US20050023549A1 - Semiconductor light emitting devices - Google Patents

Semiconductor light emitting devices Download PDF

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US20050023549A1
US20050023549A1 US10633058 US63305803A US2005023549A1 US 20050023549 A1 US20050023549 A1 US 20050023549A1 US 10633058 US10633058 US 10633058 US 63305803 A US63305803 A US 63305803A US 2005023549 A1 US2005023549 A1 US 2005023549A1
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layer
device
type
textured
contact
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US6847057B1 (en )
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Nathan Gardner
Jonathan Wierer
Gerd Mueller
Michael Krames
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Lumileds LLC
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Lumileds LLC
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    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L33/00Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/36Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the electrodes
    • H01L33/40Materials therefor
    • H01L33/405Reflective materials
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L33/00Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/0004Devices characterised by their operation
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L33/00Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/02Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
    • H01L33/20Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies with a particular shape, e.g. curved or truncated substrate
    • H01L33/22Roughened surfaces, e.g. at the interface between epitaxial layers

Abstract

A III-nitride device includes a first n-type layer, a first p-type layer, and an active region separating the first p-type layer and the first n-type layer. The device may include a second n-type layer and a tunnel junction separating the first and second n-type layers. First and second contacts are electrically connected to the first and second n-type layers. The first and second contacts are formed from the same material, a material with a reflectivity to light emitted by the active region greater than 75%. The device may include a textured layer disposed between the second n-type layer and the second contact or formed on a surface of a growth substrate opposite the device layers.

Description

    BACKGROUND
  • [0001]
    1. Field of Invention
  • [0002]
    This invention relates to semiconductor light emitting devices and, in particular, to III-nitride semiconductor light emitting devices incorporating tunnel junctions and scattering structures.
  • [0003]
    2. Description of Related Art
  • [0004]
    Semiconductor light-emitting devices including light emitting diodes (LEDs), resonant cavity light emitting diodes (RCLEDs), vertical cavity laser diodes (VCSELs), and edge emitting lasers are among the most efficient light sources currently available. Materials systems currently of interest in the manufacture of high-brightness light emitting devices capable of operation across the visible spectrum include Group III-V semiconductors, particularly binary, ternary, and quaternary alloys of gallium, aluminum, indium, and nitrogen, also referred to as III-nitride materials. Typically, III-nitride light emitting devices are fabricated by epitaxially growing a stack of semiconductor layers of different compositions and dopant concentrations on a sapphire, silicon carbide, III-nitride, or other suitable substrate by metal-organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), or other epitaxial techniques. The stack often includes one or more n-type layers doped with, for example, Si, formed over the substrate, a light emitting or active region formed over the n-type layer or layers, and one or more p-type layers doped with, for example, Mg, formed over the active region. III-nitride devices formed on conductive substrates may have the p- and n-contacts formed on opposite sides of the device. Often, III-nitride devices are fabricated on insulating substrates, such as sapphire, with both contacts on the same side of the device. Such devices are mounted so light is extracted either through the contacts (known as an epitaxy-up device) or through a surface of the device opposite the contacts (known as a flip chip device).
  • SUMMARY
  • [0005]
    In accordance with embodiments of the invention, a III-nitride device includes a first n-type layer, a first p-type layer, and an active region separating the first p-type layer and the first n-type layer. In some embodiments, the device includes a second n-type layer and a tunnel junction separating the first and second n-type layers. First and second contacts are electrically connected to the first and second n-type layers. The first and second contacts are formed from the same material, a material with a reflectivity to light emitted by the active region of at least 75%. In some embodiments, the device includes a textured layer. In devices including both a textured layer and a tunnel junction, the textured layer may be disposed between the second n-type layer and the second contact. In devices lacking a tunnel junction, the device may include a substrate, and the textured layer may be formed on a surface of the substrate opposite the device layers.
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • [0006]
    FIG. 1 illustrates a III-nitride flip chip light emitting device.
  • [0007]
    FIGS. 2 and 3 illustrate devices including tunnel junctions.
  • [0008]
    FIG. 4 is a plot of series resistance and barrier voltage vs. temperature for two displaced Al contacts on n-GaN.
  • [0009]
    FIG. 5 illustrates a multilayer contact.
  • [0010]
    FIG. 6 is a plot of the calculated reflectivity of aluminum and silver as a function of wavelength.
  • [0011]
    FIGS. 7A, 7B, and 8 illustrate devices including scattering structures.
  • [0012]
    FIGS. 9 and 10 illustrate a plan view and a cross sectional view of a small junction light emitting device.
  • [0013]
    FIGS. 11 and 12 illustrate a plan view and a cross sectional view of a large junction light emitting device.
  • [0014]
    FIGS. 13 and 14 illustrate a plan view and a cross sectional view of a top emitting light emitting device.
  • [0015]
    FIG. 15 illustrates a packaged light emitting device.
  • [0016]
    FIG. 16 illustrates external quantum efficiency as a function of current for two devices according to FIGS. 13 and 14, one with a textured layer and one without a textured layer.
  • DETAILED DESCRIPTION
  • [0017]
    FIG. 1 illustrates an example of a III-nitride flip chip device including a sapphire substrate 1, an n-type region 2, an active region 3, and a p-type region 4. A portion of the p-type region and active region are etched away to expose a part of n-type region 2. An n-contact 10 is formed on the exposed part of n-type region 2. A p-contact 9 is formed on the remaining part of p-type region 4.
  • [0018]
    Several factors limit the amount of light that can be produced and usefully extracted by the device of FIG. 1.
