JP2009170469A - Solid-state imaging device and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid-state imaging device capable of completely restraining the incidence of visible light into a pixel region, and to provide a manufacturing method for such a solid-state imaging device. <P>SOLUTION: A solid-state imaging device 1 includes a solid-state imaging element 4 having a pixel region 7, consisting of an effective pixel region 7a and a black reference pixel region 7b that are used for imaging and a microlens 9 formed above the effective pixel region 7a; a transparent lid part 5 formed above the microlens 9; a peripheral circuit part 3 formed around the solid-state imaging element 4; and a black resin 10 formed to cover the end surface of the transparent lid part 5 and the peripheral circuit part 3. A light-shielding layer 14 is provided above the black reference pixel region 7b, and an adhesion layer 15, having the light-shielding performance, is provided between the light-shielding layer 14 and the transparent lid part 5. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a semiconductor device, and more particularly, to a solid-state imaging device that improves the shielding of visible light from a peripheral circuit portion to an imaging region of a solid-state imaging device, and a manufacturing method thereof.

  In general, a solid-state imaging device such as a CMOS image sensor has a pixel region in which photoelectric conversion elements are arranged, a peripheral circuit portion, and a contact pad for external leads. The pixel area includes a black reference pixel area that serves as a reference for a black image in addition to an effective pixel area used for imaging, and a wiring layer is provided above the pixel area. A light shielding layer is formed at least on the black reference pixel and the peripheral circuit. As a solid-state image pickup apparatus using such a solid-state image pickup element, an apparatus in which an individual image pickup element is accommodated in a ceramic package is known.

  In such a solid-state imaging device, the ceramic package is covered with a transparent member. In recent years, a method has been proposed in which the transparent member is placed on each solid-state imaging device and the transparent member is sealed with a light-shielding resin (for example, Patent Document 1).

  FIG. 6 is a cross-sectional view illustrating the solid-state imaging device 101 described in Patent Document 1. In the solid-state imaging device 101, the solid-state imaging element 104 is installed in the recess 103 of the multilayer ceramic package 102. The solid-state imaging device 104 includes a light receiving unit 1041, a microlens 1042, and a color filter 1043. The electrode pad 105 at the end of the solid-state image sensor 104 and the input / output unit 106 of the internal lead wire of the ceramic package 102 are connected by a wire 107, and a transparent member 108 is formed on the solid-state image sensor 104. Thereafter, the black resin 109 is filled between the end surface of the transparent member 108 and the end portion of the recess 103, thereby blocking visible light to the solid-state image sensor 104.

  For the purpose of blocking visible light on the image sensor, a method of forming a light shielding layer in the peripheral circuit portion using an optical functional layer forming material has been proposed (for example, Patent Document 2).

FIG. 7 is a cross-sectional view showing the solid-state imaging device 201 described in Patent Document 2. In the solid-state imaging device 201, an optical functional layer forming material used for forming the color filters 202M, 202Cy, 202Y, the microlens 203, and the like on the image sensor is used, and the color filter 204 is laminated on the output unit. By covering with a protective film 205, visible light to the imaging unit is blocked.
JP 2007-142194 A (released on June 7, 2007) Japanese Patent Laid-Open No. 7-94694 (published April 7, 1995)

  However, in the solid-state imaging device 101 described in Patent Document 1, since the electrode pad 105 is a metal, it is visible that the light enters the end of the microlens 1042 from the center of the transparent member 108 as shown by the arrow in FIG. Incidence of light to the light receiving portion 1041 cannot be completely suppressed.

  Further, in the solid-state imaging device 201 described in Patent Document 2, when the color filter 204 as the light shielding film is formed by superimposing the films of the respective colors, the color filter films (204Cy, 204Y) to be formed later are uniformly applied. There is a problem that the color filter 204 is likely to be defective. Furthermore, an optical functional layer such as a color filter often uses an acrylic resin or the like. For example, heat applied in a resin filling process into the ceramic package 102 used in the solid-state imaging device 101 described in Patent Document 1 or the like. Therefore, composition deformation is likely to occur, and a defect may occur due to stress.

  The present invention has been made in view of the above problems, and an object of the present invention is to realize a solid-state imaging device capable of completely suppressing the incidence of visible light into a pixel region and a manufacturing method thereof.

  In order to solve the above problems, a solid-state imaging device according to the present invention has a pixel area composed of an effective pixel area and a black reference pixel area used for imaging, and a microlens formed above the effective pixel area. A solid-state imaging device comprising: a transparent member formed above the microlens; a peripheral circuit portion formed around the solid-state imaging device; and an end face of the transparent member and the peripheral circuit portion In a solid-state imaging device including the formed black resin, a light shielding layer is provided above the black reference pixel region, an adhesive layer is provided between the light shielding layer and the transparent member, and the adhesive layer is light-shielding. It is characterized by having.

