Solid-state imaging device

Abstract

The present invention provides a solid state imaging device in which gate-poly layout asymmetry is improved, and the difference in sensitivity between Gr (green) and Gb (green) is improved. The solid state imaging device comprises: a plurality of pixels which correspond to differing wavelengths of light and in each of which is disposed at least one photoelectric conversion part that carries out photoelectric conversion of incident light; color filters which correspond to differing wavelengths of light and which are provided on the light-entry side of the pixels; a gate electrode layer which has gate electrodes of transistors that perform signal processing of electric charge output from the pixels; and a pillar structure part which is formed between the color filters and the gate electrode layer, which has a plurality of rod-like parts, and which via the plurality of rod-like parts absorbs light having the longest wavelength among visible light.

Description

[Technical field]

[0001] The technology according to the present disclosure (the present technology) relates to a solid-state imaging device. [Background technology]

[0002] Semiconductor image sensors, such as CMOS (Complementary Metal Oxide Semiconductor) image sensors, are constantly being required to reduce pixel size and increase the number of pixels in the same image area. However, as the number of pixels increases, the signal volume decreases, making it difficult to maintain the same S / N ratio. In addition, the difference in sensitivity between R (red), Gr (green), B (blue), and Gb (green) pixels is also increasing, causing the color balance to be lost. In particular, with miniaturization, the sensitivity difference between Gr and Gb appears equal, which has a significant impact on image quality. In view of this, a method has been proposed in the past to suppress the sensitivity difference between Gr and Gb by changing the pixel size and to ensure the layout symmetry of the gate polysilis (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-129548 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technique of Patent Document 1 reduces the degree of freedom in layout.

[0005] The present disclosure has been made in consideration of the above circumstances, and has an object to provide a solid-state imaging device that can improve the layout asymmetry of the gate polysilicon and improve the sensitivity difference between Gr (green) and Gb (green). [Means for solving the problem]

[0006] One aspect of the present disclosure is a solid-state imaging device comprising a plurality of pixels each having at least one photoelectric conversion unit that corresponds to different wavelengths of light and performs photoelectric conversion on incident light, a color filter that corresponds to the different wavelengths of light and is provided on the light incident side of the pixel, a gate electrode layer having a gate electrode of a transistor that performs signal processing on electric charges output from the pixel, and a pillar structure formed between the color filter and the gate electrode layer, having a plurality of rod-shaped portions, and absorbing light with the longest wavelength of visible light by means of the plurality of rod-shaped portions.

[0007] Another aspect of the present disclosure is a solid-state imaging device comprising: a plurality of pixels each having at least one photoelectric conversion unit that corresponds to different wavelengths of light and photoelectrically converts incident light; color filters that correspond to the different wavelengths of light and are provided on the light incident side of the pixels; a gate electrode layer having a gate electrode of a transistor that performs signal processing on electric charges output from the pixels; and a pillar structure formed in the gate electrode layer, having a plurality of rod-shaped portions, and absorbing the longest light in visible light with the plurality of rod-shaped portions, wherein the gate electrode and the pillar structure are made of the same material.

[0008] Furthermore, another aspect of the present disclosure is a solid-state imaging device comprising: a plurality of circuit chips having wiring formed thereon that electrically connects to the junctions and having opposing junction surfaces bonded and stacked; a pixel chip provided on at least one of the plurality of circuit chips and having at least one photoelectric conversion unit that photoelectrically converts incident light; dummy wiring disposed on a portion of the junction surfaces of the plurality of circuit chips; and a pillar structure portion having a plurality of rod-shaped portions formed on other portions of the junction surfaces of the plurality of circuit chips excluding the dummy wiring. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic configuration diagram showing an entire solid-state imaging device 1 according to a first embodiment of the present disclosure. [Diagram 2] 1 is a plan view of a pixel region of a solid-state imaging device according to a first embodiment of the present disclosure. [Diagram 3] 3 is a cross-sectional view taken perpendicularly to a dashed line passing through the photoelectric conversion unit in FIG. 2, as viewed from the AA direction. [Figure 4] FIG. 11 is a diagram for explaining light sensitivity in a comparative example. [Diagram 5] 4A to 4C are diagrams for explaining characteristics of a pillar structure portion according to the first embodiment of the present disclosure. [Figure 6] FIG. 2 is a diagram for explaining light sensitivity in the first embodiment of the present disclosure. [Figure 7] 3A to 3C are diagrams illustrating an example of an arrangement of pillar structures in the first embodiment of the present disclosure. [Figure 8] 6A to 6C are diagrams illustrating other exemplary arrangements of pillar structure portions in the first embodiment of the present disclosure. [Figure 9] 10A to 10C are diagrams showing an example in which the diameters of the rods of the pillar structure portions are made different in the first embodiment of the present disclosure. [Figure 10] FIG. 4 is a cross-sectional view of a pixel according to a second embodiment of the present disclosure. [Figure 11] FIG. 11 is a cross-sectional view showing an example in which no measures are taken for the pillar structure portion in the second embodiment of the present disclosure. [Figure 12] 11 is a cross-sectional view showing an example in which a pillar structure portion is disposed in a p-well in the second embodiment of the present disclosure. FIG. [Figure 13] 11 is a cross-sectional view showing an example of forming an SCF film on a rod of a pillar structure in the second embodiment of the present disclosure. FIG. [Figure 14] 11 is a cross-sectional view showing an example of forming a pillar gate electrode in the second embodiment of the present disclosure. FIG. [Figure 15] 11 is a cross-sectional view showing an example of implanting impurities into a substrate in a method for forming a pillar structure according to a second embodiment of the present disclosure. FIG. [Figure 16] 11 is a cross-sectional view showing an example of forming an oxide film on a substrate and forming a groove in a pillar structure forming method according to a second embodiment of the present disclosure. FIG. [Figure 17]FIG. 11 is a cross-sectional view showing an example in which a pillar structure is formed by injecting p-type impurities into a trench when a p-well connection is present in the method for forming a pillar structure according to the second embodiment of the present disclosure. [Figure 18] 11 is a cross-sectional view showing an example of forming an SCF film at a silicon interface in the method for forming a pillar structure according to the second embodiment of the present disclosure. FIG. [Figure 19] 11 is a cross-sectional view showing an example of forming an oxide film on an SCF film in the method for forming a pillar structure according to the second embodiment of the present disclosure. FIG. [Figure 20] 11 is a cross-sectional view showing an example of removing an unnecessary oxide film in the method for forming a pillar structure according to the second embodiment of the present disclosure. FIG. [Figure 21] FIG. 11 is a cross-sectional view showing an example of forming a pillar structure by injecting silicon into a plurality of trenches in a method for forming a pillar structure according to a second embodiment of the present disclosure. [Figure 22] FIG. 11 is a cross-sectional view showing an example in which, in a method for forming a pillar structure according to a second embodiment of the present disclosure, one rod of the pillar structure is used as a pixel transistor, a gate electrode layer is formed on the front surface side of a substrate, and a gate electrode for the pixel transistor and a gate electrode for the pillar are formed. [Figure 23] FIG. 11 is a cross-sectional view showing an example of a method for forming a pillar structure according to a second embodiment of the present disclosure, in which a pixel separation layer is laminated on the back surface side of a substrate, and a groove is formed in the depth direction from the back surface side of the pixel separation layer to the substrate by etching. [Figure 24] 13 is a cross-sectional view showing an example in which an element isolation portion is formed, and a color filter, an inter-glabellar film, and an on-chip lens are laminated in a method for forming a pillar structure according to a second embodiment of the present disclosure. FIG. [Diagram 25] 13A to 13C are diagrams illustrating an example of an arrangement of pillar structures according to a third embodiment of the present disclosure. [Figure 26] 13A to 13C are diagrams illustrating other exemplary arrangements of pillar structures according to the third embodiment of the present disclosure. [Figure 27] FIG. 13 is a cross-sectional view showing an example in which a potential is formed in the depth direction of a substrate in a fourth embodiment of the present disclosure. [Figure 28]FIG. 13 is a diagram shown for explaining the relationship between the potential depth and the potential formation direction in the fourth embodiment of the present disclosure. [Figure 29] FIG. 13 is a plan view showing an example in which a pillar structure portion is formed in a pixel of each color in a fifth embodiment of the present disclosure. [Diagram 30] FIG. 13 is a cross-sectional view of a pixel according to a fifth embodiment of the present disclosure. [Diagram 31] FIG. 13 is a diagram showing an example for comparison with the fifth embodiment of the present disclosure. [Diagram 32] 13A to 13C are diagrams for explaining characteristics of a pillar structure portion according to the fifth embodiment of the present disclosure. [Diagram 33] FIG. 13 is a diagram for explaining an effect of the fifth embodiment of the present disclosure. [Diagram 34] 13 is a cross-sectional view of a pixel in a solid-state imaging device according to a sixth embodiment of the present disclosure. FIG. [Diagram 35] 13A to 13C are diagrams illustrating an example of an arrangement of pillar structures in a sixth embodiment of the present disclosure. [Diagram 36] 13A to 13C are diagrams illustrating other exemplary arrangements of pillar structures in the sixth embodiment of the present disclosure. [Figure 37] 13A and 13B are a plan view and a cross-sectional view of a pixel in a solid-state imaging device according to a seventh embodiment of the present disclosure. [Figure 38] FIG. 13 is a cross-sectional view of a seventh embodiment of the present disclosure in which no measures against dark current are taken. [Figure 39] FIG. 13 is a cross-sectional view showing a case where measures against dark current are taken in the seventh embodiment of the present disclosure. [Diagram 40] FIG. 13 is a cross-sectional view showing an example of implanting impurities into a substrate in a method for forming a pillar structure according to a seventh embodiment of the present disclosure. [Diagram 41] FIG. 13 is a cross-sectional view showing an example of forming a silicon film on the front surface side of a substrate in a pillar structure forming method according to a seventh embodiment of the present disclosure. [Diagram 42] FIG. 13 is a cross-sectional view showing an example of forming a polymer on a front surface side of a silicon film in a pillar structure forming method according to a seventh embodiment of the present disclosure. [Diagram 43]FIG. 13 is a cross-sectional view showing an example of removing a silicon film by etching in the method for forming a pillar structure according to the seventh embodiment of the present disclosure. [Diagram 44] FIG. 13 is a cross-sectional view showing an example of forming a pillar structure by removing a polymer in a pillar structure forming method according to a seventh embodiment of the present disclosure. [Diagram 45] FIG. 13 is a cross-sectional view showing an example of forming a gate electrode layer on the front surface side of a substrate in a method for forming a pillar structure according to a seventh embodiment of the present disclosure. [Figure 46] FIG. 13 is a cross-sectional view showing an example in which one rod of the pillar structure is used as a pixel transistor, and a gate electrode for the pixel transistor and a gate electrode for the pillar are formed in a gate electrode layer in a method for forming a pillar structure according to a seventh embodiment of the present disclosure. [Figure 47] FIG. 13 is a cross-sectional view showing an example of a method for forming a pillar structure according to a seventh embodiment of the present disclosure, in which a pixel separation layer is laminated on the back surface side of a substrate, and a groove is formed in the depth direction from the back surface side of the pixel separation layer to the substrate by etching. [Figure 48] FIG. 13 is a cross-sectional view showing an example in which an element isolation portion is formed, and a color filter, an inter-glabellar film, and an on-chip lens are laminated in a method for forming a pillar structure according to a seventh embodiment of the present disclosure. [Figure 49] 13 is a cross-sectional view of a pixel in a solid-state imaging device according to an eighth embodiment of the present disclosure. FIG. [Figure 50] FIG. 13 is a cross-sectional view showing a comparative example to the eighth embodiment of the present disclosure. [Figure 51] FIG. 23 is a diagram showing an example of an arrangement of pillar structures in the eighth embodiment of the present disclosure. [Figure 52] FIG. 13 is a cross-sectional view of a pixel in a solid-state imaging device according to a ninth embodiment of the present disclosure. [Figure 53] FIG. 13 is a diagram showing an example of an arrangement of pillar structures in the ninth embodiment of the present disclosure. [Figure 54] 13 is a cross-sectional view of a pixel in a solid-state imaging device according to a tenth embodiment of the present disclosure. FIG. [Figure 55]13 is a cross-sectional view showing another example of a pixel in a solid-state imaging device according to the tenth embodiment of the present disclosure. FIG. [Figure 56] FIG. 23 is a cross-sectional view of a pixel in a case where a pillar structure portion is disposed between pixels of the same color in a tenth embodiment of the present disclosure. [Figure 57] FIG. 23 is a plan view showing a pattern in which pillar structures are arranged between pixels of the same color in a tenth embodiment of the present disclosure. [Figure 58] FIG. 23 is a cross-sectional view of a pixel in a case where a pillar structure portion is disposed between pixels of different colors in a tenth embodiment of the present disclosure. [Figure 59] FIG. 23 is a plan view showing a pattern in which pillar structures are arranged between pixels of different colors in a tenth embodiment of the present disclosure. [Figure 60] FIG. 23 is a cross-sectional view of a pixel in a case where a pillar structure is disposed between pixels of the same color and between pixels of different colors in a tenth embodiment of the present disclosure. [Figure 61] FIG. 23 is a plan view showing a pattern in which pillar structures are disposed between pixels of the same color and between pixels of different colors in a tenth embodiment of the present disclosure. [Figure 62] A cross-sectional view of a pixel of a vertical splitting structure according to an eleventh embodiment of the present disclosure. [Figure 63] 12A to 12C are cross-sectional views showing a method for forming a pillar structure according to an eleventh embodiment of the present disclosure. [Figure 64] A cross-sectional view of a solid-state imaging device according to a twelfth embodiment of the present disclosure. [Figure 65] FIG. 23 is a cross-sectional view showing an example for comparison with the twelfth embodiment of the present disclosure. [Figure 66] FIG. 23 is a schematic configuration diagram of an imaging device which is an example of an electronic device according to a thirteenth embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In the description of the drawings referred to in the following description, the same or similar parts are given the same or similar reference numerals, and duplicated descriptions are omitted. However, it should be noted that the drawings are schematic, and the relationship between thickness and planar dimensions, the thickness ratio of each device and each member, etc. differ from the actual ones. Therefore, the specific thickness and dimensions should be determined with reference to the following description. In addition, it goes without saying that the drawings include parts with different dimensional relationships and ratios.

