JP2012114197A - Solid-state imaging device and method of manufacturing the same - Google Patents

Abstract

A solid-state imaging device capable of suppressing the occurrence of flare without forming a flare-preventing film and improving the offset amount measurement accuracy using optical black, and a method for manufacturing the same.
In a stacked solid-state imaging device, a photoelectric conversion film formed simultaneously in an effective pixel region and a peripheral region is configured to receive light incident on a wiring made of metal in the peripheral region. By absorbing, it functions as a flare prevention film that reduces reflection on the wiring 37, and also exposes the upper part of the wiring 37 b to prevent electrons generated in the peripheral region 130 from entering the optical black region 120.
[Selection] Figure 2

Description

  The present invention relates to a stacked solid-state imaging device in which photoelectric conversion films are stacked on a substrate.

  FIG. 18 is a perspective view showing a configuration of a conventional solid-state imaging device. The solid-state imaging device 900 includes a sensor unit 910 in which a plurality of pixels are arranged, and a wiring unit 920 provided with a metal wiring 922, a bonding pad 930, and a flare prevention film 924 in the periphery thereof. The flare prevention film 924 is made of a material containing a dye that absorbs light, and is formed so as to cover the metal wiring 922.

  Flare, also called scattered light, is noise that occurs when a part of the light enters the sensor section while the light is multiply reflected between the back of the lens and the metal wiring of the solid-state imaging device in the camera housing. It is. When flare occurs, for example, the contrast of the captured image is reduced, the captured image is partially whitened, or the color is blurred.

  In the solid-state imaging device 900 shown in FIG. 18, the metal wiring 922 is covered with a light-absorbing flare prevention film 924. Therefore, since the light incident toward the metal wiring 922 is absorbed by the flare prevention film 924, reflection on the metal wiring 922 can be prevented, and as a result, occurrence of flare can be prevented.

JP 2003-234456 A

However, in the manufacture of the solid-state imaging device, the process of forming the anti-flare film must be performed separately, and there is a problem that the manufacturing cost increases accordingly.
It is an object of the present invention to provide a solid-state imaging device and a method for manufacturing the same that can suppress the generation of flare while eliminating the step of forming a flare prevention film.

  To achieve the above object, a solid-state imaging device according to the present invention includes a substrate, an insulating film formed on the substrate, and a plurality of lower electrodes formed for each pixel in a first region on the insulating film. The first region of the insulating film includes a photoelectric conversion film formed so as to cover the plurality of lower electrodes, and a translucent upper electrode formed on the photoelectric conversion film. A wiring for reading out the signal of each pixel is embedded in the second region adjacent to the region, and the photoelectric conversion film formed in the first region further covers the wiring embedded in the insulating film. In addition, it is characterized by spreading over the insulating film in the second region.

  In the method for manufacturing a solid-state imaging device according to the present invention, an insulating film in which wiring for reading signal charges of each pixel is embedded in the second region is formed on the substrate in the first region and the second region. Forming a plurality of lower electrodes for each pixel on the insulating film in the first region; and covering the plurality of lower electrodes in the first region and in the insulating film on the insulating film in the second region The method includes a step of forming a photoelectric conversion film so as to cover a wiring embedded in the substrate, and a step of forming a translucent upper electrode on the photoelectric conversion film.

  In the above configuration, the photoelectric conversion film formed in the first region is further spread over the insulating film in the second region so as to cover the wiring embedded in the insulating film. The photoelectric conversion film has a characteristic of generating charges by absorbing incident light. For this reason, the photoelectric conversion film functions to generate a signal of each pixel in the first region, and in the second region, the anti-flare film that reduces reflection on the wiring by absorbing light incident on the wiring. Serves as a function. Further, the photoelectric conversion film extending to the second region can be formed at the same time when the photoelectric conversion film is formed in the first region. Therefore, it is possible to suppress the occurrence of flare while eliminating the step of forming the flare prevention film.

  Further, in the manufacturing method of the present invention, it is possible to manufacture a solid-state imaging device that can suppress generation of flare while eliminating the step of forming the flare prevention film.

