LED with metal reflector

Abstract

Methods and devices including a die with multiple metal reflectors and / or distributed Bragg reflectors (DBRs) can improve optical efficiency and / or reflectivity of the system. The metal reflectors can be highly reflective and cover a large portion of the die area, including at least a large portion of the n-contact area. The DBRs can also cover a large portion of the die area. As a result of one or both of these elements, reflectivity can be improved. Additionally, a transparent conductive oxide layer can cover the n-contact area to improve current spreading.

Description

[0001] Cross-references to related applications This application claims the benefit of priority to U.S. nonprovisional application No. 18 / 514,956, entitled “LED with metal reflector,” filed November 20, 2023, which is incorporated herein by reference in its entirety. Technical Field

[0002] This invention relates generally to light-emitting devices, particularly LEDs with highly reflective metal reflectors. Background Technology

[0003] The automotive and general lighting industries have witnessed significant technological advancements, one of the breakthroughs being the invention of the light-emitting diode (LED). This innovation has transformed how we perceive and experience automotive and general lighting, offering increased efficiency, durability, and versatility. Developed in response to the limitations of traditional light sources, automotive LEDs have become a key feature of modern vehicles, providing enhanced safety, aesthetics, and functionality.

[0004] In the automotive and general lighting sectors, the pursuit of increased luminous flux has been a continuous effort. Luminous flux is a measure of the total amount of visible light emitted by a light source, and it directly impacts the practical applications of LEDs.

[0005] The reflectivity of an LED die is a function of many factors, including the size of the contact area between the n-via and / or e-via. The geometry of this die and the size of its openings affect the size of the reflective elements contained within it. Reducing the size of these openings and / or otherwise adjusting the geometry of the layers within the die can allow for an increase in the size of reflective elements and a reduction in the size of absorptive or less reflective elements. This adjustment can increase the overall reflectivity and optical efficiency of the system. Summary of the Invention

[0006] Embodiments of the present invention introduce a novel method to increase the luminous flux of LEDs in conventional structures. Compatible with chip-scale package (CSP) architectures, embodiments of the present invention include a die structure characterized by a highly reflective metal reflector that covers a large portion of the die region, including the mesa bottom region (n-contact region). Reflectivity is further enhanced by incorporating a DBR that extends further into most of the die region (i.e., the emitting and non-emitting regions).

[0007] These and other embodiments, features, and advantages of the invention will become more apparent to those skilled in the art when taken in conjunction with the accompanying drawings, which have been briefly described above, and in the following more detailed description of the invention. Attached Figure Description

[0008] Figure 1 A schematic cross-sectional view of an example pcLED is shown.

[0009] Figure 2A and Figure 2B The cross-sectional view and top view of the pcLED array are shown respectively. Figure 2C A schematic top view of an LED chip is shown, from which LEDs can be formed into various shapes. Figure 2A and Figure 2B The LED array shown is shown.

[0010] Figure 3A A schematic top view of an electronic board on which a pcLED array can be mounted is shown, and Figure 3B Similarly, installations are shown. Figure 3A pcLED array on an electronic board.

[0011] Figure 4A A schematic cross-sectional view of a pcLED array arranged relative to a waveguide and a projection lens is shown. Figure 4B It shows something similar to Figure 4A The arrangement is there, but there is no waveguide.

[0012] Figure 5 An example camera flash system is illustrated schematically.

[0013] Figure 6 An example display (e.g., AR / VR / MR) system is illustrated schematically.

[0014] Figure 7 A cross-section of a die according to an embodiment of the present invention is shown, wherein metal reflectors are spaced apart from each other and cover the n-side and most of the p-side of the die.

[0015] Figure 8 A cross-section of a die according to an embodiment of the present invention is shown, wherein metal reflectors are spaced apart from each other and cover the n-side and most of the p-side of the die, and a transparent conductive oxide layer covers the entire n-side of the die.

