LED Structures and Light-Emitting Devices

Abstract

The present disclosure describes various aspects of strain management layers for light emitting devices, such as light emitting diodes (LEDs). The present disclosure describes an LED structure having a strain management region formed on and supported on a substrate, and an active region configured to provide light emission associated with the LED structure. The strain management region includes a first layer including a superlattice having a plurality of repeating first and second sublayers, and a second layer including a bulk layer. In one embodiment, at least one of the first and second sublayers and the bulk layer comprises In. x Al y Ga 1-x-y The composition includes N. A device having a plurality of LED structures and a method for making the LED structures are also described.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application benefits from and claims priority to U.S. Provisional Patent Application Serial No. 63 / 027,049, filed May 19, 2020, the disclosure of which is incorporated herein by reference in its entirety. [Background technology]

[0002] Background to the disclosure Aspects of the present disclosure relate generally to light-emitting devices such as those used in various types of displays, and more particularly to improved strain management layers in light-emitting device structures.

[0003] Some light-emitting diodes (LEDs), such as high-efficiency indium gallium nitride (InGaN) LEDs, require a layer structure beneath the active region (e.g., the region that emits light) that provides the type of material qualities necessary to form an active region with the performance levels required for modern LED applications. This layer structure, which may include multiple layers, can be generally referred to as strain-management layers or prep layers. Strain-management layers are typically used to provide suitable material properties to enable the formation of an active region with desired light-emitting characteristics, such as emission wavelength and efficiency. However, strain-management layers, such as one or more indium (In)-containing layers used with InGaN LEDs, can be prone to surface defects that result in non-ideal light-emitting performance from the active region deposited thereon. Summary of the Invention

[0004] Aspects of the present disclosure provide techniques and structures that improve strain management layers and their overall effect on performance in light-emitting devices.

[0005] Disclosure Overview The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an exhaustive overview of all contemplated aspects, nor is it intended to identify key or critical elements of all aspects or delineate the scope of any or all aspects. Its purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

[0006] This disclosure describes the application of a combination of strained layer superlattices (SLS) and strain management layers, such as bulk In-containing layers, in light-emitting devices such as LEDs. For example, such a combination may enable thick layers to restore surface morphology, provide active region improvements, and / or enable SLS to improve strain layer management and active region performance.

[0007] In one aspect of the present disclosure, an LED structure formed on a substrate is described. The LED structure includes a strain-management region supported on the substrate and an active region configured to provide light emission associated with the LED structure. The strain-management region includes a first layer including a superlattice having a plurality of repeating first and second sublayers, and a second layer including a bulk layer. In one embodiment, at least one of the first and second sublayers and the bulk layer comprises In. x Al y Ga 1-x-y Contains the composition of N.

[0008] In another aspect of the present disclosure, a light emitting device is described that includes a semiconductor template and an array of light emitting structures supported on the semiconductor template. At least one of the light emitting structures of the array of light emitting structures includes an active region configured to provide light emission associated with the at least one light emitting structure. The at least one light emitting structure also includes a strain management region that includes a first layer that includes a superlattice having a plurality of repeating first and second sublayers, and a second layer that includes a bulk layer. In one embodiment, at least one of the first and second sublayers and the bulk layer is made of In. x Aly Ga 1-x-y Contains the composition of N.

[0009] BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings depict only some implementations and therefore should not be considered limiting of the scope. [Brief explanation of the drawings]

