Semiconductor device

Abstract

Provided is a semiconductor device comprising a semiconductor substrate on which a semiconductor element is mounted, an optical element provided so as to face the semiconductor element, and a spacer that is provided so as to be sandwiched between the semiconductor substrate and the optical element and fixes the semiconductor substrate and the optical element such that a prescribed distance is provided between the semiconductor substrate and the optical element, the spacer including a layer composed of an elastically deformable or plastically deformable material.

Description

Semiconductor equipment

[0001] This disclosure relates to semiconductor devices.

[0002] In semiconductor devices such as light-emitting devices and light-receiving devices, the use of optical elements such as metalens is being considered to improve optical properties. A metalenix is, for example, a lens with a periodic microstructure. In the manufacture of light-emitting devices and light-receiving devices, for example, as described in Patent Document 1 below, an optical element is fixed on top of a semiconductor substrate via a spacer and adhesive.

[0003] International Publication No. 2023 / 090435

[0004] Furthermore, in light-emitting and light-receiving devices, precise control of the distance between optical elements and semiconductor substrates, as well as their positions, is required to improve their optical properties. However, when adhesives harden, they can deform, causing the spacer positions to shift or the distance between optical elements and semiconductor substrates to deviate from the desired distance. Moreover, precisely controlling the distance between optical elements and semiconductor substrates while applying and hardening adhesives is a complex process, resulting in low production efficiency.

[0005] Therefore, this disclosure proposes a technology that can improve the manufacturing yield of semiconductor devices and suppress increases in manufacturing time and manufacturing costs by facilitating the precise control of the positions of semiconductor substrates and optical elements, as well as the distances between them.

[0006] According to this disclosure, a semiconductor device is provided, comprising a semiconductor substrate on which a semiconductor element is mounted, an optical element provided opposite to the semiconductor element, and a spacer provided between the semiconductor substrate and the optical element, which fixes the semiconductor substrate and the optical element so that there is a predetermined distance between the semiconductor substrate and the optical element, wherein the spacer includes a layer made of an elastically or plastically deformable material.

[0007] This is an explanatory diagram illustrating a method for manufacturing a light-emitting device according to a comparative example. This is a cross-sectional view illustrating the detailed configuration of a light-emitting device according to the first embodiment of this disclosure. This is a plan view illustrating the detailed configuration of a light-emitting device according to the first embodiment of this disclosure. This is a plan view (part 1) illustrating the detailed configuration of a light-emitting device according to a modified example of the first embodiment of this disclosure. This is a plan view (part 2) illustrating the detailed configuration of a light-emitting device according to a modified example of the first embodiment of this disclosure. This is an explanatory diagram (part 1) illustrating a method for manufacturing a light-emitting device according to the first embodiment of this disclosure. This is an explanatory diagram (part 2) illustrating a method for manufacturing a light-emitting device according to the first embodiment of this disclosure. This is an explanatory diagram (part 3) illustrating a method for manufacturing a light-emitting device according to the first embodiment of this disclosure. This is a cross-sectional view illustrating the detailed configuration of a light-emitting device according to a modified example of the first embodiment of this disclosure. This is a cross-sectional view illustrating the detailed configuration of a light-receiving device according to the second embodiment of this disclosure. This is a block diagram illustrating an example of the configuration of a distance measuring device.

[0008] Preferred embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functional configuration will be denoted by the same reference numeral to avoid redundant explanation. In addition, in this specification and drawings, multiple components having substantially the same or similar functional configurations may be distinguished by adding a different alphabet after the same reference numeral. However, if there is no particular need to distinguish each of multiple components having substantially the same or similar functional configurations, only the same reference numeral will be used.

[0009] Furthermore, the drawings referenced in the following description are intended to illustrate and facilitate understanding of one embodiment of this disclosure, and for the sake of clarity, the shapes, dimensions, ratios, etc. shown in the drawings may differ from those of the actual product. In addition, the apparatus shown in the drawings may be modified in design as appropriate, taking into consideration the following description and known technology.

[0010] The descriptions of specific shapes in the following explanation do not refer only to geometrically defined shapes. More specifically, the descriptions of specific shapes in the following explanation include shapes that are similar to or have acceptable differences (errors and distortions) in light-emitting / light-receiving devices (semiconductor devices), their manufacturing processes, and their use and operation.

[0011] Furthermore, in the following explanation, "electrically connected" means connecting multiple elements directly or indirectly through other elements.

[0012] The explanation will be presented in the following order: 1. Background 2. First Embodiment 2.1 Detailed Configuration 2.2 Manufacturing Method 2.3 Modification 3. Second Embodiment 4. Summary 5. Distancing Device 6. Supplementary Information

[0013] <<1. Background>> First, with reference to Figure 1, the background to the inventor's creation of the embodiments of this disclosure will be explained. Figure 1 is an explanatory diagram for illustrating the manufacturing method of a comparative example of a light-emitting device 200a. Here, the comparative example refers to a light-emitting device 200a that the inventor had been studying before creating the embodiments of this disclosure.

[0014] As previously explained, in order to improve the optical properties of the light-emitting device 200a (see Figure 1), which is used as a light source, it is being considered to use an optical element 280 (see Figure 1), such as a metalens. A metalens is, for example, a lens having a periodic microstructure 282 (see Figure 1). Therefore, in the manufacture of the light-emitting device 200a according to the comparative example, for example, the optical element 280 is fixed above the semiconductor substrate 210 (see Figure 1), on which a light-emitting element 264 (see Figure 1), such as a semiconductor laser, is mounted, via a spacer 245 (see Figure 1) and adhesive 300 (see Figure 1).

[0015] More specifically, in the comparative example, as shown on the left side of Figure 1, for example, an adhesive 300 made of resin or the like is applied to a predetermined location on the surface of the semiconductor substrate 210 on which the semiconductor chip 260, which is provided with a light-emitting element 264, is mounted. Furthermore, a spacer 245 made of resin or the like is fixed to the optical element 280 with the adhesive 300. Then, the spacer 245 on the optical element 280 side is fixed onto the semiconductor substrate 210 with the adhesive 300 applied to the semiconductor substrate 210.