[0016] Figures 9a-9f A plan view of different layers of the die according to an embodiment of the present invention is shown. Detailed Implementation

[0017] The following detailed description should be read with reference to the accompanying drawings, in which the same reference numerals refer to the same elements. The drawings, not necessarily drawn to scale, depict alternative embodiments and are not intended to limit the scope of the invention. The detailed description illustrates the principles of the invention by way of example rather than limitation. This description will clearly enable those skilled in the art to make and use the invention, and describes several embodiments, modifications, variations, substitutions, and uses of the invention.

[0018] As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural indicators unless the context clearly indicates otherwise. Furthermore, the term “parallel” is intended to mean “substantially parallel” and includes minor deviations in parallel geometry. The term “perpendicular” refers to a direction parallel to Earth’s gravity. The term “horizontal” refers to a direction perpendicular to “perpendicular.” The term “on” means arranged to overlap (e.g., vertically) and / or in direct contact.

[0019] Figure 1 An example of a single pcLED 100 is shown, comprising a light-emitting semiconductor diode (LED) structure 102 disposed on a substrate 104 and a phosphor layer 106 disposed on the LED (also referred to in this text as a wavelength conversion structure). The light-emitting semiconductor diode structure 102 typically includes an active region disposed between n-type and p-type layers. Applying a suitable forward bias across the diode structure results in light emission from the active region. The wavelength of the emitted light is determined by the composition and structure of the active region.

[0020] For example, an LED can be a group III nitride LED that emits ultraviolet, blue, green, or red light. Alternatively, an LED formed from any other suitable material system and emitting light of any other suitable wavelength can be used. Other suitable material systems may include, for example, group III phosphide materials, group III arsenide materials, and group II-VI materials.

[0021] Depending on the required light output and the color specifications from the pcLED, any suitable phosphor material can be used. The phosphor layer may, for example, comprise phosphor particles dispersed in or bonded together with an adhesive material, or may comprise a sintered ceramic phosphor plate.

[0022] Figures 2A-2B Cross-sectional and top views of an array 200 of pcLEDs 100, including a phosphor layer 106 disposed on a substrate 202, are shown respectively. Such an array can include any suitable number of pcLEDs arranged in any suitable manner. In the example shown, the array is described as being monolithically formed on a shared substrate; however, alternatively, the pcLED array can be formed from individual, mechanically separated pcLEDs disposed on the substrate. The substrate 202 may optionally include CMOS circuitry for driving the LEDs and can be formed from any suitable material.

[0023] although Figures 2A-2BA 3×3 array of 9 pcLEDs is shown, but such an array could include, for example, dozens, hundreds, or thousands of LEDs. The width (e.g., side length) of a single LED in the array plane could be, for example, less than or equal to 1 millimeter (mm), less than or equal to 500 micrometers, less than or equal to 100 micrometers, or less than or equal to 50 micrometers. LEDs in such an array could be separated from each other by streets or alleyways having widths in the array plane of, for example, several hundred micrometers, less than or equal to 100 micrometers, less than or equal to 50 micrometers, less than or equal to 10 micrometers, or less than or equal to 5 micrometers.

[0024] Figure 2C A schematic top view of a portion of an LED chip 210 is shown, from which forms such as Figure 2A and Figure 2B The LED array shown is shown. Figure 2C An enlarged 3×3 section of the wafer is also shown. In the example wafer, individual LEDs or pcLEDs 111 with side lengths (e.g., width) W1 are arranged in a square matrix, adjacent LEDs or pcLEDs having a center-to-center distance D1 and separated by aisles 113 of width W2. W1 can be, for example, less than or equal to 1 millimeter (mm), less than or equal to 500 micrometers, less than or equal to 100 micrometers, less than or equal to 50 micrometers, or less than or equal to 10 micrometers. W2 can be, for example, several hundred micrometers, less than or equal to 100 micrometers, less than or equal to 50 micrometers, less than or equal to 10 micrometers, or less than or equal to 5 micrometers. D1 = W1 + W2.

[0025] For example, the array can be formed by dicing the wafer 210 into individual LEDs or pcLEDs and arranging these dies on a substrate. Alternatively, the array can be formed from the entire wafer 210, or by dividing the wafer 210 into smaller arrays of LEDs or pcLEDs.

