Light-emitting device and light-emitting device

Abstract

The invention relates to the technical field of semiconductor manufacturing, in particular to a light-emitting device and a light-emitting device.The light-emitting device comprises a substrate, a first conducting layer, a second conducting layer and a semiconductor laminated layer; the substrate is provided with an upper surface and a lower surface which are opposite, the first conducting layer is arranged on one side of the upper surface of the substrate, the first insulating layer is arranged between the first conducting layer and the substrate, the semiconductor laminated layer is arranged on the first conducting layer, and the second insulating layer is arranged between the first conducting layer and the semiconductor laminated layer. The second conductive layer is located between the semiconductor stack and the second insulating layer, and the central region of the second insulating layer has a first opening to expose a part of the surface of the first conductive layer to be in electrical contact with the second conductive layer. Therefore, the central light intensity density of the light-emitting device can be improved, the light beam angle is reduced, and the light source range of the light-emitting device is further improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing technology, and in particular to a light-emitting device and a light-emitting apparatus. Background Art

[0002] Light Emitting Diode (LED) is a semiconductor light-emitting element, usually made of semiconductor processes such as GaN, GaAs, GaP, GaAsP, etc., and its core is a PN junction with light-emitting characteristics. LED has the advantages of high luminous intensity, high efficiency, small size, and long service life, and is considered to be one of the most promising light sources at present. LED has been widely used in lighting, monitoring and command, high-definition broadcasting, high-end cinemas, office displays, conference interaction, virtual reality and other fields.

[0003] At present, in some application scenarios with special needs, the range of the light source is an important measurement indicator. Conventional light-emitting devices set a lateral conduction layer in the LED structure to conduct the injected current laterally, improve the uniformity of current injection to improve brightness and light efficiency, but still cannot meet the relevant range requirements.

[0004] It should be noted that the information disclosed in this background technology section is only intended to increase the understanding of the overall background of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes prior art already known to a person skilled in the art. Summary of the invention

[0005] In order to solve the technical problem of insufficient range of the light source of the conventional light emitting device, the present invention provides a light emitting device and a light emitting apparatus.

[0006] In a first aspect, the present invention provides a light-emitting device, comprising a substrate, a first conductive layer, a second conductive layer and a semiconductor stack; the substrate has an upper surface and a lower surface relative to each other, the first conductive layer is arranged on one side of the upper surface of the substrate, a first insulating layer is provided between the first conductive layer and the substrate, the semiconductor stack is arranged on the first conductive layer, a second insulating layer is provided between the first conductive layer and the semiconductor stack, and the second conductive layer is located between the semiconductor stack and the second insulating layer.

[0007] The central area of ​​the second insulating layer has a first opening to expose a portion of the surface of the first conductive layer for electrical contact with the second conductive layer, so as to increase the central light intensity density of the light emitting device, reduce the beam angle, and thereby increase the light source range of the light emitting device.

[0008] In a second aspect, the present invention provides a light-emitting device, which adopts the light-emitting device described in the above embodiment.

[0009] Based on the above, the present invention provides a light-emitting device and a light-emitting apparatus. Compared with the prior art, a first conductive layer, a second conductive layer and a second insulating layer are added between a substrate and a semiconductor stack. The central area of ​​the second insulating layer has a first opening to expose a portion of the surface of the first conductive layer for electrical contact with the second conductive layer. This can increase the central light intensity density of the light-emitting device and reduce the light beam angle, thereby achieving the effect of increasing the range of the light source of the light-emitting device. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings without creative work. The positional relationship described in the drawings in the following description is based on the direction of the components in the drawings unless otherwise specified.

[0011] Figure 1 A schematic diagram of a top view of a light emitting device provided in one embodiment of the present invention; Figure 2 for Figure 1 Schematic diagram of the cross-section structure at AA in the middle; Figure 3 A schematic diagram of the structure of a semiconductor stack provided by an embodiment of the present invention; Figure 4A-4D A schematic diagram of the structure of a first opening provided for multiple embodiments of the present invention; Figure 5 A schematic structural diagram of a third insulating layer provided in one embodiment of the present invention; Figure 6 A schematic structural diagram of a light emitting device provided in another embodiment of the present invention.