[0010] [Figure 1] An example of an LED structure using strained layer superlattice (SLS) strain management techniques is presented. [Figure 2] An example of an LED structure using a thick In-containing layer preparation technique is shown. [Figure 3] 1 shows an example of an LED structure using a combination of SLS and bulk strain management layers according to aspects of the present disclosure. [Figure 4] 1 shows an example of an LED structure using a combination of SLS and bulk strain management layers according to aspects of the present disclosure. [Figure 5] 1 illustrates an example of an LED structure including a UV superlattice structure according to aspects of the present disclosure. [Figure 6] 1 illustrates an example of an LED structure including a non-emitting quantum well structure according to aspects of the present disclosure. [Figure 7] 1 shows an example of an LED structure having a combination of SLS and bulk strain management layers on a flat surface according to aspects of the present disclosure. [Figure 8] 1 illustrates an example of an LED structure having a combination of SLS and bulk strain management layers on a pedestal according to aspects of the present disclosure. [Figure 9] 1 illustrates an example of an LED structure having a combination of SLS and bulk strain management layers over regions of a template defined by a mask, according to aspects of the present disclosure. [Figure 10] FIG. 1 illustrates a portion of an array of LED structures as part of a display, according to an aspect of the present disclosure. [Figure 11] 1 shows a flowchart illustrating a method of manufacturing an LED structure according to an aspect of the present disclosure. [Figure 12]1 shows a flowchart illustrating a method of manufacturing an LED structure according to an aspect of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] Detailed Description The detailed description set forth below in connection with the accompanying drawings or figures is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well-known components are shown in block diagram form to avoid obscuring such concepts.

[0012] There is a constant need to increase the number of light-emitting structures or light-emitting elements (e.g., pixels) in displays to provide better user experiences and enable new applications, but adding more of them presents challenges. Achieving smaller and smaller light-emitting structures to increase both number and density has made the potential for using small LEDs (e.g., microLEDs or nanoemitters) more attractive, but several technologies that enable small LEDs to generate large numbers, high densities, and different colors (e.g., red, green, blue) currently result in structures that are cumbersome, time-consuming, expensive, or have performance limitations. More sophisticated display architectures, such as those for high-density and light-field displays, could benefit from the use of small LEDs, but the requirements of such displays make them difficult to achieve. Therefore, new technologies and devices that enable the monolithic integration of multiple small light-emitting structures that generate different colors of light on the same substrate (e.g., a single integrated semiconductor device) are desirable.

[0013] For example, the use of certain semiconductor processing techniques to fabricate the light-emitting structure, such as epitaxial growth and dry etching or selective area growth (SAG), offers a promising approach for the monolithic integration of multiple micro LEDs on a single integrated semiconductor device. The quality of the materials grown on the semiconductor template to fabricate the light-emitting structure has a significant impact on the performance characteristics of the LED.

[0014] To this end, structural configurations are needed that enable the formation of small light-emitting structures with high-quality active (e.g., light-emitting) regions. For example, in the case of quantum well (QW)-based LEDs, the strategic inclusion of preparation layers can improve or enhance the morphology and / or strain characteristics of the active region within the light-emitting structure.

[0015] Two distinct approaches are commonly used for strain management in LEDs. In one approach, multiple pairs of In-containing and non-indium-containing layers form a strained-layer superlattice (SLS) as a strain management mechanism. However, the SLS approach is hindered by the tendency for pitting on the SLS surface prior to the formation of the active QW layer on the SLS surface. For example, when thin layers of InGaN-GaN pairs are deposited to form the SLS, the low-temperature epitaxial growth process required for SLS formation tends to lead to pitting. In an alternative approach, a bulk layer, such as a thick layer of InGaN, AlInN, or AlInGaN, can be used for strain management between the semiconductor template and the active QW region. In both the SLS and bulk layer approaches, In-containing layers are used because inclusion of indium has been empirically shown to improve the light-emitting efficiency of LEDs. The In content of the layer generally does not exceed that of the active QW region to prevent light absorption in the In-containing SLS or bulk layer.

[0016] The present disclosure provides for the combined application of both SLS and one or more bulk layers (such as thick InGaN, AlInN, or AlInGaN layers) as strain management layers in LEDs. Aspects presented herein use a combination of bulk layers and SLS to provide improved or optimal strain layer management and active region performance.

[0017] 1 shows a diagram illustrating an example of an LED structure 100 that uses the strained layer superlattice (SLS) strain management technique described above. The LED structure 100 is formed on a semiconductor template 110. In some implementations, techniques such as epitaxial growth and dry etching or selective area growth (SAG) may be used to define the location, shape, and size of the LED structure 100 on the semiconductor template 110. In one example, the semiconductor template 110 is formed from an n-type GaN template or epitaxial layer formed on a semiconductor substrate.

