Semiconductor Devices

Abstract

To solve a problem in which, in a semiconductor device laminated with an optical element film, higher performance can be achieved by placing microlenses on the surface, however, since the distance from the lens differs depending on a laminated optical element film, the light gathering rate of the lens varies depending on the optical element film, so it has been difficult to efficiently achieve desired color characteristics with a single lens.SOLUTION: A semiconductor device according to the present invention includes a G layer 12G including a green light emitting element 14G, an R layer 12R including a red light emitting element 14R whose conversion efficiency is lower than that of the green light emitting element 14G, and a microlens 115, and the green light emitting element 14G and the red light emitting element 14R are located between the microlens 115 and its focal point 115a in the optical axis direction of the microlens 115, and at least a part of them overlap when viewed from the same optical axis direction, and the red light emitting element 14R is arranged closer to the focal point than the green light emitting element 14G.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a structure of an optical semiconductor element and a lens in a micro light emitting and receiving device. [Background technology]

[0002] There is a demand for high-resolution microdisplays with a diagonal size of less than 1 inch, or high-resolution image sensors, that offer high brightness, high definition, and full color. The use of light-emitting and light-receiving elements of 100 μm or less has been proposed as a way to achieve high definition. However, for example, with flip-chip mounting, a conventional LED mounting technology, it has been difficult to mount microLEDs with high precision on microdisplays of less than 1 inch. On the other hand, while a monolithic structure using wafer bonding allows for high-precision processing compared to flip-chip mounting, it has been difficult to achieve full color with a monolithic structure.

[0003] As a countermeasure, a structure has been proposed that achieves full color by stacking thin LED films (see, for example, Patent Document 1).

[0004] Furthermore, micro LEDs are brighter than other micro light emitting devices such as organic electroluminescence (EL), but to achieve even higher brightness, it has been proposed to form a fine micro lens directly above the micro LED and control the direction of light emission to improve the brightness directly above (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2010-62351 A (page 6, Figure 1) [Patent Document 2] JP 2014-153385 A (Page 5, Figure 2) Summary of the Invention [Problem to be solved by the invention]

[0006] In semiconductor devices in which optical semiconductor element films are stacked, higher performance can be achieved by placing microlenses on the surface. However, since the distance from the lens varies depending on the optical semiconductor element film stack, the light collection efficiency of the lens varies depending on the optical semiconductor element film, making it difficult to efficiently achieve desirable color characteristics with a single lens. [Means for solving the problem]

[0007] The semiconductor device according to the present invention comprises: a first layer including a first optical semiconductor element; and a second layer having a light emitting efficiency higher than that of the first optical semiconductor element. Rate a second layer including a lower second optical semiconductor element and a lens member; The first optical semiconductor element and the second optical semiconductor element are disposed between the lens element and a focal point of the lens element in the optical axis direction of the lens element, at least partially overlapping when viewed from the optical axis direction, and the second optical semiconductor element is disposed closer to the focal point than the first optical semiconductor element. The first optical semiconductor element and the second optical semiconductor element each include a light-emitting layer, and the light-emitting layer is disposed within a cone surrounded by an outer periphery of the lens member and the focal point. It is characterized by: [Effects of the Invention]

[0008] According to the present invention, in a semiconductor device that enables high density mounting, light emitting efficiency is improved. Rate Low light-emitting efficiency of optical semiconductor elements Rate Since this can be compensated for by the light collection rate of the lens member, it is possible to provide a semiconductor device with desirable color characteristics. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is an enlarged plan view of a portion of a semiconductor device according to a first embodiment of the present invention. [Figure 2] 2 is a cross-sectional view taken along the line AA in FIG. 1. [Figure 3] 2 is a cross-sectional view of FIG. 1 taken along line B-B. [Figure 4]1 is a schematic plan view showing a display module using the semiconductor device of the first embodiment. [Figure 5] FIG. 2 is a diagram illustrating a microlens and its focal length f. [Figure 6] FIG. 10 is an enlarged plan view of a part of a semiconductor device according to a second embodiment of the present invention. [Figure 7] 7 is a cross-sectional view taken along the line AA in FIG. 6. [Figure 8] 7 is a cross-sectional view of FIG. 6 taken along line B-B. [Figure 9] FIG. 10 is an enlarged plan view of a portion of a semiconductor device according to a third embodiment of the present invention. [Figure 10] 10 is a cross-sectional view taken along CC in FIG. 9. [Figure 11] 10 is a cross-sectional view taken along the line DD in FIG. 9. [Figure 12] FIG. 13 is an enlarged plan view of a part of a semiconductor device according to a first modification of the third embodiment. [Figure 13] 13 is a cross-sectional view taken along CC in FIG. 12. [Figure 14] 13 is a cross-sectional view taken along the line DD in FIG. 12. [Figure 15] This figure is used to explain optical simulation using ray tracing, where (a) shows the total luminous flux L (All) when the light-emitting element is formed on the underlying insulating layer, (b) shows the luminous flux L (Lens-in) incident on the microlens from the light-emitting element, and the total luminous flux L (Lens-out) emitted from the microlens 115, and (c) shows the luminous flux L (Lens15) emitted from the microlens into a solid angle of 15 degrees on one side of the top surface. [Figure 16] (a) is a graph plotting the relationship between distance and E(ins) and E(15) from the results of Table 1, and (b) is a graph plotting the relationship between distance and E(lens) from the results of Table 1. DETAILED DESCRIPTION OF THE INVENTION

[0010] Embodiment 1 FIG. 1 is an enlarged plan view of a part of a semiconductor device 100 according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 3 is a cross-sectional view taken along line BB in FIG.

