JP2011165923A - Color solid-state imaging element, and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color solid-state imaging element that has a pixel portion where a plurality of photoelectric conversion elements are arranged on a plane in a recess region on a semiconductor substrate, the color solid-state imaging element being characterized in securing a wide normal film formation region free of a quality defect such as frame color unevenness, peeling, etc., of a color filter colored layer, having excellent color characteristics, and being made fine. <P>SOLUTION: The solid-state imaging element with an on-chip color filter is constituted by stacking a first flattening layer, the color filter colored layer including green pixels, blue pixels and red pixels such that the colored pixels are arranged on a plane corresponding to the respective photoelectric conversion elements, a second flattening layer, and microlenses in this order on a solid-state imaging element substrate having the pixel portion where the plurality of photoelectric conversion elements are arranged on the plane, the first flattening layer being a yellow layer selectively formed in a region including regions where the green pixels and red pixels are formed in the color filter colored layer and excluding a region where the blue pixels are formed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a color solid-state imaging device having a photoelectric conversion device such as a CCD or CMOS, and a manufacturing method thereof.

  In recent years, imaging devices have been widely used with the expansion of the contents of image recording, communication, and broadcasting. Various types of image pickup devices have been proposed. An image pickup device incorporating a solid-state image pickup device that has been stably manufactured with a small size, light weight, and high performance can be used as a digital camera or digital video. It has become widespread.

  The solid-state imaging device has a plurality of photoelectric conversion elements that receive an optical image from a subject and convert incident light into an electrical signal. The types of photoelectric conversion elements are roughly classified into CCD (charge coupled device) type and CMOS (complementary metal oxide semiconductor) type. In addition, there are two types of photoelectric conversion elements: linear sensors (line sensors) in which photoelectric conversion elements are arranged in a row, and area sensors (surface sensors) in which photoelectric conversion elements are two-dimensionally arranged vertically and horizontally. It is divided roughly into. In any sensor, the larger the number of photoelectric conversion elements (number of pixels), the more accurate the captured image.

  In addition, a color solid as a single-plate color sensor that can obtain color information of an object by providing various color filters that transmit light of a specific wavelength in the path of light incident on the photoelectric conversion element. Imaging devices are also widespread. As the color of the color filter, three primary colors consisting of three colors of red (R), blue (B), and green (G), or cyan (C), magenta (M), and yellow (Y) are used. Complementary color systems are generally used, and in particular, the three primary color systems are often used.

  The color filter is mainly formed using a photolithography method. That is, after applying a photosensitive colored resin of a predetermined color on a substrate, pattern exposure and development are performed on the photosensitive colored resin through an exposure photomask having a predetermined pattern, and the predetermined portion is made of a colored resin. A color filter is formed. In addition, spin coating is often used as the application of the photosensitive colored resin on the substrate. In other words, after the photosensitive colored resin is dropped on the substrate, the dropped photosensitive colored resin is spread on the substrate by rotating the substrate.

  One of the important issues in performance required for a solid-state imaging device is to improve the sensitivity to incident light. In order to increase the amount of information of an image photographed with a miniaturized solid-state imaging device, it is necessary to miniaturize and highly integrate a photoelectric conversion device serving as a light receiving unit. However, when the photoelectric conversion element is miniaturized, the area of each photoelectric conversion element is reduced, and the area ratio that can be used as the light receiving unit is also reduced. And the effective sensitivity decreases.

  As a means for preventing such a decrease in sensitivity of the miniaturized solid-state imaging device, in order to efficiently capture light into the light receiving portion of the photoelectric conversion device, the light incident from the object is condensed and photoelectrically A technique has been proposed in which a microlens that leads to a light receiving portion of a conversion element is formed on the photoelectric conversion element. By condensing the light with a microlens and guiding it to the light receiving part of the photoelectric conversion element, it becomes possible to increase the apparent aperture ratio (area) of the light receiving part and improve the sensitivity of the solid-state image sensor Become. In addition, a technique for further increasing sensitivity by shortening the distance between the microlens and the light receiving portion of the photoelectric conversion element and increasing the light capturing angle has been proposed (see Patent Document 1).