[0018] As shown in FIG. 1 , LED structure 100 includes an SLS 115 formed on a semiconductor template 110. LED structure 100 also includes an active quantum well (QW) 140 where light emission from LED structure 100 is generated, and one or more p-layers 150 that provide electrical contact to LED structure 100. Light emission from QW 140 may be electromagnetic waves having wavelengths in the visible spectrum, for example. P-layer 150 may include, for example, p-doped layers and / or contact layers. The various components of LED structure 100 are grown (e.g., epitaxially grown), deposited, or otherwise formed adjacent to one another in the exemplary configuration shown in FIG. 1 .

[0019] In one example, the SLS 115 includes one or more pairs 160 of first layers 165 and second layers 170. In some examples, the SLS 115 includes tens of pairs 160 for a total thickness of the SLS 115 of 20 nanometers or more (>20 nm). In some examples, the SLS 115 includes 20 to 60 or more pairs 160 of first and second layers. The first layer 165 includes, for example, InGaN, AlInN, or AlInGaN. The second layer 170 includes, for example, GaN. In some examples, optional layer structures (not shown) may be formed between the semiconductor template 110 and the SLS 115 or between the SLS 115 and the active QWs 140.

[0020] As mentioned above, the inclusion of SLS 115 can improve the strain characteristics of the active QWs 140 of the LED structure 100, but SLS 115 is prone to pitting, leading to potential performance issues in the light emission from the LED structure 100.

[0021] FIG. 2 illustrates an example of an LED structure 200 having a bulk layer as a strain-management layer. Similar to the LED structure 100 shown in FIG. 1, the LED structure 200 includes a combination of an active QW 140 and a p-layer 150 formed on a semiconductor template 110. Instead of an SLS structure, the LED structure 200 includes a strain-management structure 205 including a bulk layer 210 and an intermediate layer 220 formed between the active QW 140 and the semiconductor template 110. The bulk layer 210 is a thick layer, for example, including InGaN, AlInN, or AlInGaN. In some cases, the thickness of the bulk layer 210 is 50 nm or greater. The intermediate layer 220 may be formed of, for example, GaN, AlGaN, or InGaN and is configured to provide a suitable interface for the deposition of the active QW 140.

[0022] A solution proposed in this disclosure that may result in pit reduction for growing an active region (e.g., active QW140) in an LED involves a combination of aspects described in connection with LED structures 100 and 200 in FIGS. 1 and 2, respectively. Aspects presented herein provide a combination of SLS and bulk layers. A device may include one or more sets of combinations, e.g., 1 to 10 sets, or more than 10 sets. This solution may be suitable for micro-LEDs (e.g., LEDs with device pitches on the order of a few microns or less, fabricated using etching or SAG techniques), but may also be applicable to larger LEDs.

[0023] 3 shows an LED structure 300 that uses a combination of SLS and bulk strain management layers according to aspects of the present disclosure. Similar to LED structures 100 and 200 shown in FIGS. 1 and 2, respectively, LED structure 300 is formed on a semiconductor template 110. LED structure 300 includes a strain management region 315 that is formed, grown (e.g., epitaxially grown), or deposited on semiconductor template 110.

[0024] The strain management region 315 may include one or more sets 320. In one example, each set 320 includes a first prepared layer structure, such as an SLS structure 325 formed from multiple pairs of first and second layers 326 and 327, and a second prepared layer structure, such as a bulk layer 335. It should be noted that the SLS structure 325 may include additional layers to the first and second layers 326 and 327 to form a superlattice.

[0025] The strain management region 315 may include multiple pairs of SLS structures 325 and bulk layers 335. For example, the strain management region 315 may include 2 to 50 or more pairs of first layers 326 and second layers 327. Additionally, the strain management region 315 may further include 1 to 10 pairs 320 of SLS structures 325 and bulk layers 335. Furthermore, when multiple pairs 320 are included in the strain management region 315, the number of pairs in the SLS structures 325 may be tailored across the pairs 320 included in the strain management region 315.