[0016] Alternatively, for example, as shown on the right side of Figure 1, a spacer 245 is fixed to a predetermined location on the surface of the semiconductor substrate 210 on which the semiconductor chip 260, which is equipped with a light-emitting element 264, is mounted, using adhesive 300. Furthermore, adhesive 300 is applied to the upper surface of the spacer 245. In addition, the optical element 280 is fixed onto the semiconductor substrate 210 using the adhesive 300 applied to the upper surface of the spacer 245.

[0017] Furthermore, in order to improve the optical properties of the light-emitting device 200a, it is required to precisely control the distance between the optical element 280 and the light-emitting element 264, as well as their positions. However, in the light-emitting device 200a of the comparative example, the adhesive 300 deforms due to stress generated inside or on the bonding surface when the adhesive 300 hardens, which can cause the position of the spacer 245 to shift. In addition, in the comparative example, the deformation of the adhesive 300 as described above can cause the distance between the optical element 280 and the light-emitting element 264 to deviate from the desired distance and its allowable range. Moreover, precisely controlling the distance between the optical element 280 and the light-emitting element 264 while applying and hardening the adhesive 300 is a complicated process, resulting in low production efficiency. Therefore, in the light-emitting device 200a of the comparative example, there is a limit to how much the manufacturing yield can be improved, and it was difficult to avoid increasing manufacturing costs and manufacturing time. Furthermore, in the comparative example, when the adhesive 300 hardens, gas is released from the adhesive 300, which can contaminate the optical element 280, the semiconductor substrate 210, etc., and cause condensation and corrosion inside the light-emitting device 200.

[0018] Therefore, in view of these circumstances, the inventors have created the embodiments of the present disclosure described below. According to the embodiments of the present disclosure, it becomes easy to precisely control the positions of the semiconductor substrate 210 and the optical element 280, as well as the distance between the semiconductor substrate 210 and the optical element 280. As a result, according to the embodiments of the present disclosure, it is possible to improve the manufacturing yield of the light-emitting device 200 and suppress increases in manufacturing time and manufacturing costs of the light-emitting device 200. In addition, according to the embodiments of the present disclosure, it is possible to avoid clouding or contamination of the optical element 280, the semiconductor substrate 210, etc. The details of the embodiments of the present disclosure created by the inventors will be described in order below.

[0019] <<2. First Embodiment>> <2.1 Detailed Configuration> First, the detailed configuration of the light-emitting device 200 according to the first embodiment of the present disclosure will be described with reference to Figures 2A and 2B. Figure 2A is a cross-sectional view for illustrating the detailed configuration of the light-emitting device 200 according to this embodiment, and Figure 2B is a plan view for illustrating the detailed configuration of the light-emitting device 200 according to this embodiment.

[0020] In this embodiment, as shown in Figure 2A, the light-emitting device 200 (an example of a semiconductor device) mainly comprises a semiconductor substrate 210 and an optical element 280 provided facing the semiconductor substrate 210. The semiconductor substrate 210 is provided with peripheral circuits for controlling, for example, a light-emitting element (an example of a semiconductor element) 264, and is formed from a semiconductor substrate made of, for example, silicon (Si), silicon carbide (SiC), silicon germanium (SiGe), etc. Furthermore, on the surface of the semiconductor substrate 210 facing the optical element 280, for example, silicon oxide (SiO ｘ ), silicon nitride (SiN ｘ ), silicon oxynitride (SiO ｘ N ｙ ), silicon oxycarbide (SiO ｘ C ｙ ), aluminum oxide (Al ｘ O ｙ An insulating film 220 made of the following may be provided:

[0021] Furthermore, a light-emitting element 264 is mounted on the semiconductor substrate 210. More specifically, as shown in Figure 2A, a semiconductor chip 260 is bonded to the semiconductor substrate 210. The semiconductor chip 260 has a light-emitting surface on which a plurality of light-emitting elements 264 are arranged in a matrix, and is bonded to the semiconductor substrate 210 so that the light-emitting surface faces the optical element 280. The semiconductor chip 260 is formed from a semiconductor substrate made of, for example, silicon, silicon carbide, silicon germanium, etc. The light-emitting element 264 can be, for example, a semiconductor laser, an LED (Light Emitting Diode), etc. More specifically, examples of semiconductor lasers include vertical cavity surface-emitting lasers (VCSELs) and surface-emitting lasers. Unlike edge-emitting semiconductor lasers, VCSELs can emit laser light perpendicular to the surface of a multilayer structure, for example. Generally speaking, a laser refers to the "amplification of stimulated emission light," and more specifically, it refers to the phenomenon of keeping electrons in a high-energy state, amplifying that energy, and emitting it as extremely pure light (laser light). Furthermore, laser light has the characteristics of monochromaticity, coherence, and high directivity. However, the semiconductor lasers dealt with in this specification are not limited to light-emitting elements that emit such laser light; for example, they may be light-emitting elements that emit light with somewhat compromised coherence. Furthermore, examples of LEDs include OLEDs (Organic Light Emitting Diodes) and inorganic LEDs.

[0022] Furthermore, in this embodiment, for example, the semiconductor chip 260 is connected to the semiconductor substrate 210 electrically and physically via a bonding portion 250 such as a bump provided on the bonding surface using a flip-chip bonding method. In this case, the bonding portion 250 may be a bump containing gold (Au), copper (Cu), solder, etc., or a bump containing the material that constitutes the spacer 240 described later. The semiconductor chip 260 is bonded to the semiconductor substrate 210 by heating while pressing such a bump into contact with it. In this embodiment, for example, a so-called Cu-Cu bonding method may be used, in which copper electrode pads formed on the bonding surfaces of the semiconductor substrate 210 and the semiconductor chip 260 are bonded together. Moreover, this embodiment is not limited to such a flip-chip bonding method; the semiconductor substrate 210 and the semiconductor chip 260 may be physically connected by so-called direct bonding and further electrically connected by wire bonding. Furthermore, if a large amount of heat is emitted when the light-emitting element 264 mounted on the semiconductor chip 260 emits light, the drive of the elements mounted on the semiconductor chip 260 may become unstable due to the heat. Therefore, in such cases, in order to efficiently dissipate heat from the semiconductor chip 260, it is preferable to perform a flip-chip bond between the semiconductor chip 260 and the semiconductor substrate 210 using bumps such as solder, which have high thermal conductivity.

