the photoelectric conversion unit of the photodiode is also reduced, so that sensitivity is lowered.

  Since the sensitivity is reduced in this way, S / N is reduced unless noise countermeasures are taken.

  In order to improve this S / N, there has been proposed a method for producing an image using not only visible light that has been used conventionally but also infrared light.

As one configuration, a configuration has been proposed that uses the difference in absorption coefficient in the depth direction of a semiconductor depending on the wavelength band of incident light (see, for example, Patent Document 1).
As another configuration, a wavelength separation optical system such as a wavelength separation mirror or prism is used as an input optical system, and a multi-plate type configuration in which visible light and infrared light are received by individual imaging elements, respectively. It has been proposed (see, for example, Patent Documents 2 to 4).
As another configuration, there has been proposed a configuration in which a visible wavelength light and an infrared light are received by the same image sensor using a rotary wavelength resolving optical system as an input optical system (for example, Patent Document 5). reference). Specifically, for example, when an infrared light cut filter is inserted by inserting and extracting an infrared light cut filter using a rotation mechanism, the effects of near infrared light and infrared light are inserted. When an infrared light color image without an infrared light is obtained and an infrared light cut filter is extracted, an image obtained by adding the light intensities of visible light and near infrared light can be obtained.
As another configuration, a configuration has been proposed in which visible light and infrared light are received by the same imaging device by using a diaphragm optical system having a wavelength resolving function in the input optical system (for example, a patent) Reference 6).

However, in the configuration described in Patent Document 1, the layer that detects blue light is absorbed to some extent when red light or green light passes through, so that the light is detected as blue light. For this reason, even if there is no blue signal, a false signal is generated at a blue pixel when a green or red signal is input. Due to this false signal, sufficient color reproducibility cannot be obtained.
Also, in order to achieve color reproducibility, it is necessary to correct the false signal by signal processing, and a circuit for performing this signal processing calculation is required, so the circuit configuration is complicated and large-scale. become.
Furthermore, in order to receive only infrared light, or visible light and infrared light as signals and take an image, an infrared cut filter used in a normal solid-state image sensor is removed, or an infrared cut filter is cut. It is necessary to lower the rate. However, if it does in this way, infrared light will mix with visible light and will inject into a sensor part, and the hue of the image of visible light will differ from the original thing.

In addition, the configurations described in Patent Documents 2 to 4 use a wavelength resolving optical system such as a wavelength separation mirror or prism, and therefore the input optical system becomes large. For this reason, an imaging apparatus provided with a solid-state imaging device becomes complicated or large.
Similarly, the configuration described in Patent Document 5 requires an infrared light cut filter insertion / extraction mechanism, which increases the size of the imaging device.
Furthermore, the operation of inserting / extracting the infrared light cut filter cannot be performed automatically.

Further, the configuration described in Patent Document 6 uses a diaphragm optical system having a wavelength resolving function, so that the size of the image pickup apparatus is increased.
Furthermore, although both an infrared image and a visible light image can be obtained simultaneously, the output image is a composite image of the visible light image and the infrared image, and only the visible light image or only the infrared image is obtained. Cannot be output individually.

  Therefore, as another configuration for the above-described problem, four types of color filters having different filter characteristics are regularly arranged in each pixel of the image sensor having sensitivity to visible light and infrared light. A configuration has been proposed in which a visible light color image and a near-infrared light image are independently obtained by performing matrix calculation on the output of each pixel provided with four types of color filters (see, for example, Patent Document 7). .

With such a configuration, wavelength separation is performed by arranging four types of color filters, so that the problem that the input optical system becomes large does not occur.
Further, a visible light color image and a near-infrared light image are obtained independently by performing a matrix operation on the output of each pixel provided with four types of color filters having different filter characteristics. Images can be output individually and simultaneously.

JP 2004-103964 A Japanese Patent Laid-Open No. 10-210486 JP 2002-369049 A JP-A-6-121325 JP-A-9-166493 JP-A-9-130678 JP 2002-142228 A

  However, in the configuration described in Patent Document 7, calculation processing with the infrared light component is required even when a visible light image is obtained, so that the calculation processing as a whole is complicated.