[0011] In addition, the definitions of directions such as up and down in the following description are merely for the convenience of explanation and do not limit the technical ideas of the present disclosure. For example, if an object is rotated 90 degrees and observed, up and down are converted to left and right and read, and if it is rotated 180 degrees and observed, up and down are reversed and read. The effects described in this specification are merely examples and are not limiting, and other effects may also be obtained.

[0012] <First embodiment> <Overall configuration of solid-state imaging device> A solid-state imaging device 1 according to a first embodiment of the present disclosure will be described below. Fig. 1 is a schematic configuration diagram showing the entire solid-state imaging device 1 according to the first embodiment of the present disclosure.

[0013] The solid-state imaging device 1 in Fig. 1 is a back-illuminated CMOS (Complementary Metal Oxide Semiconductor) image sensor. The solid-state imaging device 1 captures image light from a subject via an optical lens, converts the amount of incident light focused on an imaging surface into an electrical signal on a pixel-by-pixel basis, and outputs the electrical signal.

[0014] As shown in FIG. 1, the solid-state imaging device 1 of the first embodiment includes a substrate 2, a pixel region 3, a vertical drive circuit 4, a column signal processing circuit 5, a horizontal drive circuit 6, an output circuit 7, and a control circuit 8. The pixel region 3 has a plurality of pixels 9 regularly arranged in a two-dimensional array on the substrate 2. The pixels 9 have the photoelectric conversion units 20Gb, 20B, 20Gr, and 20R shown in FIG. 2, and a plurality of pixel transistors (not shown). As the plurality of pixel transistors, for example, four transistors can be used: a transfer transistor, a reset transistor, a selection transistor, and an amplifier transistor. Alternatively, for example, three transistors excluding the selection transistor may be used.

[0015] The vertical drive circuit 4 is configured, for example, by a shift register, selects a desired pixel drive wiring 10, supplies a pulse for driving the pixels 9 to the selected pixel drive wiring 10, and drives each pixel 9 row by row. That is, the vertical drive circuit 4 sequentially selects and scans each pixel 9 in the pixel region 3 row by row in the vertical direction, and supplies a pixel signal based on a signal charge generated in the photoelectric conversion unit 20 of each pixel 9 according to the amount of received light to the column signal processing circuit 5 through the vertical signal line 11.

[0016] The column signal processing circuit 5 is arranged, for example, for each column of pixels 9, and performs signal processing such as noise removal for each pixel column on signals output from one row of pixels 9. For example, the column signal processing circuit 5 performs signal processing such as CDS (Correlated Double Sampling) and AD (Analog Digital) conversion for removing fixed pattern noise specific to each pixel.

[0017] The horizontal drive circuit 6 is, for example, composed of a shift register, and sequentially outputs horizontal scanning pulses to the column signal processing circuits 5, selects each of the column signal processing circuits 5 in turn, and causes each of the column signal processing circuits 5 to output pixel signals that have been subjected to signal processing to the horizontal signal line 12. The output circuit 7 performs signal processing on the pixel signals sequentially supplied from each of the column signal processing circuits 5 through the horizontal signal line 12, and outputs the processed signal. For example, the signal processing may include buffering, black level adjustment, column variation correction, various types of digital signal processing, and the like.

[0018] The control circuit 8 generates clock signals and control signals that serve as a reference for the operation of the vertical drive circuit 4, the column signal processing circuit 5, the horizontal drive circuit 6, etc., based on the vertical synchronization signal, the horizontal synchronization signal, and the master clock signal. Then, the control circuit 8 outputs the generated clock signals and control signals to the vertical drive circuit 4, the column signal processing circuit 5, the horizontal drive circuit 6, etc.

[0019] FIG 2 shows a plan view of the pixel region 3 of the solid-state imaging device 1 shown in FIG 1. As shown in FIG 2, a plurality of photoelectric conversion units 20Gb, 20B, 20Gr, 20R are arranged in a mosaic pattern. In FIG 2, the red photoelectric conversion unit 20R is labeled with the letter "R", the blue photoelectric conversion unit 20B is labeled with the letter "B", the green photoelectric conversion unit 20Gb is labeled with the letter "Gb", and the green photoelectric conversion unit 20Gr is labeled with the letter "Gr". Note that the arrangement pattern of the photoelectric conversion units 20Gb, 20B, 20Gr, 20R is not limited to that shown in FIG 3, and various arrangement patterns can be adopted.

[0020] 2 illustrates an example in which photoelectric conversion units 20Gb, 20B, 20Gr, and 20R are arranged at equal pitches in the row and column directions. The photoelectric conversion units 20Gb, 20B, 20Gr, and 20R are electrically isolated by element isolation units 31. The element isolation units 31 are formed in a lattice shape so as to surround each of the photoelectric conversion units 20Gb, 20B, 20Gr, and 20R.

[0021] Fig. 3 shows a cross-sectional view taken along a dashed line curved line passing through photoelectric conversion units 20Gb, 20B, 20Gr, and 20R in Fig. 2, cut in a vertical direction as viewed from the direction AA. As shown in Fig. 3, photoelectric conversion units 20Gb, 20B, 20Gr, and 20R may actually be arranged in a row. 3 illustrates a back-illuminated CMOS (Complementary Metal Oxide Semiconductor) image sensor as the solid-state imaging device 1. Hereinafter, the light incident surface side (upper side in FIG. 3) of each component of the solid-state imaging device 1 will be referred to as the "back surface," and the opposite surface to the light incident surface side (lower side in FIG. 3) of each component of the solid-state imaging device 1 will be referred to as the "front surface."

[0022] 3, in the solid-state imaging device 1, a substrate 2, a pixel separation layer 30, and a light-shielding film 32 are laminated in this order. A red color filter 50R, a green color filter 50Gb close to blue, a green color filter 50Gr close to red, an inter-brow membrane 27, and an on-chip lens 51 are laminated in this order on a rear surface S1 of the pixel separation layer 30. Furthermore, a gate electrode layer 23 and a wiring layer 24 are laminated in this order on a front surface S2 of the substrate 2.

[0023] Photoelectric conversion units 20Gb, 20B, 20Gr, and 20R (only photoelectric conversion units 20Gb, 20Gr, and 20R are shown in FIG. 3) are formed on the substrate 2 of the solid-state imaging device 1. FIG. 3 illustrates a case where the red photoelectric conversion unit 20R is adjacent to the green photoelectric conversion units 20Gb and 20Gr.

[0024] The substrate 2 may be, for example, a semiconductor substrate made of silicon (Si). The photoelectric conversion units 20R, 20Gb, and 20Gr each have an n-type semiconductor region and a p-type semiconductor region provided on the surface S2 side of the substrate 2, and the p-type semiconductor region and the n-type semiconductor region form a photodiode. In each of the photoelectric conversion units 20R, 20Gb, and 20Gr, a p-type semiconductor region may be further provided on the back side of the substrate 2, and the p-type semiconductor region and the n-type semiconductor region may form a photodiode. The photoelectric conversion unit 20R forms a red pixel 9, and the photoelectric conversion units 20Gb and 20Gr form a green pixel 9. Furthermore, the photoelectric conversion unit 20B forms a blue pixel 9.

[0025] In the photoelectric conversion units 20R, 20Gb, and 20Gr, signal charges corresponding to the amount of incident light are generated, and the generated signal charges are accumulated in the n-type semiconductor region. Electrons that cause dark current generated at the interface of the substrate 2 are absorbed by holes, which are majority carriers in the p-type semiconductor region formed in the substrate 2, thereby suppressing the dark current. On the surface S2 side of the substrate 2, between the photoelectric conversion units 20R, 20Gb, and 20Gr, a p-well region that serves as a charge accumulation region is formed. A floating diffusion portion (not shown) and the like are formed in the p-well region.