[0026] LEDs with dimensions (e.g., side length) less than or equal to about 50 micrometers in an array plane are generally referred to as microLEDs, and an array of such microLEDs can be called a microLED array.

[0027] Although the illustrated example shows rectangular LEDs or pcLEDs arranged in a symmetrical matrix, the LEDs or pcLEDs and the array can have any suitable shape or arrangement, and do not need to all have the same shape or size. For example, the LEDs or pcLEDs located in the center of the array may be larger than those located in the outermost parts of the array. Alternatively, the LEDs or pcLEDs located in the center of the array may be smaller than those located in the outermost parts of the array.

[0028] In a pcLED array, all pcLEDs can be configured to emit substantially the same spectrum. Alternatively, the pcLED array can be a multicolor array, where different pcLEDs in the array can be configured to emit different spectra (colors of light) by employing different phosphor compositions. Similarly, in an array of directly emitting LEDs (i.e., without wavelength conversion by phosphors), all LEDs in the array can be configured to emit substantially the same spectrum, or the array can be a multicolor array including LEDs configured to emit different colors of light.

[0029] Individual LEDs or pcLEDs in the array can be individually operable (addressable) and / or can operate as part of a group or subset of LEDs or pcLEDs in the array (e.g., adjacent).

[0030] An array of LEDs or pcLEDs, or a portion thereof, can be formed as a segmented monolithic structure, wherein the individual LEDs or pcLEDs are electrically isolated from each other by trenches and / or insulating materials, but the electrically isolated segments are physically connected to each other by portions of a semiconductor structure.

[0031] Therefore, an LED or pcLED array can be or include a monolithic multicolor matrix of individually operable LEDs or pcLED light emitters. The LEDs or pcLEDs in a monolithic array can be, for example, microLEDs as described above.

[0032] A single, individually operable LED or pcLED, or a group of adjacent such LEDs or pcLEDs, can correspond to a single pixel (image element) in a display. For example, a group of three individually operable adjacent LEDs or pcLEDs, including a red emitter, a blue emitter, and a green emitter, can correspond to a single color-tunable pixel in a display.

[0033] like Figures 3A-3B As shown, the LED or pcLED array 200 can be mounted on an electronic board 300, which includes a power supply and control module 302, a sensor module 304, and an attachment area 306. The power supply and control module 302 can receive power and control signals from an external source and signals from the sensor module 304, based on which it controls the operation of the LED / pcLED. The sensor module 304 can receive signals from any suitable sensor (e.g., a temperature or light sensor). Alternatively, the array 200 can be mounted on a separate board (not shown) from the power supply and control module and the sensor module.

[0034] A single LED or pcLED can optionally be combined with a lens or other optical element, or arranged in combination with a lens or other optical element, which is adjacent to or disposed on the phosphor layer. Such an optical element, not shown in the figure, can be referred to as a "primary optical element." Furthermore, as... Figures 4A-4B As shown, array 200 (e.g., mounted on electronic board 300) can be arranged in conjunction with secondary optical elements such as waveguides, lenses, or both for the intended application. Figure 4A In this arrangement, the light emitted by pcLED 100 is collected by waveguide 402 and guided to projection lens 404. For example, projection lens 404 can be a Fresnel lens. This arrangement can be applied, for example, to automotive headlights. Figure 4B In this arrangement, the light emitted by pcLED 100 is directly collected by projection lens 404 without the use of an intermediate waveguide. This arrangement can be particularly suitable when LEDs or pcLEDs can be spaced close enough together, and can also be used in automotive headlights and camera flash applications. For example, microLED display applications can use similar... Figures 4A-4B The optical arrangement described in the text.

[0035] In another example arrangement, the central block of LEDs or pcLEDs in the array can be associated with a single common (shared) optics, and each of the edge LEDs or pcLEDs in the array located around the central block is associated with a corresponding individual optics.