  In order to solve the above-described problems, the present invention provides a solid-state imaging device capable of receiving and detecting both visible light and infrared light without using a large-scale optical system or complicated arithmetic processing. It is to provide.

In the solid-state imaging device of the present invention, a color filter and an on-chip lens that collects incident light are respectively formed above the sensor unit to which photoelectric conversion is performed, corresponding to the sensor unit of each pixel. in the region, in some pixels, the color filter is formed, further but transmits visible light is formed infrared cut film that does not transmit infrared light, this part of the pixel, 4 Two of the pixels are arranged in a checkered pattern, and this infrared light cut film is formed in a continuous pattern in adjacent pixels at the corners of the pixels.

According to the configuration of the solid-state imaging device of the present invention described above, a color filter is formed in some of the pixels in the pixel area, and visible light is transmitted above the on-chip lens but is red. Since the infrared light cut film that does not transmit external light is formed, only visible light can be received and detected in this pixel. Thereby, a visible light image can be obtained by using an image signal obtained from the pixel on which the infrared light cut film is formed.
On the other hand, since the infrared light cut film is not formed in the remaining pixels in the pixel region, visible light and infrared light can be received and detected in the remaining pixels.
In addition, by calculating an image signal obtained from a pixel on which no infrared light cut film is formed and an image signal obtained from a pixel on which an infrared light cut film is formed, an infrared light image is obtained. Obtainable.
Furthermore, some of the pixels are arranged in a checkered pattern with 2 pixels out of 4 pixels, and the infrared light cut film is formed in a continuous pattern with adjacent pixels at the corners of the pixels, so that infrared The adhesion of the light cut film can be improved, and pattern skipping and pattern peeling of the infrared light cut film can be prevented.

According to the solid-state imaging device of the present invention having the above-described configurations, a visible light image can be obtained by using an image signal obtained from a pixel on which an infrared light cut film is formed, so that a complicated calculation is performed. Even if it does not perform, the image of visible light can be obtained by the same arithmetic processing as the solid-state image sensor which receives and detects only normal visible light.
As a result, an arithmetic circuit for performing complicated arithmetic processing is not required, so that the circuit configuration is not complicated.
In addition, depending on the presence or absence of a color filter and an infrared light cut film, a pixel that receives infrared light and a pixel that does not receive infrared light (does not receive infrared light) can be distributed. Even without providing, it becomes possible to detect and detect both visible light and infrared light.

FIG. 1 shows a schematic configuration diagram (cross-sectional view) of a solid-state imaging device according to an embodiment of the present invention.
In this embodiment, the present invention is applied to a CMOS solid-state imaging device.

In this solid-state imaging device, a sensor unit 12 that performs photoelectric conversion is formed on the surface side of the silicon substrate 11.
Although not shown, the sensor unit 12 is formed of a first conductivity type, for example, an n-type semiconductor region, and a photodiode PD is configured by a second conductivity type, for example, a p-type semiconductor region formed on the silicon substrate 11.
Although not shown, between the sensor portions 12 of each pixel, for example, a second conductivity type (p-type) element isolation region is formed, so that adjacent pixels are separated.

A wiring layer 13 is provided above the silicon substrate 11 via an insulating layer 14. In FIG. 1, three wiring layers 13 are formed.
A planarizing film 15 is formed on the insulating layer 14 above the wiring layer 13, and a color filter 16 is formed on the planarizing film 15.

The color filter 16 is provided in every other two pixels among the four pixels shown in FIG.
The left color filter 16 in the figure is a red R color filter, and the right color filter 16 in the figure is a blue B color filter.

The color filter 16 is covered with an insulating layer 17, and an on-chip lens 18 is further formed on the insulating layer 17.
The on-chip lens 18 has a curved surface whose surface is convex upward corresponding to each pixel. Thereby, the light incident on the on-chip lens 18 can be condensed and guided to the sensor unit 12.