[0023] Furthermore, in this embodiment, the semiconductor substrate 210 and the semiconductor chip 260 are not limited to being bonded together; for example, the light-emitting element 264 and peripheral circuits may be integrated onto a single substrate. Also, in this embodiment, the light-emitting device 200 may include other substrates equipped with memory elements and AI (Artificial Intelligence) function circuits.

[0024] In this embodiment, the optical element 280 can be an optical element having a fine structure 282 such as a dot pattern. In this embodiment, the optical element 280 can be, for example, a metalens. The metalens is composed of a periodic fine structure 282 and has, for example, a spectroscopic function. In this case, it can split incident light into light for each predetermined wavelength region. Specifically, the metalens is made of silicon oxide (SiO ｘ ), silicon nitride (SiN ｘ ), titanium oxide (TiO ｘ ), formed by microfabrication of an optically transparent material such as the above. Further, the fine structure 282 of the metalens may have, for example, a structure in which a plurality of pillars are periodically arranged, and furthermore, each pillar structure may have a shape of, for example, a square prism, a cylinder, a cone, or a square pyramid. Further, between the pillars, an optically transparent material having a refractive index different from that of the pillars may be embedded. Furthermore, the fine structure 282 of the metalens may have a periodic structure over the entire metalens, or may have a periodic structure for each region of the metalens.

[0025] Also, in this embodiment, the optical element 280 is not limited to being a metalens having a spectroscopic function, and may be a metalens having various optical functions. Furthermore, in this embodiment, the optical element 280 includes, for example, a lens, a Fresnel lens (a lens in which, for example, concentric notches are formed on the lens surface and cutting is performed with an angle), a color filter that selectively transmits light of a predetermined wavelength, a prism, a diffraction grating, a polarizing plate, and the like.

[0026] Furthermore, in this embodiment, since it is possible to pass current from the semiconductor substrate 210 to the optical element 280 via the spacer 240 described later, the optical element 280 may be an optical element whose optical properties (refractive index, deflection direction, lens power, etc.) change when current is passed from the semiconductor substrate 210 through the spacer 240. For example, such optical elements include liquid crystal lenses and liquid lenses. A liquid crystal lens contains a liquid crystal polymer, and the deflection direction, refractive index, and transmittance can be changed by changing the orientation angle of the liquid crystal polymer in the plane by applying a voltage. In addition, with a liquid lens, the lens power, etc. can be changed by changing the shape of the liquid lens, such as the lens curvature, by applying a voltage.

[0027] Furthermore, in this embodiment, as shown in Figure 2A, the stacked semiconductor substrates 210 and optical elements 280 are connected to each other by a spacer 240 positioned between the semiconductor substrates 210 and optical elements 280. The interior of the light-emitting device 200 is sealed by this spacer 240. More specifically, as can be seen from the top view of the light-emitting device 200 in Figure 2B, the spacer 240 has an annular structure that surrounds the semiconductor chip 260 on which the light-emitting element 264 is mounted. The spacer 240 holds and fixes the semiconductor substrates 210 and optical elements 280 so that there is a predetermined distance between them, while preventing moisture, dust, etc. from entering the interior of the light-emitting device 200. In this embodiment, the shape of the spacer 240 in plan view is not limited to an annular rectangular shape with rounded corners as shown in Figure 2B. In this embodiment, the shape of the spacer 240 may be, for example, a quadrilateral annular shape with right angles at all four corners, a polygonal annular shape, a circular annular shape, an elliptical annular shape, etc., and is not particularly limited.

[0028] Furthermore, in this embodiment, the spacer 240 includes a layer made of an elastically or plastically deformable material. More specifically, the spacer 240 includes, for example, a porous metal layer as the layer made of an elastically or plastically deformable material. This porous metal layer includes, for example, metal particles such as gold (Au), copper (Cu), silver (A), and platinum (Pt), and is a material that can be elastically or plastically deformed by pressurization or heating, and can be processed with high precision by semiconductor processes. Furthermore, in this embodiment, it is preferable that the spacer 240 has conductivity and light-shielding properties.

[0029] In this embodiment, the spacer 240 is bonded to a metal film (first metal film) 270, and is bonded to the optical element 280 via the metal film 270. The metal film 270 is made of a material that is conductive and can be precisely processed by a semiconductor process. Furthermore, in this embodiment, the metal film 270 may be composed of a laminated structure of a metal layer (first metal layer) 272 and a metal layer (second metal layer) 274. The metal layer 274 on the spacer 240 side is preferably made of a metal material such as titanium (Ti). In this embodiment, the metal film 270 is not limited to a laminated structure consisting of two metal layers 272 and 274, but may also consist of one metal layer or a laminated structure consisting of three or more metal layers.

[0030] Furthermore, in this embodiment, the spacer 240 is bonded to a metal film (second metal film) 230 and bonded to the semiconductor substrate 210 via the metal film 230. The metal film 230 is made of a material that is conductive and can be precisely processed by a semiconductor process. Furthermore, in this embodiment, the metal film 230 may be composed of a laminated structure of a metal layer (third metal layer) 234 and a metal layer (fourth metal layer) 232. The metal layer 234 in contact with the spacer 240 may have the same composition as, for example, the layer of the spacer 240 made of an elastically or plastically deformable material. In this embodiment, the metal film 230 is not limited to a laminated structure consisting of two metal layers 232 and 234, but may also consist of one metal layer or a laminated structure consisting of three or more metal layers.

[0031] As described above, in this embodiment, by using such a spacer 240, it is possible to process and join with high precision using a semiconductor process, and the spacer 240 undergoes elastic or plastic deformation due to pressurization or heating during the manufacturing process. Therefore, according to this embodiment, it becomes easy to precisely control the positions of the semiconductor substrate 210 and the optical element 280, as well as the distance between the semiconductor substrate 210 and the optical element 280. As a result, according to this embodiment, it is possible to improve the manufacturing yield of the light-emitting device 200 and suppress increases in manufacturing time and manufacturing costs of the light-emitting device 200. Furthermore, in this embodiment, even when pressurized or heated during the manufacturing process, the spacer 240 undergoes elastic or plastic deformation. Therefore, according to this embodiment, it is possible to suppress the destruction of the spacer 240 itself or its peeling off from the semiconductor substrate 210 or optical element 280. As a result, according to this embodiment, the reliability of the light-emitting device 200 can be improved.