[0036] Typically, depending on the desired application, any suitable arrangement of optical elements can be used in conjunction with the LED and pcLED arrays described herein.

[0037] The LED and pcLED arrays described herein can be used in applications that require or benefit from fine-grained intensity, spatial, and temporal control of light distribution. These applications can include, but are not limited to, precise, specific patterning of emitted light from a single LED or pcLED, or from a group of LEDs or pcLEDs (e.g., a block). Depending on the application, the emitted light can be spectrally diverse, time-adaptive, and / or environmentally responsive. Such arrays can provide pre-programmed light distributions in various intensity, spatial, or temporal patterns. The emitted light can be based at least in part on received sensor data and can be used for optical wireless communication. At the individual LED / pcLED, group, or device level, the associated electronics and optics may differ.

[0038] Arrays of independently operable LEDs or pcLEDs can be used in conjunction with lenses, lens systems, or other optics or optical systems (e.g., as described above) to provide illumination suitable for a specific purpose. For example, in operation, such adaptive lighting systems can provide illumination that varies with color and / or intensity on an illuminated scene or object, and / or aim in a desired direction. The focusing or manipulation of the light beam emitted by the LED or pcLED array can be electronically performed by activating LEDs or pcLEDs in groups or sequences of varying sizes, allowing for dynamic adjustment of the beam shape and / or direction without moving the optics or changing the focus of the lenses in the lighting device. A controller can be configured to receive data indicating the position and color characteristics of objects or people in a scene, and based on this information, control the LEDs or pcLEDs in the array to provide illumination suitable for the scene. This data can be provided by, for example, image sensors, or optical (e.g., laser scanning) or non-optical (e.g., millimeter-wave radar) sensors. Such adaptive lighting is increasingly important for automotive (e.g., adaptive headlights), mobile device cameras (e.g., adaptive flash), and VR and AR applications (such as those described below).

[0039] Figure 5 An example camera flash system 500 is schematically illustrated, comprising an LED or pcLED array and a lens system 502. This system may be, or include, the adaptive lighting system described above, wherein the LEDs or pcLEDs in the array may be individually operable. During operation of the camera flash system, illumination from some or all of the LEDs or pcLEDs in the array and lens system 502 can be adjusted—deactivated, operated at full intensity, or operated at intermediate intensity. As described above, the array may be a monolithic array, or may comprise one or more monolithic arrays. As described above, the array may be a microLED array.

[0040] The flash system 500 also includes an LED driver 506 controlled by a controller 504 (e.g., a microprocessor). The controller 504 may also be coupled to a camera 507 and a sensor 508, and operates according to instructions and profiles stored in a memory 510. The camera 507, along with the LED or pcLED array and lens system 502, may be controlled by the controller 504 to, for example, match the illumination provided by the system 502 (i.e., the field of view of the illumination system) to the field of view of the camera 507, or otherwise adapt the illumination provided by the system 502 to the scene observed by the camera, as described above. The sensor 508 may include, for example, a position sensor (e.g., a gyroscope and / or accelerometer) and / or other sensors that may be used to determine the position and orientation of the system 500.

[0041] Figure 6An example display (e.g., AR / VR / MR) system 600 is schematically illustrated, comprising an array 610 of individually operable LEDs or pcLEDs, a display 620, a light-emitting array controller 630, a sensor system 640, and a system controller 650. As described above, array 610 may be a monolithic array or may comprise one or more monolithic arrays. The array may be monochromatic. Alternatively, as described above, the array may be a multicolor array, wherein different LEDs or pcLEDs in the array are configured to emit light of different colors. Thus, the array may be or comprise a monolithic multicolor matrix of individually operable LEDs or pcLED light emitters, which may be, for example, microLEDs as described above. A single individually operable LED or pcLED in the array, or a group of adjacent such LEDs or pcLEDs, may correspond to a single pixel (image element) in the display. For example, a group of three individually operable adjacent LEDs or pcLEDs, including a red emitter, a blue emitter, and a green emitter, may correspond to a single color-tunable pixel in the display. Array 610 can be used to project light onto graphic or object patterns supporting an AR / VR / MR system. Control inputs are provided to the sensor system 640, while power and user data inputs are provided to the system controller 650. In some embodiments, the modules included in the system 600 may be compactly arranged in a single structure, or one or more components may be mounted separately and connected via wireless or wired communication. For example, the array 610, display 620, and sensor system 640 may be mounted on a headset or glasses, while the light-emitting array controller and / or system controller 650 may be mounted separately.