In the present embodiment, in particular, the infrared light cut film 21 is formed in the pixel in which the color filter 16 is formed.
This infrared light cut film 21 has a characteristic of transmitting visible light and cutting infrared light, and does not transmit infrared light at all or hardly transmits it. Thereby, it can suppress that infrared light injects into the sensor part 12 below the infrared light cut film 21.
The infrared light cut film 21 is formed in a pixel provided with the color filter 16 among many pixels, and is not formed in a pixel not provided with the color filter 16.
In the present embodiment, the infrared light cut film 21 is formed in the insulating layer 14 between the color filter 16 and the wiring layer 13.

The arrangement of the color filter 16 in each pixel is shown in the plan view of FIG.
As shown in FIG. 2, the color filter 16 is periodically arranged with a repetition unit of 8 pixels of 2 vertical pixels × 4 horizontal pixels. In the pixels in the first row and the third row (odd row) from the top, the red R color filter 16 and the blue B color filter 16 are arranged every other pixel from the left. That is, the cross-sectional view shown in FIG. 1 shows a cross-sectional view of this odd-numbered row. In the pixels in the second and fourth rows (even-numbered rows) from the top, the green G color filter 16 is arranged every other pixel from the left. In each row and column of pixels, the color filters 16 are arranged every other pixel. Further, in the pixels of each row and each column, there is a pixel in which the color filter 16 is not formed every other pixel.

In the present embodiment, as shown in the plan view of FIG. 3, the infrared light cut film 21 is formed so as to be continuous with diagonally adjacent pixels.
As shown with dots in FIG. 3, the infrared light cut films 21 are arranged every other pixel in the pixels of each row and each column. ing. On the other hand, the infrared light cut film 21 is not provided in the pixel in which the color filter 16 is not formed.
Then, the bridge pattern 21 </ b> B is provided at the corner of the pixel so that the infrared light cut film 21 is continuous with the diagonally adjacent pixels.

The width WB of the bridge pattern 21B is set in accordance with the pixel size within a range of about 0.1 to 2.0 μm, for example.
For example, when the pixel is a square having a side of 2.5 μm and the pattern of the infrared light cut film 21 is formed using an i-line exposure apparatus, the width WB of the bridge pattern 21B is about 0.4 μm. Is considered optimal.

Incidentally, in recent years, the pixel size has been miniaturized corresponding to the miniaturization and high resolution of the solid-state imaging device, and accordingly, the pattern of the infrared light cut film 21 is also miniaturized.
Here, as a comparative configuration, a plan view of FIG. 9 shows a configuration in which the infrared light cut film 21 is formed in the same pattern as the color filter 16 shown in FIG.
In the configuration shown in FIG. 9, the pattern of the infrared light cut film 21 is formed in the same pattern as the color filter 16 shown in FIG. 2, so that it is minute at the corners of the pixels (portions surrounded by broken lines in the figure). A pattern is generated. Due to the generation of this minute pattern, pattern skipping or pattern peeling due to turning or peeling of the infrared light cut film 21 may occur, resulting in a defect defect of the infrared light cut film 21.

  On the other hand, as in the present embodiment, if the infrared light cut film 21 has a bridge pattern 21B at the corners of the pixels so as to be continuous with diagonally adjacent pixels, the infrared light Since the adhesion of the cut film 21 can be improved, pattern skipping and pattern peeling can be prevented.

Furthermore, in the present embodiment, the infrared light cut film 21 is formed of a multilayer film in which a plurality of films having different refractive indexes are stacked.
Thereby, the reflected light in each layer of the multilayer film can be interfered and reflected upward without transmitting infrared light downward.
The material and film thickness of each layer constituting the multilayer film of the infrared light cut film 21 can be arbitrarily set as long as infrared light can be cut.

Examples of materials used for the multilayer film of the infrared light cut film 21 include SiO (silicon oxide such as SiO ₂ ), SiN (silicon nitride such as Si ₃ N ₄ ), Si, NbO, TiO, TaO, NbO and other dielectric materials generally used for optical films made of a dielectric multilayer film can be used. It is not limited to these materials, and other materials can be used as long as they are materials that transmit visible light.
A plurality of materials having different refractive indexes are selected from these various materials, and a multilayer film is formed by laminating films of the respective materials. Preferably, the materials are combined so that the refractive index difference between the respective films becomes large.
Examples of combinations of two materials having different refractive index differences include SiO / SiN, Si / NbO, Si / TiO, Si / TaO, SiO / NbO, SiO / TiO, and SiO / TaO.