  • [0019]
    First, the use of a silver p-contact limits the maximum junction temperature at which the device of FIG. 1 may operate. The contact area of the p-contact is generally larger than that of the n-contact, in order to maximize the light emitting area of the device since formation of the n-contact requires etching away a portion of the active region. Contacts 9 and 10 are selected for low contact resistivity, in order to minimize the voltage that must be applied to the device, and for high reflectivity, in order to reflect light incident on the contacts back into the device so it may be extracted through the substrate 1 of the flip chip of FIG. 1. Since the p-contact is generally larger than the n-contact, it is particularly important that the p-contact be highly reflective. The combination of high reflectivity and low contact resistivity has been difficult to achieve for the p-contact of III-nitride devices such as the device illustrated in FIG. 1. For example, aluminum is reasonably reflective but does not make good ohmic contact to p-type III-nitride materials. Silver is often used because it makes a good p-type ohmic contact and is very reflective, but silver suffers from poor adhesion to III-nitride layers and from susceptibility to electro-migration which can lead to catastrophic device failure. In order to avoid the problem of electro-migration in a silver contact, the contact may be protected by one or more layers of metal. To increase the light output of a device, the current through the device must be increased. As the current increases, the operating temperature of the device increases. At temperatures greater than 250° C., the difference in the coefficient of thermal expansion between the protective layer over the silver p-contact and the silver p-contact itself can cause the p-contact to delaminate from the semiconductor layers of the device, resulting in unacceptably high forward voltage and non-uniform light output. This limits the maximum current density and ultimately the light output of the device.
  • [0020]
    Second, the high index of refraction of III-nitride layers (n˜2.4) create several interfaces with a large contrast in index of refraction; for example, the interface between the sapphire substrate (n˜1.8) and the III-nitride layers. Interfaces with large contrasts in index of refraction tend to trap light inside the device.
  • [0021]
    In accordance with embodiments of the invention, structures are provided that may increase the maximum operating temperature of the device and interrupt interfaces which trap light in the device, thereby potentially increasing the amount of light generated in and usefully extracted from the device. The examples described below are III-nitride light emitting devices. The semiconductor layers of III-nitride devices have the general formula AlxInyGazN, where 0≦x≦1, 0≦y≦1, 0≦z≦1, x+y+z=1. III-nitride device layers may further contain group III elements such as boron and thallium and may have some of the nitrogen may be replaced by phosphorus, arsenic, antimony, or bismuth. Though the examples below describe III-nitride devices, embodiments of the invention may also be fabricated in other III-V materials systems including III-phosphide and III-arsenide, II-VI material systems, and any other materials systems suitable for making light emitting devices.
  • [0022]
    FIGS. 2 and 3 illustrate a first embodiment of the invention. In the device of FIG. 2, after the formation of n-type region 2, active region 3, and p-type region 4 on a suitable substrate 1, a tunnel junction 100 is formed, then another n-type layer 7. FIG. 3 illustrates an alternative implementation of a device incorporating a tunnel junction. Tunnel junction 100 of FIG. 3 is located beneath the active region, rather than above the active region as in the implementation shown in FIG. 2. Tunnel junction 100 of FIG. 3 is located between n-type layer 2 and p-type layer 4. Thus, the polarity of the device in FIG. 3 is the opposite of the polarity of the device in FIG. 2. Tunnel junction 100 allows for a conductivity change in the material grown above the tunnel junction as compared to the material below.
  • [0023]
    Tunnel junction 100 includes a heavily doped p-type layer 5, also referred to as a p++ layer, and a heavily doped n-type layer 6, also referred to as an n++ layer. P++ layer 5 may be, for example, InGaN or GaN for a blue-emitting device or AlInGaN or AlGaN for a UV-emitting device, doped with an acceptor such as Mg or Zn to a concentration of about 1018 cm−3 to about 5×1020 cm−3. In some embodiments, p++ layer 5 is doped to a concentration of about 2×1020 cm−3 to about 4×1020 cm−3. N++ layer 6 may be, for example, InGaN or GaN for a blue-emitting device or AlInGaN or AlGaN for a UV-emitting device, doped with a donor such as Si, Ge, Se, or Te to a concentration of about 1018 cm−3 to about 5×1020 cm−3. In some embodiments, n++ layer 6 is doped to a concentration of about 7×1019 cm−3 to about 9×1019 cm−3. Tunnel junction 100 is usually very thin, for example tunnel junction 100 may have a total thickness ranging from about 2 nm to about 100 nm, and each of p++ layer 5 and n++ layer 6 may have a thickness ranging from about 1 nm to about 50 nm. In some embodiments, each of p++ layer 5 and n++ layer 6 may have a thickness ranging from about 25 nm to about 35 nm. P++ layer 5 and n++ layer 6 may not necessarily be the same thickness. In one embodiment, p++ layer 5 is 15 nm of Mg-doped InGaN and n++ layer 6 is 30 nm of Si-doped GaN. P++ layer 5 and n++ layer 6 may have a graded dopant concentration. For example, a portion of p++ layer 5 adjacent to the underlying p-layer 4 may have a dopant concentration that is graded from the dopant concentration of the underlying p-type layer to the desired dopant concentration in p++ layer 5. Similarly, n++ layer 6 may have a dopant concentration that is graded from a maximum adjacent to p++ layer 5 to a minimum adjacent to n-type layer 7. Tunnel junction 100 is fabricated to be thin enough and doped enough such that tunnel junction 100 is near ohmic when reverse-biased, i.e. tunnel junction 100 displays low series voltage drop and low resistance when conducting current in reverse-biased mode. In some embodiments, the voltage drop across tunnel junction 100 when reverse-biased is about 0.1V to about 1V at current densities of 200 A/cm2.