[0012] Reference numerals: DETAILED DESCRIPTION

[0013] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0014] In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first" and "second" are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance, or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more. In addition, the term "including" and any variation thereof all mean "at least including".

[0015] See also Figure 1 and Figure 2 , Figure 1 A schematic diagram of a top view of a light emitting device provided in one embodiment of the present invention; Figure 2 for Figure 1 Schematic diagram of the cross-sectional structure at AA in the middle.

[0016] In order to solve the technical problem of insufficient range of the conventional light source of the above-mentioned light emitting device, or to achieve at least one of the above-mentioned advantages or other advantages, an embodiment of the present invention provides a light emitting device, which is a vertical structure LED light emitting device. Compared with traditional horizontal structure LED light emitting devices and flip-chip structure LED light emitting devices, vertical structure LED light emitting devices solve the problem of uneven current density distribution in the active area of ​​the device due to lateral expansion of current, and have significant advantages, including but not limited to higher light output, more uniform white light brightness, and lower cost.

[0017] As shown in the figure, the light emitting device includes a substrate 10. The substrate 10 may be a single-layer or multi-layer conductive substrate. The substrate 10 may be a metal, alloy, silicon or silicon carbide material, which has good electron transmission, heat conduction and mechanical strength, and can achieve higher efficiency, better heat dissipation performance and lower cost. However, the present invention is not limited to this, and the substrate 10 may also be made of other conductive materials or semiconductor materials, without limitation thereto.

[0018] The substrate 10 has an upper surface and a lower surface opposite to each other. A first electrode 20 is attached to the lower surface of the substrate 10. The first electrode 20 can be a single-layer, double-layer or multi-layer structure, for example, a stacked structure of Ti / Al, Ti / Al / Ti / Au, Ti / Al / Ni / Au, V / Al / Pt / Au, Ti / Ni / Pt / Au, etc.

[0019] The first conductive layer 30 is located on one side of the upper surface of the substrate 10. The first conductive layer 30 has good current conduction performance. Optionally, the first conductive layer 30 can be a transparent conductive layer, such as an indium tin oxide (ITO) film, an indium zinc oxide (IZO) film, a carbon nanotube film, a metal mesh film, etc. Of course, in some other embodiments, the first conductive layer 30 can be a metal conductive layer, including but not limited to one or more of chromium (Cr), nickel (Ni), aluminum (Al), titanium (Ti), platinum (Pt), and gold (Au), which is not limited in this case.

[0020] A first insulating layer 40 is disposed between the first conductive layer 30 and the substrate 10 . The first insulating layer 40 can isolate the current between the substrate 10 and the first conductive layer 30 .

[0021] Please combine Figure 2 See also Figure 3 As shown in the figure, the semiconductor stack 50 is disposed above the first conductive layer 30 and is electrically connected to the first conductive layer 30. In a specific implementation, the semiconductor stack 50 includes a first semiconductor layer 51, an active layer 52, and a second semiconductor layer 53 stacked sequentially from bottom to top.

[0022] The first semiconductor layer 51 may be a P-type semiconductor layer, which may provide holes to the active layer 52 under the action of a power source. In some embodiments, the first semiconductor layer 51 may include a nitride layer, an arsenide layer, or a phosphide layer doped with P-type impurities of one or more Group II elements. The P-type impurities may include one or a combination of Mg, Zn, and Be. Optionally, the first semiconductor layer 51 may be a single-layer structure or a multi-layer structure having different compositions. In addition, the setting of the epitaxial structure is not limited thereto, and other types of epitaxial structures may be selected according to actual needs.