[0026] Further, each of the photoelectric conversion units 20R, 20Gb, and 20Gr is electrically isolated by a pixel isolation layer 30 made of a p-type semiconductor region and an element isolation unit 31 formed in the pixel isolation layer 30. As shown in FIG. 3, the element isolation unit 31 has a groove 31a formed in the depth direction from the rear surface S1 side of the substrate 2. That is, the groove 31a is formed by carving between the adjacent photoelectric conversion units 20R, 20Gb, and 20Gr on the rear surface S1 side of the substrate 2. The groove 31a is formed in a lattice shape so as to surround each of the photoelectric conversion units 20Gb, 20B, 20Gr, and 20R, as shown in FIG. 2, similar to the pixel isolation layer 30 and the element isolation unit 31. An insulating film for improving the light blocking performance against red light is buried in the groove 31a.

[0027] The pixel separation layer 30 also prevents reflection of incident light. The light-shielding film 32 is formed in a lattice shape on a part of the back surface S1 side (a part of the light-receiving surface side) of the pixel separation layer 30 so as to open the light-receiving surfaces of the photoelectric conversion units 20R, 20Gb, and 20Gr. The glabellar film 27 continuously covers the entire back surface side of the color filters 50R, 50Gb, and 50Gr including the light-shielding film 32. The material of the glabellar film 27 can be, for example, an organic material such as a resin.

[0028] The on-chip lens 51 collects the irradiated light and efficiently directs the collected light to the photoelectric conversion units 20R, 20Gb, and 20Gr in the substrate 2 via the color filters 50R, 50Gb, and 50Gr. The on-chip lens 51 can be made of an insulating material that does not have light absorption properties. Examples of insulating materials that do not have light absorption properties include silicon oxide, silicon nitride, silicon oxynitride, organic SOG, polyimide resin, and fluorine resin.

[0029] The color filter 50R is formed corresponding to the wavelength of red light to be received by each pixel 9. The color filter 50R transmits the wavelength of red light and causes the transmitted light to be incident on the photoelectric conversion unit 20R in the substrate 2. The color filters 50Gr, 50Gb are formed corresponding to the wavelength of green light to be received by each pixel 9. The color filters 50Gr, 50Gb transmit the wavelength of green light and cause the transmitted light to be incident on the photoelectric conversion units 20Gr, 20Gb in the substrate 2.

[0030] The gate electrode layer 23 is formed on the surface S2 side of the substrate 2, and is configured to include a gate polysilicon (gate electrode) 26 of the pixel transistor. The wiring layer 24 is formed on the surface side of the gate electrode layer 23, and is configured to include wiring 25 stacked in multiple layers. The pixel transistors that constitute each pixel 9 are driven via the multiple layers of wiring 25 formed in the wiring layer 24.

[0031] In the solid-state imaging device 1 having the above configuration, light is irradiated from the back side of the substrate 2, the irradiated light passes through the on-chip lens 51 and the color filters 50R, 50Gb, and 50Gr, and the transmitted light is photoelectrically converted by the photoelectric conversion units 20R, 20Gb, and 20Gr to generate signal charges. The generated signal charges are then output as pixel signals through the vertical signal lines 11 shown in FIG. 1, which are formed by the wiring 25, via pixel transistors formed in the substrate 2.

[0032] <Comparative Example> Fig. 4 is a diagram for explaining the results of comparing the sensitivity of conventional solid-state imaging devices as a comparative example, with the vertical axis representing the spectrum and the horizontal axis representing the wavelength of light of each color. In Fig. 4, the thick solid line represents red light (R), the dashed line represents blue light (B), the thick dotted line represents green light close to red (Gr), and the thin dotted line represents green light close to blue (Gb). 4, red light is less easily absorbed by silicon (Si) substrate 2 than other colors of light, and is more likely to reach a greater depth from the Si light receiving surface. For this reason, an output difference between green light (Gr), (Gb) occurs near the wavelength of the red light. In the comparative example, red light (R) that has been diffracted and scattered within photoelectric conversion unit 20R is incident at an angle on wiring 25 and enters green photoelectric conversion units 20Gb, 20Gr, resulting in color mixing.

[0033] <Measures taken in accordance with the first embodiment> 3, in the first embodiment of the present technology, a pillar structure 40 having a plurality of bar-shaped portions (rods) 40a is formed between the color filters 50R, 50Gb, 50Gr and the gate electrode layer 23, that is, in the photoelectric conversion unit 20R of the substrate 2. As shown in FIG. 5, the pillar structure 40 is a filter for absorbing red wavelengths (around 650 nm to 750 nm), which are the longest wavelengths in visible light. Therefore, the pillar structure 40 suppresses red light from reaching the gate electrode 26. As a result, the output difference between green light (Gr), (Gb) generated near the wavelength of red light is improved, as shown in Fig. 6. Furthermore, even if diffraction or scattering occurs in the red photoelectric conversion unit 20R, the pillar structure 40 absorbs the obliquely incident red light by the rods 40a, and color mixing between adjacent pixels can also be suppressed.

[0034] <Other Application Examples of the First Embodiment> (1-1) Example of suppressing the component of red light incident on the gate electrode 26 (1-2) Example in which the reflected light from the gate electrode 26 suppresses leakage of the red pixel into the adjacent pixel (1-3) An example of combining (1-1) and (1-2) above (1-4) Example of suppressing the component of light of a wavelength corresponding to the color filter of each pixel from entering the gate electrode 26

[0035] <Example of (1-1)> Fig. 7(a) shows an example of the arrangement of the pillar structure 40 in the case of suppressing a component of red light incident on the gate electrode 26. In the example of Fig. 7(a), the pillar structure 40 is formed in the red pixel 9, that is, the photoelectric conversion unit 20R.

[0036] <Example of (1-2)> 7(b) to 7(d) show examples of the arrangement of the pillar structure 40 in the case where the component of the reflected light from the gate electrode 26 leaking into the adjacent pixel of the red pixel is suppressed. In the example of FIG. 7(b), the pillar structure 40 is formed in the green pixel 9, that is, the photoelectric conversion unit 20Gr. In the example of FIG. 7(c), the pillar structure 40 is formed in the green pixel 9, that is, the photoelectric conversion unit 20Gb. Furthermore, in the example of FIG. 7(d), the pillar structure 40 is formed in the blue pixel 9, that is, the photoelectric conversion unit 20B.

[0037] <Example of (1-3)> Figures 8(a) to 8(e) show examples of the arrangement of pillar structures in the case where the component of red light incident on the gate electrode 26 is suppressed, and in the case where the component of light reflected from the gate electrode 26 that leaks into an adjacent pixel of the red pixel is suppressed. In the example of Fig. 8(a), a pillar structure 41 is formed in the photoelectric conversion unit 20R, and a pillar structure 42 is formed in the photoelectric conversion unit 20Gr. In the example of Fig. 8(b), a pillar structure 41 is formed in the photoelectric conversion unit 20R, and a pillar structure 42 is formed in the photoelectric conversion unit 20Gb. In the example of Fig. 8(c), a pillar structure 41 is formed in the photoelectric conversion unit 20R, a pillar structure 42 is formed in the photoelectric conversion unit 20Gr, and a pillar structure 43 is formed in the photoelectric conversion unit 20Gb.

[0038] In the example of Fig. 8(d), a pillar structure 41 is formed in photoelectric conversion unit 20R, and a pillar structure 42 is formed in photoelectric conversion unit 20B. In the example of Fig. 8(e), a pillar structure 41 is formed in photoelectric conversion unit 20R, a pillar structure 42 is formed in photoelectric conversion unit 20Gr, a pillar structure 43 is formed in photoelectric conversion unit 20Gb, and a pillar structure 44 is formed in photoelectric conversion unit 20B. The pillar structures 41 to 44 have rods with approximately the same diameter.

[0039] <Example of (1-4)> Fig. 9 shows an example of the arrangement of pillar structures in the case where components of light with wavelengths corresponding to the color filters of each pixel that are incident on the gate electrode 26 are suppressed. In the example of Fig. 9, a pillar structure 41 is formed in the photoelectric conversion unit 20R, a pillar structure 45 is formed in the photoelectric conversion unit 20Gr, a pillar structure 46 is formed in the photoelectric conversion unit 20Gb, and a pillar structure 47 is formed in the photoelectric conversion unit 20B. The pillar structures 41, 45, 46, and 47 have different rod diameters. The rod diameters increase in the order of blue, green, and red. The red wavelength reaches deep into the substrate 2, but the green and blue wavelengths are easily absorbed within the substrate 2 and therefore have difficulty reaching deep into the substrate 2.

[0040] <Effects of the First Embodiment> As described above, according to the first embodiment, the pillar structure 40 that absorbs red light, which has the longest wavelength among visible light, by the plurality of rods 40a is formed between the color filter 50R and the gate electrode layer 23, that is, in the photoelectric conversion unit 20R, so that the red light, which has the longest wavelength, can be prevented from reaching the gate electrode layer 23. This prevents the red light from hitting the gate electrode 26 and being reflected and entering the pixel 9 adjacent to the red pixel 9, thereby preventing color mixing and improving the sensitivity difference between Gr (green) and Gb (green). Moreover, there is no need to place a dummy polysilicon in order to ensure the symmetry of the layout of the gate electrode 26, which improves the degree of freedom of the gate layout. Furthermore, by forming the pillar structure 40 between the color filter 50R and the gate electrode layer 23 and preventing red light from reaching the wiring layer 24, wiring reflection can be suppressed.

[0041] Furthermore, according to the first embodiment, the diameters of the rods of the pillar structure portions 41, 45, 46, 47 are set to three types corresponding to the wavelengths of light of the colors received by each pixel, so that it is possible to suppress the component of red light entering the gate electrode layer 23 of the red pixel 9, to suppress the component of green light entering the gate electrode layer 23 of the green pixel 9, and to suppress the component of blue light entering the gate electrode layer 23 of the blue pixel 9.

[0042] <Second embodiment> Next, a second embodiment will be described. The second embodiment is a modification of the first embodiment, and a measure against an increase in dark current caused by distortion of the silicon (Si) substrate 2 will be described. Fig. 10(a) is a plan view of a pixel region 3 in a solid-state imaging device 1 according to a second embodiment, and Fig. 10(b) is a cross-sectional view taken along a dashed line AB in Fig. 10(a) in the vertical direction. In Fig. 10, the same parts as those in Fig. 3 are denoted by the same reference numerals and detailed description thereof will be omitted.

[0043] As shown in Fig. 10(b), when a pillar structure 40 is formed in the photoelectric conversion unit 20R of the substrate 2, dark current may increase due to distortion of silicon. The pillar structure 40 is formed in the photoelectric conversion unit 20R as shown in Fig. 11. In Fig. 11, a pixel transistor Tr is connected to the gate electrode 26. This pixel transistor Tr is formed in the photoelectric conversion unit 20R.