It is a figure which shows each area | region when the solid-state imaging device which concerns on Embodiment 1 of this invention is seen from upper direction. It is sectional drawing of the pixel part of the solid-state imaging device shown in FIG. It is process sectional drawing which shows typically a part of manufacturing process of the pixel part of the solid-state imaging device shown in FIG. It is process sectional drawing which shows typically a part of manufacturing process of the pixel part of the solid-state imaging device shown in FIG. It is process sectional drawing which shows typically a part of manufacturing process of the pixel part of the solid-state imaging device shown in FIG. It is process sectional drawing which shows typically a part of manufacturing process of the pixel part of the solid-state imaging device shown in FIG. It is sectional drawing of the pixel part of the solid-state imaging device concerning Embodiment 2 of this invention. It is a figure which shows the shape of the upper electrode when it sees from the upper direction of the solid-state imaging device which concerns on Embodiment 3 of this invention. It is sectional drawing of the pixel part of the solid-state imaging device shown in FIG. It is a figure which shows the shape of a metal film and metal wiring when it sees from the upper direction of the solid-state imaging device which concerns on Embodiment 4 of this invention. It is sectional drawing of the pixel part of the solid-state imaging device shown in FIG. FIG. 11 is a process cross-sectional view schematically illustrating a part of the manufacturing process of the pixel portion of the solid-state imaging device illustrated in FIG. 10. FIG. 11 is a process cross-sectional view schematically illustrating a part of the manufacturing process of the pixel portion of the solid-state imaging device illustrated in FIG. 10. It is sectional drawing of the pixel part of the solid-state imaging device which concerns on Embodiment 5 of this invention. It is a schematic diagram for demonstrating the solid-state imaging device shown in FIG. It is sectional drawing of the pixel part of the solid-state imaging device which concerns on the modification of this invention. It is a figure which shows the shape of the metal wiring of a solid-state imaging device. It is a perspective view of the conventional solid-state imaging device.

[Embodiment 1]
1. Outline of Configuration of Solid-State Imaging Device 100 FIG. 1 is a diagram showing each region when the solid-state imaging device 100 according to Embodiment 1 of the present invention is viewed from above.

The solid-state imaging device 100 includes a pixel region 115 as a first region, a peripheral region 130 as a second region adjacent to the pixel region 115, and a pad region 140 surrounding the periphery.
The pixel area 115 is an area in which a plurality of pixels are arranged, and includes an effective pixel area 110 and a peripheral optical black area 120.

The peripheral area 130 is an area where wiring for reading signals from each pixel is provided.
The pad area 140 is an area in which a bonding pad 39 for externally connecting the wiring provided in the peripheral area 130 is provided.

2 is a cross-sectional view taken along line AA of the solid-state imaging device 100 illustrated in FIG.
In the semiconductor substrate 10, an STI (Shallow Trench Isolation) 11 that insulates pixels is formed, and a storage diode 13, a floating diffusion 15, and a reset transistor drain 19 are formed for each pixel. A gate oxide film 20 is formed on the semiconductor substrate 10. On the gate oxide film 20, a reset gate 21, a transfer gate 23, and an amplification transistor gate 25 are formed, and an interlayer insulating film 22 is formed so as to cover these gates. Copper wirings 31 and 37 and W (tungsten) plugs 27 are formed in the interlayer insulating film 22.

  On the interlayer insulating film 22, interlayer insulating films 30 and 32 are formed. In the interlayer insulating film 30, copper wirings 33 and 37 and a copper plug 35 are formed. On the interlayer insulating film 32, aluminum wirings 37a, 37b, 37c, 37d and bonding pads 39 are formed, and a protective oxide film 40 is formed so as to cover the wirings 37b, 37c, 37d. At the position where the wiring 37a is formed, there is an opening 40a in which the protective oxide film 40 is opened. A lower electrode 41 is formed for each pixel on the protective oxide film 40, and a photoelectric conversion film 42 is formed so as to cover the lower electrode 41. An upper electrode 44 having translucency is formed on the photoelectric conversion film 42. The upper electrode 44 is electrically connected to the wiring 37 a through the opening 40 a provided in the protective oxide film 40.