[0032] Furthermore, in this embodiment, since the spacer 240 is fixed to the semiconductor substrate 210 and optical element 280 by bonding with the metal films 230 and 270 without using adhesive 300, no gas is generated. Therefore, in this embodiment, the optical element 280 and semiconductor substrate 210, etc., will not become cloudy or contaminated by gas. Moreover, in this embodiment, since the spacer 240 is fixed to the semiconductor substrate 210 and optical element 280 by bonding with the metal films 230 and 270, it is possible to prevent moisture, dust, etc. from entering the inside of the light-emitting device 200 compared to when adhesive 300 is used. In other words, according to this embodiment, the reliability of sealing in the light-emitting device 200 can be improved.

[0033] Furthermore, in this embodiment, even when heated by the heat generated by the mounted light-emitting element 264, the spacer 240 undergoes elastic or plastic deformation, thus preventing the spacer 240 itself from being destroyed or peeling off from the semiconductor substrate 210 or optical element 280. As a result, the reliability of the light-emitting device 200 can be improved in this embodiment.

[0034] Furthermore, in this embodiment, if the spacer 240 has light-shielding properties, the light emitted obliquely from the light-emitting element 264 will not be radiated from the side of the light-emitting device 200. Therefore, according to this embodiment, light can be radiated in the direction of the upper front surface of the light-emitting device 200 without providing a light-shielding wall around the light-emitting element 264.

[0035] In addition, in this embodiment, if the optical element 280 is an optical element whose optical properties change when an electric current is passed through it, the spacer 240 can be made conductive so that an electric current can be passed from the semiconductor substrate 210 to the optical element 280 via the spacer 240. Therefore, in this embodiment, even if such an optical element 280 is mounted, it is possible to avoid complicating the configuration of the light-emitting device 200, and the light-emitting device 200 can be made more compact and less expensive.

[0036] In this embodiment, the light-emitting device 200 is not limited to the form shown in Figures 2A and 2B, but can be transformed into various forms.

[0037] For example, the shape of the spacer 240 in plan view is not limited to an annular shape as shown in Figure 2B. As shown in Figures 2C and 2D, in this embodiment, the spacer 240 may be composed of multiple parts. Figures 2C and 2D are plan views illustrating the detailed configuration of a light-emitting device 200 according to a modified example of this embodiment.

[0038] In the modified example shown in Figures 2C and 2D, the spacer 240 may be composed of a plurality of rectangular spacer components 240a, 240b, 240c, and 240d. Specifically, in this modified example, for example, as shown in the upper part of Figure 2C, the spacer 240 may be composed of four spacer components 240a, 240b, 240c, and 240d provided along each of the four sides of the rectangular semiconductor chip 260 (rectangular region) on which the light-emitting element 264 is provided in a plan view of the light-emitting device 200.

[0039] Also, in this modification, as shown in the lower left part of FIG. 2C, the spacer 240 may be composed of three spacer components 240a, 240c, and 240d provided respectively along two sides located on the left and right of the semiconductor chip 260 and one side located on the top. Furthermore, in this modification, as shown in the lower right part of FIG. 2C, the spacer 240 may be composed of three spacer components 240a, 240b, and 240c provided respectively along two sides located on the left and right of the semiconductor chip 260 and one side located on the bottom.

[0040] Also, in this modification, as shown on the left side of FIG. 2D, the spacer 240 may be composed of two spacer components 240a and 240b that sandwich the semiconductor chip 260 from the top and bottom. Furthermore, in this modification, as shown on the right side of FIG. 2D, the spacer 240 may be composed of two spacer components 240c and 240d that sandwich the semiconductor chip 260 from the left and right. In FIGS. 2C and 2D, the plurality of spacer components 240a, 240b, 240c, and 240d constituting the spacer 240 are each in the form of separate independent components, but the present embodiment is not limited to such a form. In the present embodiment, for example, two or more of the plurality of spacer components 240a, 240b, 240c, and 240d may be connected to each other.

[0041] <2.2 Manufacturing Method> Next, an example of a method for manufacturing the light-emitting device 200 according to the present embodiment will be described with reference to FIGS. 3A to 3C. FIGS. 3A to 3C are explanatory diagrams for explaining the method for manufacturing the light-emitting device 200 according to the present embodiment, and specifically correspond to the cross-sectional view of FIG. 2A.

[0042] First, for example, an optical element 280 provided with a microstructure 282 is attached to a holding tape 402. In this case, the surface of the microstructure 282 may be covered with a protective film (not shown) or the like. Further, for example, titanium (Ti) and then another metal film are formed on a surface of the optical element 280 located on the opposite side to the microstructure 282 such that the total film thickness of titanium and the other metal film is less than 1 μm. Then, as shown on the left side of FIG. 3A, the metal film 270 is processed to have a pattern matching the shape of the spacer 240. As for the metal composition of the other metal film, it is better to match the metal composition of the porous metal layer.

[0043] Next, as shown on the right side of FIG. 3A, a porous metal layer containing, for example, gold (Au) metal particles is formed on the metal film 270 to have a film thickness of, for example, about 200 μm, and processed to have a pattern matching the shape of the spacer 240, thereby producing the spacer 240.

[0044] Then, as shown on the left side of FIG. 3B, the optical element 280 is peeled off from the holding tape 402. Then, as shown on the right side of FIG. 3B, the optical element 280 is attached to a dicing tape 404 such that the surface of the microstructure 282 is in contact with the dicing tape 404.

[0045] Next, as shown on the left side of FIG. 3C, the optical element 280 attached to the dicing tape 404 is diced so as to correspond to the size of the optical element 280 of one light-emitting device 200.

[0046] Then, as shown on the right side of FIG. 3C, the diced optical element 280 is bonded to a semiconductor substrate 210 having a metal film 230 provided at a predetermined position. In this step, the optical element 280 and the semiconductor substrate 210 are aligned such that the spacer 240 on the optical element 280 side is bonded to the metal film 230 on the semiconductor substrate 210 side. Further, the spacer 240 and the metal film 230 are bonded by heating while bringing the spacer 240 and the metal film 230 into pressure contact. In the present embodiment, an alignment mark may be formed on the semiconductor substrate 210 or the like in order to perform alignment with high accuracy. In this way, the light-emitting device 200 can be manufactured.