[0011] 2 and 3, the semiconductor device 100 is configured by stacking, from bottom to top, a drive circuit substrate 11, an R (Red) layer 12R, a G (Green) layer 12G, and a B (Blue) layer 12B. These layers are separated by underlying insulating layers 13R, 13G, and 13B, and a red light emitting element 14R, a green light emitting element 14G, and a blue light emitting element 14B are disposed in each underlying insulating layer 13R, 13G, and 13B in overlapping positions when viewed from above. A color light emitting section 15, which is an assembly of these light emitting elements 14R, 14G, and 14B and microlenses 115 (described later), is formed adjacent to one another in a lattice pattern, as shown in FIG.

[0012] Here, the base insulating layers 13R, 13G, and 13B are formed of an insulating material that is transparent to visible light, and may be formed of the same material or different materials.

[0013] Each color light-emitting unit 15 has the same configuration, and within each color light-emitting unit 15, the red light-emitting element 14R formed in the R (Red) layer 12R, the green light-emitting element 14G formed in the G (Green) layer 12G, and the blue light-emitting element 14B formed in the B (Blue) layer 12B have substantially the same shapes in corresponding locations, so they are given the same number and distinguished by adding capital letters (R), (G), and (B) to the end of the number. Similarly, components having the same function are given the same number and distinguished by adding capital letters (R), (G), and (B) to the end of the number according to the color of the associated light-emitting element 14. However, in the course of explanation, the letters (R), (G), and (B) may be omitted if there is no particular need to distinguish them.

[0014] The red light-emitting element 14R as the second optical semiconductor element formed in the R layer 12R as the second layer has an anode layer 101R, a light-emitting layer 117R, and a cathode layer 102R stacked one on top of the other, and each layer is made of a single layer or multiple layers made of a material such as GaAs, AlGaInP, GaN, AlGaN, or InGaN, and functions as a red light-emitting element.

[0015] Furthermore, the green light-emitting element 14G as the first optical semiconductor element formed on the G layer 12G as the first layer has an anode layer 101G, a light-emitting layer 117G, and a cathode layer 102G stacked together, and each layer is made of a single layer or multiple layers made of a material such as GaN, AlGaN, InGaN, etc., and functions as a green light-emitting element.

[0016] Furthermore, the blue light-emitting element 14B as the third optical semiconductor element formed on the B layer 12B as the third layer has a stacked anode layer 101B, a light-emitting layer 117B, and a cathode layer 102B, each of which consists of a single layer or multiple layers made of a material such as GaN, AlGaN, or InGaN, and functions as a blue light-emitting element.

[0017] Each anode electrode 103 is made of a single layer or multiple layers of a transparent conductive film such as ITO (Indium Tin Oxide), a metal such as Au, Al, Pt, or Ti, or an alloy thereof, and is electrically connected to the corresponding anode layer 101 and anode electrode pad 108 described below. Each cathode electrode 104 is made of a single layer or multiple layers of a transparent conductive film such as ITO, a metal such as Au, Al, or an alloy thereof, and is electrically connected to the corresponding cathode layer 102 and cathode electrode pads 109G and 109B described below.

[0018] The interlayer insulating layers 16R, 16G, and 16B are formed so as to bury the light-emitting elements 14 formed on the base insulating layers 13R, 13G, and 13B, respectively. They are made of organic or inorganic films that are transparent to visible light. The insulating layers 107 are organic or inorganic insulating films, and are formed between the anode layer 101, the light-emitting layer 117, and the cathode layer 102 and the anode electrode 103, and between the anode layer 101, the light-emitting layer 117, and the cathode layer 102 and the cathode electrode 104, to electrically insulate them from each other.

[0019] In this embodiment, each anode electrode pad 108 is formed so as to cover a hole penetrating each underlying insulating layer 13, the lower surface of each anode electrode pad 108 is formed flush with the lower surface of each underlying insulating layer 13, and is made of a single layer or multiple layers of a metal such as Au, Al, Pt, or Ti, or an alloy thereof, and is electrically connected to each anode electrode 103, anode electrode pillars 110G and 110B described below, and a corresponding anode pad 113 described below. However, the present invention is not limited to this, and a structure in which the lower surface of each anode electrode pad 108 protrudes from the lower surface of each underlying insulating layer 13 is also possible.

[0020] In this embodiment, the cathode electrode pads 109G, 109B are formed so as to cover holes penetrating the respective base insulating layers 13, and the lower surfaces of the cathode electrode pads 109G, 109B are formed flush with the lower surfaces of the respective base insulating layers 13, and are made of a single layer or multiple layers of a metal such as Au, Al, Pt, or Ti, or an alloy thereof, and are electrically connected to the cathode electrode 104 and each cathode electrode pillar 111 described below. However, the present invention is not limited to this, and the lower surfaces of the cathode electrode pads 109G, 109B may have a structure in which they protrude further than the lower surfaces of the respective base insulating layers 13.