[0044] 12, in the second embodiment of the present disclosure, the pillar structure 40 is fixed to a p-well 33 formed between the photoelectric conversion units 20R, 20Gb, and 20Gr on the front surface S2 side of the substrate 2. A floating diffusion unit that accumulates the charge obtained in the photoelectric conversion unit 20R is formed in the p-well 33.

[0045] In the second embodiment, by fixing the pillar structure 40 to the p-well 33, photoelectric conversion in the vicinity of the floating diffusion can be suppressed, and dark current can be suppressed more than in a structure in which the pillar structure 40 is formed within the photoelectric conversion section 20. In the second embodiment of the present disclosure, the SCF film 35 that generates negative fixed charges is formed at the silicon interface between the pillar structure 40 and the substrate 2, as shown in FIG.

[0046] Furthermore, in the second embodiment of the present disclosure, as shown in FIG. 14, a pillar gate electrode 28 is formed on the gate electrode layer 23, and a ground potential (GND) or a negative potential is applied to it.

[0047] <Method of forming pillar structure according to the second embodiment> Next, a method for forming the pillar structure 40 according to the second embodiment will be described. Fig. 15 to Fig. 24 are cross-sectional views showing the steps until the pillar structure 40 is formed. First, as shown in Fig. 15, (1) impurities are injected into the substrate 2 to form the photoelectric conversion units 20R, 20Gb, and 20Gr and the pixel separation layer 30. Next, as shown in Fig. 16, (2) an oxide film 21 is formed on the front surface side of the substrate 2, and a plurality of grooves 21a are formed at the positions of the photoelectric conversion units 20R of the oxide film 21 by etching such as reactive ion etching, for example, to a depth reaching from the oxide film 21 to the photoelectric conversion unit 20R.

[0048] Next, as shown in Fig. 17, (3) when a p-well connection is present, p-type impurities are injected into the multiple trenches 21a to form a pillar structure 40. Next, as shown in Fig. 18, (4) an SCF film 35 is formed at the silicon interface. Next, as shown in Fig. 19, (5) an oxide film 36 is formed on the SCF film 35. Thereafter, as shown in Fig. 20, (6) unnecessary oxide films 21, 36 are removed. Next, as shown in Fig. 21, (7) silicon is injected into the multiple trenches 21a to form a pillar structure 40.

[0049] 22, (8) one rod of the pillar structure 40 is used as a pixel transistor Tr, and a gate electrode layer 23 is formed on the front side of the substrate 2, and a gate electrode 26 for the pixel transistor Tr and a gate electrode 28 for the pillar are formed in the gate electrode layer 23. Subsequently, as shown in FIG. 23, (9) a pixel separation layer 30 is laminated on the rear side of the substrate 2, and a groove 31a is formed in the depth direction from the rear side of the substrate 2 of the pixel separation layer 30 by etching. Furthermore, as shown in FIG. 24, (10) an insulating film is filled in the groove 31a of the pixel separation layer 30 to form an element separation portion 31, and a red color filter 50R, green color filters 50Gb, 50Gr, an inter-brow film 27, and an on-chip lens 51 are laminated in this order on the rear side of the pixel separation layer 30.

[0050] <Effects of the second embodiment> As described above, according to the second embodiment, by fixing the pillar structure 40 to the p-well 33, photoelectric conversion in the vicinity of the floating diffusion can be suppressed, and dark current can be suppressed more than in a structure in which the pillar structure 40 is formed within the photoelectric conversion section 20. Furthermore, according to the second embodiment, by forming an SCF film 35 that generates fixed charges at the silicon interface between the pillar structure 40 and the substrate 2, the dark current generated at the interface of the substrate 2 including the photoelectric conversion section 20R can be suppressed by the SCF film 35.

[0051] Furthermore, according to the second embodiment, by forming a pillar gate electrode 28 and setting the pillar gate electrode 28 to GND or a negative potential, dark current generated at the silicon interface of the substrate 2 including the photoelectric conversion unit 20R can be caused to flow to the pillar gate electrode 28, thereby suppressing the dark current.

[0052] <Third embodiment> Next, a third embodiment will be described. The third embodiment is a modification of the first embodiment, and a countermeasure against an increase in dark current caused by distortion of a silicon (Si) substrate 2 will be described. Fig. 25 and Fig. 26 are plan views of a pixel region 3 in a solid-state imaging device 1 according to the third embodiment.

[0053] <Other application examples of the third embodiment> (3-1) An example in which the reflected light from the gate electrode 26 suppresses the component leaking into the adjacent pixel of the red pixel. Surrounding the periphery of one pixel. (3-2) An example in which the reflected light from the gate electrode 26 is suppressed from leaking into the adjacent pixels of the red pixel.

[0054] <Example of (3-1)> FIG. 25 shows an example of the arrangement of the pillar structure 61 in the case where the component of the reflected light of the gate electrode 26 leaking into the adjacent pixel of the red pixel is suppressed. In the example of FIG. 25(a), the pillar structure 61 is formed around the red pixel 9, that is, the photoelectric conversion unit 20R. In the example of FIG. 25(b), the pillar structure 61 is formed around the green pixel 9, that is, the photoelectric conversion unit 20Gr. In addition, in the example of FIG. 25(c), the pillar structure 61 is formed around the green pixel 9, that is, the photoelectric conversion unit 20Gb. Furthermore, in the example of FIG. 25(d), the pillar structure 61 is formed around the blue pixel 9, that is, the photoelectric conversion unit 20B.

[0055] <Example of (3-2)> FIG. 26 shows an example of the arrangement of pillar structures 61 to 64 in the case where the reflected light of the gate electrode 26 is suppressed from leaking into the adjacent pixel of the red pixel. In the example of FIG. 26(a), the pillar structure 61 is formed around the photoelectric conversion unit 20R, and the pillar structure 62 is formed around the photoelectric conversion unit 20Gr. In the example of FIG. 26(b), the pillar structure 61 is formed around the photoelectric conversion unit 20R, and the pillar structure 63 is formed around the photoelectric conversion unit 20Gb. In the example of FIG. 26(c), the pillar structure 61 is formed around the photoelectric conversion unit 20R, the pillar structure 62 is formed around the photoelectric conversion unit 20Gr, and the pillar structure 63 is formed around the photoelectric conversion unit 20Gb. In the example of FIG. 26(d), the pillar structure 61 is formed around the photoelectric conversion unit 20R, and the pillar structure 64 is formed around the photoelectric conversion unit 20B.

[0056] In the example of Figure 26(c), a pillar structure 61 is formed around the photoelectric conversion unit 20R, a pillar structure 62 is formed around the photoelectric conversion unit 20Gr, a pillar structure 63 is formed around the photoelectric conversion unit 20Gb, and a pillar structure 64 is formed around the photoelectric conversion unit 20B.

[0057] <Effects of the Third Embodiment> As described above, according to the third embodiment, the pillar structure portions 61 are disposed between the pixels 9, and the dark current source is placed farther away from the photodiode, thereby making it possible to suppress the dark current.

[0058] <Fourth embodiment> Next, a fourth embodiment will be described. The fourth embodiment is a modification of the first embodiment. 27 is a cross-sectional view showing an example of the arrangement of the pillar structure 40 in the solid-state imaging device 1 according to the fourth embodiment. When the pillar structure 40 is formed inside the substrate 2, the silicon volume of the substrate 2 is reduced by the amount of the pillar structure 40, and therefore the charge may be reduced due to the reduction in the photoelectric conversion unit 20R.

[0059] 28, a potential is formed at the interface of the substrate 2, that is, at a location deep from the surface S2 of the substrate 2. This makes it possible to suppress a reduction in charge due to the reduction in size of the photoelectric conversion unit 20R.

[0060] <Fifth embodiment> Next, a fifth embodiment will be described. The fifth embodiment is a modification of the first embodiment, and a measure to prevent light with a long wavelength from reaching the wiring layer 24 will be described. Fig. 29 is a plan view of a pixel region 3 in a solid-state imaging device 1 according to a fifth embodiment, and Fig. 30 is a cross-sectional view taken along the vertical direction of the pixel region 3 in Fig. 29. In Fig. 30, the same parts as those in Fig. 3 above are denoted by the same reference numerals and detailed description thereof will be omitted.

[0061] 29, the pillar structures 40 are formed in each of the photoelectric conversion units 20R, 20Gr, 20Gb, and 20B. Note that the pillar structures 40 have rods with substantially the same diameter between the pixels 9.

[0062] <Comparative Example> FIG. 31 is a diagram for explaining an example of a sensor surface in a conventional solid-state imaging device as a comparative example. 31, red light is less absorbed by silicon (Si) substrate 2 than other colors of light, and is more likely to reach a greater depth from the Si light receiving surface. As a result, red light reaches wiring 25, and reflection from the wiring occurs on the sensor surface.

[0063] <Measures taken in accordance with the fifth embodiment> 30, in the fifth embodiment of the present technology, a pillar structure 40 is formed between each of the photoelectric conversion units 20R, 20Gr, 20Gb, 20B and the gate electrode layer 23. As shown in FIG. 32, the pillar structure 40 is a filter for absorbing red wavelengths (around 650 nm to 750 nm), which are the longest wavelengths in visible light, and therefore suppresses red light from reaching the wiring 25. For this reason, as shown in FIG. 33, it is possible to suppress reflection of the wiring.

[0064] Sixth embodiment Next, a sixth embodiment will be described. The sixth embodiment is a modification of the first embodiment. Fig. 34 is a cross-sectional view of a pixel 9 in a solid-state imaging device 1 according to the sixth embodiment. In Fig. 34, the same parts as those in Fig. 3 above are denoted by the same reference numerals and detailed description thereof will be omitted.

[0065] 34, the pillar structure 40A is formed in the same gate electrode layer 23 as the gate electrode 26. In addition, the pillar structure 40A is formed from the same poly material as the gate electrode 26.

[0066] <Other application examples of the sixth embodiment> (6-1) Example of suppressing the component of red light incident on the gate electrode 26 (6-2) Example in which the reflected light from the gate electrode 26 suppresses leakage of the red pixel into the adjacent pixel (6-3) An example of combining (6-1) and (6-2) above (6-4) Example of suppressing the component of light of wavelength corresponding to the color filter of each pixel from entering the gate electrode 26

[0067] <Example of (6-1)> Fig. 35(a) shows an example of the arrangement of pillar structures for suppressing red light components incident on the gate electrode 26. Here, it is assumed that a pillar structure 41A is formed in a red pixel 9, pillar structures 42A and 43A are formed in a green pixel 9, and a pillar structure 44A is formed in a blue pixel 9. In the example of Fig. 35(a), the pillar structure 41A is formed in the red pixel 9, that is, on the gate electrode layer 23 side of the photoelectric conversion unit 20R.