[0023] The active layer 52 may be a quantum well structure (Quantum Well, referred to as QW). In some embodiments, the active layer 52 may also be a multiple quantum well structure (Multiple Quantum Well, referred to as MQW), wherein the multiple quantum well structure includes multiple quantum well layers (Well) and multiple quantum barrier layers (Barrier) alternately arranged in a repeated manner, for example, a multiple quantum well structure of GaN / AlGaN, InAlGaN / InAlGaN, InGaN / AlGaN, InGaP / AlGaInP, AlGaInP / AlGaInP or InGaAs / AlGaAs. In addition, the composition and thickness of the well layer in the active layer 52 determine the wavelength of the generated light. In order to improve the luminous efficiency of the active layer 52, it can be achieved by changing the depth of the quantum well, the number of layers, thickness and / or other characteristics of the paired quantum wells and quantum barriers in the active layer 52.

[0024] The second semiconductor layer 53 may be an N-type semiconductor layer, which may provide electrons to the active layer 52 under the action of a power source. In some embodiments, the second semiconductor layer 53 may include a nitride layer, an arsenide layer, or a phosphide layer doped with N-type impurities of one or more group IV elements. The N-type impurities may include one or a combination of Si, Ge, and Sn. Optionally, the second semiconductor layer 53 may be a single-layer structure or a multi-layer structure, and the multi-layer structure has different compositions.

[0025] When the power is turned on, the current flows from bottom to top through the first semiconductor layer 51 , the active layer 52 and the second semiconductor layer 53 via the conduction of the first conductive layer 30 , thereby causing the semiconductor stack 50 to emit light.

[0026] On the basis of the above, a second insulating layer 60 is provided between the semiconductor stack 50 and the first conductive layer 30. The second insulating layer 60 can isolate the current conduction between the first conductive layer 30 and the semiconductor stack 50. The second insulating layer 60 exposes a portion of the upper surface of the first conductive layer 30. The exposed upper surface of the first conductive layer 30 is electrically connected to the second electrode 70. The second electrode 70 can add current and conduct the current to the first conductive layer 30. Optionally, the second electrode 70 can be made of a transparent conductive material or a metal material.

[0027] The second conductive layer 80 is located between the semiconductor stack 50 and the second insulating layer 60. Specifically, the second conductive layer 80 is located between the first semiconductor layer 51 and the second insulating layer 60. The central region of the second insulating layer 60 has a first opening 90. The first opening 90 exposes a portion of the surface of the first conductive layer 30 to electrically contact the second conductive layer 80, so that the first conductive layer 30 is electrically connected to the second conductive layer 80.

[0028] When the second electrode 70 is powered by an additional power source, current enters the first conductive layer 30 through the second electrode 70. Due to the first insulating layer 40 and the second insulating layer 60, the current will flow laterally along the first conductive layer 30. When the current expands to the central area of ​​the second insulating layer 60, the first opening 90 exposes the electrical connection between the first conductive layer 30 and the second conductive layer 80, so that the current is conducted to the second conductive layer 80 and flows through the first semiconductor layer 51, the active layer 52 and the second semiconductor layer 53 in sequence, so that the semiconductor stack 50 emits light.

[0029] Based on the above, by adding a first conductive layer 30, a stacked conductive layer 80 and a second insulating layer 60 between the substrate 10 and the semiconductor stack 50, and opening 90 in the central area of ​​the second insulating layer 60 to expose the electrical contact between the first conductive layer 30 and the second conductive layer 80, the current injection point is adjusted to the central area of ​​the light-emitting device, so that the current density of the current injection area in the central area is higher than that of other outer areas, so as to increase the central light intensity density of the light-emitting device, reduce the light beam angle, and achieve the effect of increasing the light source range of the light-emitting device.