[0042] System 600 can incorporate various optical devices (not shown) to couple the light emitted by array 610 to display 620. Any suitable optical device can be used for this purpose.

[0043] For example, sensor system 640 may include external sensors such as cameras, depth sensors, or audio sensors to monitor the environment, and internal sensors such as accelerometers or two-axis or three-axis gyroscopes to monitor the position of the AR / VR / MR headset. Other sensors may include, but are not limited to, barometric pressure, stress, temperature, or any other suitable sensors required for local or remote environmental monitoring. In some embodiments, control input may include detected touch or tap, gesture input, or control based on the position of the headset or display.

[0044] In response to data from sensor system 640, system controller 650 can send images or instructions to light-emitting array controller 630. Changes or modifications to images or instructions can also be made through user data input or automatic data input as needed. User data input can include, but is not limited to, data input provided by audio commands, haptic feedback, eye or pupil positioning, or connected keyboard, mouse, or game controller.

[0045] Figure 7 A light-emitting device according to an embodiment of the present invention is depicted. The light-emitting device includes a semiconductor structure 710 having an active region 715 capable of emitting light (e.g., visible light, such as blue light). The semiconductor structure may be or includes a p-type doped semiconductor material stacked with an n-type doped semiconductor material, with the active region located therebetween. The semiconductor structure may include GaN and includes a p-surface 724 (of the p-type doped semiconductor) located on top of a mesa and extending horizontally, and an n-surface 723 (the surface of the n-type doped semiconductor material) extending horizontally below the mesa (i.e., the n-surface may include the entire bottom region of the mesa). The p-surface may be configured to be vertically higher than the n-surface. A p-side transparent conductive oxide (TCO) 721 directly contacts the p-surface of the semiconductor structure. The TCO mentioned in this specification may be, for example, indium tin oxide (ITO).

[0046] n-side transparent conductive oxide (TCO) 720 is located on the n-side of the semiconductor structure (by... Figure 7 (The recess in the semiconductor structure is shown). The n-side TCO can partially overlap with the p-side TCO in the vertical direction, but this is not required. The n-side TCO directly contacts the n-surface of the semiconductor structure to diffuse current on the n-side. It can diffuse current laterally, making the contact area on the n-side smaller. Compared to using metal to form an ohmic contact at this location, the n-side TCO in the stack that provides current to the n-surface improves reflectivity. Here, the n-side TCO forms an ohmic contact on the n-surface. The n-side TCO can be or include the same material as the p-side TCO, although this is not required, and the n-side TCO can be or include a different material than the p-side TCO.

[0047] Alternatively, a very thin dielectric layer between the TCO and the contact metal is also possible for adhesive purposes. In either case, a smaller contact area is beneficial because it increases the size the DBR 730 can have, which increases the die's reflectivity. The DBR 730 works in conjunction with multiple metal reflectors 735 to prevent light leakage within the die. The DBR can be a stack of dielectric layers alternating between low and high RI dielectric layers. This DBR stack can be optimized to reflect the color of light emitted by the semiconductor structure, such as blue light.

[0048] The DBR can be positioned between the n-side TCO and the metal reflector, making direct contact with both. The DBR can be positioned above most or all of the n-surface and most of the p-surface (e.g., overlapping it vertically). That is, the DBR can cover the entire n-surface. Above the area of ​​the n-surface, the DBR can extend vertically below the p-surface.