  In addition, it is possible to periodically and periodically laminate the films by fixing the thicknesses of the respective films.

FIG. 4 shows a cross-sectional view of one embodiment of the film configuration of the multilayer film of the infrared light cut film 21.
In the film configuration shown in FIG. 4, an infrared light cut film 21 is configured by a multilayer film in which a first film 1 and a second film 2 having different refractive indexes are alternately stacked four times in total for a total of eight layers. Yes.
The thickness of each first film 1 is the same, and the thickness of each second film 2 is the same.

Preferably, when the center wavelength of the infrared light to be cut is λ0 and the refractive index of the film is n, the thickness t = x · λ0 / 4n (x = 0.9 to 1.1) is satisfied. The film thickness of the first film 1 and the film thickness of the second film 2 are set.
By setting the film thickness so as to satisfy the above conditions, the reflectance of the multilayer film with respect to infrared light can be effectively increased.

  For example, in the lamination of SiO film (silicon oxide film) / SiN film (silicon nitride film), the SiO film has a thickness of 131 nm and the SiN film has a thickness of 95 nm.

  In addition, when the same material as the material of the layer (insulating layer or the like) that is in contact with the infrared light cut film 21 at the lower layer or the upper layer is used for the first film 1, As shown in the cross-sectional view of FIG. 5, the first film 1 is arranged in the uppermost layer and the lowermost layer, and the uppermost layer and the lowermost layer are thicker than the first film 1 in a regular portion. It may be formed.

  The number of films to be stacked is not limited to two, and may be three or more. Further, the number of films to be stacked is not particularly limited as long as the total number is three or more. In the case of a total of two layers, it is difficult to obtain sufficient reflectance for infrared light, and it is difficult to sufficiently cut infrared light.

The solid-state imaging device of the present embodiment can be manufactured as follows, for example.
First, layers up to the uppermost wiring layer 13 are formed, and the uppermost wiring layer 13 is covered with an insulating layer 14.
Next, for example, by using a low-temperature sputtering apparatus, the respective films constituting the multilayer film are successively and sequentially formed, thereby forming the infrared light cut film 21 composed of the multilayer film. At this time, the film formation temperature of each of the multilayer films is preferably set to 250 ° C. or less, more preferably 150 ° C. or less so as not to affect the lower layers already formed.
Thereafter, the infrared light cut film 21 is covered with the insulating layer 14, and the flattening film 15, the color filter 16, and the on-chip lens 18 are sequentially formed.

By forming the infrared light cut film 21 using a low temperature film formation technique such as low temperature sputtering, it is possible to form a film at a low temperature. Thereby, since other layers are not affected at the time of film formation, the infrared light cut film 21 can be disposed without being caught by the place of the infrared light cut film 21.
Each of the films constituting the multilayer film of the infrared light cut film 21 is preferably made of a plurality of materials having a refractive index difference as large as possible. It is also suitable for forming a large material continuously.

According to the configuration of the solid-state imaging device of the present embodiment described above, the infrared light cut film 21 that transmits visible light but does not transmit infrared light is formed in the pixel on which the color filter 16 is formed. Thus, only visible light can be received and detected in this pixel. Thereby, a visible light image can be obtained using an image signal obtained from the pixel on which the color filter 16 is formed.
In addition, since the infrared light cut film 21 is not formed in the pixel in which the color filter 16 is not formed, visible light and infrared light can be received and detected in this pixel.
Therefore, an image signal (visible light + infrared light) obtained from a pixel on which the color filter 16 is not formed and an image signal (visible light only) obtained from the pixel on which the color filter is formed are calculated. Thus, an infrared light image can be obtained. The arithmetic processing in this case is simple arithmetic processing as compared with the configuration described in Patent Document 7 described above.