  On the upper electrode 44, a metal film 51 made of a metal material is formed in the optical black region 120, and a planarization film 50 is formed so as to cover the metal film 51. On the planarizing film 50, a color filter 52, a planarizing film 54, and a micro lens 56 for each pixel are formed.

As described above, in the solid-state imaging device 100, the insulating film including the gate oxide film 20, the interlayer insulating films 22, 30, 32, and the protective oxide film 40 is formed on the semiconductor substrate 10, and photoelectric conversion is performed on the insulating film. A film 42 is formed, and a structure of a so-called stacked solid-state imaging device in which wirings 37 for reading signals of each pixel are embedded in the insulating film.
2. Detailed Description of Solid-State Imaging Device 100 The configuration of the main part of the solid-state imaging device 100 will be described in detail with reference to FIG.

  The photoelectric conversion film 42 is formed of, for example, an inorganic photoconductive film such as an α-Si film and continuously extends to both the pixel region 115 and the peripheral region 130. In particular, in the peripheral region 130, the wiring 37a is formed. It extends so as to cover the wiring 37 except for.

  The photoelectric conversion film 42 has sensitivity in the visible light region, and creates electrons and holes from incident light. In the pixel region 115, the photoelectric conversion film 42 functions to absorb light and generate signal charges for each pixel. On the other hand, in the peripheral region 130, the photoelectric conversion film 42 absorbs light incident toward the wiring 37, thereby reducing reflection on the wiring 37 and serving as a flare prevention film.

  The electrons generated in the photoelectric conversion film 42 in the peripheral region 130 are recombined with holes in the photoelectric conversion film 42 and disappear after a certain period of time. Therefore, the possibility that the electrons enter the pixel region 115 and affect the image quality is low. If there is a possibility that the electrons may enter the optical black area 120, take measures such as a specification that does not use a signal extracted from a pixel in the portion closest to the peripheral area 130 in the optical black area 120. Can do.

  The upper electrode 44 is formed of, for example, ITO (Indium Tin Oxide) or ZnO (Zinc Oxide), and extends to both the pixel region 115 and the peripheral region 130. The wiring 37a is in the opening 40a, which is an opening of the protective oxide film 40, and is connected to the upper electrode 44 through the opening 40a. Although not shown, the upper electrode 44 is connected to the negative electrode of the power source, for example, the ground. Although not shown, the lower electrode 41 is also connected to the positive electrode of the power supply via the storage diode 13, the floating diffusion 15, and the reset transistor drain 19. Therefore, a bias voltage is generated between the upper electrode 44 and the lower electrode 41 in the photoelectric conversion film 42 in the pixel region 115. Electrons generated in the photoelectric conversion film 42 are attracted to the lower electrode 41 by the bias voltage. Thereafter, the electrons are extracted outside as signal charges through the lower electrode 41 of each pixel.

  The metal film 51 is made of a metal material having a lower electrical resistivity than the material of the upper electrode 44, has a property of reflecting light, and functions as a light shielding film. Therefore, most of the light incident on the optical black region 120 is reflected by the metal film 51, and the incident light on the photoelectric conversion film 42 is reduced. Also, as shown in FIG. 1, the effective pixel region 110 width 110a, the optical black region 120 width 120a, and the peripheral region 130 width 130a are approximately 100: 5: 50. Is smaller than the area of the effective pixel region 110. Therefore, there is little multiple reflected light due to the light reflected by the metal film 51 in the optical black region 120, and there is little possibility of causing flare due to the multiple reflected light entering the effective pixel region 110.

The optical black area 120 is used to detect the offset amount of the solid-state imaging device 100. When signal charges not caused by incident light are present in the photoelectric conversion film 42 in the optical black region 120, the signal charges are transferred to the storage diode 13 and then extracted outside. This current caused by signal charges not caused by incident light is called dark current. By subtracting the signal charge amount measured in the optical black region 120 from the signal charge amount measured in the effective pixel region 110, an appropriate signal charge amount in the effective pixel region 110 can be measured.
3. Manufacturing Method of Solid-State Imaging Device 100 The manufacturing method of the solid-state imaging device 100 according to Embodiment 1 of the present invention will be described with reference to FIGS. To do.