[0049] Metal reflectors can be referred to as segmented structures or multiple structures (e.g., first and / or second metal layers) that are physically spaced apart and / or electrically isolated from each other. For example, a metal reflector may include at least a first metal reflector disposed above the entire n-surface and partially above the p-surface, and a second metal reflector disposed entirely above the p-surface. That is, the first metal reflector may cover the entire n-surface. In terms of volume and / or area, most metal reflectors may be disposed on a single layer. Each metal reflector may have its maximum area disposed on the same layer as each other, for example, extending in the same direction as each other, such as in the horizontal direction. To enable the metal reflectors to conduct current to their respective TCOs, they may have portions extending downwards into the DBR to directly contact the TCO; these portions may extend perpendicular to one of the directions of maximum area extension, for example, these portions may extend in the vertical direction. Metal reflectors, particularly the first metal reflector, may not extend downwards below the p-surface, for example, they may not extend below the p-side TCO. The first metal reflector may not extend below the n-side TCO, but may directly contact its surface in at least two regions, each above the p-surface. The first metal reflector may not directly contact the n-side TCO above the n-surface, although this is not required. Because the first metal reflector does not extend downwards below the p-surface, and because the contact area with the TCO is located vertically above the p-surface, light interaction is minimized, thereby improving the optical efficiency of the die. The second metal reflector, positioned entirely above the p-side, may extend below the n-side TCO and through the first insulating layer 725. The first insulating layer may comprise an oxide, such as SiO2. The first insulating layer may be a stepped structure extending downwards from the p-surface to directly contact the n-surface. The first metal reflector may have a topmost flat surface aligned with the topmost flat surface of the second metal reflector.

[0050] The metal reflectors can each have direct physical and electrical contact with a corresponding bonding structure 745, and the bonding structure 745 can have direct physical and electrical contact with a corresponding electrical contact 750. The bonding structures may not have direct physical or electrical contact with each other, and the electrical contacts may not have direct physical or electrical contact with each other. The bonding structures can be disposed in a second insulating layer 740, which may be or include the same or different material as the first insulating layer, and / or have the same refractive index as the first insulating layer. The bonding structures may include one or more materials different from the metal reflectors and electrical contacts, and the electrical contacts may include one or more materials different from the metal reflectors (e.g., they may be composed of different materials). The bonding structures and / or electrical contacts may include metals, such as non-silver metals. For example, the metal reflector may have a higher reflectivity than the bonding structure, and / or the bonding structure may have a higher conductivity than the metal reflector. That is, the metal reflector may be highly reflective and may be or include materials such as silver (e.g., the metal reflector may be composed of one or more materials that are the same as each other, such as a metal).

[0051] Although the figure only shows one contact area between the n-side TCO and the n-surface, the die according to embodiments of the present invention can of course have multiple contact areas. For example, the die can have one or more n-side TCOs spaced apart from each other, one or more p-side TCOs spaced apart from each other, one or more bonding layers spaced apart from each other, and one or more metal reflectors spaced apart from each other. In one example, the die can have a single continuous p-side TCO in direct contact with one or more second metal reflectors, and multiple n-side TCOs, each in direct contact with one or more first metal reflectors. That is, each of the n-side TCOs and p-side TCOs can be in direct contact with multiple metal reflectors or a single metal reflector, respectively. Each of the one or more n-side TCOs can contact the n-surface, with a total contact area smaller than the entire area of ​​the corresponding n-side TCO. The n-side TCOs can directly contact the n-surface in multiple spaced and discontinuous contact areas.

[0052] Figure 8A light-emitting device according to an embodiment of the present invention is depicted. In this die, the n-side TCO 720 can be described as two regions separated by a dashed line 722. The bottom region of the n-side TCO includes a planar region (i.e., a region having two flat surfaces extending parallel to each other in the length direction) covering most or all of the n-surface 723 (the entire n-surface includes the entire length between two adjacent sidewalls of adjacent mesa, as shown). This advantageously increases the current diffusion area of ​​the n-side TCO. The first insulating layer 725 may not extend downwards to the horizontally extending n-surface, although it may be disposed on a portion of the sidewall of the mesa above the p-surface 724. The top region of the n-side TCO, vertically above the dashed line, includes the remainder of the n-side TCO, which may be a stepped structure directly contacting the first metal reflector 735. The bottom and top regions of the n-side TCO can be deposited in separate steps. For example, the bottom region can be deposited in the same steps as the p-side TCO 721. In any case, the bottom and top regions of the n-side TCO can form a monolithic continuous structure.