Further, since an image of visible light can be obtained by using an image signal obtained from the pixel on which the color filter 16 is formed, only normal visible light is received and detected without performing complicated calculations. A visible light image can be obtained by the same arithmetic processing as that of the solid-state imaging device.
Accordingly, an image of visible light can be obtained by the same arithmetic processing as that of a solid-state imaging device that receives and detects only normal visible light without performing complicated calculation.

  In addition, depending on the presence or absence of the color filter 16 and the infrared light cut film 21, pixels that receive infrared light and pixels that do not receive infrared light (do not receive infrared light) can be distributed. Even without providing an optical system, both visible light and infrared light can be received and detected.

  Furthermore, according to the present embodiment, the infrared light cut film 21 has the bridge pattern 21B at the corners of the pixels so that the infrared light cut film 21 is continuous with the diagonally adjacent pixels. The adhesion of 21 can be improved, and pattern skipping and pattern peeling of the infrared light cut film 21 can be prevented.

Note that the above-described embodiment may be modified so that a bridge pattern is also provided in the pattern of the color filter 16.
However, when the color filter 16 has the arrangement shown in FIG. 2, the adjacent color filters have different colors (green G, red R, or blue B), and therefore, different color filters in the middle of the bridge pattern. The boundary is formed.
On the other hand, when the adjacent color filters have the same color, they can be continuously formed in a bridge pattern similarly to the infrared light cut film 21.

Next, FIG. 6 shows a plan view of an infrared light cut film pattern in a solid-state imaging device according to another embodiment of the present invention.
In the present embodiment, as shown in FIG. 6, among the patterns of the infrared light cut film 21, each pattern is spaced as a pattern excluding the edge portion corresponding to the corner portion of the pixel.
Other configurations are the same as those of the previous embodiment shown in FIGS. The infrared light cut film 21 is preferably composed of a multilayer film in which a plurality of films having different refractive indexes are laminated, as in the previous embodiment.

The pattern spacing of the infrared light cut film 21 is set corresponding to the pixel size within a range of about 0.1 μm to 2.0 μm, for example, similarly to the width of the bridge pattern 21B of the previous embodiment. To do.
In addition, in the case where the pattern spacing of the infrared light cut film 21 is increased, if the pattern spacing is excessively widened, a problem of color mixing due to infrared light obliquely incident from adjacent pixels tends to occur, which is not preferable. .

According to the above-described embodiment, a visible light image can be obtained using an image signal obtained from a pixel on which the color filter 16 is formed, as in the previous embodiment, and a complicated Even if the calculation is not performed, an image of visible light can be obtained by a calculation process similar to that of a solid-state imaging device that receives and detects only normal visible light.
Accordingly, an image of visible light can be obtained by the same arithmetic processing as that of a solid-state imaging device that receives and detects only normal visible light without performing complicated calculation.
Also, an image signal (visible light + infrared light) obtained from a pixel on which the color filter 16 is not formed and an image signal (visible light only) obtained from the pixel on which the color filter is formed are calculated. Thus, an infrared light image can be obtained.
Then, depending on the presence or absence of the color filter 16 and the infrared light cut film 21, pixels that receive infrared light and pixels that do not receive infrared light (does not receive infrared light) can be distributed. Even without providing an optical system, both visible light and infrared light can be received and detected.

  Furthermore, according to the present embodiment, among the patterns of the infrared light cut film 21, the patterns are spaced apart from each other as the pattern excluding the edge portions corresponding to the corner portions of the pixels. Since there is no minute pattern in the pattern of the light cut film 21, the adhesion of the infrared light cut film 21 can be improved, thereby preventing pattern skipping or pattern peeling of the infrared light cut film pattern. Can do.

  It should be noted that the above-described embodiment may be modified so that the pattern of the color filter 16 is also spaced.

Next, a plan view of the pattern of the infrared light cut film in the solid-state imaging device of still another embodiment of the present invention is shown in FIG.
In the present embodiment, as shown in FIG. 7, the pattern of the infrared light cut film 21 is formed larger than the size (pitch) of the pixels 22 indicated by broken lines in the figure. As a result, the patterns overlap in the vicinity of the corners of the pixels, and the patterns are continuously formed with diagonally adjacent pixels.
Other configurations are the same as those of the previous embodiment shown in FIGS. The infrared light cut film 21 is preferably composed of a multilayer film in which a plurality of films having different refractive indexes are laminated, as in the previous embodiment.