[0047] In this embodiment, the method for manufacturing the light-emitting device 200 is not limited to the method shown in Figures 3A to 3C.

[0048] Furthermore, the light-emitting device 200 according to this embodiment can be manufactured using methods, apparatus, and conditions commonly used in the manufacture of semiconductor devices. In other words, the light-emitting device 200 according to this embodiment can be manufactured using existing semiconductor device manufacturing methods (semiconductor processes).

[0049] Examples of the manufacturing methods mentioned above include the PVD (Physical Vapor Deposition) method, the CVD (Chemical Vapor Deposition) method, and the ALD (Atomic Layer Deposition) method. Examples of PVD methods include vacuum deposition, electron beam (EB) deposition, various sputtering methods (magnetron sputtering, RF (Radio Frequency)-DC (Direct Current) coupled bias sputtering, ECR (Electron Cyclotron Resonance) sputtering, counter-target sputtering, high-frequency sputtering, etc.), ion plating, laser ablation, molecular beam epitaxy (MBE (Molecular Beam Epitaxy)), and laser transfer. Examples of CVD methods include plasma CVD, thermal CVD, metal-organic (MO) CVD, and optical CVD. Furthermore, other methods include electrolytic plating, electroless plating, spin coating, immersion, casting, microcontact printing, drop casting, various printing methods such as screen printing, inkjet printing, offset printing, gravure printing, and flexographic printing, as well as stamping, spraying, air doctor coater, blade coater, rod coater, knife coater, squeeze coater, reverse roll coater, transfer roll coater, gravure coater, kiss coater, cast coater, spray coater, slit orifice coater, and calender coater. In addition, patterning methods include shadow masking, laser transfer, chemical etching such as photolithography, physical etching using ultraviolet light or lasers, and nanoimprinting. Moreover, planarization techniques include CMP (Chemical Mechanical Polishing), laser planarization, and reflow.

[0050] <2.3 Modified Examples> Next, with reference to Figure 4, an example of the configuration of the light-emitting device 200 according to a modified example of this embodiment will be described. Figure 4 is a cross-sectional view illustrating the detailed configuration of the light-emitting device 200 according to a modified example of this embodiment. In the following description, points common to the first embodiment described above will be omitted from the explanation.

[0051] In this modified example, as shown in Figure 4, the spacer 240 is in contact with a portion of the surface of the optical element 280 facing the semiconductor substrate 210, where the light-emitting element 264 on the semiconductor chip 260 is in contact. In other words, in this modified example, there is no space between the upper surface of the light-emitting element 264 and the optical element 280. Furthermore, in this modified example as well, the spacer 240 includes a layer made of a material that can be elastically or plastically deformed, and can be precisely processed by a semiconductor process.

[0052] In this modified example, since the spacer 240 undergoes elastic or plastic deformation, the distance between the semiconductor substrate 210 and the optical element 280 can be precisely controlled so that the light-emitting element 264 contacts a portion of the surface of the optical element 280 that faces the semiconductor substrate 210. As a result, this modified example makes it possible to make the light-emitting device 200 even thinner (lower profile).

[0053] <<3. Second Embodiment>> As described above, the technology of this disclosure is not limited to being applied to the light-emitting device 200, but can also be applied to the light-receiving device 202. Hereinafter, an example of the configuration of the light-receiving device 202 according to the second embodiment of this disclosure will be described with reference to Figure 5. Figure 5 is a cross-sectional view illustrating the detailed configuration of the light-receiving device 202 according to this embodiment. In the following description, points common to the first embodiment and its modified examples described above will be omitted from the explanation.

[0054] In this embodiment, unlike the first embodiment, the semiconductor chip 260 has a light-receiving surface in which a plurality of light-receiving elements 266 are arranged in a matrix, as shown in Figure 5, and is bonded to the semiconductor substrate 210 so that the light-receiving surface faces the optical element 280. That is, the semiconductor chip 260 is equipped with light-receiving elements 266 that can detect visible light, infrared rays, ultraviolet rays, X-rays, etc., and generate electrical signals. More specifically, the light-receiving elements 266 can be, for example, a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor.

[0055] In this embodiment as well, the spacer 240 includes a layer made of a material that is elastically or plastically deformable, can be precisely processed by a semiconductor process, and has light-shielding properties. Furthermore, in this embodiment as well, the spacer 240 is bonded to a metal film 270 and bonded to the optical element 280 via the metal film 270. The metal film 270 is made of a material that is conductive and can be precisely processed by a semiconductor process. In addition, in this embodiment as well, the spacer 240 is bonded to a metal film 230 and bonded to the semiconductor substrate 210 via the metal film 230. The metal film 230 is made of a material that is conductive and can be precisely processed by a semiconductor process.

[0056] As described above, in this embodiment as well, by using such a spacer 240, it is possible to process and bond it with high precision using a semiconductor process, and the spacer 240 undergoes elastic or plastic deformation due to pressurization or heating during the manufacturing process. Therefore, according to this embodiment, it becomes easy to precisely control the positions of the semiconductor substrate 210 and the optical element 280, and the distance between the semiconductor substrate 210 and the optical element 280. As a result, according to this embodiment, it is possible to improve the manufacturing yield of the light receiving device 202 and suppress increases in manufacturing time and manufacturing costs of the light receiving device 202. Furthermore, in this embodiment, even if the light receiving device 202 is subjected to pressurization or heating during the manufacturing process, the spacer 240 undergoes elastic or plastic deformation. Therefore, according to this embodiment, it is possible to suppress the destruction of the spacer 240 itself or its peeling off from the semiconductor substrate 210 or optical element 280. As a result, according to this embodiment, the reliability of the light receiving device 202 can be improved.

[0057] Furthermore, in this embodiment as well, since the spacer 240 is fixed to the semiconductor substrate 210 and optical element 280 by bonding with the metal films 230 and 270 without using adhesive 300, no gas is generated. Moreover, in this embodiment, since the spacer 240 is fixed to the semiconductor substrate 210 and optical element 280 by bonding with the metal films 230 and 270, it is possible to prevent moisture, dust, etc. from entering the inside of the light receiving device 202 compared to when adhesive 300 is used.