JP 2008-270500 A

  As described above, it is possible to increase the sensitivity by shortening the distance between the microlens and the light receiving portion of the photoelectric conversion element and increasing the light capturing angle. FIG. 2 is a partial cross-sectional schematic diagram for explaining the main part of a conventional color solid-state imaging device formed up to the first color filter 11. The upper part of the pixel part A where the multilayer wiring is not provided is dug out, and the thickness of the pixel part A of the substrate 2 is made thinner than the surrounding multilayer wiring part B. Thereby, the distance between the photoelectric conversion element 3 and the microlens to be formed above the pixel portion A via the first color filter 11 and other color filters can be shortened. Here, in the multilayer wiring portion B, a plurality of wiring layers 4 are laminated and disposed via an interlayer insulating film 5 between the wiring layers. The color filter is also formed around the outer periphery of the substrate beyond the pixel portion A.

  However, since there is a step near the boundary between the surface of the pixel portion having a low surface position and the upper surface of the multilayer wiring portion having a high surface position, when forming a color filter in the pixel portion prior to the formation of the microlens, FIG. As shown, the thickness of the color filter layer near the step tends to be partially thicker than the center of the pixel portion, and this tendency becomes remarkable when the spin coating method is used. This is because a liquid pool is formed in the stepped portion in the coating process of the colored resin constituting the color filter. In FIG. 2, a stepped portion C, which is a region where the thickness of the color filter layer in the vicinity of the step is partially thick, generates a region overlapping with the pixel portion A, and a portion where the color filter is formed with a uniform thickness is a stepped portion. The pixel portion A inside the portion C is limited to a portion near the center of the substrate far from the outer periphery of the substrate.

  The thickness of the color filter coloring layer formed in the vicinity of the stepped portion C that is the peripheral portion of the pixel portion A of the solid-state imaging device 1 is partially thicker than the central portion of the pixel portion A having a uniform thickness. As a result, the change in light transmittance between the color filter in the vicinity of the stepped portion and the color filter in the central portion appears as unevenness, which causes “frame color unevenness” that results in poor quality of the solid-state imaging device 1. Further, in a general manufacturing method in which a color filter pattern is formed by a photolithographic method using a photo-curing type colored resin, a locally thick portion of the colored layer is a main exposure spectrum compared to other portions. Since the amount of transmitted light of i-line (wavelength 365 nm) decreases and the degree of curing becomes insufficient, and the stress inside the film also increases, the color filter pattern easily peels off at the stepped portion C including the portion immediately below the stepped portion. Further, by forming a locally thick portion of the colored layer as a solid film, peeling at the stepped portion C can be prevented, but the effective pixel region in which the color filter colored layer has a uniform thickness in the pixel portion A The problem of narrowing remains.

  Further, the thickness of the color filter coloring layer may be set so as to satisfy the required color characteristics according to the chromaticity and lightness specific to the constituent material. However, in the case of a miniaturized solid-state imaging device, if the film thickness is sufficient to satisfy the color characteristics of the colored pixels, the ratio of the thickness / pixel size of the colored pixels to be patterned increases, In some cases, it is unavoidable that the film thickness is inevitably limited and compromised with insufficient color characteristics.

  The present invention is proposed in view of the above problems, and the problem to be solved by the present invention is to provide a color solid-state imaging having a pixel portion in which a plurality of photoelectric conversion elements are arranged in a plane in a recessed area on a semiconductor substrate. An element is to provide a fine color solid-state imaging device having a good color characteristic while ensuring a wide normal film forming region in which quality defects such as frame color unevenness and peeling of a color filter coloring layer do not occur. .

  As a means for solving the above-mentioned problem, the invention according to claim 1 is characterized in that a first image pickup element substrate having a pixel portion in which a plurality of photoelectric conversion elements are arranged in a recessed area on a semiconductor substrate A flattened layer, a color filter colored layer including a green pixel, a blue pixel, and a red pixel in which colored pixels are arranged in a plane corresponding to each photoelectric conversion element, a second flattened layer, and a microlens are stacked in this order. In the solid-state imaging device with an on-chip color filter, the first planarization layer includes a region in which the green pixel and the red pixel are formed in the color filter coloring layer, and a region excluding the region in which the blue pixel is formed. A color solid-state imaging device, which is a yellow layer selectively formed.

  The invention according to claim 2 is characterized in that the yellow layer which is the first flattening layer is made of a coloring composition mainly composed of a pigment having a color index PY139. This is a color solid-state imaging device.