  In addition, in order to solve the above-described problem, the method for manufacturing a solid-state imaging device according to the present invention arranges a photoelectric conversion element on a substrate, thereby obtaining a pixel area composed of an effective pixel area and a black reference pixel area. Forming a metal wiring layer including a light-shielding layer on the pixel region, forming a peripheral circuit portion around the pixel region and the metal wiring layer, and forming a micro on the metal wiring layer. A step of forming a lens, a step of forming an adhesive layer on the light shielding layer, a step of placing a transparent member on the adhesive layer so as to cover the microlens, an end surface of the transparent member, and the periphery Forming a black resin so as to cover the circuit portion, wherein the light shielding layer is located above the black reference pixel region, and the adhesive layer has a light shielding property.

  According to the above configuration, since the black resin is formed so as to cover the end face of the transparent member and the peripheral circuit portion, visible light incident from the peripheral circuit portion does not enter the pixel region. Further, a light shielding layer is provided above the black reference pixel region, and an adhesive layer having a light shielding property is provided between the light shielding layer and the transparent member. As described above, since the light shielding layer and the adhesive layer overlap with each other above the black reference pixel region, visible light (see FIG. 6) incident on the end of the microlens from the center of the transparent member is also black. There is no incidence on the reference pixel.

  Further, unlike the configuration described in Patent Document 2, it is not necessary to form a light shielding layer using an optical functional layer forming material that blocks visible light on the peripheral circuit portion. For this reason, defects do not occur due to stress due to color filter defects, heat applied in the resin filling process during package formation, and the like. Therefore, there is an effect that it is possible to realize a solid-state imaging device and a manufacturing method thereof that can completely suppress the incidence of visible light on the pixel region.

  In the solid-state imaging device and the method for manufacturing the solid-state imaging device according to the present invention, it is preferable that the light shielding layer is made of metal.

  According to said structure, a light shielding layer can be formed using the metal wiring layer formed above a pixel area.

  In the solid-state imaging device and the method for manufacturing the solid-state imaging device according to the present invention, the metal may be at least one selected from the group consisting of titanium, titanium nitride, aluminum, tantalum, tungsten, and copper.

  In the solid-state imaging device according to the present invention, it is preferable that the light shielding layer is at least one metal wiring layer formed between the pixel region and the microlens.

  In the solid-state imaging device and the method for manufacturing the solid-state imaging device according to the present invention, it is preferable that the adhesive layer includes particles that block visible light.

  According to said structure, the light absorptivity improves with the particle | grains which interrupt | block visible light.

  In the solid-state imaging device and the method for manufacturing the solid-state imaging device according to the present invention, the particles are preferably black pigments, black dyes, or carbon particles.

  In the solid-state imaging device and the method for manufacturing the solid-state imaging device according to the present invention, the black resin preferably contains a black dye or carbon particles.

  According to said structure, the light absorptivity can further be improved by using black dye or a carbon particle.

In the solid-state imaging device and the manufacturing method of the solid-state imaging device according to the present invention, Si _x O _y , Si _x N _y or Si _x N _y O _z (x, y, z) is formed on the surface of the peripheral region of the solid-state imaging device. In any case, it is preferable that an insulating film made of a natural number) is formed.

According to the above configuration, an insulating film made of Si _x O _y , Si _x N _y or Si _x N _y O _z (where x, y, and z are natural numbers) is generally used for forming a solid-state imaging device. Since the insulating film is used, the manufacturing process can be prevented from becoming complicated.

  In the solid-state imaging device according to the present invention, as described above, a light shielding layer is provided above the black reference pixel region, an adhesive layer is provided between the light shielding layer and the transparent member, and the adhesive layer is shielded from light. It has sex. Also, in the method for manufacturing a solid-state imaging device according to the present invention, as described above, the step of forming a pixel region including an effective pixel region and a black reference pixel region by arranging photoelectric conversion elements on a substrate. Forming a metal wiring layer including a light shielding layer on the pixel area; forming a peripheral circuit portion around the pixel area and the metal wiring layer; and forming a microlens on the metal wiring layer A step of forming an adhesive layer on the light shielding layer, a step of placing a transparent member on the adhesive layer so as to cover the microlens, an end surface of the transparent member, and the peripheral circuit portion. Forming a black resin so as to cover, the light shielding layer is located above the black reference pixel region, and the adhesive layer has light shielding properties. Therefore, there is an effect that it is possible to realize a solid-state imaging device and a manufacturing method thereof that can completely suppress the incidence of visible light on the pixel region.

  An embodiment of the present invention will be described below with reference to FIGS.