  • [0024]
    Tunnel junction 100 is fabricated such that when a voltage is applied across contacts 9 and 10 such that the p-n junction between active region 3 and p-type layer 4 is forward biased, tunnel junction 100 quickly breaks down and conducts in the reverse-bias direction with a minimal voltage drop. Each of the layers in tunnel junction 100 need not have the same composition, thickness, or dopant composition. Tunnel junction 100 may also include an additional layer between p++ layer 5 and n++ layer 6 that contains both p- and n-type dopants.
  • [0025]
    A light emitting device incorporating a tunnel junction permits the use of two n-contacts rather than different n- and p-contacts, since both contacts are formed on n-type layers, layers 2 and 7. The use of two n-contacts eliminates the silver p-contact described above and resulting limitation on maximum operating temperature. Any n-contact with a reflectivity to light emitted by the active region greater than 75% may be used in a flip chip device. An example of a suitable n-contact is aluminum. Aluminum makes low resistance contact to both etched and unetched n-type III-nitride. FIG. 6 illustrates the calculated reflectivity of aluminum vs. silver at wavelengths between 250 and 550 nm. FIG. 6 demonstrates that aluminum has high reflectivity over the illustrated range, and is more reflective than silver in UV wavelengths. Since both contacts may be the same material, some deposition and etching steps required to deposit different contact materials on the p- and n-regions of the device may potentially be eliminated.
  • [0026]
    Tunnel junction 100 also acts as a hole spreading layer to distribute positive charge carriers in p-type layer 4. Carriers in n-type III-nitride material have a much longer diffusion length than carriers in p-type III-nitride material, thus current can spread more readily in an n-type layer than a p-type layer. Since current spreading on the p-side of the p-n junction occurs in n-type layer 7, the devices illustrated in FIGS. 2 and 3 may have better p-side current spreading than a device lacking a tunnel junction.
  • [0027]
    FIG. 4 illustrates the performance of a test device with aluminum contacts. Current vs. voltage measurements were taken between two contacts both deposited on the same n-layer, and the resistance and barrier voltage (the smallest voltage necessary to pass non-zero current) were recorded. As illustrated in FIG. 4, there is little change in both the resistance and the barrier voltage as temperature increases to 600° C., indicating a stable contact.
  • [0028]
    The contacts illustrated in FIGS. 2 and 3 may be single or multilayer contacts. Single layer contacts may have a thickness ranging between about 0.5 and about 5 microns. An example of a multilayer contact is illustrated in FIG. 5. The contact 9 illustrated in FIG. 5 has two layers, an aluminum layer 9A between about 750 Å and about 5000 Å thick that provides a high quality reflector, and an aluminum alloy layer 9B between about 0.5 microns and about 5 microns thick. Alloy layer 9B prevents electro-migration of the aluminum in layer 9A at high current density. The elements in alloy layer 9B other than aluminum may be present in small amounts just large enough to fill in grain boundaries in the aluminum, for example, less than 5%. Examples of suitable alloys are Al—Si, Al—Si—Ti, Al—Cu, and Al—Cu—W. The composition of layers 9A and 9B may be selected to have similar coefficients of thermal expansion to avoid stress-related delamination at elevated temperatures.
  • [0029]
    FIGS. 7A and 7B illustrate embodiments of a device including a textured layer to improve the extraction of photons from the device. Textured layer 12 is formed over second n-type layer 7. Since the textured layer is typically of the same conductivity type as the nearest underlying layer, in the embodiment illustrated in FIGS. 7A and 7B, textured layer 12 is an n-type layer, though in other embodiments a p-type layer may be textured. Textured layer 12 may be composed of any III-N semiconductor, although it is often GaN or a composition of AlInGaN that is transparent to the light emitted by the active region. Textured layer 12 interrupts the smooth surface of the III-nitride layers and scatters light out of the device. Textured layer 12 may be formed by several techniques known in the art. For example, a textured layer may be formed by depositing a SiNe “nanomask,” that is, a thin layer of SiNx of varying coverage, on the device prior to growth of the textured layer. The presence of Si on the device changes the growth mode of subsequently grown GaN from two dimensional to three dimensional, resulting in a textured surface. The characteristics of the textured layer can be adjusted by varying the thickness of the nanomask and by the growth conditions used to deposit GaN on top of the nanomask, and is known in the art.
  • [0030]
    In the embodiment illustrated in FIG. 7A, textured layer 12 includes pyramids or pillars of semiconductor material separated by pockets 16 which may be filled with air or another material with a low index of refraction as compared to III-nitride materials. For example, a low index of refraction material may have an index of refraction less than about 2. Layer 12 may have a thickness of about 200 Å to about 10,000 Å, usually between about 500 Å and about 4000 Å. The ratio of pockets to material may vary from about 10% of the volume of layer 12 as pockets, up to about 90% of the volume of layer 12 as pockets, with the volume of layer 12 as pockets usually between about 50% and about 90%.
  • [0031]
    In the embodiments illustrated in FIGS. 7A and 7B, a contact is formed over textured layer 12. Contact 9 may be deposited on textured layer 12 by, for example, evaporation or sputtering, to form a conformal layer over textured layer 12, as illustrated in FIG. 7B. In the embodiment illustrated in FIG. 7A, a material with a low index of refraction may be deposited over textured layer 12 in pockets 16 as a thick layer, then patterned to open holes in the low index material down to the textured layer 12. Contact 13 may then be deposited by, for example, evaporation or sputtering. Alternatively, contact 13 of FIG. 7A may be a smooth metal mirror that is bonded to textured layer 12, trapping air in pockets 16. Mirror 13 may be formed by depositing a film of reflective metal on a host substrate with thermal properties similar to the device, such as, for example, GaN, GaAs, Al2O3, Cu, Mo, or Si. The mirror/host substrate combination is then bonded, at elevated temperature (for example, between about 200° C. and about 1,000° C.) and pressure (for example, between about 50 psi and about 500 psi), to a cleaned surface of the LED wafer such that the metal mirror faces the textured surface of the LED wafer. Thin metal layers or layers of a transparent material such as indium tin oxide may be deposited on the textured surface prior to bonding. Also, the air pockets in textured layer 12 may be filled with a low-index-of-refraction dielectric, such as MgF, prior to bonding of the mirror. The mirror material and the bonding method are selected such that the forward voltage of the device is not substantially affected by mirror 13.