[0058] Furthermore, in this embodiment as well, if the spacer 240 has light-shielding properties, light will not enter the light-receiving element 266 from the side of the light-receiving device 202. Therefore, according to this embodiment, it is not necessary to provide a light-shielding wall around the light-receiving element 266, and the area of ​​the semiconductor chip 260 can be made smaller.

[0059] In addition, in this embodiment, if the optical element 280 is an optical element whose optical properties change when an electric current is passed through it, the spacer 240 is made conductive so that an electric current can be passed from the semiconductor substrate 210 to the optical element 280 via the spacer 240. Therefore, in this embodiment, even if such an optical element 280 is mounted, it is possible to avoid complicating the configuration of the light receiving device 202, and the light receiving device 202 can be made more compact and less expensive.

[0060] In this embodiment, the light receiving device 202 is not limited to the form shown in Figure 5, but can be transformed into various forms.

[0061] <<4. Summary>> The technology of this disclosure may be applied not only to light-emitting devices 200 and light-receiving devices 202, but also to various semiconductor devices. In such cases, the semiconductor device has a semiconductor substrate 210 on which semiconductor elements are mounted, and a counter substrate (not shown) provided facing the semiconductor substrate 210. In the above semiconductor device, the semiconductor substrates 210 and the counter substrate, which are stacked on top of each other, are connected and fixed to each other by spacers 240. Furthermore, in the above semiconductor device, the spacers 240 are made of a material that can be elastically or plastically deformed and can be processed with high precision by a semiconductor process (specifically, for example, the bonding between a semiconductor chip 260 and a semiconductor substrate 210). In addition, in the above semiconductor device, the spacers 240 are bonded to metal films 230, 270 made of a material that can be processed with high precision by a semiconductor process, and are bonded to the semiconductor substrate 210 and the counter substrate via the metal films 230, 270.

[0062] According to the technology of this disclosure, it becomes easy to precisely control the positions of the semiconductor substrate 210, optical element 280, and opposing substrate, as well as the distance between the optical element 280 and the opposing substrate. As a result, according to the technology of this disclosure, it is possible to improve the manufacturing yield of semiconductor devices and suppress increases in manufacturing time and manufacturing costs. In addition, since the technology of this disclosure does not use adhesive 300, it is possible to avoid clouding or contamination of the inside of the semiconductor device. Furthermore, in semiconductor devices according to the technology of this disclosure, even if pressure or heat is applied during the manufacturing process, the spacer 240 undergoes elastic or plastic deformation. Therefore, according to the technology of this disclosure, it is possible to suppress the destruction of the spacer 240 itself or the peeling of the spacer 240 from the semiconductor substrate 210, optical element 280, and opposing substrate.

[0063] Furthermore, according to the technology of this disclosure, since the spacer 240 is joined by joining the metal films 230 and 270, it is possible to prevent moisture, dust, etc. from entering the inside of the semiconductor device compared to when using adhesive 300. In other words, according to the technology of this disclosure, the reliability of sealing the semiconductor device can be improved.

[0064] <<5. Distance Measuring Device>> The technology described herein can be applied to a variety of semiconductor devices. For example, the technology described herein may be applied to distance measuring devices. With reference to Figure 6, an example of the configuration of a distance measuring device 100 to which this technology is applied will be described. Figure 6 is a block diagram showing an example of the configuration of a distance measuring device 100.

[0065] As shown in Figure 6, the distance measuring device 100 includes a light source device 110, a light receiving device 120, and a control unit 130. For example, the technology according to this disclosure can be applied to the light source device 110 and the light receiving device 120.

[0066] The light source device 110 includes a light-emitting unit 113, a drive circuit 114, a power supply circuit 111, and a light-emitting optical system 115. The light-receiving device 120 includes a light-receiving optical system 121, a light-receiving unit 122, and a processing unit 123.

[0067] The control unit 130 has a distance measuring unit 131. The control unit 130 may be included in the light source device 110, included in the light receiving device 120, or configured separately from the light source device 110 and the light receiving device 120.

[0068] The light-emitting unit 113 has a plurality of light-emitting elements arranged in two dimensions that emit laser light. Each light-emitting element can be, for example, a VCSEL.

[0069] The drive circuit 114 has an electrical circuit for driving the light-emitting unit 113. The power supply circuit 111 generates the power supply voltage for the drive circuit 114 from an input voltage supplied from, for example, a battery (not shown) provided in the distance measuring device 100. The drive circuit 114 drives the light-emitting unit 113 with the power supply voltage.

[0070] Light emitted from the light-emitting unit 113 is directed onto the subject S to be measured via the light-emitting optical system 115. The reflected light from the subject S is then incident on the imaging surface of the light-receiving unit 122 via the light-receiving optical system 121.

[0071] The light-receiving unit 122 has a light-receiving element such as a CCD sensor or a CMOS sensor, and as described above, receives reflected light from the subject S that is incident on it via the light-receiving optical system 121, converts it into an electrical signal and outputs it.

[0072] The light receiving unit 122 performs processes such as CDS (Correlated Double Sampling) processing and AGC (Automatic Gain Control) processing on the electrical signal obtained by photoelectric conversion of the received light, and further performs A / D (Analog / Digital) conversion processing.

[0073] The light-receiving unit 122 then outputs the image signal as digital data to the processing unit 123, which will be described later. The light-receiving unit 122 also outputs a frame synchronization signal to the drive circuit 114. This allows the drive circuit 114 to make the light-emitting element in the light-emitting unit 113 emit light at a timing corresponding to the frame period of the light-receiving unit 122.

[0074] The processing unit 123 is composed of an image processing processor such as a DSP (Digital Signal Processor). The processing unit 123 performs various image signal processing operations on the digital signal (image signal) input from the light receiving unit 122.

[0075] The control unit 130 is composed of, for example, a microcomputer having a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc., or an information processing device such as a DSP. The control unit 130 controls the drive circuit 114 for controlling the light emission operation of the light emission unit 113, and controls the light receiving operation of the light receiving unit 122.

[0076] Furthermore, the control unit 130 also functions as a distance measuring unit 131. The distance measuring unit 131 measures the distance to the subject S based on the image signal input via the processing unit 123 (i.e., the image signal obtained by receiving reflected light from the subject S).