In FIG. 3A, the formation of the gate oxide film 20, the interlayer insulating films 22, 30, 32, and the protective oxide film 40, which are insulating films in which the wirings 31, 33, 37 are embedded, is completed.
Next, as shown in FIG. 3B, in the effective pixel region 110 and the optical black region 120, the lower electrode 41 is formed for each pixel. Specifically, a metal film made of Al, W, Mo (molybdenum), TiN (titanium nitride) or the like is deposited on the protective oxide film 40 to a thickness of 100 to 300 nm, and is formed by a general photolithography technique and an etching technique. The The lower electrode 41 is separated for each pixel, and this area determines the effective aperture ratio of the pixel. For example, when the separation width between pixels is 1/10 to 2/10 of the pixel size in a pixel size of 1.0 μm to 1.4 μm, the aperture ratio is estimated to be about 64% to about 81%.

  As shown in FIG. 4A, a material 42a for the photoelectric conversion film 42 is deposited on the protective oxide film 40 on which the lower electrode 41 is formed by plasma CVD or sputtering. Specifically, an α-Si film is deposited to 100 nm to 1 μm on one surface.

  As shown in FIG. 4B, a resist pattern 70 is formed on the material 42a of the photoelectric conversion film 42 by a general photolithography technique. The resist pattern 70 is formed so as to cover the effective pixel region 110, the optical black region 120, and the wiring 37 excluding the wiring 37 a in the peripheral region 130.

  Next, as illustrated in FIG. 5A, the photoelectric conversion film 42 is formed so as to extend to the effective pixel region 110, the optical black region 120, and the peripheral region 130. Specifically, the material 42a of the photoelectric conversion film 42 other than the masked portion is removed by etching the material 42a of the photoelectric conversion film 42 by a general etching technique using the resist pattern 70 as a mask. Thereafter, the resist pattern 70 is removed.

  As shown in FIG. 5B, an upper electrode 44 is formed on the photoelectric conversion film 42 in the effective pixel region 110, the optical black region 120, and the peripheral region 130. Specifically, on the photoelectric conversion film 42 in the effective pixel region 110, the optical black region 120, and the peripheral region 130, and on the protective oxide film 40 in the pad region 140, an upper portion made of ITO or ZnO is formed by sputtering or CVD. The material of the electrode 44 is deposited on the surface of several tens nm to several hundreds nm. A resist pattern is formed on the material of the upper electrode 44 by a general photolithography technique. The resist pattern is formed on the effective pixel area 110, the optical black area 120, and the peripheral area 130. The material of the upper electrode 44 other than the masked portion is removed by etching the material of the upper electrode 44 by a general etching technique using the resist pattern as a mask. Thereafter, the resist pattern is removed.

  A metal film 51 is selectively formed on the upper electrode 44 in the optical black region 120 as shown in FIG. Specifically, the material of the metal film 51 is formed on the upper electrode 44 in the effective pixel region 110, the optical black region 120, and the peripheral region 130 and on the protective oxide film 40 in the pad region 140 by sputtering or CVD. Deposit 300 nm. A resist pattern is formed in the peripheral region 120 on the material of the metal film 51 by a general photolithography technique. The material of the metal film 51 other than the optical black region 120 is removed by etching the material of the metal film 51 by a general etching technique using the resist pattern as a mask. Thereafter, the resist pattern is removed.

On the upper electrode 44 on which the metal film 51 is formed in the effective pixel region 110 and the optical black region 120, as shown in FIG. 6B, a planarization film 50 made of an organic material, a color filter 52, and planarization are performed. A film 54 and a microlens 56 are sequentially formed.
4). Effect According to the present embodiment, the photoelectric conversion film 42 extending in the peripheral region 130 has a characteristic of generating charges by absorbing incident light. Therefore, the photoelectric conversion film 42 functions as a flare prevention film that reduces reflection on the wiring 37 by absorbing light incident on the wiring 37 made of metal in the peripheral region 130. As shown in FIGS. 4A to 5B, the photoelectric conversion film 42 is formed simultaneously in the effective pixel region 110 and the peripheral region 130, so that the step of forming the flare prevention film is unnecessary. Nevertheless, the solid-state imaging device 100 that can suppress the occurrence of flare is possible.