  The invention according to claim 3 is a step of forming the first planarization layer, a step of forming a color filter coloring layer, a step of forming a second planarization layer, a step of forming a microlens, In the manufacturing method of the color solid-state imaging device in which the first flattening layer is formed, the first flattening layer is formed on the external connection terminal when the first flattening layer is formed, and the microlens is formed and then the first flattening layer on the external connection terminal is formed. 3. The method for manufacturing a color solid-state imaging device according to claim 1, wherein the planarizing layer is removed by dry etching.

  In the color solid-state imaging device according to the present invention, the first planarization layer is formed as a blue pixel prior to forming the color filter coloring layer in the recessed region on the semiconductor substrate having the pixel portion in which a plurality of photoelectric conversion elements are arranged in a plane. By selectively providing a yellow layer in a region other than the region, a fine film formation region with good color characteristics is secured while ensuring a wide normal film formation region in which quality defects such as frame color unevenness and peeling of the color filter coloring layer do not occur. A color solid-state imaging device can be provided.

It is a cross-sectional schematic diagram for demonstrating an example of a structure of the color solid-state image sensor of this invention. It is a partial cross-sectional schematic diagram for demonstrating the structure of the conventional color solid-state image sensor about the principal part in the middle of a process. It is a cross-sectional schematic diagram for demonstrating the manufacturing process of the color solid-state image sensor of this invention about a main process, Comprising: (a) forms a 1st planarization layer, (b) forms a micro lens. Until then, an example is shown. It is a partial plane schematic diagram for demonstrating an example of the plane arrangement | sequence of each color filter color in the color solid-state image sensor of this invention. It is the simplified partial cross-section schematic diagram which shows the application | coating state of colored resin in the conventional application | coating process.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view for explaining an example of the configuration of the color solid-state imaging device of the present invention in a wafer state.

On the semiconductor substrate 2, a pixel portion A is formed in which a plurality of photoelectric conversion elements are arranged in a plane in a recessed region formed by digging to a depth of about 1 to 2 μm. In addition, a multilayer wiring portion B around the outer periphery of the pixel portion, in which a plurality of wiring layers electrically connected to the pixel portion are stacked, and an external connection terminal 15
A one-chip area Z consisting of a connection terminal portion D in which one of the two is disposed corresponds to one solid-state image sensor 1, and a scribe line for cutting the one-chip area Z from adjacent chips is provided. The scribe part E to be formed is formed, and by cutting at the scribe part E, individual chips are obtained. That is, by imposing a plurality of chips on a single wafer, it is possible to form a plurality of chips at once by batch processing as a wafer.

  The color solid-state imaging device 1 according to the present invention includes a first flattening layer 6 and a green pixel 16 in which colored pixels are arranged in a plane corresponding to each photoelectric conversion element on a substrate 2 having the pixel portion A, blue This is a solid-state imaging device with an on-chip color filter in which a color filter coloring layer including the pixel 17 and the red pixel 18, the second planarization layer 7, and the microlens 8 are stacked in this order. The first planarizing layer 6 includes a region in which the green pixel 16 and the red pixel 18 are formed in the color filter coloring layer, and is selectively formed in a region excluding the region in which the blue pixel 17 is formed. Has a layer.

  As described above, the thickness of the substrate 2 in the region of the pixel portion A is made thinner than that of the surrounding multilayer wiring portion B, thereby coloring the photoelectric conversion element and the first planarizing layer and the color filter above it. Since the distance between the layer and the microlens to be formed via the second planarization layer can be shortened, a highly sensitive color solid-state imaging device can be obtained.

  In the solid-state imaging device 1, the plurality of wiring layers 4 are disposed on a semiconductor substrate 2 having a pixel portion A in which the plurality of photoelectric conversion elements 3 are arranged in advance via an interlayer insulating film 5 between the wiring layers. A multilayer wiring portion B is formed in a stacked arrangement. In the multilayer wiring part forming step, a processing step such as an etching method is appropriately added to the photolithography method or the printing method as well as the conventional step forming step for forming a step near the boundary between the pixel portion and the multilayer wiring portion. It is possible to use a general method, and detailed description is omitted.