The pattern of the infrared light cut film 21 is made larger than the size of the pixel 22 by about 0.05 μm to 5.0 μm, for example, corresponding to the size of the pixel 22.
For example, when the pixel is a square having a side of 2.5 μm and the pattern of the infrared light cut film 21 is formed using an i-line exposure apparatus, the pattern of the infrared light cut film 21 is changed to the pixel 22. The size of about 2.6 μm to 3.5 μm, which is about 0.1 μm to 0.5 μm larger than the size of the above, is considered optimal.

If the pattern of the infrared light cut film 21 is made larger than the size of the pixel 22, the infrared light incident on the end portion of the adjacent infrared light by the enlarged infrared light cut film 21 is changed in the pixel to be photoelectrically converted. Since a part is cut, the sensitivity is reduced accordingly.
Therefore, the amount by which the pattern of the infrared light cut film 21 is made larger than the size of the pixel 22 is the amount of color mixture from the pixel to which adjacent infrared light is to be photoelectrically converted and the infrared light at the pixel to which infrared light is to be photoelectrically converted. The sensitivity is set in consideration of each.

According to the present embodiment described above, a visible light image is obtained using an image signal obtained from a pixel on which the color filter 16 is formed, as in the previous embodiment shown in FIGS. Even without performing complicated calculations, a visible light image can be obtained by the same calculation process as that of a solid-state imaging device that receives and detects only normal visible light.
Accordingly, an image of visible light can be obtained by the same arithmetic processing as that of a solid-state imaging device that receives and detects only normal visible light without performing complicated calculation.
Also, an image signal (visible light + infrared light) obtained from a pixel on which the color filter 16 is not formed and an image signal (visible light only) obtained from the pixel on which the color filter is formed are calculated. Thus, an infrared light image can be obtained.
Then, depending on the presence or absence of the color filter 16 and the infrared light cut film 21, pixels that receive infrared light and pixels that do not receive infrared light (does not receive infrared light) can be distributed. Even without providing an optical system, both visible light and infrared light can be received and detected.

Furthermore, since the pattern of the infrared light cut film 21 is formed larger than the size of the pixel 22, the infrared light cut film 21 is provided from a pixel where photoelectric conversion of adjacent infrared light is desired. Further, it is possible to prevent color mixture due to incidence of infrared light on a pixel to which visible light is to be photoelectrically converted.
Therefore, the color reproducibility of the color pixel can be improved, and the resolution can be prevented from being lowered.

Note that the pattern of the color filter 16 may be larger than the pixel size by modifying the above-described embodiment.
However, when the color filters 16 are arranged as shown in FIG. 2, the adjacent color filters have different colors (green G and red R or blue B), so that the boundary between the color filters of different colors is appropriately set. Form in position.
On the other hand, when the adjacent color filters have the same color, they can be continuously formed in the same manner as the infrared light cut film 21.

  In addition, the configuration of this embodiment and the configuration of each of the previous embodiments (a configuration in which a pattern continuous with adjacent pixels is formed by a bridge pattern, a configuration in which a pattern is spaced at the corners of the pixels) Combinations are also possible.

Subsequently, a solid-state imaging device according to another embodiment of the present invention will be described.
In the present embodiment, in order to prevent color mixing from a pixel to which infrared light is to be photoelectrically converted, the pattern of the infrared light cut film 21 is set at a pitch different from the pixel size (pitch) corresponding to the angle of view of the pixel. Shift.
That is, pupil correction is applied to the pattern of the infrared light cut film 21.
Specifically, as will be described later, in the pixel at the end of the pixel region, the pattern of the infrared light cut film 21 is shifted from the position of the pixel in the semiconductor portion toward the center of the pixel region.
Other configurations are the same as those of the previous embodiment shown in FIGS. The infrared light cut film 21 is preferably composed of a multilayer film in which a plurality of films having different refractive indexes are laminated, as in the previous embodiment.

