Solid-state imaging device and electronic device

Abstract

The present invention suppresses the influence of incident light in a dam region for blocking the outflow of resin from a chip mounted region. This solid-state imaging element is provided with a pixel region in which a plurality of pixels are arranged, and a chip mounted region in which a chip is mounted. A dam region for blocking the outflow of resin from the chip mounted region is disposed around the chip mounted region. The dam region has in at least a part thereof a saw-shape facing outward. The incident light is repeatedly reflected at the saw-shape of the dam region, absorbed, and attenuated.

Description

[Technical field]

[0001] The present technology relates to a solid-state imaging element, and more particularly to a solid-state imaging element and an electronic device that are provided with a chip mounting region on which a chip is mounted in addition to a pixel region. [Background technology]

[0002] In a solid-state imaging element, in addition to the pixel region, an area for mounting a chip to add functions may be provided on the substrate. For example, flip-chip mounting using solder bumps is known. In this case, a resin with good fluidity, for example, called underfill resin, is filled between the substrate and the chip to improve the connection reliability. Since there is a risk that this resin will flow into the pixel region or wire bond pads, a dam region is provided around the flip-chip mounting area. For example, a solid-state imaging element has been proposed that has a slit that blocks the outflow of resin in the dam region (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-147974 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned conventional technology, the long side of the dam region is flat, so that incident light is reflected and diffused by the bottom and sides of the slit, which may cause flare in the pixel region and degrade the optical characteristics.

[0005] This technology was developed in light of these circumstances, and its purpose is to suppress the effects of incident light in the dam area that blocks the outflow of resin from the chip mounting area. [Means for solving the problem]

[0006] The present technology has been made to solve the above-mentioned problems, and a first aspect thereof is a solid-state imaging device and an electronic device including a pixel region in which a plurality of pixels are arranged, a chip mounting region in which a chip is mounted, and a dam region arranged around the chip mounting region and having at least a portion of a sawtooth shape facing outward, thereby providing an effect of attenuating the reflection of incident light in the dam region.

[0007] In addition, in the first aspect, it is preferable that the sawtooth shape in the dam region has a protruding portion with an angle of 90 degrees or less, thereby achieving the effect of sufficiently attenuating reflection of incident light due to the sawtooth shape.

[0008] In addition, in the first aspect, the pixel region may include a first on-chip lens on the incident light side, the dam region may include a second on-chip lens having the same shape as the first on-chip lens, and the sawtooth shape in the dam region may be a structure in which the second on-chip lenses are connected to each other, so that the basic structure of the dam in the dam region has a sawtooth shape.

[0009] In addition, in this first aspect, a size of the sawtooth shape in the dam region may be an integer multiple of an arrangement pitch of the second on-chip lenses.

[0010] In addition, the first aspect may further include an anti-reflection film formed on the upper surface of the second on-chip lens in the dam region, thereby providing the effect of preventing reflection of incident light.

[0011] In addition, in this first aspect, the sawtooth shape in the dam region may be formed on an entire side of the dam region, or may be formed on all four sides of the dam region.

[0012] Also, in this first aspect, the sawtooth shape in the dam region may be a dam that blocks the outflow of light-shielding resin covering the upper and side surfaces of the chip, and may also be a dam that blocks the outflow of underfill resin that is filled in the area where the chip is flip-chip mounted in the chip mounting region. [Brief description of the drawings]

[0013] [Figure 1] 1 is a plan view showing an example of a solid-state imaging element 100 according to an embodiment of the present technology. [Diagram 2] 1 is a cross-sectional view showing an example of a solid-state imaging element 100 according to a first embodiment of the present technology. [Diagram 3] 2 is a plan view showing an example of a shape of a dam 142 according to the first embodiment of the present technology. FIG. [Figure 4] 1 is a perspective view showing an example of a shape of a dam 142 according to a first embodiment of the present technology. FIG. [Diagram 5] 5 is a flowchart showing an example of a method for forming a dam 142 according to the first embodiment of the present technology. [Figure 6] 11 is a cross-sectional view showing an example of a solid-state imaging element 100 according to a second embodiment of the present technology. [Figure 7] 13 is a plan view showing an example of a shape of a dam 143 according to a second embodiment of the present technology. FIG. [Figure 8] 13 is a perspective view showing an example of a shape of a dam 143 according to a second embodiment of the present technology. FIG. [Figure 9] FIG. 8 is a diagram showing an example of a system configuration of an electronic device 800 which is an application example of an embodiment of the present technology. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, modes for carrying out the present technology (hereinafter, referred to as embodiments) will be described. The description will be made in the following order. 1. First embodiment (example of a linear dam with a cylindrical shape partially formed into a sawtooth shape) 2. Second embodiment (example in which the basic structure of the dam has a sawtooth shape) 3.Application example (electronic equipment)