[0026] Continuing to refer to FIG. 3 , the first layer 326 and the second layer 327 forming the SLS structure 325 include, for example, GaN and InGaN layers repeated to form a stack. The bulk layer 335 includes an In-containing layer, such as, for example, InGaN, AlInN, or AlInGaN, and is configured to provide improved surface morphology (e.g., reduced pit formation) over using a superlattice alone as a strain management mechanism. According to the present disclosure, at least one of the first layer 326, the second layer 327, and the bulk layer 335 may be an In-containing layer. In one example, one of the first layer 326, the second layer 327, and the bulk layer 335 includes an In-containing layer. x Al y Ga 1-x-y In another example, one or more of the first layer 326, the second layer 327 and the bulk layer 335 may include In. x Al y Ga 1-x-y Each of these layers may contain N at a different composition, i.e., the composition of each of these layers may differ from the composition of the other layers. For example, In for the bulk layer x Al y Ga 1-x-y The composition of N may be based on the value of x ranging from 0 to 0.15. x Al y Ga 1-x-y The composition of N may be based on the value of x in the range of 0 to 0.3, and In for the second layer in the SLS structure. x Al y Ga 1-x-y The composition of N may be based on the value of x in the range of 0 to 0.1.

[0027] 3, bulk layer 335 may have a thickness greater than that of the individual pairs (e.g., pair of layers 326 and 327) in SLS structure 325. Bulk layer 335 may further include aspects described in connection with bulk layer 210 in FIG. 2. Active QW 340 includes, for example, a multiple quantum well (MQW) structure configured to emit light during operation of LED structure 300. The emitted light may be in an electromagnetic wavelength range, for example, in the visible spectrum. LED structure 300 also includes one or more p-layers 350 for providing electrical contact to LED structure 300.

[0028] 3, LED structure 300 is shown with SLS structure 325 positioned below bulk layer 335 in set 320, i.e., closer to semiconductor template 110 than bulk layer 335, or farther from active QW 340 than bulk layer 335. However, aspects presented herein may also be applied to the reverse order of the first and second layers within set 320.

[0029] 4 shows an exemplary LED structure 400 in which the strain management region 415 includes one or more sets 420 of bulk layers 335 and SLS structures 425. In each set 420, the SLS structures 425 are positioned above the bulk layers 335, e.g., farther from the semiconductor substrate 110 than the bulk layers 335 within each set 420. Additionally, FIG. 4 shows that the order of the first layer 326 and second layer 327 within the SLS structures 425 has been switched from the SLS structure 325 of FIG.

[0030] 5 shows an exemplary LED structure 500 including a superlattice structure designed to produce light emission at a shorter wavelength than the active QW layer if the superlattice were electrically addressed as an active region. As shown in FIG. 5, the LED structure 500 includes a semiconductor template 110 supporting a structure including the active QW 340 and p-layer 350, similar to the structures shown in FIGS. 3 and 4. In addition, the LED structure 500 includes a strain management region 515 including a UV superlattice (UVSL) stack 520. The UVSL stack 520 may be, for example, a bulk layer5 The bulk layer 535 may include a bulk layer 535 and a UVSL structure 525. The bulk layer 535 may be formed, for example, of an InGaN layer. The UVSL structure 525 may include, for example, a first layer 526 and a second layer 527 that are repeated to form the UVSL structure 525. By way of example, the UVSL structure 525 may be configured such that, if the layers are electrically addressed (i.e., if an appropriate voltage or current is applied across the UVSL structure 525), the layers will result in electromagnetic emission in the ultraviolet (UV) wavelength range. For example, the first layer 526 may be a thin InGaN layer having a thickness on the order of about 1 nanometer, and the second layer 527 may be a slightly thicker GaN layer having a thickness on the order of about a few nanometers. The first layer 526 and the second layer 527 may be repeated several times, such as 5 to 10 times. However, the UVSL structure 525 does not emit electromagnetic waves in the UV wavelength range because the LED structure 500 is electrically addressed with appropriate electrical input to cause light emission specifically from the active QWs 340, and not from the UVSL structure 525. That is, although the LED structure 500 is configured for light emission from the active QWs 340 and not from the UVSL structure 525, the presence of the strain management region 515 promotes improved strain management, defect reduction, and surface properties of the active QWs 340, thus resulting in improved light emission characteristics from the active QWs 340 compared to when the strain management region 515 is not included within the LED structure 500.