  A color filter coloring layer is provided by sequentially arranging a plurality of color filters on a surface of the light receiving surface of the pixel portion A in order by colored pixels for each color. That is, in this example, the green pixel 16, the blue pixel 17, and the red pixel 18 are provided by a photolithography method. In the present invention, prior to this, the first planarization layer 6 is formed by a photolithography method. The first planarizing layer 6 is coated and formed to have an appropriate film thickness of about 0.2 μm, thereby avoiding a portion where the color filter coloring layer at the stepped portion C shown in FIG. can do. In addition, in the connection terminal portion D for electrical connection from the multilayer wiring to the outside, the scribe portion E having a scribe line for separating individual chips from a wafer device in which a plurality of solid-state imaging elements are collectively formed, etc. Although a portion to be selectively removed occurs in a later process, once the first planarization layer 6 is formed widely on the wafer device, the functions of planarization and surface protection during the process are actively utilized. You can also.

  In the present invention, a yellow layer using a yellow colored resin is used for the first planarizing layer 6 to separate a yellow component that is originally included as a common color component in the green pixel 16 and the red pixel 18. Can be configured. That is, since the yellow layer has color characteristics that reduce the transmittance of light in the wavelength region of approximately 400 to 450 nm, the green layer and the red layer are superimposed on the predetermined portion of the yellow layer, respectively, so that While improving a color characteristic to the desired color characteristic, it can reduce and use the yellow component contained in the conventional green layer and red layer. However, since the blue pixel 17 originally does not contain a yellow component, the first planarization layer 6 using the yellow layer is not formed in the region where the blue pixel 17 is formed. In general, it is desirable to use a pigment having a higher resistance than a dye as a material for giving the yellow component, and the same applies to green, blue, and red materials as a color filter coloring layer.

The first planarization layer 6 using the yellow layer is a green pixel 16 used for the color filter coloring layer.
In addition, since the yellow pigment can be dispersed in a resin of the same system as that of the blue pixel 17 and the red pixel 18 to form a coating material, the mutual adhesion can be maintained well and high reliability can be maintained. Further, since the common yellow component can be reduced and used from the coating material for forming the green pixel 16 and the red pixel 18, the necessity of the green pixel 16 and the red pixel 18 for obtaining a certain color characteristic is required. The film thickness to be reduced can be made thinner than in the case where no yellow layer is used for the first planarizing layer 6, which leads to improvement in resolution and adhesion. Furthermore, the material management and photolithography process conditions for forming green pixels and red pixels in which the common yellow component is greatly reduced are preferable because they can be manufactured more easily because the allowable range is expanded.

  The yellow pigment contained in the yellow layer used for the first planarization layer 6 is a green pigment or red pixel 18 in the green pixel 16 that forms the upper layer in the yellow layer that maintains an appropriate film thickness as the planarization layer. What is necessary is just to optimize the color characteristic combined with the red pigment in the inside. Accordingly, in consideration of the color characteristics, the film thickness, and the pigment ratio of the pigment in each layer of the green pixel and the red pixel, the type of yellow pigment in the yellow layer can be selected in consideration of the film thickness and the pigment ratio.

  Specifically, it is possible that the yellow layer which is the first planarizing layer is made of a coloring composition mainly composed of the pigment having the color index PY150.

  In addition, it is possible that the yellow layer, which is the first planarizing layer, is made of a coloring composition whose main component is the pigment having the color index PY139.

  In addition, it is possible that the yellow layer, which is the first planarizing layer, is made of a coloring composition whose main component is the pigment having the color index PY185.

  In addition, it is possible that the yellow layer as the first planarizing layer is made of a coloring composition containing a pigment obtained by mixing any two or more of the color indexes PY150, PY139, and PY185.

  FIG. 3 is a schematic cross-sectional view for explaining the main steps of the method for manufacturing a color solid-state imaging device of the present invention, where (a) is a state in which a first planarization layer is formed, and (b) These show an example of a state in which a microlens is formed.

  In the present invention, first, the first planarizing layer 6 is formed on the light receiving surface side prior to the formation of the color filter. As a method of forming the first planarization layer, a step of applying a photosensitive yellow colored resin liquid to the light receiving surface side surface of a wafer device formed in a lump on a wafer and provided with a plurality of solid-state imaging elements. Then, an exposure process using a photomask, a development process using an alkaline solution, and a resin curing process using heat treatment are sequentially performed.

  The photosensitive yellow colored resin liquid is a pigment-dispersed negative color resist in which a yellow pigment is dispersed, and is applied to the entire wafer and then dried by pre-baking to selectively shield resin-unnecessary portions. Align and expose using a photomask. Specifically, the photosensitive yellow colored resin is left at least in a region where a color filter coloring layer for green pixels and red pixels will be formed later and in a portion immediately below the wafer step.