  • [0032]
    An optional polarization selection layer 14 that polarizes the photons emitted by the active region, such as a wire grid polarizer, may be formed on a side of the substrate opposite the device layers. Wire grid polarizers are explained in more detail in U.S. Pat. Nos. 6,122,103 and 6,288,840, both of which are incorporated herein by reference. Wire grid polarizers reflect photons of a polarization that is parallel to the wires, and transmit photons of a polarization that is perpendicular to the wires. If a photon is emitted from the active region and has a polarization that causes it to be reflected from the wire grid polarizer, it will propagate towards the textured surface. Upon reflecting from the textured surface, the direction of polarization of the photon will be changed, possibly allowing the photon to pass through the polarizer. The light emitted outside the device, then, will be linearly polarized. The combination of the wire grid polarizer and reflecting textured surface recycles photons until they achieve a certain polarization. Polarization selection layer 14 may be formed at any stage of the processing, and is often formed as the last processing step, prior to singulating the dice from the wafer. A wire grid polarizer may be formed by the following method: a layer of metal is deposited on the wafer, followed by a layer of photoresist over the metal. The photoresist is patterned by exposing it to radiation, for example by shining short-wavelength light through a photomask with the wire-grid polarizer pattern already formed on it, by using the interference pattern from two laser beams to project an array of lines of light of varying intensity onto the photoresist, or by drawing the wire-grid polarizer pattern on the photoresist with an electron beam. Once the photoresist is exposed, it is developed and rinsed, resulting in lines of photoresist remaining on the metal layer. The metal layer is etched by chemicals (wet etching), a reactive ion beam (RIE), a plasma-enhanced reactive ion beam, an inductively-coupled plasma (ICP), or other appropriate technique known in the art. The remaining photoresist is then chemically stripped from the wafer, resulting in a pattern of metal lines remaining on the wafer. The periodicity of wires in a wire grid polarizer may be optimized for the wavelength of emission of the device, resulting in very high reflecting efficiency.
  • [0033]
    Tunnel junction devices incorporating any of scattering layer 12, bonded metal layer 13, and polarizing grid 14 may also be formed in a device with the polarity reversed from the devices shown in FIGS. 7A and 7B, as illustrated in FIG. 3.
  • [0034]
    Growth of a textured layer on a device with a tunnel junction may offer several advantages. The tunnel junction in the device of FIGS. 7A and 7B permits growth of textured layer 12 on an n-type layer. Texturing p-type III-nitride layers has several disadvantages. First, scattering layers etched into p-type nitride layers generally do not provide a surface suitable for electrical contact. Contacts formed on such scattering layers often add significantly to the forward voltage of the device and exhibit poor reliability. Also, the formation of a p-type textured layer on a p-type layer by a SiNe nanomask is problematic because the presence of the donor Si in the nanomask is likely to result in the formation of a p-n junction, which will increase the forward bias voltage of the LED. Further, the pockets in a p-type textured layer would undesirably reduce the amount of p-type material available for current spreading. Formation of a textured layer on n-type layer 7 may eliminate the above-described electrical and reliability problems of textured layers formed on p-type III-nitride layers.
  • [0035]
    The tunnel junction of FIGS. 7A and 7B also allows the textured layer to be located above the active region of the device, permitting growth of the active region before growth of the textured layer. Since the dislocation density of textured III-nitride layers tends to be greater than the dislocation density in a smooth III-nitride layer, it is difficult to grow a high-quality active region on a textured surface. The use of a tunnel junction avoids both texturing a p-type region and texturing a region grown before the active region.
  • [0036]
    Bonding a mirror 13 to a textured layer 12 also may improve the light extraction in the device. Bonding a flat mirror onto textured layer 12 produces air pockets 16 between the mirror and the scattering layer. These air pockets also function as scattering centers. Such air pockets may not be formed if the contact is deposited by traditional techniques such as sputtering, evaporation, or electroplating, rather than by bonding.
  • [0037]
    The use of textured layer 12 with polarization selection layer 14 where polarization is desired may eliminate some inefficiencies associated with traditional polarizers, which function by absorbing light of the incorrect polarization. Textured layer 12 acts as a polarization randomizer. When photons of undesirable polarization reflect off polarization selection layer 14, they may reflect again off textured layer 12 which changes the polarization direction of the photons. After one or more reflections between polarization selection layer 14 and textured layer 12, the photons may acquire the correct polarization to pass through the polarizer. Thus, photons which are emitted from the active region with an incorrect polarization can eventually acquire the correct polarization. In the case where an external absorbing polarizer is used, photons with initially incorrect polarization are absorbed and therefore lost. In the case where no textured layer is present, there will be little randomization of the polarization direction of the reflected, incorrectly polarized light. Therefore this light will reflect back and forth inside the LED until it is ultimately absorbed and lost.
  • [0038]
    FIG. 8 illustrates an alternative embodiment of a device including a textured structure to improve the extraction of photons from the device. Textured structure 12 is formed on the back of substrate 1, opposite the device layers. In this embodiment, the substrate must have a refractive index substantially higher than the ambient medium, so that most light from the active region interacts with the textured surface. The refractive index of the substrate should be greater than 1.8. Therefore, substrate 1 is typically SiC (n˜2.5). The device illustrated in FIG. 8 does not require a tunnel junction. Textured structure 12 may be, for example, a rough n-type GaN layer. Both p- and n-contacts are formed on the side of the substrate opposite the texturing. The textured layer may be deposited by epitaxial growth prior to growth of the LED device layers on the opposing side of the substrate. The characteristic features of the texturing are identical to those described above in reference to FIGS. 7A and 7B.