In the conventional process for forming the anti-flare film, the material for the anti-flare film is once applied to the entire surface of the solid-state imaging device, and then the upper portion of the pixel region is removed by dry etching. At this time, the pixel region may be damaged by etching, and dark current and image defects may occur. However, in the manufacturing method of the present embodiment, the photoelectric conversion film 42 that functions as a flare prevention film is also formed on the pixel region 115, so that a separate step for forming the flare prevention film is not necessary. Therefore, dark current and image defects due to etching damage can be suppressed.
[Example 2]
FIG. 7A is a cross-sectional view of the solid-state imaging device 200 according to Embodiment 2 of the present invention, and FIG. 7B is a partially enlarged view of FIG. 7A. Since the configuration other than the following is the same as that of the solid-state imaging device 100, description thereof is omitted.

  An upper electrode 44 is formed to extend from the pixel region 115 on the photoelectric conversion film 42 in the peripheral region 130. Further, in the peripheral region 130, the wirings 37c and 37d are embedded in the protective oxide film 40, and the wirings 37a and 37b are formed and exposed in the openings 40a and 40b, respectively, where the protective oxide film 40 is opened. Yes.

  The wiring 37a exposed through the opening 40a is electrically connected to the upper electrode 44, and the voltage of the upper electrode 44 is supplied from the wiring 37a. The wiring 37 b exposed through the opening 40 b is in contact with and electrically connected to the photoelectric conversion film 42 covering the wiring 37 b, and is connected to a higher voltage than the upper electrode 44. That is, although not shown, the wiring 37b is connected to the positive electrode of the power source, and the upper electrode 44 is also connected to the negative electrode of the power source, for example, ground, not shown, and photoelectric conversion in the peripheral region 130 is performed. An electric field having the wiring 37b as a positive electrode is generated in the film.

In the peripheral region 130, incident light is converted into electrons in the photoelectric conversion film 42, and the electrons are attracted to the exposed wiring 37 b by an electric field and discharged to the outside through the wiring 37 b. Therefore, it is possible to suppress that electrons generated in the peripheral region 130 enter the optical black region 120 and enter the electrons in the optical black region 120 to affect the magnitude of the current. That is, the accuracy of measuring the offset amount of the optical black region 120 is further improved.
[Example 3]
FIG. 8 is a diagram illustrating the shape of the upper electrode 44 when viewed from above the solid-state imaging device 300 according to Embodiment 3 of the present invention. The upper electrode 44 includes an upper electrode 44 a provided in the effective pixel region 110 and the optical black region 120 and an upper electrode 44 b provided in the peripheral region 130. The upper electrode 44b is formed as a peripheral electrode made of the same material as the upper electrode 44a. The upper electrode 44 has a groove 150 at the boundary between the peripheral region 130 and the optical black region 120, and is electrically and physically disconnected at the groove 150. That is, there is a gap between the upper electrode 44 a in the pixel region 115 and the upper electrode 44 b in the peripheral region 130.

  Different voltages are applied to the upper electrode 44a in the pixel region 115 and the upper electrode 44b in the peripheral region 130, respectively. The voltage supply unit 160 of the upper electrode 44a is electrically connected to the bonding pad 39 in the pad region 140, whereby a voltage is applied to the upper electrode 44a in the pixel region 115.