  As the resin formation unnecessary portion, it is also appropriate to include at least a region where a color filter coloring layer of a blue pixel will be formed later, and to include a scribe portion E which finally becomes a scribe line of the wafer in the formation unnecessary portion. The yellow colored resin liquid is not formed in the region where the blue pixel is formed or in the scribe portion. On the other hand, in the connection terminal portion D having the external connection terminals 15, it is more useful to protect the external connection terminals 15 in the subsequent steps by leaving them as the first planarization layer 6 made of a yellow colored resin.

  The yellow colored layer constituting the first planarization layer 6 is appropriate in that it has the effect of the planarization treatment and does not interfere with the increase in sensitivity. is there. Further, it is also appropriate for obtaining appropriate color characteristics when overlapping the subsequent green pixels and red pixels.

  Next, a step of forming a color filter coloring layer is performed by a photolithography method. For example, a photosensitive negative resist that is a green pigment dispersion resin is applied. Here, the step C shown in FIG. 2 is sufficiently obtained due to the flattening effect of the base by the first flattening layer 6 and the film thickness reducing effect of the green layer due to the color characteristics of the yellow layer which is the flattening layer. The pixel film thickness on the pixel portion A becomes uniform by being limited to a narrow region. After applying the resist, through the pre-baking, selective exposure, development, and heat treatment steps, the green pixel 16 as the color filter first color 11 is patterned to a thickness of, for example, 0.7 μm. Together with 0.2 μm, the total film thickness is 0.9 μm. In the selective exposure, alignment with the photoelectric conversion element 3 provided below is important, and governs the quality of the miniaturized solid-state imaging element.

  Next, the remaining color layers including the second color of the color filter and subsequent color filters are formed. When forming a blue pixel and a red pixel sequentially, a photosensitive negative resist that is a pigment-dispersed resin of a selected color is applied and formed through each step of pre-baking, selective exposure, development, heat treatment, etc. It is the same. However, as described above, the base for forming the blue pixel does not have the yellow layer as the first planarization layer, and the base for forming the red pixel has the yellow layer. In addition, the same process is performed when the color filter coloring layer other than the above three colors of green, blue, and red is used, but it is necessary to leave the yellow layer, which is the first flattening layer, as a base. What is necessary is just to judge at any time according to the color characteristic to be performed. Furthermore, as will be described later, since it is preferable to make the pixel film thickness thinner than in the case of the first color after the second color, considering the required color characteristics, the pigment material and content ratio, and the dispersion resin The prescription is appropriately selected.

  With the above, the color filter forming step of sequentially arranging the color filters of a plurality of colors on the light receiving surface side surface of the pixel portion by color is finished, and then, through the second planarizing layer 7 provided on each color filter color, A microlens forming step for arranging the microlenses 8 in a plane is performed.

  The second planarization layer 7 covers the uneven thickness of each color of the color filter and minute irregularities in the pixel portion A, and provides a flat and uniform base for forming a microlens. A transparent acrylic resin solution is applied and formed to a thickness of 0.2 μm, and is cured by heat treatment through exposure and development steps as necessary.

  After forming the second planarizing layer 7, a photosensitive positive resist, which is a transparent resin as a lens material, is applied and formed on the planarizing layer, pre-baked, selectively exposed, and developed with an organic alkali developing aqueous solution, By using the heat reflow behavior by adding a heat treatment step, the microlenses 8 that are repeatedly arranged in the same unit are arranged in the upper region of the pixel portion A so as to coincide with the pixel pitch and have a convex lens shape of 0.5 μm in height. A plurality of lenses are aligned.

  Finally, the solid-state imaging device is completed through a connection terminal portion forming step and a step for mounting each chip by separating a large number of solid-state imaging devices on the wafer device. The connection terminal portion formation step is a step of selectively removing the first planarization layer 6 formed on the external connection terminal 15 in FIG. 3B, and is a photolithography method using a positive resist. After the necessary window opening pattern is formed, it can be removed by dry etching. Since the pigment component of the yellow layer constituting the first planarizing layer 6 does not contain a metal, it is possible to open the external connection terminal 15 well without causing a residue by dry etching.