[0031] In one embodiment, the UVSL stack 520, including the UVSL structure 525 and the bulk layer 535, may be repeated two or more times within the strain management region 515. The In content of each of the first layer 526, the second layer 527, and / or the bulk layer 535 may be tailored for desired material properties and light-emitting performance from the active QW 340. Additional layers, such as electron blocking layers, buffer or spacer layers, and other functional layers, may also be included in the LED structure 500.

[0032] FIG. 6 shows another exemplary LED structure. LED structure 600 includes a semiconductor template 610, illustratively formed of n-GaN. LED structure 600 also includes a strain management region 615 formed on semiconductor template 610. Strain management region 615 includes, for example, a UVSL preparation layer 625 formed on semiconductor template 610. UVSL preparation layer 625 may include, for example, a combination of UVSL structure 525 and bulk layer 535 of FIG. 5 repeated two or more times within UVSL preparation layer 625. LED structure 600 also includes a blue QW structure 635. Blue QW structure 635 is, in one example, a multiple quantum well structure configured for emission in the blue wavelength range when blue QW structure 635 is electrically addressed with a voltage or current specifically suitable for blue emission. LED structure 600 further includes a red multiple quantum well (MQW) structure 640 and, finally, a p-GaN layer 650 for providing electrical contact to LED structure 600.

[0033] Again, the LED structure 600 is UVSL 6 Although the LED structure 600 is configured for emission from red MQW structure 640, rather than either UV or blue QW structure 635, the presence of strain management region 615 promotes improved strain management, defect reduction, and surface properties of red MQW structure 640, thus resulting in improved red emission characteristics compared to when strain management region 615 is not included within LED structure 600. While elements 625, 635, and 640 are described using specific wavelength descriptors, such as UV, blue, and red, an important factor is that the design wavelength of the superlattice and quantum well structures within non-emitting strain management region 615 is shorter than the intended emission wavelength from the active QW region, i.e., red MQW structure 640. For example, the use of UVSL 625 and blue QW structure 635 may improve emission performance even if red MQW region 640 were replaced with a multiple quantum well structure intended for emission in the orange, yellow, or green wavelength ranges.

[0034] It should be noted that additional intermediate layers, such as electron blocking layers, buffer or spacer layers, or other functional layers, may be included within LED structure 600. For example, LED structure 600 may optionally include a spacer layer 672 (e.g., formed from GaN), a barrier layer 674 (also formed from GaN, for example), or an electron blocking layer 676 (e.g., formed from AlGaN). The inclusion of such additional layers may be selected to provide functionality such as reduced current leakage, improved confinement of dopants within particular layers, improved surface properties, and reduced defects within the functional layers, particularly the active QW region.

[0035] The exemplary implementations shown in FIGS. 3-6 are non-exclusive, and LED structures may be based on any combination of the aspects shown in FIGS. 3-6. Furthermore, additional layers not shown in FIGS. 3-6, such as intermediate layers, may be included in LED structures 300, 400, 500, or 600 without departing from the spirit of the present disclosure. For example, the active QW 340 in the implementations shown in FIGS. 3-6 may be formed directly adjacent to the strain-management region 315, 415, 515, or 615, while in other implementations, one or more layers may be formed between the strain-management region and the active QW 340. For example, the additional layers described above with respect to LED structure 600 may be incorporated into any of LED structures 300, 400, and 500.

[0036] 7-9 show examples of LED structures having a combination of strain management regions formed as a planar device or an array of miniature LED devices according to aspects of the present disclosure. For example, planar LED structure 700 of FIG. 7 includes a planar substrate 710 having multiple layers 720 formed thereon. Planar substrate 710 and layers 720 may include the same or similar configurations as LED structures 300, 400, 500, and 600 shown in FIGS. 3-6.