[0030] It should be noted that in the embodiment of the present invention, the central area of ​​the second insulating layer 60 refers to the range where the ratio of the minimum distance S from the edge of the area to the edge of the light-emitting device in a top view to the minimum side length L of the light-emitting device is between 1:4 and 1:13. In some preferred embodiments, in a top view, the ratio of the distance W between the leftmost and rightmost points of the first opening 90 along the horizontal direction to the minimum side length L of the light-emitting device is 0.5-0.9, which facilitates the design of the size of the first opening 90 during the manufacturing process.

[0031] On the basis of the above, the top-view projection area of ​​the first opening 90 is 30% to 70% of the top-view projection area of ​​the semiconductor stack 50. Specifically, when the top-view projection area of ​​the first opening 90 is less than 30% of the top-view projection area of ​​the semiconductor stack 50, current crowding may occur in the process of current passing through the first opening 90, which in turn leads to the adverse effect of local temperature increase of the light-emitting device. When the area of ​​the first opening 90 is less than 70% of the top-view projection area of ​​the semiconductor stack 50, the current density in the central area is higher than that in other areas of the outer edge, so as to achieve the effect of increasing the central light intensity density of the light-emitting device and reducing the beam angle. If the area of ​​the first opening 90 is greater than 70% of the top-view projection area of ​​the semiconductor stack 50, the difference between the current density of the current injection area in the central area of ​​the light-emitting device and other areas of the outer edge is small, and the beam angle cannot be stably reduced.

[0032] Please combine Figure 2 See also Figure 4A-4BAs shown in the figure, in some preferred embodiments, the shape of the first opening 90 is square or circular. Of course, in other embodiments, other regular or irregular patterns can also be used, as long as the current injection point can be adjusted to the central area of ​​the light-emitting device, and this case is not limited to this. In some preferred embodiments, the first opening 90 includes at least one graphic opening 91. In specific implementation, the number of graphic openings 91 can be determined according to the actual product, and this case is not limited to this. Figure 4C-4D As shown, the number of the patterned openings 91 can be multiple. The multiple patterned openings 91 are relatively concentrated in the central area of ​​the light-emitting device to form the first opening 90, so that the current is injected into the central area of ​​the light-emitting device through the first opening 90 after being conducted through the first conductive layer 30, so that the current density in the central area of ​​the light-emitting device is greater than that in other areas of the outer edge, so as to increase the central light intensity density of the light-emitting device, reduce the beam angle, and achieve the effect of increasing the range of the light source of the light-emitting device.

[0033] In some preferred embodiments, the thickness of the second conductive layer is 3000-15000 angstroms. This is to balance the current lateral conduction capability of the second conductive layer 80 and the production cost. Optionally, the material of the second conductive layer 80 is the same as that of the first conductive layer 30, which is convenient for simplifying the process. Of course, in some other embodiments, the material of the second conductive layer 80 can be different from that of the first conductive layer 30, which can be selected according to actual production requirements.

[0034] On the basis of the above, the light emitting device has a plurality of through holes 100. The plurality of through holes 100 extend from the substrate 10 toward the semiconductor stack 50 and penetrate the second semiconductor layer 53 to expose the electrical connection between the substrate 10 and the second semiconductor layer 53, and at least one through hole 100 is located within the central area of ​​the second insulation 60. That is, in a top view, there is at least one through hole 100 within the central area, which can effectively improve the current density in the central area of ​​the light emitting interval.

[0035] In some preferred embodiments, the light emitting device further includes a reflective layer 110. The reflective layer 110 is located between the second conductive layer 80 and the first semiconductor layer 51. The reflective layer 110 has a reflectivity of more than 90%, and can reflect the light radiated from the semiconductor stack 50 toward the substrate 10. The reflective layer 110 can be made of a metal material, including but not limited to at least one of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Ti, Cr, Zn, Pt, Au and Hf or an alloy thereof.

[0036] Furthermore, please combine Figure 2 See also Figure 5The light emitting device further includes a third insulating layer 120. The third insulating layer 120 is located between the reflective layer 110 and the first semiconductor layer 51. A plurality of second openings 121 are provided on the third insulating layer 120, and the plurality of second openings 121 are filled with the material of the reflective layer 110.