  FIG. 9A is a cross-sectional view of the solid-state imaging device 300. Since the configuration other than the following is the same as that of the solid-state imaging device 100, the description thereof is omitted. The upper electrode 44 extends on the photoelectric conversion film 42 in the effective pixel region 110, the optical black region 120, and the peripheral region 130. The wirings 37b and 37c are covered with a protective oxide film 40. The wiring 37 a is formed and exposed in the opening portion 40 a of the protective oxide film 40, and is in contact with the photoelectric conversion film 42. Therefore, a voltage is applied to the upper electrode 44b from the wiring 37a, and an electric field having the upper electrode 44b as a positive electrode is generated in the photoelectric conversion film 42 in the peripheral region 130.

  The upper electrode 44 is electrically and physically disconnected between the pixel region 115 and the peripheral region 130. Electrons generated in the photoelectric conversion film 42 in the peripheral region 130 are attracted to the upper electrode 44b and discharged to the outside. Therefore, it is possible to suppress the electrons generated in the peripheral region 130 from being mixed into the electrons in the optical black region 120 and affecting the current magnitude. As a result, the accuracy of offset amount measurement in the optical black region 120 is further improved. Note that when a certain number or more of holes are present in the photoelectric conversion film 42 in the peripheral region 130, recombination of electrons and holes occurs.

Further, the voltage supply unit 160 may be supplied not only from one direction as shown in FIG. 8 but also from a plurality of directions, for example, from four sides, so that the applied voltage of the upper electrode 44 is uniform over the entire pixel region 115. Good (not shown).
[Example 4]
1. Configuration of Solid-State Imaging Device 400 FIG. 10 is a diagram showing the shapes of the metal film 51 and the metal wiring 53 when viewed from above the solid-state imaging device 400 in Embodiment 4 of the present invention. The metal wiring 53 is formed in a mesh shape that passes between adjacent pixels in the effective pixel region 110. The metal wiring 53 is formed continuously with the metal film 51, and the end thereof is connected to the bonding pad 39 in the pad region 140. The metal wiring 53 is made of the same material as the metal film 51 formed in the optical black region 120, and the material of the metal film 51 and the metal wiring 53 has a lower electrical resistivity than that of the upper electrode 44.

11 is a cross-sectional view taken along line AA of the solid-state imaging device 400 illustrated in FIG. Since the configuration other than the following is the same as that of the solid-state imaging device 100, the description thereof is omitted. In the effective pixel region 110, the metal wiring 53 is formed so as to cover a part of the upper surface of the upper electrode 44. The metal wiring 53 is formed on the gap between the adjacent lower electrodes 41.
2. Manufacturing Method With respect to the manufacturing method of the solid-state imaging device 400 according to the fourth embodiment of the present invention, the main steps will be described with reference to FIGS. 12 and 13, focusing on the differences from the first embodiment of the present invention. .

  As shown in FIG. 12A, on the semiconductor substrate 10, the interlayer insulating films 22, 30, 32, which are insulating films in which the wirings 31, 33, 37 are embedded, the photoelectric conversion film 42, and the upper part The formation of the electrode 44 has been completed. The material of the metal film 51 and the metal wiring 53 on the upper electrode 44 in the effective pixel region 110, the optical black region 120, and the peripheral region 130, and on the protective oxide film 40 and the bonding pad 39 in the pad region 140 by sputtering or CVD. 51a is deposited to 100 nm to 300 nm.

  As shown in FIG. 12B, on the material 51 a of the metal film 51 and the metal wiring 53, on the gap between the adjacent lower electrodes 41 in the effective pixel region 110 and the optical black region 120 by a general photolithography technique. Then, a resist pattern 71 is formed.

  Next, as shown in FIG. 13A, a metal film 51 that covers the upper electrode 44 in the optical black region 120, and a mesh-like metal wiring 53 that passes between adjacent pixels in the effective pixel region 110, Form. Specifically, the material 51a of the metal film 51 and the metal wiring 53 other than the masked portion is etched by etching the material 51a of the metal film 51 and the metal wiring 53 by a general etching technique using the resist pattern 71 as a mask. Remove. Thereafter, the resist pattern 71 is removed.