[0037] In another example, the array 800 of FIG. 8 includes a plurality of LED structures 820 formed on a patterned substrate 830. The patterned substrate 830 includes raised pedestal regions 832 on which the LED structures 820 are formed and separated by lower recessed regions 834. For example, one or more of the LED structures 820 may first be formed like the LED structures 700 of FIG. 7, and then an etching process can be used to separate the LED structures into separate LED structures 820. The lower recessed regions 834 can, in some examples, serve to further electrically isolate adjacent LED structures 820, although the lower recessed regions 834 may optionally be removed such that the array 800 of a plurality of LED structures 820 is formed on a planar substrate (e.g., the planar substrate 710 of FIG. 7). Alternatively, the pedestals 832 may first be formed on the patterned substrate 830, and then the LED structures 820 can be formed on the pedestals 832, for example, by a masked deposition process. LED structure 820 may include the same or similar components as LED structures 300, 400, 500, and 600 shown in FIGS.

[0038] In yet another example, the array 900 of FIG. 9 includes a plurality of LED structures 920 formed on a patterned substrate 940. The patterned substrate 940 includes lower recessed regions 942, separated by raised regions 944, in which the LED structures 920 are formed. As an example, the recessed regions 942 may first be formed using a masked etching process, and then the LED structures 920 may be formed therein in a masked deposition process. The LED structures 920 may include the same or similar configuration as the LED structures 300, 400, 500, and 600 shown in FIGS. 3-6. As an example, the recessed regions 942 may have a diameter of 1 micron or less. In other examples, the recessed regions may have a diameter greater than 1 micron. The specific size of the recesses is presented merely to illustrate potential applications of the concepts presented herein; again, the concepts described above may be applied to LED structures of any size.

[0039] Although only a portion of an LED structure is shown in FIGS. 3-9, the concepts presented herein may be applied to planar and non-planar LED structures.

[0040] FIG. 10 illustrates a top view of an exemplary LED array 1000 according to aspects of the present disclosure. The LED array 1000 illustratively includes a plurality of LED structures 1010, 1020, and 1030, emitting light at red, green, and blue wavelengths, respectively, supported on a substrate 1040. The array may be part of a light-emitting device, for example, forming or being part of a display, where the arrangement of pixels, their shape, their number, their size, and their corresponding wavelength emissions can be tailored for a particular application. As mentioned above, the display can be a high-resolution, high-density display, such as those used in light-field applications. Any of the LED structures 1010, 1020, and / or 1030 may be formed using aspects described in connection with FIGS. 3-9.

[0041] 11 shows a simplified flowchart illustrating a method 1100 of fabricating an LED structure according to an aspect of the present disclosure. In step 1110, method 1100 includes forming a strain management region. Step 1110 may include aspects described in connection with FIGS. 3-9. In step 1120, method 1100 includes forming an active region configured to generate light associated with the LED structure.

[0042] Further details of an exemplary embodiment of step 1110 of method 1100 are shown in FIG. 12. As shown in the example illustrated in FIG. 12, in an embodiment, step 1110 further includes forming a first preparation layer structure in step 1210. The first preparation layer structure may include, for example, a superlattice structure (e.g., SLS structure 325) or a bulk layer (e.g., bulk layer 335), as described above. Step 1110 also includes forming a second preparation layer structure in step 1220. The second preparation layer structure may also include, for example, a superlattice structure (e.g., SLS structure 325) or a bulk layer (e.g., bulk layer 335). Decision 1230 is made to determine whether additional preparation layers are desired for the particular LED structure being formed. If the answer to decision 1230 is YES, more preparation layers are needed, and then the process returns to step 1210. If the answer to decision 1230 is NO, and more preparation layers are not needed, the process returns to step 1210 of method 1100 of FIG. 11. 1 Go to 20.

[0043] This disclosure describes various techniques and structures that enable the use of strain management structures within light emitting devices (eg, LEDs) for improved light emitting performance from the devices.

[0044] Therefore, although the present disclosure has been provided in accordance with the illustrated implementations, those skilled in the art will readily recognize that there may be variations to the embodiments, and that these variations are within the scope of the present disclosure. Accordingly, many modifications may be made by those skilled in the art without departing from the scope of the claims.