[0037] When the second electrode 70 is powered, the current is conducted through the first conductive layer 30 and injected into the second conductive layer 80 through the first opening 90. Part of the current is extended horizontally from the central area to the outer edge through the second conductive layer 80, and is uniformly conducted to the first semiconductor layer 51 through multiple second openings 121 to improve the current uniformity of the entire light-emitting device. Part of the current is directly conducted to the substrate 10 through the through hole 100 within the range of the first opening 90. While making the current density in the center of the light-emitting device greater than that in other areas of the outer edge, the luminous efficiency of the entire light-emitting device can also be improved.

[0038] In some preferred embodiments, the second semiconductor stack 53 has a fluorescent layer 130 on a side away from the substrate 10. The fluorescent layer 130 is formed of a wavelength conversion material. According to the different wavelength conversion materials applied, the light radiated by the light emitting device finally has different properties. In specific implementation, the wavelength conversion material may include silica gel and phosphor, which may be selected according to the actual product and application scenario.

[0039] In another preferred embodiment, Figure 6 As shown, the light emitting device is a horizontal vertical structure LED. The substrate 10 can be an insulating substrate, for example, made of AlN. AlN material has high thermal conductivity, excellent electrical insulation and good thermal expansion coefficient. However, the present invention is not limited to this, and other insulating materials can also be used for support, without limitation to this.

[0040] The first conductive layer 30 is located on the upper surface of the substrate 10. The first conductive layer 30 has good current conduction performance. The first insulating layer 40 is disposed between the first conductive layer 30 and the substrate 10. The first insulating layer 40 can isolate the current conduction between the substrate 10 and the first conductive layer 30.

[0041] A third conductive layer 140 is disposed between the substrate 10 and the first insulating layer 40. The first insulating layer 40 exposes a portion of the upper surface of the third conductive layer 140. The exposed upper surface of the third conductive layer 140 is electrically connected to the first electrode 20.

[0042] The semiconductor stack 50 is disposed above and connected to the first conductive layer 30. The third conductive layer 140 extends toward the semiconductor stack 50 and penetrates the second semiconductor layer 53 to form a through hole 100, so that the third conductive layer 140 is in electrical contact with the second semiconductor layer 53.

[0043] A second insulating layer 60 is provided between the semiconductor stack 50 and the first conductive layer 30. The second insulating layer 60 can isolate the current conduction between the first conductive layer 30 and the semiconductor stack 50. It should be noted that the first insulating layer 40 and the second insulating layer 60 contact each other at the first electrode 20, thereby separating the first electrode 20 from the first conductive layer 30.

[0044] The second insulating layer 60 exposes a portion of the upper surface of the first conductive layer 30. The exposed upper surface of the first conductive layer 30 is electrically connected to the second electrode 70. The second electrode 70 can add current and conduct the current to the first conductive layer 30.

[0045] The second conductive layer 80 is located between the semiconductor stack 50 and the second insulating layer 60. The reflective layer 110 is located between the second conductive layer 80 and the first semiconductor layer 51. The third insulating layer 120 is located between the reflective layer 110 and the first semiconductor layer 51. A plurality of second openings 121 are provided on the third insulating layer 120, and the plurality of second openings 121 expose the reflective layer 110 to be in electrical contact with the first semiconductor layer 51. The second semiconductor stack 53 has a fluorescent layer 130 on a side away from the substrate 10.

[0046] In a specific implementation, a power source is added to the second electrode 70, and current enters the first conductive layer 30 through the second electrode 70. Due to the first insulating layer 40 and the second insulating layer 60, the current will flow laterally along the first conductive layer 30. When the current expands to the central area of ​​the second insulating layer 60, the first opening 90 exposes the electrical connection between the first conductive layer 30 and the second conductive layer 80, so that the current is conducted to the second conductive layer 80, and flows through the first semiconductor layer 51, the active layer 52 and the second semiconductor layer 53 in sequence, so that the semiconductor stack 50 emits light, and then is conducted to the first electrode 20 through the through hole 100 and the third conductive layer 140.