  • [0039]
    FIG. 9 is a plan view of a small junction device (i.e. an area less than one square millimeter). FIG. 10 is a cross section of the device shown in FIG. 9, taken along axis CC. FIGS. 9 and 10 illustrate an arrangement of contacts that may be used with any of the epitaxial structures 20 illustrated in FIGS. 2, 3, 7A, 7B and 8. The device shown in FIGS. 9 and 10 has a single via 21 etched down to an n-type layer of epitaxial structure 20 below the active region. An n-contact 10 is deposited in via 21. N-via 21 is located at the center of the device to provide uniformity of current and light emission. A p-contact 9 provides electrical contact to the p-side of the active region of epitaxial structure 20. In embodiments with a tunnel junction, p-contact 9 may be formed on an n-type layer and may be the same structure and material as n-contact 10. In other embodiments, p-contact 9 may be formed on a p-type layer and may be a bonded layer 13 as illustrated in FIG. 7A. In still other embodiments, p-contact 9 includes an optional guard metal layer (not shown) covering a thin p-contact, and a thick p-metal layer deposited over the guard metal layer. N-contact 10 is separated from the p-contact 9 by one or more dielectric layers 22. A p-submount connection 24, for example, a wettable metal for connecting to solder, connects to p-contact 9 and an n-submount connection 23 connects to n-contact 10.
  • [0040]
    As illustrated in FIG. 9, the device is connected to a submount by three submount connections, two p-submount connections 24 and one n-submount connection 23. N-submount connection 23 may be located anywhere within n-contact region 10 (surrounded by insulating layer 22) and need not be located directly over via 21. Similarly, p-submount connections 24 may be located anywhere on p-contact 9. As a result, the connection of the device to a submount is not limited by the shape or placement of p-contact 9 and n-contact 10.
  • [0041]
    FIG. 11 is a plan view of a large junction device (i.e. an area greater than or equal to one square millimeter). FIG. 12 is a cross section of the device shown in FIG. 11, taken along axis DD. FIGS. 11 and 12 also illustrate an arrangement of contacts that may be used with any of the epitaxial structures 20 illustrated in FIGS. 2, 3, 7A, 7B, and 8. The active region of epitaxial structure 20 is separated into four regions separated by three trenches in which n-contacts 10 are formed. Each region is connected to a submount by four p-submount connections 24 formed on p-contact 9. As described above, in devices including a tunnel junction, p-contact 9 may be formed on an n-type layer and may be the same structure and materials as n-contact 10. In other embodiments, p-contact 9 may be formed on a p-type layer and may have a structure or material different from n-contact 10, or p-contact 9 may be a bonded layer 13 as illustrated in FIG. 7A. N-contact 10 surrounds the four active regions. N-contact 10 is connected to a submount by six n-submount connections 23. The n- and p-contacts may be electrically isolated by an insulating layer 22.
  • [0042]
    The devices illustrated in FIGS. 9-12 are typically mounted in flip chip configuration, such that most of the light exiting the device exits through the growth substrate 1. FIGS. 13 and 14 illustrate a top emitting device, where most of the light exiting the device exits through the top surface of the epitaxial layers, the same surface on which the contacts are formed. FIG. 13 is a plan view of the top emitting device. FIG. 14 is a cross sectional view of a portion of FIG. 13, along axis E. Though FIG. 14 shows a textured top epitaxial layer, epitaxial layers 20 may be any of the epitaxial structures shown in FIGS. 2, 3, 7A, 7B and 8. Fingers of p-contact 9 interpose fingers of n-contact 10. The area covered by contacts 9 and 10 may be minimized if contacts 9 and 10 are formed from a material that is absorbing to light emitted by the active region of the device. The device may be wire bonded to the leads of a package.
  • [0043]
    FIG. 16 illustrates the relative external quantum efficiency (a.u.) as a function of current for two devices like the device illustrated in FIGS. 13 and 14, one with a textured layer formed over a tunnel junction and one with a tunnel junction but no textured layer. The dashed line in FIG. 16 represents the device with a textured layer and the solid line represents the device without a textured layer. As illustrated in FIG. 16, the device including a textured layer has a higher external quantum efficiency than the device without the textured layer, indicating that the textured layer contributes to the amount of light extracted from the device.
  • [0044]
    FIG. 15 is an exploded view of a packaged light emitting device. A heat-sinking slug 100 is placed into an insert-molded leadframe 106. The insert-molded leadframe 106 is, for example, a filled plastic material molded around a metal frame that provides an electrical path. Slug 100 may include an optional reflector cup 102. The light emitting device die 104, which may be any of the devices described above, is mounted directly or indirectly via a thermally conducting submount 103 to slug 100. An optical lens 108 may be added.
  • [0045]
    Having described the invention in detail, those skilled in the art will appreciate that, given the present disclosure, modifications may be made to the invention without departing from the spirit of the inventive concept described herein. Therefore, it is not intended that the scope of the invention be limited to the specific embodiments illustrated and described.

Claims (50)

  1. 1. A III-nitride light emitting device comprising:
    a first layer of first conductivity type;
    a first layer of second conductivity type;
    an active region;
    a tunnel junction, the tunnel junction comprising:
    a second layer of first conductivity type having a dopant concentration greater than the first layer of first conductivity type; and
    a second layer of second conductivity type having a dopant concentration greater than the first layer of second conductivity type;
    a third layer of first conductivity type;
    a first contact electrically connected to the first layer of first conductivity type; and
    a second contact electrically connected to the third layer of first conductivity type;
    wherein:
    the first and second contacts comprise the same material;
    the first and second contact material has a reflectivity to light emitted by the active region greater than 75%;
    the active region is disposed between a layer of first conductivity type and a layer of second conductivity type; and
    the tunnel junction is disposed between the first layer of first conductivity type and the third layer of first conductivity type.