[0021] The anode electrode pillars 110G, 110B are formed on the anode electrode 103, and the upper surfaces of the anode electrode pillars 110G, 110B are formed on the same plane as the upper surfaces of the interlayer insulating layers 16G, 16B, and are made of a single layer or multiple layers of metal such as Cu, Ni, Ti, etc., and are electrically connected to the corresponding anode electrode 103 and anode pad 113. Each cathode electrode pillar 111 is formed on the cathode electrode 104, and the upper surfaces of the anode electrode pillars 110G, 110B are formed on the same plane as the upper surfaces of the interlayer insulating layers 16G, 16B, and are made of a single layer or multiple layers of metal such as Cu, Ni, Ti, etc., and are electrically connected to each cathode electrode 104, a cathode pad (not shown), and a cathode common wiring 114 (described later).

[0022] The drive circuit board 11, which serves as a control board, has a drive circuit for light-emitting elements formed on a Si or glass substrate using known CMOS or TFT technology, and drives and controls the lighting of the light-emitting elements 14. Anode pads 113R, 113G, and 113B are formed on the surface of the drive circuit board 11 and are electrically connected to the corresponding light-emitting elements 14 via anode electrode pads 108 and anode electrode pillars 110, respectively, to supply current from the drive circuit to the light-emitting elements. Dummy pads 116 are formed at positions corresponding to the cathode electrode pillars 111.

[0023] The cathode common wiring 114 is made of a single layer or multiple layers of a metal such as Au, Al, or Ti, or an alloy thereof, and is electrically connected to all of the cathode layers 102 in the semiconductor device 100 and to cathode pads (not shown) provided on the drive circuit board 11 via each cathode electrode pillar 111, each cathode electrode 104, and each cathode electrode pad 109.

[0024] Here, a configuration in which the cathode common wiring 114 is connected to a cathode pad (not shown) on the drive circuit board 11 has been described. However, the cathode pad does not necessarily have to be on the drive circuit board 11, and it may be configured to be connected to a cathode pad on another circuit board by, for example, known wire bonding. Further, a dummy pad may be configured as a cathode pad, a cathode electrode pad 109R (not shown) may be formed on the underlying insulating layer 13R, and each light-emitting element may be electrically connected via the cathode electrode pad 109R.

[0025] As described above, in each color light-emitting unit 15, since current paths for flowing current to the red light-emitting element 14R, the green light-emitting element 14G, and the blue light-emitting element 14B are formed, a predetermined current can be passed between each anode pad 113R, 113G, 113B and the cathode pad, thereby causing them to emit light individually.

[0026] Further, the light emitted by the red light-emitting element 14R is light having a longer wavelength than the light emitted by the green light-emitting element 14G and the blue light-emitting element 14B, and the light emitted by the green light-emitting element 14G is light having a longer wavelength than the light emitted by the blue light-emitting element 14B. For example, the wavelength of the light emitted by the red light-emitting element 14R is 601 to 780 nm, the wavelength of the light emitted by the green light-emitting element 14G is 491 to 600 nm, and the wavelength of the light emitted by the blue light-emitting element 14B is 400 to 490 nm.

[0027] Further, in each color light-emitting unit, the luminous efficiency (efficiency of the total luminous flux (lm = lumen) emitted from a light source with respect to the power (W = watt) applied) is different. As a result, the luminous efficiency has a relationship of R < G < B.

[0028] The microlens 115 as a lens member is formed of an organic material or an inorganic material that is transparent to visible light on the interlayer insulating layer 16B and the cathode common wiring 114. As will be described later, the focal length f is set by the radius of curvature and refractive index of the microlens 115, the refractive indices of the materials of the interlayer insulating layer 16 and the underlying insulating layer 13, and the like.

[0029] FIG. 4 is a schematic plan view showing a display module 200 using the semiconductor device 100. As shown in FIG.

[0030] As shown in the figure, the display module 200 comprises a semiconductor device 100, connection pads 11a formed on the upper surface of a drive circuit board 11 of the semiconductor device 100, and a flexible substrate 120 electrically connected to the connection pads 11a via an anisotropic conductive film (not shown) or the like. The plan view shown in Fig. 1 corresponds to a partially enlarged view of a partial region 190 of the semiconductor device 100 indicated by the dotted line in Fig. 4.

[0031] The flexible substrate 120 is electrically connected to an external device that supplies data signals for images to be displayed on the semiconductor device 100, which functions as a display, and power supply voltage for the semiconductor device 100, and these data signals, power supply voltage, etc. are supplied to the semiconductor device 100 via the flexible substrate 120.

[0032] 5 is a diagram illustrating the microlens 115 and its focal length f, etc. These will be described with reference to FIG.