[0047] In some preferred embodiments, the present invention further provides a light-emitting device, which uses the above-mentioned light-emitting device.

[0048] In summary, the light-emitting device and the light-emitting apparatus provided by the present invention, compared with the prior art, are configured by adding a first conductive layer, a second conductive layer and a second insulating layer between a substrate and a semiconductor stack, wherein a central area of ​​the second insulating layer has a first opening to expose a portion of the surface of the first conductive layer for electrical contact with the second conductive layer, and the injection point of the current is adjusted to the central area of ​​the light-emitting device, so that the current density of the current injection area in the central area is higher than that of other areas on the outer edge, thereby improving the central light intensity density of the light-emitting device, reducing the light beam angle, and achieving the effect of increasing the light source range of the light-emitting device.

[0049] Although the terms such as substrate, conductive layer, insulating layer, etc. are used more frequently in this article, the possibility of using other terms is not excluded. These terms are used only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional restrictions is contrary to the spirit of the present invention.

[0050] In addition, those skilled in the art should understand that, although there are many problems in the prior art, each embodiment or technical solution of the present invention can be improved in only one or several aspects, without having to solve all the technical problems listed in the prior art or background technology at the same time. Those skilled in the art should understand that the content not mentioned in a claim should not be used as a limitation on the claim.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A light emitting device, characterized in that: include a substrate having opposing upper and lower surfaces; A first conductive layer is disposed on one side of the upper surface of the substrate; a first insulating layer, located between the first conductive layer and the substrate; A semiconductor stack is disposed on the first conductive layer; A second insulating layer, located between the first conductive layer and the semiconductor stack; A second conductive layer, located between the semiconductor stack and the second insulating layer; The central area of ​​the second insulating layer has a first opening to expose a portion of the surface of the first conductive layer so as to be in electrical contact with the second conductive layer.

2. The light emitting device according to claim 1, characterized in that: In a top view, the ratio of the distance W between the leftmost end and the rightmost end of the first opening along the horizontal direction to the minimum side length L of the light emitting device is 0.5 to 0.

9.

3. The light emitting device according to claim 1, characterized in that: The top-view projection area of ​​the first opening is 30% to 70% of the top-view projection area of ​​the semiconductor stack.

4. The light emitting device according to claim 1, characterized in that: The first opening is in a square or circular shape.

5. The light emitting device according to claim 1, characterized in that: The first opening includes at least one patterned opening.

6. The light emitting device according to claim 1, characterized in that: The thickness of the second conductive layer is 3000-15000 angstroms.

7. The light emitting device according to claim 1, characterized in that: The light emitting device has a plurality of through holes, the semiconductor stack comprises a first semiconductor layer, an active layer and a second semiconductor layer from bottom to top, and the plurality of through holes penetrate from the substrate to the second semiconductor layer to expose the substrate and electrically contact the second semiconductor layer.

8. The light emitting device according to claim 7, characterized in that: At least one of the through holes is located in a central region of the second insulating layer.

9. The light emitting device according to claim 7, characterized in that: The light emitting device further includes a reflective layer located between the second conductive layer and the first semiconductor layer.

10. The light emitting device according to claim 9, characterized in that: The light emitting device further comprises a third insulating layer, the third insulating layer is located between the reflective layer and the first semiconductor layer, a plurality of second openings are provided on the third insulating layer, and the plurality of second openings expose the reflective layer to be in electrical contact with the first semiconductor layer.

11. The light emitting device according to claim 7, characterized in that: The second semiconductor layer has a fluorescent layer on a side away from the substrate.

12. A light emitting device, characterized in that: The light-emitting device adopts the light-emitting device according to any one of claims 1-11.

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