  The pupil correction amount of the infrared light cut film 21 depends on the position of the pixel in the pixel region, but is about ˜2.0 μm, for example.

Note that the color filter 16 and the on-chip lens 18 are also shifted from the position of the pixel in the semiconductor portion, similarly to the infrared light cut film 21.
However, since these are formed higher than the infrared light cut film 21 as shown in FIG. 1, it is desirable that the correction amount be larger than that of the infrared light cut film. The correction amount is set according to the height from.

FIG. 8 shows a plan view of the pattern of the infrared light cut film in the pixel at the right end of the pixel region of the solid-state imaging device of the present embodiment.
In the pixel at the right end, light is incident obliquely from the left. Therefore, as shown in FIG. 8, the pattern of the infrared light cut film 21 is indicated by a broken line in the drawing and corresponds to the silicon substrate 11 in FIG. The pixel 22 is shifted to the left (that is, toward the center of the pixel region) from the position of the pixel 22.

  Similarly, although not shown, in the pixel at the left end portion of the pixel region, the pattern of the infrared light cut film 21 is shifted to the right from the position of the pixel 22 in the semiconductor portion (that is, toward the center portion of the pixel region). In the pixel at the upper end of the pixel region, the pattern of the infrared light cut film 21 is shifted below the position of the pixel 22 in the semiconductor portion (that is, toward the center of the pixel region), and the pixel at the lower end of the pixel region In FIG. 5, the pattern of the infrared light cut film 21 is shifted above the position of the pixel 22 in the semiconductor portion (that is, toward the center of the pixel region).

According to the present embodiment described above, a visible light image is obtained using an image signal obtained from a pixel on which the color filter 16 is formed, as in the previous embodiment shown in FIGS. Even without performing complicated calculations, a visible light image can be obtained by the same calculation process as that of a solid-state imaging device that receives and detects only normal visible light.
Accordingly, an image of visible light can be obtained by the same arithmetic processing as that of a solid-state imaging device that receives and detects only normal visible light without performing complicated calculation.
Also, an image signal (visible light + infrared light) obtained from a pixel on which the color filter 16 is not formed and an image signal (visible light only) obtained from the pixel on which the color filter is formed are calculated. Thus, an infrared light image can be obtained.
Then, depending on the presence or absence of the color filter 16 and the infrared light cut film 21, pixels that receive infrared light and pixels that do not receive infrared light (does not receive infrared light) can be distributed. Even without providing an optical system, both visible light and infrared light can be received and detected.

Further, according to the present embodiment, in the pixel at the end of the pixel area, the pattern of the infrared light cut film 21 is shifted to the center side of the pixel area from the position of the pixel 22 of the semiconductor part. It is possible to prevent color mixing due to the incidence of infrared light from pixels that are desired to photoelectrically convert adjacent infrared light to pixels that are provided with the infrared light cut film 21 and that are desired to photoelectrically convert visible light.
Therefore, the color reproducibility of the color pixel can be improved, and the resolution can be prevented from being lowered.

  When pupil correction is performed as in the present embodiment, the infrared light cut film or on-chip lens and the semiconductor portion may be relatively shifted, so either of these may be shifted. Since changing the distance between the central part and the peripheral part of the pixel region may affect the photodiode and transistor characteristics of the pixel, it is preferable to change the distance between the infrared light cut film and the on-chip lens.

  In addition, the configuration of this embodiment and the configuration of each of the above-described embodiments (a configuration in which a pattern continuous with adjacent pixels is formed by a bridge pattern, a configuration in which a pattern is provided at the corner of the pixel, and a pixel size Can be combined with a larger pattern).

  In FIG. 1, the infrared light cut film 21 is formed in the insulating layer 14 between the wiring layer 13 and the color filter 16, but in the present invention, the place where the infrared light cut film 21 is formed is the other place. It may be a place. For example, it may be formed in an insulating layer between the color filter and the on-chip lens, on the on-chip lens, or above the on-chip lens.