Here, an example of a plane arrangement that affects the relationship between the position and film thickness of each color filter described above will be described with reference to FIG. A color filter pixel Bayer suitable for performing single-plate color imaging with a single solid-state image sensor in a method that maintains an effective resolution by interpolation calculation using surrounding pixel outputs without increasing the total number of pixels. ) An example of an array. In accordance with human visibility, the number of colored pixels of the green pixel 31 is set to be twice as large as the number of colored pixels of the blue pixel 32 and the red pixel 33.

  In the example of the Bayer arrangement, it is desirable that the green pixel 31 is the color filter first color 11 and the blue pixel 32 and the red pixel 33 are formed after the second color. This is because the green pixel 31 occupies a relatively large area and is connected to the colored pixels of the same color located diagonally, thereby further improving the adhesion.

  In general, it is desirable to make the pixel film thickness of the second and subsequent colors of the color filter in the effective area of the pixel portion thinner than the pixel film thickness of the first color. By doing so, the color filter second color and the third color have a pixel film thickness that is thinner than the first color even in the stepped portion C, and the thin pixel film in the form in which the first color sinks into the already-patterned missing part. Thickness is formed, and the adverse effect of the step portion is reduced. Accordingly, the frame color unevenness and peeling in the second and third color filter colors do not matter. Further, in the area of the pixel portion A, when the first color is green in the Bayer array, each pixel of the color filter second color and third color is formed with four sides surrounded by a high wall of the first color. Therefore, it is difficult for defects such as peeling to occur.

Examples of the solid-state imaging device of the present invention will be described below.
<Example 1>
[Process]
A photosensitive negative color resist, which is a yellow pigment-dispersed resin, is applied by spin coating onto a semiconductor device in which an area where a large number of light receiving elements made of photoelectric conversion elements are arranged is dug about 1 μm from the top surface of the chip. Then, a prebaking treatment was performed at 70 ° C. for 1 minute, and after selective exposure, development and heat treatment were performed to form a first planarization layer made of a yellow colored layer. At this time, the yellow pigment had a color represented by a color index of PY139, and the formed yellow colored layer had a thickness of 0.2 μm and a transmittance of 430 nm wavelength light was 15%. It should be noted that the yellow colored layer was left as a protective film on the external connection terminal of the connection terminal portion except for a region where the blue pixel was formed later.
Next, a green negative color resist (pigment dispersion type) is spin-coated and pre-baked (70 ° C., 1 minute) on the green colored layer, which is the first color of the color filter, and selectively exposed, developed, and heat-treated to form a green pixel. The pattern was laminated and formed in a thickness of 0.7 μm on a portion to be a green pixel pattern on the yellow colored layer. The total film thickness combined with the yellow layer was 0.9 μm, and the spectral transmittance of the two layers was 5% or less with 430 nm wavelength light, and it was confirmed that the color characteristics of a predetermined green pixel were satisfied.
Subsequently, the blue and red colored layers were also formed in a predetermined arrangement by a photolithography method in the same manner as the green colored layer. Blue was patterned directly on a substrate without a yellow layer, and a blue solid region was also provided on the multilayer wiring portion around the chip for light shielding. The thickness of the blue pixel was 0.7 μm, which was the same as the thickness of the green pixel alone, but was thinner than the total thickness of the green pixel with the yellow layer added. Further, red was patterned on the yellow layer in the same manner as green. The film thickness of the red pixel is 0.6 μm, and the total film thickness of the red pixel with the yellow layer added is also 0.8 μm, which is thinner than the green pixel. It was confirmed that the spectral transmittance according to the total film thickness of the red pixel was 5% or less with light having a wavelength of 400 to 430 nm, and the color characteristics of the predetermined red pixel were satisfied.
Next, an acrylic resin solution was applied and formed on the surface of the color filter pattern with a thickness of 0.2 μm by spin coating, and heat treatment was performed to form a second planarization layer.
Next, a positive resist to be a lens was applied and formed, and after prebaking, selectively exposed.
Then, it developed with the organic alkali developing aqueous solution (TMAH type: 0.5%), and formed the micro lens of 0.5 micrometer height with the heat flow method.
Next, a transparent resin is applied and formed in a thickness of 5 μm as a positive resist, pre-baked at 100 ° C. for 120 seconds, and then selectively exposed to a portion where the transparent resin is to be removed, such as a connection terminal portion and a scribe line. Then, it developed with organic alkali developing aqueous solution (TMAH type | system | group: 0.5%).
Next, using the positive resist pattern as an etching mask, the resin under the opening was etched away by dry etching. The dry etching is performed using an ULVAC NA1300 output of 500 W, a gas pressure of 50 Pa, and an O ₂ flow rate of 600 cm ³ / min. (1 hPa, 0 ° C.), N ₂ flow rate 10 cm ³ / min. (1 hPa, 0 ° C.), etching rate 0.5 μm / min. For 3 minutes and removed by 1.5 μm etching.
Next, about 5.5 μm thickness of the positive resist remaining without being dry-etched was stripped and removed with a stripping solution.
Finally, heat treatment was performed at 100 ° C. for 2 minutes in order to remove moisture.
[Evaluation]
The obtained solid-state imaging device was a high-quality color solid-state imaging device in which almost no frame color unevenness or coating unevenness was observed, and the color filter coloring layer was not peeled off in the vicinity of the wafer level difference.
Further, the pixel sensitivity of each color of green, blue, and red is good and uniform in the chip, and is a high-quality color solid-state imaging device.