[0053] Figures 9a-9f The various layers of the light-emitting device according to an embodiment of the present invention are depicted in a plan view. Specifically, Figure 9a The n-surface 723 is shown, which is surrounded by the p-surface 724. Figure 9b Metal reflectors 735, spaced apart from each other, are shown. DBR 730 is visible within a ring separated by a first metal reflector 736 and a second metal reflector 737. Figures 9c-9e Parts of the metal reflector 735, the second insulating layer 740, and the bonding structure 745 are shown. Figure 9f Electrical contacts 750 are shown spaced apart from each other, making the second insulating layer 740 visible in between.

[0054] The disclosure provided in this specification is intended to illustrate, but not necessarily limit, the described embodiments. As used herein, the term "implementation" means an implementation that is illustrated by way of example rather than limitation. The techniques described in the foregoing text and figures may be mixed and matched as needed to produce alternative implementations. It will be apparent to those skilled in the art that many variations, changes, and substitutions can be made to the above embodiments without departing from the invention. Furthermore, it should be understood that all aspects of the invention are not limited to the specific descriptions, configurations, or relative proportions set forth herein, and are subject to various conditions and variables. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in carrying out the invention. Therefore, it is contemplated that the invention will also cover any such alternatives, modifications, variations, or equivalents. All such alternatives will be apparent to those skilled in the art based on this disclosure and are intended to fall within the scope of the appended claims.

Claims

1. A light-emitting device, comprising: p-type doped semiconductor, active layer, and n-type doped semiconductor coupled to the p-type doped semiconductor through the active layer; One or more first transparent conductive oxide (TCO) layers directly contact the p-type doped semiconductor; One or more first metal layers, each first metal layer directly contacting at least one of the one or more first TCO layers; One or more second TCO layers include a contact region that directly contacts the n-type doped semiconductor and a second region that extends beyond the contact region. The one or more second TCO layers are spaced apart from and overlap with the one or more first TCO layers in the vertical direction. and One or more second metal layers, each second metal layer directly contacting at least one of the one or more second TCO layers.

2. The light-emitting device according to claim 1, wherein the one or more first metal layers comprise the same material as the one or more second metal layers.

3. The light-emitting device according to claim 1, wherein the one or more first metal layers do not overlap with the one or more second metal layers.

4. The light-emitting device according to claim 1, wherein the one or more first metal layers are spaced apart from each of the one or more second metal layers.

5. The light-emitting device according to claim 4, wherein the one or more second metal layers directly contact the one or more second TCO layers above the n-type doped semiconductor surface.

6. The light-emitting device according to claim 1, wherein the one or more second metal layers do not directly contact the n-type doped semiconductor.

7. The light-emitting device according to claim 1, wherein the one or more second metal layers do not directly contact the p-type doped semiconductor.

8. The light-emitting device according to claim 1, wherein the one or more second TCO layers comprise indium tin oxide.

9. The light-emitting device according to claim 1 further includes a first insulating layer, wherein the one or more second TCO layers are disposed on the first insulating layer.

10. The light-emitting device according to claim 9, wherein the first insulating layer extends on the p-type doped semiconductor.

11. The light-emitting device according to claim 1, wherein the first insulating layer directly contacts the surface of the n-type doped semiconductor.

12. The light-emitting device according to claim 1, further comprising a bonding structure on the one or more second metal layers.

13. The light-emitting device of claim 12, wherein the bonding structure comprises a material different from the one or more second metal layers.

14. The light-emitting device of claim 12, further comprising a second bonding structure on the one or more first metal layers.

15. The light-emitting device of claim 12, further comprising an electrical contact on the bonding structure, the electrical contact comprising a material different from the bonding structure.

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