[0077] Furthermore, the distance measuring unit 131 measures the distance to each part of the subject S in order to identify the three-dimensional shape of the subject S. In addition, the control unit 130 may be configured to control the power supply circuit 111.

[0078] Here, we will explain the specific distance measurement method used in the distance measuring device 100. As for the distance measurement method used in the distance measuring device 100, for example, the STL (Structured Light) method or the ToF (Time of Flight) method can be employed.

[0079] The STL method is a method of measuring distance based on an image obtained by capturing a subject S illuminated with light having a predetermined light / dark pattern, such as a dot pattern or a grid pattern.

[0080] In the STL method, a patterned light with a dot pattern is projected onto the subject S. The patterned light is divided into multiple blocks, each block being assigned a different dot pattern, and the dot patterns do not overlap between blocks. When the STL method is adopted, the light-emitting unit 113 functions as the light source for the STL.

[0081] Furthermore, the Time of Flight (ToF) method measures the distance to an object by detecting the time of flight (time difference) of light emitted from the light-emitting unit 113, reflected by the object, and reaching the light-receiving unit 122.

[0082] When adopting the so-called direct ToF method as the ToF method, a SPAD (Single Photon Avalanche Diode) is used as the light receiving unit 122, and the light emitting unit 113 is pulse-driven.

[0083] In this case, the distance measuring unit 131 calculates the time difference from emission to reception of light emitted from the light-emitting unit 113 and received by the light-receiving unit 122 based on the image signal input via the processing unit 123, and calculates the distance to each part of the subject S based on this time difference and the speed of light.

[0084] Furthermore, when the so-called indirect ToF method (phase difference method) is adopted as the ToF method, an IR (infrared light) image sensor is used as the light-receiving element of the light-receiving unit 122. In addition, when the indirect ToF method is adopted, the light-emitting unit 113 functions as an infrared light source.

[0085] The above shows an example of the configuration of the distance measuring device 100. Each of the above components may be made using general-purpose materials, or it may be made using devices specialized for the function of each component. Such a configuration can be appropriately changed according to the technological level at the time of implementation. Furthermore, the components of the distance measuring device 100 shown in the illustration are functional concepts and are not limited to being physically configured as shown. In other words, the specific form of distribution and integration of the distance measuring device 100 is not limited to that shown, and all or part of it may be functionally or physically distributed and integrated in any unit according to various loads and usage conditions.

[0086] For example, by applying the technology of this disclosure to the light source device 110 and the light receiving device 120, the height and cost of the light source device 110 and the light receiving device 120 can be reduced. Furthermore, since the light source device 110 and the light receiving device 120 can be integrated, the height and cost of the distance measuring device 100 can be reduced. In the distance measuring device 100, for example, a semiconductor chip 260 on which a light-emitting element 264 is mounted and a semiconductor chip 260 on which a light-receiving element 266 is mounted may be stacked on a semiconductor substrate 210 on which peripheral circuits etc. Furthermore, in the distance measuring device 100, an optical element 280 may be provided so as to face each semiconductor chip 260. In this case, the optical element 280 can be fixed on the semiconductor substrate 210 so as to face the semiconductor chip 260 using the technology of this disclosure. Furthermore, by using the technology of this disclosure, the semiconductor chip 260 on which the light-emitting element 264 is mounted and the semiconductor chip 260 on which the light-receiving element 266 is mounted may be bonded to the semiconductor substrate 210. In particular, when a large amount of heat is emitted when the light-emitting element 264 emits light, the heat from the light-emitting element 264 can be transferred to the semiconductor substrate 210 by joining it using the spacer 240 according to the embodiment of this disclosure, which has high thermal conductivity, and the heat from the semiconductor chip 260 can be efficiently dissipated.

[0087] Furthermore, the technology disclosed herein can be applied not only to the light source device 110 applied to the distance measuring device 100, but also to display devices. The display devices can be, for example, display devices for VR (Virtual Reality), MR (Mixed Reality), or AR (Augmented Reality), display devices for smartphones and television equipment, electronic viewfinders (EVFs), or small projectors. The technology disclosed herein can also be applied to various lighting devices.

[0088] Furthermore, the technology of this disclosure can be applied not only to the light receiving device 120 applied to the distance measuring device 100, but also to imaging devices that detect the distribution of the amount of incident visible light and capture it as an image. Furthermore, the technology of this disclosure can be applied to imaging devices (physical quantity distribution detection devices) such as fingerprint detection sensors that capture the distribution of incident amounts of infrared rays, X-rays, or particles as an image, or to fingerprint detection sensors that detect the distribution of other physical quantities such as pressure or capacitance and capture it as an image. <<6. Supplement>> Although preferred embodiments of this disclosure have been described in detail above with reference to the attached drawings, the technical scope of this disclosure is not limited to such examples. It is clear that a person with ordinary skill in the art of this disclosure may come up with various modifications or alterations within the scope of the technical idea described in the claims, and these will naturally also be understood to fall within the technical scope of this disclosure.

[0089] Furthermore, the effects described herein are merely descriptive or illustrative and not limiting. In other words, the technology relating to this disclosure may produce other effects that will be apparent to those skilled in the art from the description herein, in addition to or in lieu of the effects described herein.