[0033] Let W1 be the diameter of microlens 115, W2 be the diameter of bottom surface 119 of light-emitting layer 117 of light-emitting element 14 that is disposed perpendicular to the optical axis of microlens 115 and whose center is on the optical axis, f be the focal length of microlens 115, and d0 be the inscribed distance from the bottom surface of microlens 115 to bottom surface 119 of light-emitting layer 117 that contacts the inner surface of a cone formed by the outer periphery of microlens 115 and its focal point 115a. Here, it is assumed that bottom surface 119 of light-emitting layer 117 is formed in an area surrounded by a circle with diameter W2.

number

[0034] Furthermore, the focal length f of the microlens 115 is calculated by the following formula.

number

[0035] Here, the refractive index n2 of the interlayer insulating layer 16 is a value at the wavelength (here, red) at which the luminous efficiency of the light emitting element 14 having the diameter W2 of the lower surface 119 of the light emitting layer 117 is lowest among RGB.

[0036] Generally, the focal point of a lens has the best light collection efficiency. However, as shown in FIG. 5, when the difference between diameter W1 of microlens 115 and diameter W2 of lower surface 119 of light-emitting layer 117 of light-emitting element 14 is small, and lower surface 119 is positioned at focal length f, the light collection efficiency at the center of light-emitting element 14 is good, but light emitted from areas other than the center is bent in a direction that spreads outward due to refraction when it enters microlens 115 and then exits microlens 115, and as a result, the light collection efficiency of light emitted from the entire light-emitting element 14 cannot be sufficiently increased.

[0037] Therefore, as shown in Figure 5, by positioning the lower surface 119 of the light-emitting layer 117 of the light-emitting element 14 at a position inscribed distance d0 from the microlens 115, it is possible to increase the incidence efficiency of all light emitted from the entire light-emitting element 14 onto the microlens 115 while maximizing the light collection rate.

[0038] In order to verify the above structure, optical simulations were performed by ray tracing, and the results will be described with reference to FIG.

[0039] In the simulation, first, as shown in Figure 15(a), the state in which the light-emitting element 14 is formed on the base insulating layer 13 is used as a reference, and the total luminous flux in that case is defined as L(All).Next, as shown in Figure 15(b), the light-emitting element 14 is covered with an interlayer insulating layer 16 and a microlens 115 is formed on top of that.The luminous flux incident from the light-emitting element 14 to the microlens 115 is defined as L(Lens-in), and the total luminous flux L emitted from the microlens 115 is defined as (Lens-out).As shown in Figure 15(c), the luminous flux emitted from the microlens 115 into a solid angle within a range of 15 degrees on one side of the top surface is defined as L(Lens15).

[0040] At this time, the incidence efficiency E(ins) of the microlens 115 is Define E(ins)=L(Lens-in) / L(All), The ratio E(15) of the light beams emitted within a solid angle of 15 degrees on one side of the light incident on the microlens 115 is Define E(15)=L(Lens15) / L(Lens-in), The ratio E(lens) of the luminous flux in the solid angle of 15 degrees on one side after passing through the microlens 115 in the total luminous flux emitted from the light emitting element 14 is E(lens)=L(Lens15) / L(All)=E(in)×E(15) and Table 1 shows how the respective ratios change when the distance between the microlens 115 and the light emitting element 14 is changed. [Table 1]

[0041] Fig. 16(a) is a graph plotting the relationship between distance and E(ins) and E(15) based on the results of Table 1, and Fig. 16(b) is a graph plotting the relationship between distance and E(lens) based on the results of Table 1. As these results show, E(ins) improves by bringing the light emitting element 14 closer to the microlens 115, while E15 improves by bringing it closer to the focal point f of the microlens 115. As a result, the luminous flux ratio E(lens) within a solid angle of 15 degrees on one side after passing through the microlens 115 is highest closer to the microlens 115 than the focal point f.

[0042] As shown in Figure 2, the semiconductor device 100 of this embodiment has a configuration in which a drive circuit board 11, an R layer 12R, a G layer 12G, and a B layer 12B are stacked from the bottom, and the lower surfaces of each of the light-emitting layers 117R, 117G, and 117B, which are arranged in the relationship described in Figure 5 with respect to the optical axis of the microlens 115, are located at distances d1, d2, and d3, respectively, from the lower surface of the microlens 115.

[0043] Based on the above considerations, the focal length f of the microlens 115 is set so that the inscribed distance d0 is closest to the distance d1 of the light-emitting layer 117R of the red light-emitting element 14R, which has the lowest light-emitting efficiency among the red light-emitting element 14R, the green light-emitting element 14G, and the blue light-emitting element 14B. Here, as shown in Fig. 2, the focal length f is set so that the inscribed distance d0 is approximately equal to the distance d1 from the bottom surface of the microlens 115 to the bottom surface of the light-emitting layer 117R.

[0044] In this embodiment, the focal point 115a is located farther from the microlens 115 than the interface between the drive circuit board 11 and the R layer 12R. In other words, the focal point 115a is located inside the drive circuit board 11. However, without being limited thereto, the focal point 115a may be located farther from the microlens 115 than at least the light-emitting layer 117.

[0045] As a result, the low light emitting efficiency of the red light emitting element 14R is compensated for by the light collection efficiency of the microlens 115, which is improved compared to the light emitting elements 14G and 14B arranged at other positions, and the difference in light intensity of the light emitting elements 14 of each color is compensated for.