[0015] <1. First embodiment> [Plane of solid-state imaging device] FIG. 1 is a plan view showing an example of a solid-state imaging device 100 according to an embodiment of the present technology.

[0016] The solid-state imaging device 100 includes a pixel region 102, a chip mounting region 103, and a dam region 104 on a semiconductor substrate 101. The semiconductor substrate 101 is made primarily of a semiconductor material such as silicon (Si).

[0017] The pixel region 102 is a region in which a plurality of pixels, each having a photoelectric conversion unit that generates and accumulates a photocharge according to the amount of received light, are two-dimensionally arranged in a matrix in the row and column directions.

[0018] The chip mounting area 103 is an area for mounting, for example, by flip-chip mounting, a chip on which a circuit for performing predetermined signal processing is formed.

[0019] The dam region 104 is a region disposed around the chip mounting region 103. In this dam region 104, a dam for blocking the outflow of resin from the chip mounting region 103 is provided.

[0020] A plurality of electrode pads 109 are formed on the outer periphery of the solid-state imaging element 100. The electrode pads 109 are used for probe contacts and wire bonding in the inspection process.

[0021] [Cross section of solid-state imaging element] 2 is a cross-sectional view showing an example of a solid-state imaging element 100 according to a first embodiment of the present technology. The drawing shows a portion including ends of a pixel region 102 and a chip mounting region 103, and a dam region 104 therebetween.

[0022] In the pixel region 102, photodiodes as photoelectric conversion units are formed in the semiconductor substrate 101 for each pixel, and OCLs (on-chip lenses) 122 are formed for each pixel on the upper side of the semiconductor substrate 101. An anti-reflection film (low reflection film) using, for example, an LTO (Low Temperature Oxide) film is formed on the upper surface of the OCLs 122. In addition, a color filter layer 121 that transmits light of a predetermined wavelength, such as R (red), G (green), or B (blue), is formed between the OCLs 122 and the semiconductor substrate 101.

[0023] The OCL 122 is formed of, for example, silicon nitride (SiN), or a resin-based material such as a styrene-based resin, an acrylic-based resin, a styrene-acrylic copolymer-based resin, or a siloxane-based resin. The material of the anti-reflection film includes silicon nitride (SiN), hafnium oxide (HfO2), aluminum oxide (Al2O3), zirconium oxide (ZrO2), tantalum oxide (Ta2O5), titanium oxide (TiO2), lanthanum oxide (LA2O3), praseodymium oxide (Pr2O3), cerium oxide (CeO2), neodymium oxide (Nd2O3), promethium oxide (Pm2O3), and the like. 3), samarium oxide (Sm2O3), europium oxide (Eu2O3), gadolinium oxide (Gd2O3), terbium oxide (Tb2O3), dysprosium oxide (Dy2O3), holmium oxide (Ho2O3), thulium oxide (Tm2O3), ytterbium oxide (Yb2O3), lutetium oxide (Lu2O3), yttrium oxide (Y2O3), etc. may also be used.

[0024] In the chip mounting area 103, the chip 130 is flip-chip mounted on the semiconductor substrate 101. Specifically, the electrode portions 139 of the chip 130 and the electrode portions 159 of the semiconductor substrate 101 are electrically connected via the solder bumps 155.

[0025] In order to fill the gaps between the chip 130 and the semiconductor substrate 101 other than the solder bumps 155, underfill resin 150 is filled. The underfill resin 150 is made of, for example, a UV (ultraviolet) curable resin or a thermosetting resin, and is formed by being injected into the gaps between the chip 130 and the semiconductor substrate 101 and then cured.