[0068] <Example of (6-2)> Figures 35(b) to 35(d) show examples of the arrangement of pillar structures in the case where the component of the reflected light from the gate electrode 26 leaking into the adjacent pixel of the red pixel is suppressed. In the example of Figure 35(b), the pillar structure 42A is formed on the gate electrode layer 23 side of the green pixel 9, that is, the photoelectric conversion unit 20Gr. In addition, in the example of Figure 35(c), the pillar structure 43A is formed on the gate electrode layer 23 side of the green pixel 9, that is, the photoelectric conversion unit 20Gb. Furthermore, in the example of Figure 7(d), the pillar structure 44A is formed on the gate electrode layer 23 side of the blue pixel 9, that is, the photoelectric conversion unit 20B.

[0069] <Example of (6-3)> Figures 36(a) to 36(e) show examples of the arrangement of pillar structures in the case where the component of red light incident on the gate electrode 26 is suppressed, and in the case where the component of light reflected from the gate electrode 26 that leaks into an adjacent pixel of the red pixel is suppressed.

[0070] In the example of Fig. 36(a), a pillar structure 41A is formed on the gate electrode layer 23 side of the photoelectric conversion unit 20R, and a pillar structure 42A is formed on the gate electrode layer 23 side of the photoelectric conversion unit 20Gr. In the example of Fig. 36(b), a pillar structure 41A is formed on the gate electrode layer 23 side of the photoelectric conversion unit 20R, and a pillar structure 42A is formed on the gate electrode layer 23 side of the photoelectric conversion unit 20Gb. In the example of Fig. 36(c), a pillar structure 41A is formed on the gate electrode layer 23 side of the photoelectric conversion unit 20R, a pillar structure 42A is formed on the gate electrode layer 23 side of the photoelectric conversion unit 20Gr, and a pillar structure 43A is formed on the gate electrode layer 23 side of the photoelectric conversion unit 20Gb.

[0071] In the example of Fig. 36(d), a pillar structure 41A is formed on the gate electrode layer 23 side of the photoelectric conversion unit 20R, and a pillar structure 44A is formed on the gate electrode layer 23 side of the photoelectric conversion unit 20B. In the example of Fig. 36(e), a pillar structure 41A is formed on the gate electrode layer 23 side of the photoelectric conversion unit 20R, a pillar structure 42A is formed on the gate electrode layer 23 side of the photoelectric conversion unit 20Gr, a pillar structure 43A is formed on the gate electrode layer 23 side of the photoelectric conversion unit 20Gb, and a pillar structure 44A is formed on the gate electrode layer 23 side of the photoelectric conversion unit 20B. The pillar structures 41A to 44A have rods with approximately the same diameter.

[0072] <Example of (6-4)> Fig. 36(f) shows an example of the arrangement of pillar structures in the case where the component of the wavelength light corresponding to the color filter of each pixel that is incident on the gate electrode 26 is suppressed. In the example of Fig. 36(f), a pillar structure 41A is formed on the gate electrode layer 23 side of the photoelectric conversion unit 20R, a pillar structure 45A is formed on the gate electrode layer 23 side of the photoelectric conversion unit 20Gr, a pillar structure 46A is formed on the gate electrode layer 23 side of the photoelectric conversion unit 20Gb, and a pillar structure 47A is formed on the gate electrode layer 23 side of the photoelectric conversion unit 20B. The pillar structures 41A, 45A, 46A, and 47A have different rod diameters. The rod diameters increase in the order of blue, green, and red. The red wavelength reaches deep into the substrate 2, but the green and blue wavelengths are easily absorbed within the substrate 2 and therefore have difficulty reaching deep into the substrate 2.

[0073] <Effects of the sixth embodiment> As described above, according to the sixth embodiment, even if the pillar structure portion 40A is formed in the gate electrode layer 23, the same effects as those of the first embodiment can be obtained.

[0074] Seventh embodiment Next, a seventh embodiment will be described. The seventh embodiment is a modification of the first embodiment, and a countermeasure against the increase in dark current will be described. Fig. 37(a) is a plan view of a pixel region 3 in a solid-state imaging device 1 according to a seventh embodiment, and Fig. 37(b) is a cross-sectional view taken along a dashed line AB in Fig. 37(a) in the vertical direction. In Fig. 37, the same parts as those in Fig. 3 above are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0075] As shown in Fig. 37(b), even if a pillar structure 40 is formed in the gate electrode layer 23, dark current may increase if left as is. In Fig. 11, a pixel transistor Tr is connected to the gate electrode 26 as shown in Fig. 38. This pixel transistor Tr is formed in the gate electrode layer 23. In the seventh embodiment of the present disclosure, as shown in FIG. 39, a pillar gate electrode 28 is formed on the gate electrode layer 23, and a ground potential (GND) or a negative potential is applied to the pillar gate electrode 28.

[0076] <Method of forming a pillar structure according to the seventh embodiment> Next, a method for forming the pillar structure 40A according to the seventh embodiment will be described. Figures 40 to 48 are cross-sectional views showing the steps until the pillar structure 40A is formed. First, as shown in Figure 40, (1) impurities are injected into the substrate 2 to form the photoelectric conversion units 20R, 20Gb, and 20Gr and the pixel separation layer 30. Next, as shown in Figure 41, (2) a silicon film 22 is formed on the surface S2 side of the substrate 2.

[0077] Next, as shown in Fig. 42, (3) a polymer 29 is formed on the surface side of the silicon film 22. Next, as shown in Fig. 43, (4) the silicon film 22 is removed by etching. In the step of Fig. 43, the portion of the silicon film 22 where the polymer 29 is formed remains. Thereafter, as shown in Fig. 44, (5) the polymer 29 is removed to form a pillar structure portion 40A. Next, as shown in Fig. 45, (6) a gate electrode layer 23 is formed on the surface side of the substrate 2.

[0078] Then, as shown in Fig. 46, (7) one rod of the pillar structure portion 40A is used as a pixel transistor Tr, and a gate electrode 26 for the pixel transistor Tr and a gate electrode 28 for the pillar are formed in the gate electrode layer 23. Subsequently, as shown in Fig. 47, (8) a pixel separation layer 30 is laminated on the rear surface side of the substrate 2, and a groove 31a is formed in the pixel separation layer 30 in the depth direction from the rear surface side of the substrate 2 by etching. Furthermore, as shown in Fig. 48, (9) an insulating film is filled in the groove 31a of the pixel separation layer 30 to form an element separation portion 31, and a red color filter 50R, green color filters 50Gb, 50Gr, an inter-brow film 27, and an on-chip lens 51 are laminated in this order on the rear surface side of the pixel separation layer 30.

[0079] <Effects of the Seventh Embodiment> As described above, according to the seventh embodiment, by forming the pillar gate electrode 28 and setting the pillar gate electrode 28 to GND or a negative potential, it is possible to cause a dark current generated at the silicon interface of the substrate 2 including the photoelectric conversion portion 20R to flow to the pillar gate electrode 28 via the pillar structure portion 40A, thereby suppressing the dark current.

[0080] <Eighth embodiment> Next, an eighth embodiment will be described. The eighth embodiment is a modification of the first embodiment, and a case where the eighth embodiment is applied to a pixel having a rear surface global shutter structure will be described. Fig. 49 is a cross-sectional view of the pixel region 3 in the solid-state imaging device 1 according to the eighth embodiment cut in the vertical direction. In Fig. 10, the same parts as those in Fig. 3 are denoted by the same reference numerals and detailed description thereof will be omitted.

[0081] 49, in the eighth embodiment of the present disclosure, a floating diffusion (FD) 33a serving as a depletion layer is formed between the photoelectric conversion units 20R, 20Gb, and 20Gr on the front surface S2 side of the substrate 2. The FD 33a accumulates the charge obtained in the photoelectric conversion unit 20R. In the pixel 9 having the rear surface global shutter structure, the charge is held in the FD 33a until the pixel signal is read out.

[0082] <Comparative Example> Fig. 50 is a cross-sectional view of a pixel 9 having a back-surface global shutter structure in a conventional solid-state imaging device as a comparative example. In Fig. 50, the same parts as those in Fig. 49 are given the same reference numerals and detailed description thereof will be omitted. In the pixel 9 having the conventional rear surface global shutter structure, PLS (Parasitic Light Sensitivity) occurs, in which the amount of stored charge fluctuates, due to photoelectric conversion of the transmitted and reflected light components of light to the FD 33a.

[0083] <Measures taken in accordance with the eighth embodiment> Returning to Figure 49, in the eighth embodiment of the present disclosure, by arranging a pillar structure 70 at the interface between the photoelectric conversion section 20R and the gate electrode layer 23, it is possible to suppress the reflected components and directly incident components due to the gate polysilicon onto the FD33a, particularly in relation to light leakage from oblique directions, thereby suppressing the PLS components.

[0084] <Other application examples of the eighth embodiment> (8-1) MEM retention structure without pixel sharing (8-2) FD retention structure without pixel sharing (8-3) MEM retention structure with pixel sharing

[0085] <Example of (8-1)> Fig. 51(a) shows an example of the arrangement of pillar structures in a non-pixel-sharing MEM holding structure. In the example of Fig. 51(a), when an FD33a and a memory unit (MEM) are present in each of the photoelectric conversion units 20R and 20Gb, pillar structures 71 are arranged around the FD33a and the MEM in the photoelectric conversion units 20R and 20Gb. When an FD33a and a MEM are present in each of the photoelectric conversion units 20Gr and 20B, pillar structures 72 are arranged around the FD33a and the MEM in the photoelectric conversion units 20Gr and 20B.

[0086] <Example of (8-2)> Fig. 51(b) shows an example of the arrangement of pillar structures in a non-pixel-sharing FD holding structure. In the example of Fig. 51(b), when an FD33a exists in each of the photoelectric conversion units 20R and 20Gb, a pillar structure 71 is arranged around the FD33a in the photoelectric conversion units 20R and 20Gb. When an FD33a exists in each of the photoelectric conversion units 20Gr and 20B, a pillar structure 72 is arranged around the FD33a in the photoelectric conversion units 20Gr and 20B.

[0087] <Example of (8-3)> Fig. 51(c) shows an example of the arrangement of pillar structures in a pixel sharing and MEM holding structure. In the example of Fig. 51(c), when one FD33a and MEM are shared between the photoelectric conversion units 20R and 20Gb, a pillar structure 71 is arranged around the FD33a and MEM. When one FD33a and MEM are shared between the photoelectric conversion units 20Gr and 20B, a pillar structure 72 is arranged around the FD33a and MEM.

[0088] <Effects of the eighth embodiment> As described above, according to the eighth embodiment, in a pixel 9 having a back-surface global shutter structure, by arranging the pillar structure 70 at the interface between the photoelectric conversion unit 20R and the gate electrode layer 23, it is possible to suppress the reflected component and directly incident component due to the gate poly to the FD33a, particularly with respect to light leakage from an oblique direction, and the FD33a can thereby suppress the PLS component.

[0089] <Ninth embodiment> Next, a ninth embodiment will be described. The ninth embodiment is a modification of the first embodiment, and a case where the embodiment is applied to a pixel having a surface global shutter structure will be described. Fig. 52 is a cross-sectional view of a pixel 9A in a solid-state imaging device 1 according to the ninth embodiment. In Fig. 52, the same parts as those in Fig. 49 are denoted by the same reference numerals and detailed description thereof will be omitted.