A comparative example of the solid-state imaging device of the present invention will be described below.
<Comparative example 1>
[Process]
An acrylic resin solution is applied in a thickness of 0.1 μm to a light-receiving element formation area on a semiconductor device in which an area where a large number of light-receiving elements made of photoelectric conversion elements are arranged is dug by about 1 μm with respect to the upper surface of the chip, Heat treatment.
Next, a green negative color resist (pigment dispersion type) is spin-coated and pre-baked (70 ° C., 1 minute) on the green colored layer, which is the first color of the color filter, and selectively exposed, developed, and heat-treated to form a green pixel. The pattern was formed to a thickness of 0.9 μm.
Subsequently, the blue and red colored layers were also formed in a predetermined arrangement by a photolithography method in the same manner as the green colored layer. At this time, the blue and red pixel thicknesses were made larger than the green pixel thickness.
Hereinafter, it was formed in the same manner as in Example 1 and was designated as Comparative Example 1.
[Evaluation]
In the obtained solid-state imaging device, frame color unevenness occurred in the stepped portion of the wafer. For a step difference of 1 μm in height difference, the flat range of the frame color unevenness extends from the step to about 30 μm. In addition, the green pixels near the step were peeled off and the shape was distorted.
Further, the blue and red pixel thicknesses were also affected by the thickness of the step as in the case of the green color, and pixel peeling occurred for blue.
Further, the pixel sensitivity of each color of green, blue, and red was also inferior in uniformity within the chip.

DESCRIPTION OF SYMBOLS 1 ... Solid-state image sensor 2 ... Board | substrate 3 ... Photoelectric conversion element 4 ... Wiring layer 5 ... Interlayer insulating film 6 ... 1st planarization layer 7 ... 2nd flatness Layer 8 ... micro lens 11 ... color filter first color 15 ... external connection terminal 16, 31 ... green pixel 17, 32 ... blue pixel 18, 33 ... red pixel 20 .... Colored resin A ... Pixel part B ... Multilayer wiring part C ... Step part C '... Step D ... Connection terminal part E ... Scribing part Z ... 1 chip area

Claims (3)

  Green in which colored pixels are arranged in a plane corresponding to each of the first planarization layer and each photoelectric conversion element on a solid-state imaging element substrate having a pixel portion in which a plurality of photoelectric conversion elements are arranged in a plane in a recessed area on a semiconductor substrate In the solid-state imaging device with an on-chip color filter in which a color filter coloring layer including a pixel, a blue pixel, and a red pixel, a second planarization layer, and a microlens are stacked in this order, the first planarization layer has a color A color solid-state image pickup device comprising a yellow layer selectively formed in a region excluding a region where a blue pixel is formed, including a region where a green pixel and a red pixel are formed in a filter coloring layer.   2. The color solid-state imaging device according to claim 1, wherein the yellow layer which is the first planarizing layer is formed of a coloring composition mainly containing a pigment having a color index PY139.   A method for manufacturing a color solid-state imaging device, wherein the step of forming the first planarization layer, the step of forming a color filter coloring layer, the step of forming the second planarization layer, and the step of forming a microlens are performed in this order. The first planarization layer is formed on the external connection terminal when the first planarization layer is formed, and after the microlens is formed, the first planarization layer on the external connection terminal is removed by dry etching. The method for producing a color solid-state imaging device according to claim 1 or 2.