  FIG. 1A is a cross-sectional view showing the solid-state imaging device 1 according to the present embodiment, and FIG. 1B is a partially enlarged view of the solid-state imaging device 1. The solid-state imaging device 1 has an imaging region unit 2 and a peripheral circuit unit 3. The imaging region unit 2 is provided with a solid-state imaging device 4 and a transparent lid unit 5. The solid-state imaging device 4 is configured by providing a pixel region 7, a color filter 8 and a microlens 9 on a substrate 6.

  As shown in FIG. 1B, the pixel area 7 has a photoelectric conversion element including an effective pixel area 7a and a black reference pixel area 7b. The microlens 9 is provided above the effective pixel region 7a, and the color filter 8 and the microlens 9 form an optical functional layer. The transparent lid 5 is fixed so as to cover the microlens 9, and a black resin 10 is formed on the end surface of the transparent lid 5.

  In the peripheral circuit unit 3, a contact pad 11 provided at an end of the substrate 6 is connected to a metal wiring input / output unit 13 on the wiring substrate by a wire 12. The black resin 10 molds the entire surface of the peripheral circuit portion 3, the contact pads 11, and the wires 12, and preferably contains a black dye or carbon particles.

  On the other hand, a metal light shielding layer 14 is provided above the black reference pixel region 7b. The metal light shielding layer 14 is formed by using at least one of the laminated metal wiring layers 16 and is configured by sequentially laminating titanium, titanium nitride, aluminum, and titanium nitride from below. In FIG. 1B, the metal light shielding layer 14 is formed on the uppermost layer of the metal wiring layer 16.

  In addition, tantalum (Ta), tungsten (W), and copper can also be used as a metal which forms the metal light shielding layer 14. Further, instead of the metal light shielding layer 14, a light shielding layer composed of components other than metal may be provided.

  Further, an adhesive layer 15 is provided between the metal light shielding layer 14 and the transparent lid 5, and at least a part of the metal light shielding layer 14 overlaps the adhesive layer 15. The adhesive layer 15 includes particles that block visible light and has a light shielding property. The particles are preferably black pigments, black dyes or carbon particles.

  As described above, the metal light-shielding layer 14 provided above the black reference pixel region 7b of the solid-state imaging device 1 and the light-shielding adhesive layer 15 are overlapped, so that the transparent lid 5 indicates the arrow shown in FIG. Even when such visible light is incident, the incident of the visible light on the pixel region 7 can be completely suppressed. The length x of the overlapping portion between the metal light-shielding layer 14 and the adhesive layer 15 varies depending on the size of the solid-state imaging device 1, for example, x ≧ 5 μm.

The surface of the peripheral circuit unit 3 is covered with an insulating film represented by Si _x O _y , Si _x N _y , and Si _x N _y O _z (where x, y, and z are natural numbers). Since these insulating films transmit light, they can be suitably used for an image sensor.

  Hereinafter, the manufacturing process of the solid-state imaging device 1 will be described with reference to FIGS.

  As shown in FIG. 2, the pixel region 7 is formed by arranging photoelectric conversion elements on the substrate 6, and the metal wiring layer 16 is stacked thereon to form the imaging region portion 2. Subsequently, the peripheral circuit unit 3 is formed around the imaging region unit 2. Further, the contact pad 11 shown in FIG. 1A is formed, and the wire 12 is connected to the input / output unit 13 of the metal wiring on the wiring board by using a known wire bonding technique.

  The outer peripheral portion of the imaging region portion 2 is formed by using at least one layer of the metal wiring layer 16 at the formation stage of the metal wiring layer 16 so that the photoelectric conversion element provided in the black reference pixel region 7b functions as a black reference pixel. The light shielding layer 14 is formed.

  Next, as shown in FIG. 3, an optical functional layer including a color filter 8 and a microlens 9 is formed on the imaging region portion 2. The color filter 8 is a dye layer of three colors of red (Red), green (Green), and blue (Blue) corresponding to each light receiving unit. The microlens 9 is formed after flattening on the color filter 8 using an organic protective film. Further, an antireflection layer using an inorganic material is formed as necessary.

  Next, as shown in FIG. 4, a black dye-containing adhesive layer 15 is formed so as to overlap the metal light-shielding layer 14 outside the imaging region portion 2. Specifically, a material containing, as a main component, an acrylic ultraviolet curable resin and an epoxy thermosetting resin, and a mixture containing a water-permeable material such as zeolite and a black dye such as carbon particles, is used for the peripheral circuit portion 3. After uniformly coating on the upper surface, the adhesive layer 15 is formed using a known photolithography technique. Subsequently, the transparent lid 5 is placed on and adhered to the adhesive layer 15.

  Subsequently, as shown in FIG. 5, the end surface of the transparent lid portion 5, the substrate 6 including the contact pads 11 and the wires 12 are encapsulated with the black resin 10 using a known mold resin mold encapsulation technique. As a result, as shown in FIG. 1A, the metal light shielding layer 14 is provided above the black reference pixel region 7b of the solid-state imaging device 1, and the metal light shielding layer 14 and the adhesive layer 15 are configured to overlap. .