[0026] The upper and side surfaces of chip 130 and underfill resin 150 around chip 130 are covered with light-shielding resin 160 made of a black resin or the like having light-shielding properties in order to prevent reflection. Like underfill resin 150, light-shielding resin 160 is also made of a UV (ultraviolet) curable resin or a thermosetting resin, and is formed by applying it using a dispenser and then curing it.

[0027] On the other hand, the color filter layer 121 and OCL 122 formed in the pixel region 102 are extended and formed in the dam region 104. In this example, the pixel region 102 and the dam region 104 are separated by a distance equivalent to four pixels, and the OCL 122 and the color filter layer 121 are also formed in the region between the pixel region 102 and the dam region 104. The region between the pixel region 102 and the dam region 104 may be omitted, or may be considered as part of the dam region 104.

[0028] In addition, a slit 141 for blocking the underfill resin 150 may be formed as a dam in the dam region 104. This slit 141 is covered with the light-shielding resin 160, and therefore does not affect the reflection of incident light.

[0029] A dam 142 for blocking the light blocking resin 160 is formed on the outer periphery of the dam region 104. However, this dam 142 may also have the function of blocking the underfill resin 150. The shape of this dam 142 will be described below.

[0030] [Dam Shape] Fig. 3 is a plan view showing an example of the shape of the dam 142 according to the first embodiment of the present technology, and Fig. 4 is a perspective view showing an example of the shape of the dam 142 according to the first embodiment of the present technology.

[0031] The dam 142 has a semicircular cylindrical shape formed by linearly connecting the OCLs 122, and has a sawtooth shape facing the outside of the dam region 104. This sawtooth shape is provided in at least a part of the dam region 104. For example, it may be provided on a part or all of one side facing the pixel region 102. It may also be provided on all of the four sides.

[0032] It is desirable that the angle of the protrusions of the sawtooth shape (jagged shape) of the dam 142 is 90 degrees or less. This causes the incident light to be repeatedly reflected at the opening between the protrusions and to be attenuated. This makes it possible to prevent the occurrence of flare.

[0033] In addition, since the dam 142 has a shape in which the OCLs 122 are connected in a straight line, the size of the dam 142 is an integer multiple of the arrangement pitch of the OCLs 122 .

[0034] [How the dam was formed] FIG. 5 is a flowchart showing an example of a method for forming the dam 142 according to the first embodiment of the present technology.

[0035] Circuits such as a light receiving section and a transfer channel region are formed on the semiconductor substrate 101, and transfer electrodes, a light shielding film, etc. are formed (step S911). Furthermore, after forming an interlayer insulating film on the entire surface, a planarizing film is formed, and a color filter layer 121 is formed thereon (step S912).

[0036] A lens material layer that will become the OCL 122 or the dam 142 is formed on the color filter layer 121 (step S913). The lens material layer is formed by applying, for example, a resin by spin coating or the like and curing it.

[0037] Next, a resist is formed on the lens material layer in the patterns of OCL 122 and dam 142 (step S914). Then, the resist is patterned into the shape of OCL 122 or dam 142 by a photolithography process, and then the resist is softened by heating, for example, and processed into the shape of OCL 122 or dam 142.

[0038] Then, the resist and the lens material layer in the shape of the OCL 122 or the dam 142 are etched back (step S915). This etching can be performed by anisotropic reactive ion etching (RIE) using, for example, CF4 / O2 as an etching gas.

[0039] This transfers the hemispherical shape of the resist to the lens material layer, forming the shapes of OCL 122 and dam 142.

[0040] In this way, according to the first embodiment of the present technology, by providing the dam 142 having a sawtooth shape toward the outside of the dam region 104, it is possible to attenuate the reflection of incident light and prevent the occurrence of flare. This makes it possible to improve the optical characteristics in the pixel region 102.

[0041] <2. Second embodiment> In the first embodiment described above, a sawtooth shape is provided on a part of the linear cylindrical shape, but the basic structure of the dam does not have to be linear. In this second embodiment, an example in which the basic structure of the dam has a sawtooth shape will be described. Note that the overall configuration of the solid-state imaging device 100 is the same as that of the first embodiment described above, so a detailed description will be omitted.