[0090] Furthermore, this technology can also take the following configurations: (1) A semiconductor device comprising: a semiconductor substrate on which a semiconductor element is mounted; an optical element provided so as to face the semiconductor element; and a spacer provided so as to be sandwiched between the semiconductor substrate and the optical element, fixing the semiconductor substrate and the optical element so that there is a predetermined distance between the semiconductor substrate and the optical element, wherein the spacer includes a layer made of a material that can be elastically or plastically deformed. (2) The semiconductor device according to (1) above, wherein in a plan view of the semiconductor device, the spacer has an annular shape surrounding the semiconductor element. (3) The semiconductor device according to (1) above, wherein the spacer is composed of a plurality of components. (4) The semiconductor device according to (3) above, wherein in a plan view of the semiconductor device, the spacer is composed of two components that sandwich the region on which the semiconductor element is provided from above and below, or from the left and right. (5) The semiconductor device according to (3) above, wherein in a plan view of the semiconductor device, the spacer is composed of three components provided along each of the three sides of the rectangular region on which the semiconductor element is provided. (6) The semiconductor device according to (3), wherein the spacer is composed of four components provided along each of the four sides of the rectangular region on which the semiconductor element is provided in a plan view of the semiconductor device. (7) The semiconductor device according to any one of (1) to (6), wherein the spacer is bonded to the optical element via a first metal film. (8) The semiconductor device according to (7), wherein the first metal film has a laminated structure consisting of a first metal layer and a second metal layer. (9) The semiconductor device according to any one of (1) to (8), wherein the spacer is bonded to the semiconductor substrate via a second metal film. (10) The semiconductor device according to (9), wherein the second metal film has a laminated structure consisting of a third metal layer and a fourth metal layer. (11) The semiconductor device according to (10), wherein the third metal layer in contact with the layer made of an elastically deformable or plastically deformable material has the same composition as the layer made of an elastically deformable or plastically deformable material.(12) The semiconductor device according to any one of (1) to (11), wherein the spacer includes a porous metal layer as a layer made of the elastically deformable or plastically deformable material. (13) The semiconductor device according to (12), wherein the porous metal layer includes at least one metal particle selected from the group consisting of gold, copper, silver, and platinum. (14) The semiconductor device according to any one of (1) to (13), wherein the optical element has a microstructure. (15) The semiconductor device according to (14), wherein the optical element has a dot pattern. (16) The semiconductor device according to any one of (1) to (13), wherein the optical element is an element whose optical properties change when current is passed from the semiconductor substrate through the spacer. (17) The semiconductor device according to any one of (1) to (16), wherein the semiconductor element is in contact with a part of the surface of the optical element facing the semiconductor substrate. (18) A semiconductor device according to any one of (1) to (17) above, wherein a semiconductor chip on which the semiconductor elements are arranged is bonded to the semiconductor substrate. (19) A semiconductor device according to any one of (1) to (18) above, wherein the semiconductor element is a light-emitting element. (20) A semiconductor device according to (19) above, wherein the light-emitting element is a semiconductor laser. (21) A semiconductor device according to any one of (1) to (18) above, wherein the semiconductor element is a light-receiving element. (22) A semiconductor device according to (21) above, wherein the light-receiving element is an image sensor. (23) A semiconductor device comprising: a semiconductor substrate on which semiconductor elements are mounted; a counter substrate provided so as to face the semiconductor elements; and a spacer provided so as to be sandwiched between the semiconductor substrate and the counter substrate, and fixing the semiconductor substrate and the counter substrate so that there is a predetermined distance between the semiconductor substrate and the counter substrate, wherein the spacer includes a layer made of an elastically deformable or plastically deformable material.

[0091] 100 Distance measuring device 110 Light source device 111 Power supply circuit 113 Light-emitting unit 114 Drive circuit 115 Light-emitting optical system 120, 202 Light-receiving device 121 Light-receiving optical system 122 Light-receiving unit 123 Processing unit 130 Control unit 131 Distance measuring unit 200, 200a Light-emitting device 210 Semiconductor substrate 220 Insulating film 230, 270 Metal film 232, 234, 272, 274 Metal layer 240, 245 Spacer 240a, 240b, 240c, 240d Spacer component 250 Joint 260 Semiconductor chip 264 Light-emitting element 266 Light-receiving element 280 Optical element 282 Microstructure 300 Adhesive 402 Holding tape 404 Dicing tape

Claims

1. A semiconductor device comprising: a semiconductor substrate on which a semiconductor element is mounted; an optical element provided opposite to the semiconductor element; and a spacer provided between the semiconductor substrate and the optical element, which fixes the semiconductor substrate and the optical element so that there is a predetermined distance between the semiconductor substrate and the optical element, wherein the spacer includes a layer made of an elastically or plastically deformable material.

2. The semiconductor device according to claim 1, wherein, in a plan view of the semiconductor device, the spacer has an annular shape surrounding the semiconductor element.

3. The semiconductor device according to claim 1, wherein the spacer is composed of a plurality of components.

4. The semiconductor device according to claim 3, wherein, in a plan view of the semiconductor device, the spacer is composed of two components that sandwich the region on which the semiconductor element is provided from above and below, or from the left and right.

5. The semiconductor device according to claim 3, wherein, in a plan view of the semiconductor device, the spacer is composed of three components provided along each of the three sides of the rectangular region on which the semiconductor element is provided.

6. The semiconductor device according to claim 3, wherein the spacer is composed of four components provided along each of the four sides of the rectangular region on which the semiconductor element is provided, in a plan view of the semiconductor device.

7. The semiconductor device according to claim 1, wherein the spacer is bonded to the optical element via a first metal film.

8. The semiconductor device according to claim 7, wherein the first metal film has a laminated structure comprising a first metal layer and a second metal layer.

9. The semiconductor device according to claim 1, wherein the spacer is bonded to the semiconductor substrate via a second metal film.

10. The semiconductor device according to claim 9, wherein the second metal film has a laminated structure comprising a third metal layer and a fourth metal layer.

11. The semiconductor device according to claim 10, wherein the third metal layer in contact with the layer made of the elastically or plastically deformable material has the same composition as the layer made of the elastically or plastically deformable material.

12. The semiconductor device according to claim 1, wherein the spacer includes a porous metal layer as a layer made of the elastically deformable or plastically deformable material.

13. The semiconductor device according to claim 12, wherein the porous metal layer comprises at least one metal particle selected from the group consisting of gold, copper, silver, and platinum.

14. The semiconductor device according to claim 1, wherein the optical element has a microstructure.

15. The semiconductor device according to claim 14, wherein the optical element has a dot pattern.

16. The semiconductor device according to claim 1, wherein the optical element is an element whose optical properties change when an electric current is passed from the semiconductor substrate through the spacer.

17. The semiconductor device according to claim 1, wherein the semiconductor element is in contact with a part of the surface of the optical element that faces the semiconductor substrate.

18. The semiconductor device according to claim 1, wherein the semiconductor element is a light-emitting element.

19. The semiconductor device according to claim 1, wherein the semiconductor element is a light-receiving element.

20. A semiconductor device comprising: a semiconductor substrate on which a semiconductor element is mounted; a counter substrate provided opposite to the semiconductor element; and a spacer provided between the semiconductor substrate and the counter substrate, which fixes the semiconductor substrate and the counter substrate so that there is a predetermined distance between them, wherein the spacer includes a layer made of an elastically or plastically deformable material.

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