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims. That is, embodiments obtained by combining technical means appropriately modified within the scope of the claims are also included in the technical scope of the present invention.

  The present invention can be suitably applied to a solid-state imaging device that needs to improve the shielding of visible light.

(A) is sectional drawing which shows the solid-state imaging device which concerns on embodiment of this invention, (b) is the elements on larger scale of the said solid-state imaging device. It is sectional drawing which shows the manufacturing method of the solid-state imaging device concerning embodiment of this invention, and has shown the state in which the pixel area | region, the metal wiring layer, and the peripheral circuit part were formed. It is sectional drawing which shows the manufacturing method of the solid-state imaging device which concerns on embodiment of this invention, and has shown the state which formed the optical function layer in the structure shown in FIG. It is sectional drawing which shows the manufacturing method of the solid-state imaging device which concerns on embodiment of this invention, and has shown the state which formed the contact bonding layer and the transparent cover part in the structure shown in FIG. It is sectional drawing which shows the manufacturing method of the solid-state imaging device which concerns on embodiment of this invention, and has shown the state which black resin was molded to the structure shown in FIG. It is sectional drawing which shows the conventional solid-state imaging device. It is sectional drawing which shows the other conventional solid-state imaging device.

Explanation of symbols

  1 Solid-state imaging device.

4 Solid-state image sensor 5 Transparent lid (transparent member)
6 Substrate 7 Pixel area 7a Effective pixel area 7b Black reference pixel area 9 Micro lens 10 Black resin 14 Metal light shielding layer (light shielding layer)
15 Adhesive layer 16 Metal wiring layer

Claims (15)

A solid-state imaging device comprising a pixel area composed of an effective pixel area and a black reference pixel area used for imaging, and a microlens formed above the effective pixel area;
A transparent member formed above the microlens;
A peripheral circuit portion formed around the solid-state image sensor;
In a solid-state imaging device comprising a black resin formed so as to cover an end face of the transparent member and the peripheral circuit portion,
A light shielding layer is provided above the black reference pixel region;
An adhesive layer is provided between the light shielding layer and the transparent member,
The solid-state imaging device, wherein the adhesive layer has a light shielding property.   The solid-state imaging device according to claim 1, wherein the light shielding layer is made of metal.   The solid-state imaging device according to claim 2, wherein the metal is at least one selected from the group consisting of titanium, titanium nitride, aluminum, tantalum, tungsten, and copper.   The solid-state imaging device according to claim 2, wherein the light shielding layer is at least one metal wiring layer formed between the pixel region and the microlens.   The solid-state imaging device according to claim 1, wherein the adhesive layer includes particles that block visible light.   The solid-state imaging device according to claim 5, wherein the particles are black pigment, black dye, or carbon particles.   The solid-state imaging device according to claim 1, wherein the black resin contains a black dye or carbon particles. An insulating film made of Si _x O _y , Si _x N _y or Si _x N _y O _z (where x, y, and z are natural numbers) is formed on the surface of the peripheral region of the solid-state imaging device. The solid-state imaging device according to claim 1, wherein the solid-state imaging device is provided. Forming a pixel region composed of an effective pixel region and a black reference pixel region by arranging photoelectric conversion elements on a substrate;
Forming a metal wiring layer including a light shielding layer on the pixel region;
Forming a peripheral circuit portion around the pixel region and the metal wiring layer;
Forming a microlens on the metal wiring layer;
Forming an adhesive layer on the light shielding layer;
Placing a transparent member on the adhesive layer so as to cover the microlens;
A step of forming a black resin so as to cover the end face of the transparent member and the peripheral circuit portion,
The light shielding layer is located above the black reference pixel region,
The method for manufacturing a solid-state imaging device, wherein the adhesive layer has a light shielding property.   The method for manufacturing a solid-state imaging device according to claim 9, wherein the light shielding layer is formed of a metal.   The method of manufacturing a solid-state imaging device according to claim 10, wherein the metal is at least one selected from the group consisting of titanium, titanium nitride, aluminum, tantalum, tungsten, and copper.   The method for manufacturing a solid-state imaging device according to claim 9, wherein the adhesive layer includes particles that block visible light.   The method of manufacturing a solid-state imaging device according to claim 12, wherein the particles are black pigment, black dye, or carbon particles.   The method for manufacturing a solid-state imaging device according to claim 9, wherein the black resin contains a black dye or carbon particles. An insulating film made of Si _x O _y , Si _x N _y or Si _x N _y O _z (where x, y, and z are natural numbers) is formed on the surface of the peripheral circuit portion. The manufacturing method of the solid-state imaging device of any one of Claims 9-14.

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