[0046] In this embodiment, the configuration is such that the drive circuit board 11, the R layer 12R, the G layer 12G, and the B layer 12B are stacked from the bottom, but this is not limited to this, and the configuration may also be such that the drive circuit board 11, the R layer 12R, the B layer 12B, and the G layer 12G are stacked from the bottom.

[0047] As described above, according to the semiconductor device 100 of this embodiment, among the plurality of stacked light-emitting elements 14 having different light-emitting efficiencies, the low light-emitting efficiency of the light-emitting element 14R having the lowest light-emitting efficiency can be compensated for by the light-collection efficiency of the microlens 115, and the difference in the light intensity of the light-emitting elements 14 of each color can be compensated for, so that white light, for example, can be efficiently achieved.

[0048] Furthermore, although it has been described that the focal length f is set so that the inscribed distance d0 and the distance d1 from the bottom surface of the light-emitting layer 117R to the bottom surface of the microlens 115 are approximately equal, this embodiment is not limited to this. The red light-emitting element 14R, the green light-emitting element 14G, and the blue light-emitting element 14B may be disposed between the microlens 115 and the focal point (for example, within a cone (shown by a dotted line in FIG. 2) surrounded by the focal point 115a and the outer periphery of the microlens 115), and the red light-emitting element 14R may be disposed closer to the focal length f than the light-emitting elements 14G and 14B. This makes it possible to compensate for the lower luminous efficiency of the light-emitting element 14R with the light-collection efficiency of the microlens 115 and to compensate for the difference in the amount of light emitted by the light-emitting elements 14 of each color, compared to when the microlens 115 and the red light-emitting element 14R are disposed at positions farther apart than the light-emitting elements 14G or 14B, for example.

[0049] In addition, one way to compensate for differences in the luminous efficiency of light-emitting elements is to adjust the amount of current flowing through each light-emitting element. However, this method requires a wider range of current adjustment for light-emitting elements with low luminous efficiency, which can complicate control and lead to increased costs.

[0050] Embodiment 2 6 is an enlarged plan view of a part of a semiconductor device 400 according to a second embodiment of the present invention, FIG. 7 is a cross-sectional view taken along line AA in FIG. 6, and FIG. 8 is a cross-sectional view taken along line BB in FIG.

[0051] 1, 2, and 3, the main difference between the configuration of the semiconductor device 400 and the configuration of the semiconductor device 100 of the first embodiment is that the stacking order of the stacked structure is, from bottom to top, the drive circuit board 11, the B (Blue) layer 12B, the R (Red) layer 12R, and the G (Green) layer 12G. Therefore, the same reference numerals will be used to designate parts of the semiconductor device 400 of the present embodiment that are common to the semiconductor device 100 of the first embodiment, or drawings will be omitted to omit the explanation, and the differences will be mainly described.

[0052] 7 and 8, semiconductor device 400 of this embodiment has a configuration in which, from bottom to top, drive circuit substrate 11, B (Blue) layer 12B, R (Red) layer 12R, and G (Green) layer 12G are stacked. These layers are separated by underlying insulating layers 13B, 13R, and 13G, and blue light-emitting elements 14B, red light-emitting elements 14R, and green light-emitting elements 14G are arranged in overlapping positions on underlying insulating layers 13B, 13R, and 13G, respectively. A plurality of color light-emitting units 25, which are aggregates of these light-emitting elements 14 and microlenses 415 serving as lens members, are formed adjacent to each other in a lattice pattern, as shown in FIG. 6 (corresponding to color light-emitting unit 15 in FIG. 1).

[0053] In the semiconductor device 400, the lower surfaces of the light emitting layers 117B, 117R, and 117G of the light emitting elements 14 in each layer 12 are disposed at distances d1, d2, and d3 from the lower surface of the microlens 415, respectively.

[0054] 5, the focal length f of the microlens 415 is set so that the inscribed distance d0 is closest to the distance d2 of the light-emitting layer 117R of the red light-emitting element 14R, which has the lowest light-emitting efficiency among the blue light-emitting element 14B, the red light-emitting element 14R, and the green light-emitting element 14G. Here, as shown in FIG. 7, the focal length f is set so that the inscribed distance d0 is approximately equal to the distance d2 from the bottom surface of the microlens 415 to the bottom surface of the light-emitting layer 117R.

[0055] As a result, the low light emitting efficiency of the red light emitting element 14R is compensated for by the light collection efficiency of the microlens 415, which is improved compared to the light emitting elements 14G and 14B arranged in other positions, and the difference in light intensity of the light emitting elements 14 of each color is compensated for.

[0056] As described above, according to the semiconductor device 400 of the present embodiment, the low luminous efficiency of the light emitting element 14 with the lowest luminous efficiency among the plurality of stacked light emitting elements 14 with different luminous efficiencies can be compensated for by the light collection efficiency of the microlens 415, thereby making it possible to compensate for the difference in the amount of light of each color of the light emitting elements 14. Furthermore, since the red light emitting element 14R with the lowest luminous efficiency is positioned closer to the microlens 415 than in the first embodiment, it is possible to further increase the efficiency of incidence on the microlens 415.