As shown in FIG. 13B, as in the first embodiment of the present invention, in the effective pixel region 110 and the optical black region 120, on the upper electrode 44 on which the metal film 51 and the metal wiring 53 are formed. Then, a planarizing film 50 made of an organic material, a color filter 52, a planarizing film 54, and a microlens 56 are sequentially formed.
3. Effect In the effective pixel region 110, the metal wiring 53 is formed in a mesh shape on the upper electrode 44 in the gap between the adjacent lower electrodes 41. Therefore, the combined resistance of the upper electrode 44 and the metal wiring 53 can be significantly reduced without reducing the aperture ratio beyond the width of the gap between the adjacent lower electrodes 41. As a result, it is possible to prevent the image from deteriorating due to a large voltage drop at the central portion and the peripheral portion of the imaging pixel region, which has been a problem due to the high wiring resistance of the conventional upper electrode 44.
[Example 5]
FIG. 14 is a cross-sectional view of solid-state imaging device 500 in Embodiment 5 of the present invention. Since the configuration other than the following is the same as that of the solid-state imaging device 100, description thereof is omitted.

  In the peripheral region 130, planarization films 50 and 54 and a color filter 52 are formed on the upper electrode 44 covering the photoelectric conversion film 42 so as to cover the entire upper electrode 44. The planarization films 50 and 54 and the color filter 52 are each made of the same material as that in the pixel region 115.

  As shown in FIG. 15A, in the case where the color filter 52 is formed only in the effective pixel region 110 and the optical black region 120, the thickness of the planarizing film 54 in the peripheral portions 55a of both ends of the optical black portion 120 is as follows. It becomes uneven. Therefore, a step in the color filter structure can be formed in the pixel region 115 that generates a signal by photoelectric conversion. When this configuration is adopted, an optical interference fringe due to a step is likely to be generated in the effective pixel region 110, which may cause noise in the captured image.

  On the other hand, when the color filter 52 is formed in the effective pixel region 110, the optical black region 120, and the peripheral region 130 as shown in FIG. Uneven portions are formed. The peripheral region 130 is separated from the light receiving unit, and even if a step of the color filter structure is formed in the peripheral region 130, the captured image is not affected. In this manner, by forming the color filter 52 in the peripheral region 130, the step of the color filter structure around the pixel can be alleviated, and deterioration in image quality due to optical interference fringes caused by the step can be suppressed. It becomes.

Further, when any one of the red, green, and blue color filters 52 is formed in the effective pixel region 110, the optical black region 120, and the peripheral region 130, the peripheral region is simultaneously formed with the step of forming the predetermined color filter 52 in the pixel region 115. Since the color filter 52 can be formed on 130, the manufacturing method is simple. In the peripheral region 130, if a resin mixed with a black pigment is formed instead of the color filter 52, the light shielding effect is higher than the case of forming a blue color filter, but the simplicity of the manufacturing process is inferior. It becomes. In addition, since the blue color filter has a better light shielding effect than the green and red color filters, it is desirable to use a color filter that blocks blue light as a color filter in the peripheral region.
[Modification]
1. Photoelectric Conversion Film In the embodiment, in the pixel region 115, the photoelectric conversion film 42 is continuously formed without being separated for each pixel, but is separated for each pixel as shown in FIG. A solid-state imaging device 600 using the photoelectric conversion film 42 may be used. In the solid-state imaging device 600, the insulating film 45 is embedded in the gap for each pixel of the photoelectric conversion film 42. By adopting this configuration, it is possible to prevent the charge in each pixel from entering another pixel, and to reduce degradation of a captured image caused by crosstalk due to obliquely incident light.

Further, as shown in FIG. 16B, if the spectral sensitivity of the photoelectric conversion film 42 separated for each pixel is varied, the spectral sensitivity for each pixel is varied without using a color filter having a different spectral sensitivity for each pixel. The solid-state imaging device 700 may be used. If this structure is taken, the process of manufacturing a color filter can be reduced.
2. Scanning circuit As the scanning circuit, for example, an arbitrary scanning circuit such as a MOS scanning circuit or a CCD may be used.
3. Metal Wiring The shape of the metal wiring 53 shown in the third embodiment on the effective pixel region 110 may take other shapes such as a stripe shape in addition to the mesh shape as described above.