[0042] [Cross section of solid-state imaging element] FIG. 6 is a cross-sectional view showing an example of a solid-state imaging device 100 according to the second embodiment of the present technology.

[0043] The solid-state imaging device 100 in the second embodiment basically has the same cross-sectional structure as that in the first embodiment described above, except for the structure of the dam 143 formed on the outer periphery of the dam region 104 to hold back the light-shielding resin 160. The shape of the dam 143 will be described below.

[0044] [Dam Shape] Fig. 7 is a plan view showing an example of the shape of the dam 143 according to the second embodiment of the present technology, and Fig. 8 is a perspective view showing an example of the shape of the dam 143 according to the second embodiment of the present technology.

[0045] The dam 143 has a shape in which the OCLs 122 are connected in a zigzag pattern, and has a sawtooth shape toward the outside and inside of the dam region 104. This sawtooth dam 143 may be provided in at least a part of the dam region 104, and may have a straight semicircular cylindrical shape in other parts. For example, it may be provided on a part or all of one side toward the pixel region 102, or on all of the four sides. Also, the dam 142 of the first embodiment described above may be formed in the straight part.

[0046] It is desirable that the angle of the protrusions of the sawtooth shape (jagged shape) of the dam 143 is 90 degrees or less. This causes the incident light to be repeatedly reflected at the opening between the protrusions and to be attenuated. This makes it possible to prevent the occurrence of flare.

[0047] In addition, since the dam 143 has a shape in which the OCLs 122 are connected in a zigzag pattern, the size of the sawtooth shape of the dam 143 is an integer multiple of the arrangement pitch of the OCLs 122 .

[0048] The dam 143 in the second embodiment is formed in the same manner as in the first embodiment.

[0049] In this way, according to the second embodiment of the present technology, by providing the dam 143 having a sawtooth shape toward the outside of the dam region 104, it is possible to attenuate the reflection of incident light and prevent the occurrence of flare. This makes it possible to improve the optical characteristics in the pixel region 102.

[0050] Although the above-mentioned first and second embodiments have been described by way of example in which one dam is arranged, a plurality of dams may be arranged.

[0051] <3. Application Examples> [Electronic equipment] FIG. 9 is a diagram showing an example of a system configuration of an electronic device 800 which is an application example of the embodiment of the present technology.

[0052] Electronic device 800 is a mobile terminal having a function as an imaging device. Electronic device 800 includes imaging section 810, shutter button 830, power button 840, control section 850, storage section 860, wireless communication section 870, display section 880, and battery 890.

[0053] The imaging unit 810 is an image sensor that captures an image of a subject. The imaging unit 810 includes the solid-state imaging element 100 described above.

[0054] The shutter button 830 is a button for instructing the imaging timing of the imaging section 810 from outside the electronic device 800. The power button 840 is a button for instructing the power of the electronic device 800 to be turned on and off from outside the electronic device 800.

[0055] The control unit 850 is a processing unit that controls the entire electronic device 800. The storage unit 860 is a memory that stores data and programs necessary for the operation of the electronic device 800. The wireless communication unit 870 performs wireless communication with the outside of the electronic device 800. The display unit 880 is a display that displays images and the like. The battery 890 is a power supply source that supplies power to each unit of the electronic device 800.

[0056] The above-mentioned embodiment shows an example for realizing the present technology, and the matters in the embodiment and the matters specified in the claims correspond to each other. Similarly, the matters specified in the claims and the matters in the embodiment of the present technology having the same name correspond to each other. However, the present technology is not limited to the embodiment, and can be realized by applying various modifications to the embodiment within the scope of the gist of the technology.

[0057] It should be noted that the effects described in this specification are merely examples and are not limiting, and other effects may also be obtained.