  In FIG. 2, square pixels are arranged in a matrix, but the present invention may have other configurations for the shape and arrangement of the pixels. For example, other shapes such as diamond-shaped quadrilaterals diagonally with respect to rows and columns, hexagons and octagons with a honeycomb structure may be used, and the positions of the pixels are staggered for each row. It is good also as arrangement. The present invention is also applied to a pixel having a honeycomb structure.

  In each of the above-described embodiments, the case where three color filters of the primary colors of red R, green G, and blue B are used as the color filter 16 has been described. However, complementary color filters (cyan Cy, magenta Mg) , Yellow Ye) and other color filters may be used.

Further, in each of the above-described embodiments, the color filter 16 is not formed in a pixel that does not have the infrared light cut film 21 and receives and detects visible light and infrared light. However, in the present invention, visible light is not formed. It is also possible to form a color filter in a pixel that receives infrared light.
For example, among the color filters formed on pixels that receive only visible light, the same color filter as the color filter of any color can be formed on the pixels that receive visible light and infrared light. is there. With this configuration, an image signal from a pixel that receives only visible light on which the same color filter is formed is subtracted from an image signal from a pixel that receives visible light and infrared light, thereby obtaining an infrared signal. An optical image signal is obtained.
Accordingly, there is an advantage that the arithmetic processing for obtaining the image signal of the infrared light can be simplified.

In each of the above embodiments, the case where a silicon substrate is used has been described. However, the present invention can also be applied to the case where a semiconductor substrate other than a silicon substrate is used.
Moreover, it is good also as a structure which formed the silicon epitaxial layer in the surface side of the silicon substrate, and formed the sensor part in this silicon epitaxial layer.

  In each of the above-described embodiments, the case where the present invention is applied to a CMOS solid-state image sensor has been described. However, the present invention can be similarly applied to solid-state image sensors having other configurations, for example, CCD solid-state image sensors. .

  The present invention is not limited to the above-described embodiment, and various other configurations can be taken without departing from the gist of the present invention.

1 is a schematic configuration diagram (cross-sectional view) of a solid-state imaging device according to an embodiment of the present invention. It is a top view which shows arrangement | positioning of the color filter of FIG. It is a top view which shows arrangement | positioning of the infrared-light cut film | membrane of FIG. It is sectional drawing which shows one form of the multilayer film of the infrared-light cut film | membrane of FIG. It is sectional drawing which shows the other form of the multilayer film of the infrared-light cut film | membrane of FIG. It is a top view which shows arrangement | positioning of the infrared-light cut film of the solid-state image sensor of other embodiment of this invention. It is a top view which shows arrangement | positioning of the infrared-light cut film | membrane of the solid-state image sensor of further another embodiment of this invention. It is a top view which shows arrangement | positioning of the infrared-light cut film in the pixel of the right side of the pixel area | region of the solid-state image sensor of another embodiment of this invention. It is a top view which shows arrangement | positioning of the infrared-light cut film of the solid-state image sensor of the structure which made the pattern of the infrared-light cut film substantially the same as the pattern of a pixel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st film | membrane, 2nd film | membrane, 11 Silicon substrate, 12 Sensor part, 14, 17 Insulating layer, 15 Planarization film | membrane, 16 Color filter, 18 On-chip lens, 21 Infrared light cut film | membrane, 21B Bridge pattern

Claims (4)

A color filter and an on-chip lens that collects incident light are respectively formed above the sensor unit that performs photoelectric conversion, corresponding to the sensor unit of each pixel,
In some of the pixel regions, the color filter is formed, and an infrared light cut film that transmits visible light but does not transmit infrared light is formed.
The some pixels are arranged in a checkered pattern with 2 out of 4 pixels,
A solid-state imaging device, wherein the infrared light cut film is formed in a continuous pattern in adjacent pixels at corners of pixels. 2. The solid-state imaging device according to claim 1, wherein none of the color filter and the infrared light cut film is formed in pixels other than the some of the pixels in the pixel region. The infrared cutoff film is a solid-state imaging device according to claim 1 or claim 2 comprising a multilayer film formed by laminating films having different refractive indices. 4. The solid-state imaging device according to claim 1, wherein the infrared light cut film is formed in a continuous pattern of adjacent pixels only at the corners of the pixels. 5.

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