In addition, the metal wiring 53 in the effective pixel region 110 may be formed over the entire effective pixel region as shown in the embodiment and the modification, for example, as shown in FIG. A shape in which the metal wiring 53 is formed only in a part of the effective pixel region 1110 and four ends thereof are connected to the bonding pad 39, as shown in FIG. 17B, the metal is formed only in a part of the effective pixel region 110. A shape in which the wiring 53 is formed and two ends of the wiring 53 are connected to the bonding pad 39 may be adopted. Note that a metal film 51 is formed in the optical black region 120.
4). Others The configuration of the solid-state imaging device according to the present invention is not limited to the configuration of the solid-state imaging device according to the above-described embodiments and modifications, and various modifications and changes can be made within the scope of the effects of the present invention. Application is possible. In addition, the processes used in the above steps can be replaced with other equivalent processes without departing from the technical idea. Moreover, it is also possible to change a process order and to change a material kind.

  INDUSTRIAL APPLICABILITY The present invention can be used for a digital camera or the like, and is useful for realizing a solid-state imaging device that does not require a step of forming a flare prevention film, yet suppresses occurrence of flare and suppresses deterioration of image quality.

DESCRIPTION OF SYMBOLS 10 Semiconductor substrate 37 Wiring 41 Lower electrode 42 Photoelectric conversion film 44 Upper electrode 51 Metal film 52 Color filter 53 Metal wiring 100,200,300,400,500,600,700,900 Solid-state imaging device 110 Effective pixel area 115 Pixel area 120 Optical black area 130 Peripheral area 140 Pad area

Claims (10)

A substrate,
An insulating film formed on the substrate;
A plurality of lower electrodes formed for each pixel in the first region on the insulating film;
A photoelectric conversion film formed to cover the plurality of lower electrodes in the first region of the insulating film;
An upper electrode having translucency formed on the photoelectric conversion film, and
In the insulating film, a wiring for reading a signal of each pixel is embedded in a second region adjacent to the first region,
The photoelectric conversion film formed in the first region further spreads on the insulating film in the second region so as to cover the wiring embedded in the insulating film. . A part of the insulating film in the second region is opened, and the wiring exposed through the opening is in contact with the photoelectric conversion film existing thereon, and is connected to the positive electrode of the power source,
On the other hand, on the photoelectric conversion film in the second region, the upper electrode extends from the first region and is connected to a negative electrode of a power source. The solid-state imaging device described. On the photoelectric conversion film in the second region, a peripheral electrode made of the same material as the upper electrode is formed apart from the upper electrode,
The solid-state imaging device according to claim 1, wherein different voltages are respectively applied to the upper electrode and the peripheral electrode in the first region. The photoelectric conversion film is formed so as to cover the entire insulating film so as to cover the plurality of lower electrodes in the first region and cover the wiring in the second region. The solid-state imaging device according to 1. The first region includes an effective pixel region and an optical black region around the effective pixel region,
The solid-state imaging device according to claim 1, wherein a light shielding film is formed on the upper electrode in the optical black region. The solid-state imaging device according to claim 5, wherein the light-shielding film is formed of a metal material having an electrical resistivity smaller than that of the upper electrode. The wiring made of the same material as that of the light shielding film is formed on the upper electrode so as to pass between adjacent pixels in at least a part of the effective pixel region. The solid-state imaging device described. The upper electrode covers the entire photoelectric conversion film,
The solid-state imaging device according to claim 4, wherein a color filter is formed so as to cover the entire upper electrode. The solid-state imaging device according to claim 8, wherein the color filter portion in the second region is a color filter that transmits blue light. Forming an insulating film in which wiring for reading signal charges of each pixel is embedded in the second region on the substrate in the first region and the second region;
Forming a plurality of lower electrodes for each pixel on the insulating film in the first region;
Forming a photoelectric conversion film so as to cover the plurality of lower electrodes in the first region, and to cover a wiring embedded in the insulating film on the insulating film in the second region;
Forming a translucent upper electrode on the photoelectric conversion film. A method for manufacturing a solid-state imaging device.

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