[0058] The present technology can also be configured as follows. (1) a pixel region in which a plurality of pixels are arranged; a chip mounting area in which a chip is mounted; a dam region disposed around the chip mounting region and having at least a portion thereof facing outward in a sawtooth shape; A solid-state imaging device comprising: (2) The sawtooth shape in the dam region has a protruding portion with an angle of 90 degrees or less. The solid-state imaging device according to (1) above. (3) the pixel region includes a first on-chip lens on an incident light side; the dam region includes a second on-chip lens having the same shape as the first on-chip lens; The sawtooth shape in the dam region is a structure in which the second on-chip lenses are connected to each other. The solid-state imaging device according to (1) or (2). (4) The size of the sawtooth shape in the dam region is an integer multiple of the arrangement pitch of the second on-chip lenses. The solid-state imaging device according to (3) above. (5) Further comprising an anti-reflection film formed on the upper surface of the second on-chip lens in the dam region. The solid-state imaging device according to (3) or (4). (6) The sawtooth shape in the dam region is formed on an entire side of the dam region. The solid-state imaging device according to any one of (1) to (5). (7) The sawtooth shape in the dam region is formed on all four sides of the dam region. The solid-state imaging device according to any one of (1) to (5). (8) The sawtooth shape in the dam region is a dam that blocks the outflow of light-shielding resin that covers the upper and side surfaces of the chip. The solid-state imaging device according to any one of (1) to (7). (9) The sawtooth shape in the dam region is a dam that blocks the outflow of underfill resin that fills an area in the chip mounting region where the chip is flip-chip mounted. The solid-state imaging device according to any one of (1) to (7). (10) A solid-state imaging device comprising: a pixel region in which a plurality of pixels are arranged; a chip mounting region in which a chip is mounted; and a dam region arranged around the chip mounting region and having at least a portion thereof shaped like a sawtooth facing outward. An electronic device comprising: [Explanation of symbols]

[0059] 100 Solid-state image sensor 101 Semiconductor substrate 102 pixel area 103 Chip mounting area 104 Dam Area 109 Electrode Pads 121 Color filter layer 122 On-chip lens (OCL) 130 Chips 139 Electrode section 141 Slit 142, 143 Dam 150 Underfill resin 155 Solder Bumps 159 Electrode section 160 Light-shielding resin 800 Electronic equipment 810 Imaging unit

Claims

1. A pixel region provided on a semiconductor substrate and having a plurality of pixels arranged therein; a chip mounting area on the semiconductor substrate where a chip is mounted; a dam region having a sawtooth shape at least partially facing the pixel region, the dam region being disposed around the chip mounting region and having a dam for blocking the outflow of resin from the chip mounting region; the pixel region includes a first on-chip lens on an incident light side; the dam region includes a second on-chip lens having the same shape as the first on-chip lens; The sawtooth shape in the dam region is a structure in which the second on-chip lenses are connected to each other. Solid-state imaging element.

2. The sawtooth shape in the dam region has a protruding portion with an angle of 90 degrees or less.

2. The solid-state imaging device according to claim 1.

3. The size of the sawtooth shape in the dam region is an integer multiple of the arrangement pitch of the second on-chip lenses.

2. The solid-state imaging device according to claim 1.

4. The second on-chip lens may further include an anti-reflection film formed on an upper surface of the second on-chip lens in the dam region.

2. The solid-state imaging device according to claim 1.

5. The dam area is rectangular, The sawtooth shape in the dam region is formed on an entire side of the dam region toward the chip mounting region.

2. The solid-state imaging device according to claim 1.

6. The dam area is rectangular, The sawtooth shape in the dam region is formed on all four sides of the dam region.

2. The solid-state imaging device according to claim 1.

7. The sawtooth shape in the dam region is a dam that blocks the outflow of the light-shielding resin that covers the upper and side surfaces of the chip.

2. The solid-state imaging device according to claim 1.

8. The sawtooth shape in the dam region is a dam that blocks the outflow of underfill resin that fills an area in the chip mounting region where the chip is flip-chip mounted.

2. The solid-state imaging device according to claim 1.

9. A solid-state imaging element comprising: a pixel region provided on a semiconductor substrate and having a plurality of pixels arranged therein; a chip mounting region in which a chip is mounted on the semiconductor substrate; and a dam region provided with a dam for blocking the outflow of resin from the chip mounting region, arranged around the chip mounting region, and having at least a portion of a saw-tooth shape toward the chip mounting region; the pixel region includes a first on-chip lens on an incident light side; the dam region includes a second on-chip lens having the same shape as the first on-chip lens; The sawtooth shape in the dam region is a structure in which the second on-chip lenses are connected to each other. electronic equipment.

Images