  2. 2. The device of claim 1 wherein:
    the second layer of first conductivity type has a dopant concentration ranging from about 1018 cm−3 to about 5×1020 cm−3; and
    the second layer of second conductivity type has a dopant concentration ranging from about 1018 cm−3 to about 5×1020 cm−3.
  3. 3. The device of claim 1 wherein the second layer of first conductivity type has a dopant concentration ranging from about 2×1020 cm−3 to about 4×1020 cm−3.
  4. 4. The device of claim 1 wherein the second layer of second conductivity type has a dopant concentration ranging from about 7×1019 cm−3 to about 9×1019 cm−3.
  5. 5. The device of claim 1 wherein the tunnel junction has a voltage drop ranging from between about 0V to about 1V when operated in reverse-biased mode.
  6. 6. The device of claim 1 wherein the tunnel junction has a voltage drop ranging from between about 0.1V to about 1V when operated in reverse-biased mode.
  7. 7. The device of claim 1 wherein:
    the second layer of first conductivity type has a thickness ranging from about 1 nm to about 50 nm; and
    the second layer of second conductivity type has a thickness ranging from about 1 nm to about 50 nm.
  8. 8. The device of claim 1 wherein the tunnel junction has a thickness ranging from about 2 nm to about 100 nm.
  9. 9. The device of claim 1 further comprising a textured layer disposed between the third layer of first conductivity type and the second contact.
  10. 10. The device of claim 9 wherein the textured layer comprises islands of semiconductor material and pockets between the islands.
  11. 11. The device of claim 10 wherein the islands of semiconductor material comprise about 10% to about 90% of a volume of the textured layer.
  12. 12. The device of claim 10 wherein the islands of semiconductor material comprise about 10% to about 50% of a volume of the textured layer.
  13. 13. The device of claim 10 wherein the pockets are filled with air.
  14. 14. The device of claim 10 wherein the pockets are at least partially filled with a material having an index of refraction less than about 2.
  15. 15. The device of claim 10 wherein the second contact is formed over the textured layer and fills the pockets.
  16. 16. The device of claim 9 wherein the textured layer has a thickness between about 200 Å and about 10,000 Å.
  17. 17. The device of claim 9 wherein the textured layer has a thickness between about 500 Å and about 4000 Å.
  18. 18. The device of claim 9 wherein the second contact is bonded to the textured layer.
  19. 19. The device of claim 18 further comprising at least one void disposed between the textured layer and the second contact.
  20. 20. The device of claim 1 further comprising:
    a submount;
    a first interconnect connecting the first contact to the submount; and
    a second interconnect connecting the second contact to the submount.
  21. 21. The device of claim 20 further comprising:
    a plurality of leads connected to the submount; and
    a lens overlying the submount.
  22. 22. The device of claim 21 further comprising:
    a heat sink disposed between the leads and the submount.
  23. 23. The device of claim 1 wherein the first and second contacts comprise aluminum.
  24. 24. The device of claim 1 wherein at least one of the first and second contacts comprises a multilayer contact.
  25. 25. The device of claim 24 wherein the multilayer contact comprises a first layer of aluminum and a second layer overlying the first layer, the second layer comprising a material selected from a group consisting of Al—Si, Al—Si—Ti, AlCu, and Al—Cu—W.
  26. 26. A III-nitride light emitting device comprising:
    a first layer of first conductivity type;
    a first layer of second conductivity type;
    an active region;
    a tunnel junction, the tunnel junction comprising:
    a second layer of first conductivity type having a dopant concentration greater than the first layer of first conductivity type; and
    a second layer of second conductivity type having a dopant concentration greater than the first layer of second conductivity type; and
    a textured layer overlying the tunnel junction;
    wherein the active region is disposed between a layer of first conductivity type and a layer of second conductivity type.
  27. 27. The device of claim 26 further comprising:
    a first contact electrically connected to the first layer of first conductivity type; and
    a second contact electrically connected to the textured layer.
  28. 28. The device of claim 27 wherein a surface of the second contact adjacent to the textured layer is substantially flat, the device further comprising at least one void disposed between the textured layer and the second contact.
  29. 29. The device of claim 28 wherein the void is filled with air.
  30. 30. The device of claim 26 further comprising a polarization selection layer.
  31. 31. The device of claim 30 further comprising a substrate having a first surface and a second surface opposite the first surface, wherein the first layer of first conductivity type overlies the first surface and the polarization selection layer is disposed on the second surface.
  32. 32. The device of claim 30 wherein the polarization selection layer comprises a wire grid polarizer.
  33. 33. The device of claim 26 further comprising:
    a submount;
    a first interconnect connecting the first contact to the submount; and
    a second interconnect connecting the second contact to the submount.
  34. 34. The device of claim 33 further comprising:
    a plurality of leads connected to the submount; and
    a lens overlying the submount.
  35. 35. The device of claim 34 further comprising:
    a heat sink disposed between the leads and the submount.
  36. 36. The device of claim 26 wherein the textured layer comprises islands of semiconductor material and pockets.
  37. 37. The device of claim 36 wherein the islands of semiconductor material comprise about 10% to about 90% of a volume of the textured layer.
  38. 38. The device of claim 36 wherein the islands of semiconductor material comprise about 10% to about 50% of a volume of the textured layer.
  39. 39. The device of claim 36 wherein the pockets ate filled with air.
  40. 40. The device of claim 36 wherein the pockets are at least partially filled with a material having an index of refraction less than about 2.