[0090] 52, the pixel 9A has a surface global shutter structure. The pixel 9A includes a substrate 2, a gate electrode layer 23, a wiring layer 24, a red color filter 50R, a green color filter 50Gb close to blue, a green color filter 50Gr close to red, an inter-glabellar membrane 27, and an on-chip lens 51, which are laminated in this order. Photoelectric conversion units 20R, 20Gb, and 20Gr are formed in positions corresponding to the color filters 50R, 50Gb, and 50Gr, respectively, on the substrate 2. In addition, an FD 33a is formed on the substrate 2 on the wiring layer 24 side. In the ninth embodiment of the present disclosure, the pillar structure 80 is disposed at the interfaces between the photoelectric conversion units 20R, 20Gb, and 20Gr and the gate electrode layer 23, and on the gate electrode .

[0091] <Other application examples of the ninth embodiment> (9-1) MEM retention structure without pixel sharing (9-2) FD retention structure without pixel sharing (9-3) MEM retention structure with pixel sharing

[0092] <Example of (9-1)> Fig. 53(a) shows an example of the arrangement of pillar structures in a non-pixel-sharing MEM holding structure. In the example of Fig. 53(a), when an FD33a and a memory unit (MEM) are present in each of the photoelectric conversion units 20R and 20Gb, pillar structures 81 are arranged around the FD33a and the MEM in the photoelectric conversion units 20R and 20Gb and above the FD33a and the MEM. When an FD33a and a MEM are present in each of the photoelectric conversion units 20Gr and 20B, pillar structures 82 are arranged around the FD33a and the MEM in the photoelectric conversion units 20Gr and 20B and above the FD33a and the MEM.

[0093] <Example of (9-2)> Fig. 53(b) shows an example of the arrangement of pillar structures in a non-pixel-sharing FD holding structure. In the example of Fig. 53(b), when an FD33a exists in each of the photoelectric conversion units 20R and 20Gb, pillar structures 81 are arranged around and above the FD33a in the photoelectric conversion units 20R and 20Gb. When an FD33a exists in each of the photoelectric conversion units 20Gr and 20B, pillar structures 82 are arranged around and above the FD33a in the photoelectric conversion units 20Gr and 20B.

[0094] <Example of (9-3)> Fig. 53(c) shows an example of the arrangement of pillar structures in a pixel sharing and MEM holding structure. In the example of Fig. 53(c), when one FD33a and MEM are shared between photoelectric conversion units 20R and 20Gb, pillar structures 81 are arranged around the FD33a and MEM and above the MEM. When one FD33a and MEM are shared between photoelectric conversion units 20Gr and 20B, pillar structures 82 are arranged around the FD33a and MEM and above the MEM.

[0095] <Effects of the ninth embodiment> As described above, according to the ninth embodiment, in the pixel 9A having the surface global shutter structure, the pillar structure 80 is disposed at the interface between the photoelectric conversion units 20R, 20Gr, 20Gb and the gate electrode layer 23, and on the gate electrode 26, and the PLS component can be suppressed by absorbing and blocking the light incident on the FD 33a.

[0096] <Tenth embodiment> Next, a tenth embodiment will be described. The tenth embodiment is a modification of the first embodiment, and a case where it is applied to a pixel having a dual pixel structure will be described. Fig. 54 is a cross-sectional view of a pixel 9 in a solid-state imaging device 1 according to the tenth embodiment. In Fig. 54, the same parts as those in Fig. 3 are denoted by the same reference numerals and detailed description thereof will be omitted.

[0097] In Figure 54, pixel 9 has a dual pixel structure in which, for example, photoelectric conversion unit 20R is separated into two photoelectric conversion units 20Ra and 20Rb by element isolation unit 34a, which is the first element isolation unit among element isolation units 34, and adjacent photoelectric conversion units 20Gr and 20Gb are insulated and separated by element isolation units 34b1 and 34b2. In the pixel 9 of the dual pixel structure, the phase difference characteristics are improved by forming an element isolation section 34a between pixels of the same color, but there is an issue of color mixing caused by scattering from the interface of the element isolation section 34. Although it is possible to use an absorbent such as a color filter as a countermeasure against scattering, it is difficult to introduce it into fine pixels due to the high technical difficulty of processing.

[0098] Therefore, in the tenth embodiment of the present disclosure, as shown in Fig. 54(a), a pillar structure 91 is formed on the element isolation portion 34a between pixels of the same color on the incident light side. In this way, the pillar structure 91 can absorb the scattered components on the element isolation portion 34a. 54(b), a pillar structure 92 is formed below the different color element isolation portions 34b1 and 34b2 on the back surface side. In this way, the internal reflection components in the photoelectric conversion portion 20Rb can be absorbed by the pillar structure 92.

[0099] These pillar structures 91, 92 can be microfabricated, and by creating different rod diameters corresponding to the color filters 50R, 50Gb, 50Gr of each pixel 9, it becomes possible to absorb different wavelengths. Furthermore, in the tenth embodiment of the present disclosure, as shown in FIG. 54(c), a pillar structure 91 may be formed on the element isolation portion 34a, and a pillar structure 92 may be formed below the element isolation portions 34b1 and 34b2.

[0100] <Other application examples according to the tenth embodiment> (10-1) Combination of same-color pillar structure and different-color through-hole DTI on the input side (10-2) Combination of same-color pillar structure on the input side and through-hole DTI

[0101] <Example of (10-1)> Fig. 55(a) shows an example of the arrangement of pillar structures in a combination of same-color pillar structures on the incident light side and different-color through-hole DTIs. In the example of Fig. 55(a), a through-hole DTI 35 is formed instead of the different-color element isolations 34b1 and 34b2. In this case, by forming a pillar structure 91 on the element isolation 34a between same-color pixels on the incident light side, the pillar structure 91 can absorb the scattered components on the element isolation 34a.

[0102] <Example of (10-2)> Fig. 55(b) shows an example of the arrangement of pillar structures in a combination of same-color pillar structures on the incident light side and through-hole DTIs. In the example of Fig. 55(b), through-hole DTI 35 is formed instead of element isolation portions 34a, 34b1, and 34b2. In this case, too, by forming a pillar structure 91 on through-hole DTI 35 between same-color pixels on the incident light side, the pillar structure 91 can absorb the scattered components on element isolation portion 34a.

[0103] <Another example of the arrangement of the pillar structure according to the tenth embodiment> As shown in FIG. 56, in the tenth embodiment of the present disclosure, when a pillar structure 91 is formed on an element isolation portion 34a between same-color pixels on the incident light side, the following arrangement example is possible. (10-3) Dual pixel adaptation (10-4) Applied to 2x2 on-chip lens pixels

[0104] <Example of (10-3)> Fig. 57(a) shows an example of the arrangement of pillar structures when applied to a dual pixel pixel. In the example of Fig. 57(a), when an element isolation section 34a is formed from the photoelectric conversion section 20R to the photoelectric conversion section 20Gb, the pillar structure section 91-1 is formed on the element isolation section 34a from the photoelectric conversion section 20R to the photoelectric conversion section 20Gb. When an element isolation section 34a is formed from the photoelectric conversion section 20Gr to the photoelectric conversion section 20B, the pillar structure section 91-2 is formed on the element isolation section 34a from the photoelectric conversion section 20Gr to the photoelectric conversion section 20B.

[0105] <Example of (10-4)> Fig. 57(b) shows an example of the arrangement of pillar structures in the case of application to a 2x2 on-chip lens pixel. In the example of Fig. 57(b), when an element isolation section 34a is formed from the photoelectric conversion section 20R to the photoelectric conversion section 20Gr, the pillar structure section 91-3 is formed on the element isolation section 34a from the photoelectric conversion section 20R to the photoelectric conversion section 20Gr. When an element isolation section 34a is formed from the photoelectric conversion section 20Gb to the photoelectric conversion section 20B, the pillar structure section 91-4 is formed on the element isolation section 34a from the photoelectric conversion section 20Gb to the photoelectric conversion section 20B.

[0106] As shown in FIG. 58, in the tenth embodiment of the present disclosure, when a pillar structure 92 is formed under element isolation portions 34b1 and 34b2 between different color pixels on the rear surface side, the following arrangement examples are possible. (10-5) Applied to dual pixel pixels (10-6) Applied to 2x2 on-chip lens pixels

[0107] <Example of (10-5)> Fig. 59(a) shows an example of the arrangement of pillar structures when applied to a dual pixel pixel. In the example of Fig. 59(a), pillar structures 92-1 to 92-5 are formed around each of the photoelectric conversion units 20R, 20Gr, 20Gb, and 20B. Fig. 59(b) also shows an example of the arrangement of pillar structures when applied to a dual pixel pixel. In the example of Fig. 59(a), pillar structures 92-1 to 92-3 are formed only in the direction in which there are many mixed color components of the photoelectric conversion units 20R, 20Gr, 20Gb, and 20B.

[0108] <Example of (10-6)> Fig. 59(c) shows an example of the arrangement of pillar structures when applied to a 2 × 2 on-chip lens pixel. In the example of Fig. 59(c), pillar structures 92-1 to 92-5 are formed around each of the photoelectric conversion units 20R, 20Gr, 20Gb, and 20B, similarly to the example of Fig. 59(a).

[0109] As shown in Figure 60, in the tenth embodiment of the present disclosure, when a pillar structure 91 is formed on the element isolation portion 34a between same-color pixels on the incident light side and a pillar structure 92 is formed below the element isolation portions 34b1, 34b2 between different-color pixels on the back surface side, the following arrangement examples are possible. (10-7) Applied to dual pixel pixels (10-8) Applied to 2x2 on-chip lens pixels

[0110] <Example of (10-7)> Figures 61(a) and (b) show examples of the arrangement of pillar structures when applied to a dual pixel pixel. In the example of Figure 61(a), pillar structures 91-1, 91-2 and pillar structures 92-1 to 92-5 are formed in the same manner as in the above examples (10-3) and (10-5). In the example of Figure 61(b), pillar structures 91-1, 91-2 and pillar structures 92-1 to 92-3 are formed in the same manner as in the above examples (10-3) and (10-5).

[0111] <Example of (10-8)> Fig. 61(c) shows an example of the arrangement of pillar structures when applied to a 2 × 2 on-chip lens pixel. In the example of Fig. 61(c), pillar structures 91-1 to 91-4 and pillar structures 92-1 to 92-5 are formed in the same manner as in the above examples (10-4) and (10-6).

[0112] <Effects of the Tenth Embodiment> As described above, according to the tenth embodiment, the pillar structure 91 is formed between pixels of the same color on the incident light side of the element isolation portion 34a, and the color mixing between adjacent pixels can be suppressed by absorbing the scattered components. Also, the pillar structure 92 is formed between pixels of different colors on the back side of the element isolation portions 34b1 and 34b2, and the internally reflected components can be absorbed, thereby suppressing color mixing between adjacent pixels. Therefore, by introducing an element isolation section between same-color pixels into dual pixels and 2 × 2 on-chip lens pixels, it is possible to improve phase difference characteristics and suppress color mixing at the same time.