Claims

1. 1. An indium gallium nitride light emitting diode (LED) structure formed on a substrate, the indium gallium nitride LED structure comprising: a strain management region supported on the substrate; an active region configured to emit light having a wavelength range in the visible spectrum; the strain management region is formed between the substrate and the active region and includes multiple sets of multiple layers; Each of the plurality of sets of the plurality of layers comprises: a first layer including a superlattice having a plurality of repeating first sublayers and a plurality of second sublayers; a second layer comprising a bulk layer; the first layer is positioned farther from the active region than the second layer; At least one of the plurality of first sublayers and the plurality of second sublayers or the bulk layer of the strain management region is made of In ｘ Al ｙ Ga １－ｘ－ｙ Indium gallium nitride LED structure, including a composition of N.

2. 10. The indium gallium nitride LED structure of claim 1, wherein the first layer is disposed adjacent to the substrate.

3. In of the bulk layer ｘ Al ｙ Ga １－ｘ－ｙ 3. The indium gallium nitride LED structure of claim 1 or claim 2, wherein the composition of N is based on a value of x ranging from 0 to 0.

15.

4. In of the plurality of first sublayers ｘ Al ｙ Ga １－ｘ－ｙ 3. The indium gallium nitride LED structure of claim 1 or claim 2, wherein the composition of N is based on a value of x ranging from 0 to 0.

3.

5. In of the plurality of second sublayers ｘ Al ｙ Ga １－ｘ－ｙ 3. The indium gallium nitride LED structure of claim 1 or claim 2, wherein the composition of N is based on a value of x ranging from 0 to 0.

1.

6. An indium gallium nitride LED structure as described in any one of claims 1 to 3, wherein the plurality of first sublayers are GaN layers and the plurality of second sublayers are InGaN layers.

7. 7. The indium gallium nitride LED structure of claim 1, wherein the active region comprises at least one quantum well.

8. The indium gallium nitride LED structure of claim 7, further comprising a GaN barrier layer between the strain management region and the at least one quantum well.

9. a semiconductor template; an array of light emitting structures supported on the semiconductor template, wherein at least one light emitting structure of the array of light emitting structures comprises: an active region configured to emit light having a wavelength range in the visible spectrum; a strain management region formed between the semiconductor template and the active region, the strain management region including multiple sets of multiple layers; Each of the plurality of sets of the plurality of layers comprises: a first layer including a superlattice having a plurality of repeating first sublayers and a plurality of second sublayers; a second layer comprising a bulk layer; the first layer is positioned farther from the active region than the second layer; At least one of the plurality of first sublayers and the plurality of second sublayers or the bulk layer of the strain management region is made of In ｘ Al ｙ Ga １－ｘ－ｙ An indium gallium nitride light emitting device comprising a composition of N.

10. 10. The indium gallium nitride light emitting device of claim 9, wherein the first layer is disposed adjacent to the semiconductor template.

11. In of the bulk layer ｘ Al ｙ Ga １－ｘ－ｙ 11. The indium gallium nitride light emitting device of claim 9 or claim 10, wherein the composition of N is based on a value of x ranging from 0 to 0.

15.

12. In of the plurality of first sublayers ｘ Al ｙ Ga １－ｘ－ｙ 11. The indium gallium nitride light emitting device of claim 9 or claim 10, wherein the composition of N is based on a value of x ranging from 0 to 0.

3.

13. In of the plurality of second sublayers ｘ Al ｙ Ga １－ｘ－ｙ 11. The indium gallium nitride light emitting device of claim 9 or claim 10, wherein the composition of N is based on a value of x ranging from 0 to 0.

1.

14. An indium gallium nitride light-emitting device as described in any one of claims 9 to 11, wherein the plurality of first sublayers are GaN layers and the plurality of second sublayers are InGaN layers.

15. 15. The indium gallium nitride light emitting device of claim 9, wherein the active region comprises at least one quantum well.

16. The indium gallium nitride light-emitting device of claim 15, further comprising a GaN barrier layer between the strain management region and the at least one quantum well.

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