  41. 41. The device of claim 36 wherein the second contact is formed over the textured layer and fills the pockets.
  42. 42. The device of claim 26 wherein the textured layer has a thickness between about 200 Å and about 10,000 Å.
  43. 43. The device of claim 26 wherein the textured layer has a thickness between about 500 Å and about 4000 Å.
  44. 44. A III-nitride light emitting device comprising:
    a substrate having a first surface and a second surface opposite the first surface;
    a layer of first conductivity type formed on the first surface;
    a layer of second conductivity type;
    an active region disposed between the layer of first conductivity type and the layer of second conductivity type; and
    a textured layer formed on the second surface.
  45. 45. The device of claim 44 wherein the substrate is SiC.
  46. 46. The device of claim 44 wherein the textured layer comprises islands of semiconductor material and pockets.
  47. 47. The device of claim 46 wherein the islands of semiconductor material comprise about 10% to about 90% of a volume of the textured layer.
  48. 48. The device of claim 46 wherein the islands of semiconductor material comprise about 10% to about 50% of a volume of the textured layer.
  49. 49. The device of claim 44 wherein the textured layer has a thickness between about 200 Å and about 10,000 Å.
  50. 50. The device of claim 44 wherein the textured layer has a thickness between about 500 Å and about 4000 Å.
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Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050105576A1 (en) * 2003-11-14 2005-05-19 Kim Jin K. Modulation doped tunnel junction
US20050236636A1 (en) * 2004-04-23 2005-10-27 Supernova Optoelectronics Corp. GaN-based light-emitting diode structure
US20060049417A1 (en) * 2004-09-09 2006-03-09 Elite Optoelectronics Inc. III-nitride based on semiconductor device with low-resistance ohmic contacts
US20070023769A1 (en) * 2003-09-16 2007-02-01 Keiji Nishimoto Led lighting source and led lighting apparatus
US20070029541A1 (en) * 2005-08-04 2007-02-08 Huoping Xin High efficiency light emitting device
WO2007018789A1 (en) * 2005-07-21 2007-02-15 Cree, Inc. Blue led with roughened high refractive index surface layer for high light extraction
US20070085095A1 (en) * 2005-10-17 2007-04-19 Samsung Electro-Mechanics Co., Ltd. Nitride based semiconductor light emitting diode
US20070194330A1 (en) * 2006-02-23 2007-08-23 Cree, Inc. High efficiency LEDs with tunnel junctions
US20070201134A1 (en) * 2006-02-24 2007-08-30 Seiko Epson Corporation Optical device and method for manufacturing optical device
EP1845564A2 (en) * 2006-04-13 2007-10-17 Osram Opto Semiconductors GmbH Radiation emitting body and method for manufacturing a radiation emitting body
US20080179608A1 (en) * 2007-01-30 2008-07-31 Sharp Kabushiki Kaisha Nitride semiconductor light-emitting device
US20090065763A1 (en) * 2006-05-23 2009-03-12 Meijo University Light-emitting semiconductor device
US20090127574A1 (en) * 2005-07-01 2009-05-21 Bougrov Vladislav E Semiconductor Structure and Method of Manufacturing a Semiconductor Structure
DE102007060202A1 (en) * 2007-12-14 2009-06-25 Osram Opto Semiconductors Gmbh Polarized radiation-emitting semiconductor component
US20100032701A1 (en) * 2008-08-05 2010-02-11 Sharp Kabushiki Kaisha Nitride semiconductor light emitting device and method of manufacturing the same
US20100041170A1 (en) * 2004-10-28 2010-02-18 Philips Lumileds Lighting Company, Llc Package-Integrated Thin Film LED
US20100254129A1 (en) * 2006-04-18 2010-10-07 Cree, Inc. Saturated yellow phosphor converted led and blue converted red led
US20110220871A1 (en) * 2008-09-05 2011-09-15 Sharp Kabushiki Kaisha Nitride semiconductor light-emitting device and semiconductor light-emitting device
US8124957B2 (en) 2006-02-22 2012-02-28 Cree, Inc. Low resistance tunnel junctions in wide band gap materials and method of making same
CN102891232A (en) * 2012-09-29 2013-01-23 中国科学院半导体研究所 The semiconductor light emitting device and manufacturing method thereof
JP2015503849A (en) * 2012-01-10 2015-02-02 コーニンクレッカ フィリップス エヌ ヴェ led light output which is controlled by the selective regions roughening

Families Citing this family (92)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2316989A3 (en) * 2002-04-15 2014-12-03 The Regents of The University of California Non-polar (Al, B, In, Ga) quantum well and heterostructure materials and devices
US8809867B2 (en) * 2002-04-15 2014-08-19 The Regents Of The University Of California Dislocation reduction in non-polar III-nitride thin films
US7956360B2 (en) * 2004-06-03 2011-06-07 The Regents Of The University Of California Growth of planar reduced dislocation density M-plane gallium nitride by hydride vapor phase epitaxy
JP4178836B2 (en) * 2002-05-29 2008-11-12 ソニー株式会社 Gallium nitride-based semiconductor device and a manufacturing method thereof
US7427555B2 (en) * 2002-12-16 2008-09-23 The Regents Of The University Of California Growth of planar, non-polar gallium nitride by hydride vapor phase epitaxy