[0113] <Eleventh embodiment> Next, an eleventh embodiment will be described. The eleventh embodiment is a modification of the first embodiment, and a case where it is applied to pixels having a vertical splitting structure will be described. Fig. 62 is a cross-sectional view of a pixel 9B of a vertical splitting structure according to the eleventh embodiment. In Fig. 62, the same parts as those in Fig. 3 are denoted by the same reference numerals and detailed description thereof will be omitted.

[0114] The pixel 9B includes, for example, a green photoelectric conversion unit 110, a blue photoelectric conversion unit 111, and a red photoelectric conversion unit 112. For example, the blue photoelectric conversion unit 111 and the red photoelectric conversion unit 112 are provided in a substrate 113. The blue photoelectric conversion unit 111 is located closer to the light incident side than the red photoelectric conversion unit 112. The green photoelectric conversion unit 110 is provided above the blue photoelectric conversion unit 111.

[0115] The green photoelectric conversion unit 110 is formed by stacking a first electrode 101, a photoelectric conversion layer 102, and a second electrode 103. The first electrode 101 is connected to a third electrode 105. The third electrode 105 is an electrode for storing electric charge. The first electrode 101 and the third electrode 105 are covered with an insulating layer 104. The photoelectric conversion layer 102 is formed on the insulating layer 104, and the second electrode 103 is formed on the photoelectric conversion layer 102. An insulating layer 106, a color filter 107, an glabellar membrane 108, and an on-chip lens 51 are stacked in this order on the second electrode 103.

[0116] The first electrode 101, the second electrode 103, and the third electrode 105 are each composed of a light-transmitting conductive film. The photoelectric conversion layer 102 is composed of a layer containing an organic photoelectric conversion material having at least green sensitivity. The photoelectric conversion layer 102 may also be composed of an inorganic material. The insulating layers 104 and 106, the glabellar membrane 108, and the substrate 113 are composed of well-known insulating materials (for example, silicon oxide or silicon nitride).

[0117] The light incident surface of the substrate 113 is designated as an upper side, and the opposite side is designated as a lower side. A wiring layer 116 consisting of a plurality of wirings 115 is provided below the substrate 113. A transfer transistor 114 consisting of a vertical transistor is provided within the substrate 113. A gate electrode of the transfer transistor 114 extends to the blue photoelectric conversion unit 111 and is connected to the wiring 115. The charge accumulated in the blue photoelectric conversion unit 111 is output to the wiring 115 via the transfer transistor 114. The red photoelectric conversion unit 112 is connected to the gate electrode of a transfer transistor 117. The charge accumulated in the red photoelectric conversion unit 112 is output to a wiring 115 via a transfer transistor 114.

[0118] The electric charge accumulated in the green photoelectric conversion unit 110 is accumulated in the third electrode 105 via the first electrode 101, and is output to the wiring 115 via a transfer transistor (not shown). In pixel 9B with a vertical splitting structure, an issue is the separation of wavelength splitting of the stacked photoelectric conversion units 110, 111, and 112. As a measure to improve the separation characteristics, the vertical size of each of the photoelectric conversion units 110, 111, and 112 can be adjusted, but complete separation is difficult.

[0119] Therefore, in the eleventh embodiment of the present disclosure, a pillar structure 121 is formed between the green photoelectric conversion unit 110 and the blue photoelectric conversion unit 111, and a pillar structure 122 is formed between the blue photoelectric conversion unit 111 and the red photoelectric conversion unit 112. Then, a pillar structure 123 is formed between the red photoelectric conversion unit 112 and the wiring layer 116. The pillar structure 121 selectively absorbs green light, the pillar structure 122 absorbs blue light, and the pillar structure 123 absorbs red light and IR light.

[0120] <Method of forming pixel 9B according to 11th embodiment> Next, a method for forming the pixel 9B according to the eleventh embodiment will be described. FIG. 63 is a cross-sectional view showing a process for forming the pixel 9B. First, as shown in FIG. 63(1), impurities are injected into the substrate 113 to form the blue photoelectric conversion section 111 and the pillar structure section 122. Then, as shown in FIG. 63(2), the substrate 2 is regrown by lateral epitaxy using silicon. Then, as shown in FIG. 63(3), a red / blue separation section is formed at the position where the pillar structure section 122 is to be formed. After that, the red photoelectric conversion section 111 is formed at the regrown location by lateral epitaxy, and a gate electrode of the transfer transistor 114 connected to the blue photoelectric conversion section 111 is formed.

[0121] <Effects of the eleventh embodiment> As described above, according to the 11th embodiment, in pixel 9B having a vertical spectroscopic structure using an organic sensor, by forming pillar structures 121, 122, and 123 between each photoelectric conversion section 110, 111, and 112, it is possible to form a filter in a desired wavelength region, thereby improving the spectroscopic characteristics. In addition, in the 11th embodiment, the pillar structures 121, 122, and 123 can be finely processed between the steps of the existing back surface process, and by creating different rod diameters corresponding to the filters between each of the photoelectric conversion units 110, 111, and 112, it becomes possible to absorb different wavelengths.

[0122] <Twelfth embodiment> Next, a twelfth embodiment will be described. The twelfth embodiment is a modification of the first embodiment, and will be described in terms of its application to CuCu bonding. FIG. 64 is a cross-sectional view of a solid-state imaging device 1C according to the twelfth embodiment. 64, the solid-state imaging device 1C is composed of, from the top, a lens layer 233, a color filter layer 232, a light-shielding wall layer 221, a photoelectric conversion layer 222, and wiring layers 211 and 212. The lens layer 233, the color filter layer 232, the light-shielding wall layer 221, and the photoelectric conversion layer 222 constitute a pixel chip, and the wiring layers 211 and 212 constitute a circuit chip.

[0123] The lens layer 233 transmits incident light, which is light entering from above in the figure, so as to be collected in the photoelectric conversion layer 222. The color filter layer 232 transmits only light of a specific wavelength from the incident light that has transmitted through the lens layer 233 in units of pixels 9C. More specifically, the color filter layer 232 extracts and transmits light of wavelengths corresponding to light of colors such as R, Gr, Gb, and B in units of pixels.

[0124] The light-shielding wall layer 221 is a layer in which light-shielding walls 2211 are provided, and these light-shielding walls 2211 block incident light from adjacent pixels 9C so that only light from each pixel 9C formed at each convex portion of the lens layer 233 is incident on the PD of the photoelectric conversion layer 222 corresponding to the pixel 9C directly below it.

[0125] The photoelectric conversion layer 222 is a layer in which a photodiode (PD) is formed, which generates charges according to the amount of incident light through photoelectric conversion, and transfers the generated charges to the FD via a transfer transistor (not shown) provided in the wiring layer 211. The wiring layer 211 includes a reset transistor, a transfer transistor, an amplifying transistor, a selection transistor, and an FD, and outputs a pixel signal corresponding to the charge to a wiring 2121 of the wiring layer 212 via a wiring 2221. In addition, a dummy wiring 2222 made of copper (Cu) is provided in the wiring layer 211 to reinforce the strength of the joint between the wiring layers 211 and 212.

[0126] The wiring layer 212 is provided with a circuit for processing pixel signals input from the wiring 2121 of the wiring layer 212 via the wiring 2221 of the wiring layer 211. In addition, the wiring layer 212 is provided with dummy wiring 2122 made of copper (Cu) for bonding with the dummy wiring 2222 of the wiring layer 211.

[0127] <Comparative Example> Fig. 65 is a cross-sectional view of a solid-state imaging device serving as a comparative example to the twelfth embodiment. In Fig. 65, the same parts as those in Fig. 64 above are given the same reference numerals, and detailed description thereof will be omitted. 65, the long wavelength components of light incident through the lens layer 233 reach the wiring layer 212, are reflected by the wiring 2121, and return to the photoelectric conversion layer 222, where they are photoelectrically converted and become mixed color signal components. Another issue is that light is emitted due to the circuit operation in the circuit chip, and is reflected in the pixel chip.

[0128] <Measures taken in accordance with the twelfth embodiment> 64, in the twelfth embodiment of the present disclosure, a pillar structure 240 is formed in a portion of the bonding surface F of the wiring layers 211, 212 where there are no dummy wirings 2122, 2222. The pillar structure 240 can absorb the longest wavelength component of visible light and prevent it from reaching the wiring 2121 in the wiring layer 212. In addition, the pillar structure 240 can absorb the luminescent component from the circuit chip and prevent it from reaching the photoelectric conversion layer 222.

[0129] <Effects of the twelfth embodiment> As described above, according to the twelfth embodiment, by forming the pillar structure 240 at a location on the bonding surface F of the wiring layers 211, 212 where there are no dummy wirings 2122, 2222, it is possible to absorb long wavelength components such as red light by the pillar structure 240 and prevent the components from reaching the wiring layer 212 on the circuit chip side. In addition, the pillar structure 240 can also absorb light emitted from the circuit chip to prevent the components from reaching the photoelectric conversion layer 222. Therefore, it is possible to suppress color mixing caused by reflection of long wavelength components reaching the circuit chip, and it is also possible to prevent light emitted from the circuit chip from reaching the pixel chip.

[0130] <Other embodiments> As described above, the present technology has been described by the first to twelfth embodiments and modified examples, but the descriptions and drawings forming part of this disclosure should not be understood as limiting the present technology. If the gist of the technical contents disclosed in the above first to twelfth embodiments is understood, it will be clear to those skilled in the art that various alternative embodiments, examples, and operation techniques can be included in the present technology. In addition, the configurations disclosed in the first to twelfth embodiments and modified examples can be appropriately combined within a range that does not cause contradictions. For example, the configurations disclosed in multiple different embodiments may be combined, and the configurations disclosed in multiple different modified examples of the same embodiment may be combined.

[0131] <Applications to electronic devices> Next, an electronic device according to a thirteenth embodiment of the present disclosure will be described. Fig. 66 is a schematic configuration diagram of an imaging device 300, which is an example of an electronic device according to the thirteenth embodiment of the present disclosure. 66, the imaging device 300 includes an optical system including a lens group 301, a solid-state imaging device 302, a DSP circuit 303 which is a camera signal processing circuit, a frame memory 304, a display device 305, a recording device 306, an operation system 307, and a power supply system 308. Of these, the DSP circuit 303, the frame memory 304, the display device 305, the recording device 306, the operation system 307, and the power supply system 308 are connected to each other via a bus line 309.

[0132] The lens group 301 captures incident light (image light) from a subject and forms an image on the imaging surface of the solid-state imaging device 302. The solid-state imaging device 302 converts the amount of incident light formed on the imaging surface by the lens group 301 into an electrical signal on a pixel-by-pixel basis and outputs the electrical signal as a pixel signal. The solid-state imaging device of the present embodiment described above is used as this solid-state imaging device 302. The display device 305 is a panel-type display device such as a liquid crystal display device or an organic EL (electro luminescence) display device, and displays moving or still images captured by the solid-state imaging device 302. The recording device 306 records the moving or still images captured by the solid-state imaging device 302 on a recording medium such as a non-volatile memory, a video tape, or a DVD (Digital Versatile Disk).