[0057] Furthermore, although it has been described that the focal length f is set so that the inscribed distance d0 and the distance d2 from the bottom surface of the light-emitting layer 117R to the bottom surface of the microlens 115 are approximately equal, this embodiment is not limited to this. The red light-emitting element 14R and the green light-emitting element 14G may be disposed between the microlens 415 and the focal point (for example, within a cone (shown by a dotted line in FIG. 2) surrounded by the focal point 115a and the outer periphery of the microlens 115), and the red light-emitting element 14R may be disposed closer to the focal length f than the light-emitting element 14G. This makes it possible to compensate for the lower luminous efficiency of the light-emitting element 14R with the light-collection efficiency of the microlens 415, and to compensate for the difference in the light intensity of the light-emitting elements 14 of each color, compared to when the microlens and the red light-emitting element 14R are disposed at positions farther apart than the light-emitting element 14G, for example.

[0058] It should be noted that the incidence efficiency of blue light-emitting element 14B onto microlens 415 is lower compared to the first embodiment, but blue has a higher light-emitting efficiency than red and its ratio in the color mixture used to realize white is low. Therefore, even if the incidence efficiency onto microlens 415 is reduced, the incidence efficiency of red is improved to compensate for this, and as a result, it is possible to realize white efficiently.

[0059] Embodiment 3 9 is an enlarged plan view of a part of a semiconductor device 500 according to a third embodiment of the present invention, FIG. 10 is a cross-sectional view taken along line CC in FIG. 9, and FIG. 11 is a cross-sectional view taken along line DD in FIG.

[0060] 1 to 3, the main difference between the configuration of this semiconductor device 500 and the configuration of the semiconductor device 100 of the first embodiment shown in Figures 1 to 3 is that a light receiving element 514 is provided instead of the light emitting element 14. Therefore, the same reference numerals will be used to designate parts of the semiconductor device 500 of the present embodiment that are common to the semiconductor device 100 of the first embodiment, or the drawings will be omitted to omit the explanation, and the differences will be mainly described.

[0061] 10 and 11, the semiconductor device 500 has a configuration in which, from bottom to top, an individual electrode selection circuit substrate 511, an R (Red) layer 512R, a G (Green) layer 512G, and a B (Blue) layer 512B are stacked. These layers are separated by underlying insulating layers 13R, 13G, and 13B, and a red light receiving element 514R, a green light receiving element 514G, and a blue light receiving element 514B are arranged in overlapping positions on the underlying insulating layers 13R, 13G, and 13B, respectively. A color light receiving section 515, which is an assembly of these light receiving elements 514R, 514G, and 514B and microlenses 115 (described later), is formed adjacent to one another in a lattice pattern, as shown in FIG.

[0062] Each color light receiving section 515 has the same configuration, and the red light receiving element 514R formed on the R layer 512R, the green light receiving element 514G formed on the G layer 512G, and the blue light receiving element 514B formed on the B layer 512B in each color light receiving section 515 are formed in substantially the same shape at corresponding locations, and therefore are given the same number and distinguished by adding capital letters (R), (G), and (B) to the end of the number. Similarly, components having the same function are given the same number and distinguished by adding capital letters (R), (G), and (B) to the end of the number according to the color of the associated light receiving element 514. However, in the course of explanation, the letters (R), (G), and (B) may be omitted if there is no particular need to distinguish them.

[0063] The red light receiving element 514R as the second optical semiconductor element formed on the R layer 512R as the second layer has a stacked individual electrode 601R, a photoelectric conversion element 617R, and a common electrode 602R, and functions as a red light receiving element; the green light receiving element 514G as the first optical semiconductor element formed on the G layer 512G as the first layer has a stacked individual electrode 601G, a photoelectric conversion element 617G, and a common electrode 602G, and functions as a green light receiving element; and the blue light receiving element 514B as the third optical semiconductor element formed on the B layer 512B as the third layer has a stacked individual electrode 601B, a photoelectric conversion element 617B, and a common electrode 602B, and functions as a blue light receiving element.

[0064] The photoelectric conversion element 617 is made of an organic semiconductor and absorbs light of a specific wavelength to generate electron-hole pairs. For example, the photoelectric conversion element 617R selectively absorbs red light, the photoelectric conversion element 617G selectively absorbs green light, and the photoelectric conversion element 617B selectively absorbs blue light. The individual electrodes 601R, 601G, and 601B and the common electrodes 602R, 602G, and 602B are made of a transparent conductive film such as ITO. The photoelectric conversion element 617 is sandwiched between the individual electrode 601 and the common electrode 602, and charges generated in the photoelectric conversion element 617 are extracted.

[0065] Each individual electrode pad 608 and common electrode pad 609 is made of a single layer or multiple laminated layers of a transparent conductive film such as ITO, a metal such as Au or Al, or an alloy thereof, and is electrically connected to the corresponding individual electrode 601 and common electrode 602 and the corresponding individual electrode pillar 610 and common electrode pillar 611 described below. The individual electrode pillars 610G, 610B and common electrode pillars 611R, 611G, 611B are made of a single layer or multiple laminated layers of a metal such as Cu, Ni, or Ti, and electrically connect the corresponding individual electrode pads 608 or common electrode pads 609 above and below.

[0066] The individual electrode selection circuit board 511 serving as a control board has an individual electrode selection circuit formed on a Si or glass substrate using known CMOS or TFT technology, and extracts signals from selected light receiving elements 514 (pixels). Individual pads 613R, 613G, and 613B are formed on the surface of the individual electrode selection circuit board 511 and are electrically connected to the corresponding light receiving elements 514 via individual electrode pads 608 and individual electrode pillars 610, and transmit signals from the light receiving elements 514 to the individual electrode selection circuit of the individual electrode selection circuit board 511. Dummy pads 116 are formed at positions corresponding to the common electrode pillars 611.

[0067] The common electrode wiring 614 is made of a single layer or multiple layers of a metal such as Au or Al, or an alloy thereof, and is electrically connected to all common electrodes 602 in the semiconductor device 500 and to common electrode connection pads (not shown) provided on the individual electrode selection circuit board 511 via each common electrode pillar 611 and each common electrode pad 609.

[0068] The microlens 115 is formed on the interlayer insulating layer 16B and the common electrode wiring 614 from an organic or inorganic material that is transparent to visible light, and the focal length f calculated by equation (2) is set based on the radius of curvature and refractive index of the microlens 115, the refractive index of the interlayer insulating layer 16, etc.

[0069] In this embodiment, the relationship of the photoelectric conversion efficiency of each photoelectric conversion element 617 is as follows: Photoelectric conversion element 617R<Photoelectric conversion element 617G<Photoelectric conversion element 617B As shown in FIG. 10, the lower surfaces of the photoelectric conversion elements 617R, 617G, and 617B, which are arranged in relation to the lower surface 119 of the light-emitting layer 117 described in FIG. 5, are arranged at distances d1, d2, and d3, respectively, from the lower surface of the microlens 115 with respect to the optical axis of the microlens 115, and the inscribed distance of the lower surface of the photoelectric conversion element 617 from the lower surface of the microlens 115 obtained by equation (1) is d0.

[0070] 5, the inscribed distance d0 is calculated assuming that the lower surface of a photoelectric conversion element 617 with a diameter W2 is placed instead of the lower surface 119 of the light-emitting layer 117. In other words, W2 in formula (1) here is the diameter of the lower surface of the photoelectric conversion element 617.

[0071] 5, the focal length f of the microlens 115 is set so that the inscribed distance d0 is closest to the distance d1 of the photoelectric conversion element 617R of the red light receiving element 514R, the green light receiving element 514G, and the blue light receiving element 514B, which has the poorest photoelectric conversion efficiency. Here, as shown in Fig. 10, the focal length f is set so that the inscribed distance d0 is approximately equal to the distance d1 between the bottom surface of the photoelectric conversion element 617R and the bottom surface of the microlens 115.

[0072] As a result, the low photoelectric conversion efficiency of the red light receiving element 514R is compensated for by the light collection efficiency of the microlens 115, which is improved compared to the light receiving elements 514G and 514B arranged at other positions.

[0073] Furthermore, although it has been described that the focal length f is set so that the inscribed distance d0 and the distance d1 between the bottom surface of the red light receiving element 514R and the bottom surface of the microlens 115 are approximately equal, this embodiment is not limited to this. The red light receiving element 514R as the second optical semiconductor element, the green light receiving element 514G as the first optical semiconductor element, and the blue light receiving element 514B may be disposed between the microlens 115 and the focal point, and the red light receiving element 514R may be disposed closer to the focal length f than the green light receiving element 514G and the blue light receiving element 514B. This makes it possible to compensate for the lower photoelectric conversion efficiency of the red light receiving element 514R with the light collection efficiency of the microlens 115, and to compensate for the difference in photoelectric conversion efficiency of the light receiving elements of each color, compared to, for example, a case in which the microlens 115 and the red light receiving element 514R are disposed farther apart than the green light receiving element 514G and the blue light receiving element 514B.

[0074] (Variation 1) 12 is an enlarged plan view of a portion of a semiconductor device 700 according to a first modification of the third embodiment of the present invention, FIG. 13 is a cross-sectional view taken along line CC in FIG. 12, and FIG. 14 is a cross-sectional view taken along line DD in FIG.

[0075] 9, 10, and 11, the main difference between the configuration of the semiconductor device 700 of Modification 1 and the configuration of the semiconductor device 500 of Embodiment 3 shown in the above-described Figures is that the formation area of ​​the photoelectric conversion element 717 (617 in Figure 10) of each light-receiving element 514 is expanded. Therefore, the same reference numerals will be used to designate parts of the semiconductor device 700 of Modification 1 that are common to the semiconductor device 500 of Embodiment 3, or explanations thereof will be omitted by omitting drawings, and the differences will be mainly described.

[0076] As shown in Figures 9 to 11, in the semiconductor device 500 of embodiment 3, the photoelectric conversion element 617 is formed only in the area sandwiched between the individual electrode 601 and the common electrode 602, but in the semiconductor device 700 of this modification 1, as shown in Figures 12 to 14, the photoelectric conversion element 717 is formed beyond the area sandwiched between the individual electrode 601 and the common electrode 602.