[0133] An operation system 307 issues operation commands for various functions of the image capture device under the operation of a user. A power supply system 308 appropriately supplies various types of power to these devices as operating power for the DSP circuit 303, the frame memory 304, the display device 305, the recording device 306, and the operation system 307.

[0134] Such an imaging device 300 is applied to a camera module for a mobile device such as a video camera, a digital still camera, or even a mobile phone, etc. By using the solid-state imaging device according to the embodiment described above as the solid-state imaging device 302, it is possible to provide an imaging device with excellent color balance.

[0135] The present disclosure can also be configured as follows. (1) A plurality of pixels each including at least one photoelectric conversion unit that corresponds to a different wavelength of light and performs photoelectric conversion on incident light; color filters corresponding to the different wavelengths of light and provided on the light incident side of the pixels; a gate electrode layer having a gate electrode of a transistor that performs signal processing on the charge output from the pixel; a pillar structure portion formed between the color filter and the gate electrode layer, the pillar structure portion having a plurality of rod-shaped portions, the plurality of rod-shaped portions absorbing light having the longest wavelength among visible light; A solid-state imaging device comprising: (2) The pillar structure is disposed in at least one pixel of red, blue, and green visible light. The solid-state imaging device according to (1) above. (3) The diameters of the rod-shaped portions of the pillar structure are largest in blue, largest in green, and largest in red. The solid-state imaging device according to (2) above. (4) The pillar structure is at ground potential or negative potential. The solid-state imaging device according to (1) above. (5) The pillar structure is fixed to a charge accumulation region that accumulates the charge obtained in the photoelectric conversion unit. The solid-state imaging device according to (1) above. (6) The pillar structure has a treatment film formed on the rod-shaped portion, the treatment film generating a fixed charge. The solid-state imaging device according to (1) above. (7) The solid-state imaging device described in (1), wherein the pixel has a dual pixel structure in which the photoelectric conversion unit is separated into two by a first element isolation unit, and adjacent photoelectric conversion units are insulated and separated by a second element isolation unit. (8) The pillar structure is disposed between the same-color elements on the light incident side of the first element isolation portion. The solid-state imaging device according to (7) above. (9) The pillar structure is disposed between different colors on the rear surface side of the second element isolation portion. The solid-state imaging device according to (7) above. (10) The pillar structure is disposed between the same color elements on the light incident side of the first element isolation section and between the different color elements on the back surface side of the second element isolation section. The solid-state imaging device according to (7) above. (11) The pixel has a vertical splitting structure in which a plurality of photoelectric conversion units corresponding to different wavelengths of light are arranged, The pillar structure is disposed between a plurality of adjacent photoelectric conversion units. The solid-state imaging device according to (1) above. (12) The pixel has a global shutter structure. The solid-state imaging device according to (1) above. (13) The pixel has a surface global shutter structure, The pillar structure is disposed at an interface between the photoelectric conversion unit and the gate electrode layer and on the gate electrode. The solid-state imaging device according to (12) above. (14) The pixel has a back surface global shutter structure, The pillar structure is disposed at an interface between the photoelectric conversion unit and the gate electrode layer. The solid-state imaging device according to (12) above. (15) A plurality of pixels each including at least one photoelectric conversion unit that corresponds to a different wavelength of light and performs photoelectric conversion on incident light; color filters corresponding to the different wavelengths of light and provided on the light incident side of the pixels; a gate electrode layer having a gate electrode of a transistor that performs signal processing on the charge output from the pixel; a pillar structure portion formed in the gate electrode layer, the pillar structure portion having a plurality of rod-shaped portions, the plurality of rod-shaped portions absorbing light having the longest wavelength among visible light; Equipped with A solid-state imaging device in which the gate electrode and the pillar structure are made of the same material. (16) The pillar structure is disposed in at least one pixel of red, blue, and green visible light. The solid-state imaging device according to (15) above. (17) The diameters of the rod-shaped portions of the pillar structure are largest in red, largest in green, and largest in blue. The solid-state imaging device according to (16) above. (18) A plurality of circuit chips are stacked on each other, with wiring formed on the bonding surfaces and the bonding surfaces facing each other being bonded together; a pixel chip provided on at least one of the plurality of circuit chips, the pixel chip having at least one photoelectric conversion unit arranged therein for photoelectrically converting incident light; dummy wiring arranged on a part of the bonding surfaces of the plurality of circuit chips; a pillar structure portion having a plurality of rod-shaped portions formed on the bonding surfaces of the plurality of circuit chips except for the dummy wirings; A solid-state imaging device comprising: (19) The pillar structure absorbs light having the longest wavelength in visible light by the plurality of rod-shaped portions. The solid-state imaging device according to (18) above. [Explanation of symbols]

[0136] 1, 1C...solid-state imaging device, 2...substrate, 3...pixel region, 4...vertical drive circuit, 5...column signal processing circuit, 6...horizontal drive circuit, 7...output circuit, 8...control circuit, 9, 9A, 9B, 9C...pixel, 10...pixel drive wiring, 11...vertical signal line, 12...horizontal signal line, 20, 20B, 20Gb, 20Gr, 20R, 20Ra, 20Rb...photoelectric conversion section, 21...oxide film, 21a...groove, 22...silicon film, 23...gate electrode layer, 24...wiring layer, 25...wiring, 26...gate electrode, 27...glabellar membrane, 28... Pillar gate electrode, 29... Polymer, 30... Pixel isolation layer, 31, 34, 34a, 34b1, 34b2... Element isolation portion, 31a... Groove portion, 32... Light shielding film, 33... p-well, 33a... FD, 35... SCF film, 36... Oxide film, 40, 40A, 41, 41A, 42, 42A, 43, 43A, 44, 44A, 45, 45A, 46, 46A, 47, 47A, 61, 62, 63, 64, 70, 71, 72, 80, 81, 82, 91, 91-1, 91-2, 91-3, 91-4, 9 2, 92-1, 92-2, 92-3, 92-4, 92-5, 121, 122, 123, 240...pillar structure portion, 40a...rod-shaped portion (rod), 50Gb, 50Gr, 50R...color filter, 51...on-chip lens, 101...first electrode, 102...photoelectric conversion layer, 103...second electrode, 104, 106...insulating layer, 105...third electrode, 107...color filter, 108...glabellar membrane, 110, 111, 112...photoelectric conversion portion, 113...substrate, 114...transfer transistor, 115... Wiring, 116...wiring layer, 117...transfer transistor, 211, 212...wiring layer, 221...light-shielding wall layer, 222...photoelectric conversion layer, 232...color filter layer, 233...lens layer, 300...imaging device, 301...lens group, 302...solid-state imaging device, 303...DSP circuit, 304...frame memory, 305...display device, 306...recording device, 307...operation system, 308...power supply system, 309...bus line, 2121, 2221...wiring, 2122, 2222...dummy wiring, 2211...light-shielding wall

Claims

1. A plurality of pixels each including at least one photoelectric conversion unit that corresponds to a different wavelength of light and performs photoelectric conversion on incident light; color filters corresponding to the different wavelengths of light and provided on the light incident side of the pixels; a gate electrode layer having a gate electrode of a transistor that performs signal processing on the charge output from the pixel; a pillar structure portion formed between the color filter and the gate electrode layer, the pillar structure portion having a plurality of rod-shaped portions, the plurality of rod-shaped portions absorbing light having the longest wavelength among visible light; Equipped with A pillar gate electrode connected to the pillar structure is formed in the gate electrode layer, and the pillar gate electrode is set to a ground potential or a negative potential. Solid-state imaging device.

2. A plurality of pixels each including at least one photoelectric conversion unit that corresponds to a different wavelength of light and performs photoelectric conversion on incident light; color filters corresponding to the different wavelengths of light and provided on the light incident side of the pixels; a gate electrode layer having a gate electrode of a transistor that performs signal processing on the charge output from the pixel; a pillar structure portion formed between the color filter and the gate electrode layer, the pillar structure portion having a plurality of rod-shaped portions, the plurality of rod-shaped portions absorbing light having the longest wavelength among visible light; Equipped with The pillar structure is fixed to a charge accumulation region that accumulates the charge obtained in the photoelectric conversion unit. Solid-state imaging device.

3. A plurality of pixels each including at least one photoelectric conversion unit that corresponds to a different wavelength of light and performs photoelectric conversion on incident light; color filters corresponding to the different wavelengths of light and provided on the light incident side of the pixels; a gate electrode layer having a gate electrode of a transistor that performs signal processing on the charge output from the pixel; a pillar structure portion formed between the color filter and the gate electrode layer, the pillar structure portion having a plurality of rod-shaped portions, the plurality of rod-shaped portions absorbing light having the longest wavelength among visible light; Equipped with The pixel has a dual pixel structure in which the photoelectric conversion unit is separated into two by a first element isolation unit, and adjacent photoelectric conversion units are insulated and isolated from each other by a second element isolation unit, The pillar structure is disposed between different colors on the rear surface side of the second element isolation portion. Solid-state imaging device.

4. A plurality of pixels each including at least one photoelectric conversion unit that corresponds to a different wavelength of light and performs photoelectric conversion on incident light; color filters corresponding to the different wavelengths of light and provided on the light incident side of the pixels; a gate electrode layer having a gate electrode of a transistor that performs signal processing on the charge output from the pixel; a pillar structure portion formed between the color filter and the gate electrode layer, the pillar structure portion having a plurality of rod-shaped portions, the plurality of rod-shaped portions absorbing light having the longest wavelength among visible light; Equipped with The pixel has a dual pixel structure in which the photoelectric conversion unit is separated into two by a first element isolation unit, and adjacent photoelectric conversion units are insulated and isolated from each other by a second element isolation unit, The pillar structure is disposed between the same color elements on the light incident side of the first element isolation section and between the different color elements on the back surface side of the second element isolation section. Solid-state imaging device.

5. The pillar structure portion is arranged in at least one pixel of red, blue, and green of the visible light. The solid-state imaging device according to claim 1 .

6. The diameters of the plurality of rod-shaped portions of the pillar structure are largest in blue, largest in green, and largest in red. The solid-state imaging device according to claim 5 .

7. A plurality of circuit chips are stacked on each other, with wiring formed on the bonding surfaces and the bonding surfaces facing each other being bonded together; a pixel chip provided on at least one of the plurality of circuit chips, the pixel chip having at least one photoelectric conversion unit arranged thereon for photoelectrically converting incident light; dummy wiring arranged on a part of the bonding surfaces of the plurality of circuit chips; a pillar structure portion having a plurality of rod-shaped portions formed on the bonding surfaces of the plurality of circuit chips except for the dummy wirings; A solid-state imaging device comprising:

8. The pillar structure absorbs light having the longest wavelength in visible light by the plurality of rod-shaped portions. The solid-state imaging device according to claim 7 .

Images