[0077] Here, the manufacturing process is simplified because there is no need to align the formation area of ​​the photoelectric conversion element 717 with the individual electrode 601 and the common electrode 602. However, the area where photoelectric conversion is actually performed by the photoelectric conversion element 717 is limited to the area sandwiched between the individual electrode 601 and the common electrode 602.

[0078] In this embodiment, the configuration is such that the individual electrode selection circuit board 511, the R layer 512R, the G layer 512G, and the B layer 512B are stacked from the bottom, but this is not limited to this and the configuration may be such that the individual electrode selection circuit board 511, the R layer 512R, the B layer 512B, and the G layer 512G are stacked from the bottom, or further, as in the second embodiment, the configuration may be such that the individual electrode selection circuit board 511, the B layer 512B, the R layer 512R, and the G layer 512G are stacked from the bottom.

[0079] As described above, according to the semiconductor device (500, 700) of this embodiment, the low photoelectric conversion efficiency of the photoelectric element 514 having the lowest photoelectric conversion efficiency among the plurality of stacked photoelectric elements 514 having different photoelectric conversion efficiencies can be compensated for by the light collection efficiency of the microlens 115, making it possible to compensate for the difference in photoelectric conversion efficiency of the photoelectric elements 514 of each color, and making the conversion efficiency of each color uniform.

[0080] Furthermore, in the above claims and in the description of the embodiments, terms such as "top" and "bottom" are used for convenience and do not limit the absolute positional relationship in the state in which the semiconductor device is arranged. [Industrial Applicability]

[0081] In the above-described embodiments, the present invention has been described as a microdisplay or an image pickup element alone, but the present invention can also be used in imaging devices, cameras, video cameras, and the like. [Explanation of symbols]

[0082] 11 drive circuit board, 11a connection pad, 12R R layer, 12G G layer, 12B B layer, 13 base insulating layer, 14R red light emitting element, 14G green light emitting element, 14B blue light emitting element, 15 color light emitting section, 16 interlayer insulating layer, 25 color light emitting section, 100 semiconductor device, 101 anode layer, 102 cathode layer, 103 anode electrode, 104 cathode electrode, 107 insulating layer, 108 anode electrode pad, 109G cathode electrode pad, 109B cathode electrode pad, 110G anode electrode pillar, 110B anode electrode pillar, 111 cathode electrode pillar, 113 anode pad, 114 cathode common wiring, 115 microlens, 115a focus of microlens, 116 Dummy pad, 117 Light-emitting layer, 119 Lower surface of light-emitting layer 117, 120 Flexible substrate, 200 Display module, 302 Optical axis, 400 Semiconductor device, 415 Microlens, 500 Semiconductor device, 511 Individual electrode selection circuit board, 512R R layer, 512G G layer, 512B B layer, 514R Red light-receiving element, 514G Green light-receiving element, 514B Blue light-receiving element, 515 Color light-receiving section, 601 Individual electrode, 602 Common electrode, 608 Individual electrode pad, 609 Common electrode pad, 610 Individual electrode pillar, 611 Common electrode pillar, 613 Individual pad, 614 Common electrode wiring, 617 Photoelectric conversion element, 700 Semiconductor device, 717 Photoelectric conversion element.

Claims

1. a first layer including a first optical semiconductor element; a second layer including a second optical semiconductor element having a lower light emission efficiency than the first optical semiconductor element; Lens member and the first optical semiconductor element and the second optical semiconductor element, The second optical semiconductor element is disposed between the lens element and a focal point of the lens element in the optical axis direction of the lens element, so as to overlap at least partially when viewed from the optical axis direction, and is closer to the focal point than the first optical semiconductor element, and the first optical semiconductor element and the second optical semiconductor element each include a light-emitting layer, and the light-emitting layer is disposed within a cone surrounded by the outer periphery of the lens element and the focal point. A semiconductor device characterized by:

2. a third layer including a third optical semiconductor element; a control board for controlling the first optical semiconductor element, the second optical semiconductor element, and the third optical semiconductor element; the second layer is disposed on the control board; the first layer is disposed on the second layer; the third layer is disposed on the first layer; 2. The semiconductor device according to claim 1, wherein the lens member is disposed on the third layer.

3. 3. The semiconductor device according to claim 2, wherein the focal point is located inside the control substrate.

4. a third layer including a third optical semiconductor element; a control board for controlling the first optical semiconductor element, the second optical semiconductor element, and the third optical semiconductor element; the third layer is disposed on the control board; the second layer is disposed on the third layer; the first layer is disposed on the second layer; 2. The semiconductor device according to claim 1, wherein the lens member is disposed on the first layer.

5. the first optical semiconductor element is a first light emitting element, the second optical semiconductor element is a second light emitting element, The second light-emitting element is 2. The semiconductor device according to claim 1, wherein said first light emitting element emits light having a longer wavelength than light emitted by said second light emitting element.

6. 5. The semiconductor device according to claim 2, wherein the second optical semiconductor element emits light having a longer wavelength than the light emitted by the first optical semiconductor element and the third optical semiconductor element.

7. 7. The semiconductor device according to claim 1, wherein a plurality of assemblies each consisting of the first optical semiconductor element, the second optical semiconductor element, and the lens member are arranged adjacent to each other along a plane perpendicular to the optical axis direction.

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