JP4486506B2 (en) 2002-12-16 2010-06-23 ザ リージェンツ オブ ザ ユニバーシティ オブ カリフォルニアThe Regents of The University of California Growth of non-polar gallium nitride low dislocation density by hydride vapor phase growth method
US7504274B2 (en) 2004-05-10 2009-03-17 The Regents Of The University Of California Fabrication of nonpolar indium gallium nitride thin films, heterostructures and devices by metalorganic chemical vapor deposition
US7091661B2 (en) * 2003-01-27 2006-08-15 3M Innovative Properties Company Phosphor based light sources having a reflective polarizer
US7074631B2 (en) * 2003-04-15 2006-07-11 Luminus Devices, Inc. Light emitting device methods
US20040259279A1 (en) 2003-04-15 2004-12-23 Erchak Alexei A. Light emitting device methods
US7166871B2 (en) 2003-04-15 2007-01-23 Luminus Devices, Inc. Light emitting systems
US7274043B2 (en) * 2003-04-15 2007-09-25 Luminus Devices, Inc. Light emitting diode systems
US7098589B2 (en) * 2003-04-15 2006-08-29 Luminus Devices, Inc. Light emitting devices with high light collimation
US7262550B2 (en) * 2003-04-15 2007-08-28 Luminus Devices, Inc. Light emitting diode utilizing a physical pattern
US7211831B2 (en) * 2003-04-15 2007-05-01 Luminus Devices, Inc. Light emitting device with patterned surfaces
US6831302B2 (en) 2003-04-15 2004-12-14 Luminus Devices, Inc. Light emitting devices with improved extraction efficiency
US7083993B2 (en) * 2003-04-15 2006-08-01 Luminus Devices, Inc. Methods of making multi-layer light emitting devices
US7450311B2 (en) * 2003-12-12 2008-11-11 Luminus Devices, Inc. Optical display systems and methods
US7084434B2 (en) * 2003-04-15 2006-08-01 Luminus Devices, Inc. Uniform color phosphor-coated light-emitting diode
US7521854B2 (en) * 2003-04-15 2009-04-21 Luminus Devices, Inc. Patterned light emitting devices and extraction efficiencies related to the same
US7667238B2 (en) * 2003-04-15 2010-02-23 Luminus Devices, Inc. Light emitting devices for liquid crystal displays
US7105861B2 (en) * 2003-04-15 2006-09-12 Luminus Devices, Inc. Electronic device contact structures
US7601223B2 (en) * 2003-04-29 2009-10-13 Asm International N.V. Showerhead assembly and ALD methods
WO2005022654A3 (en) * 2003-08-28 2005-06-09 Matsushita Electric Ind Co Ltd Semiconductor light emitting device, light emitting module, lighting apparatus, display element and manufacturing method of semiconductor light emitting device
US20090023239A1 (en) * 2004-07-22 2009-01-22 Luminus Devices, Inc. Light emitting device processes
US7344903B2 (en) * 2003-09-17 2008-03-18 Luminus Devices, Inc. Light emitting device processes
US7341880B2 (en) * 2003-09-17 2008-03-11 Luminus Devices, Inc. Light emitting device processes
CN100521120C (en) * 2003-12-09 2009-07-29 加利福尼亚大学董事会;科学技术振兴机构 Highly efficient (B, Al, Ga, In) N based light emitting diodes via surface roughening
US7022550B2 (en) * 2004-04-07 2006-04-04 Gelcore Llc Methods for forming aluminum-containing p-contacts for group III-nitride light emitting diodes
US7332365B2 (en) * 2004-05-18 2008-02-19 Cree, Inc. Method for fabricating group-III nitride devices and devices fabricated using method
US7791061B2 (en) * 2004-05-18 2010-09-07 Cree, Inc. External extraction light emitting diode based upon crystallographic faceted surfaces
US7538357B2 (en) * 2004-08-20 2009-05-26 Panasonic Corporation Semiconductor light emitting device
US20060038188A1 (en) 2004-08-20 2006-02-23 Erchak Alexei A Light emitting diode systems
US20060091412A1 (en) * 2004-10-29 2006-05-04 Wheatley John A Polarized LED
KR100682873B1 (en) * 2004-12-28 2007-02-15 삼성전기주식회사 Semiconductor emitting device and manufacturing method for the same
US7170100B2 (en) 2005-01-21 2007-01-30 Luminus Devices, Inc. Packaging designs for LEDs
US7692207B2 (en) * 2005-01-21 2010-04-06 Luminus Devices, Inc. Packaging designs for LEDs
US20060204865A1 (en) * 2005-03-08 2006-09-14 Luminus Devices, Inc. Patterned light-emitting devices
WO2006099138A3 (en) * 2005-03-10 2006-11-23 Univ California Technique for the growth of planar semi-polar gallium nitride
JP5570116B2 (en) * 2005-05-31 2014-08-13 独立行政法人科学技術振興機構 Selection lateral epitaxial growth using the sidewall (sleo) defect reduction methods and apparatus nonpolar and semipolar iii Nitride by method
JP5743127B2 (en) * 2005-06-01 2015-07-01 ザ リージェンツ オブ ザ ユニバーシティ オブ カリフォルニア Semipolar (Ga, Al, In, B) N thin film, a method and apparatus for the production and growth of heterostructures and devices
WO2007009035A3 (en) * 2005-07-13 2007-09-20 Troy J Baker Lateral growth method for defect reduction of semipolar nitride films
EP1750310A3 (en) * 2005-08-03 2009-07-15 Samsung Electro-Mechanics Co., Ltd. Omni-directional reflector and light emitting diode adopting the same
KR100706796B1 (en) * 2005-08-19 2007-04-12 삼성전자주식회사 Nitride-based top emitting light emitting device and Method of fabricating the same
US20070045640A1 (en) * 2005-08-23 2007-03-01 Erchak Alexei A Light emitting devices for liquid crystal displays
KR101347848B1 (en) * 2005-09-09 2014-01-06 재팬 사이언스 앤드 테크놀로지 에이젼시 Method for enhancing growth of semi-polar (Al,In,Ga,B)N via metalorganic chemical vapor deposition
US20070085098A1 (en) * 2005-10-17 2007-04-19 Luminus Devices, Inc. Patterned devices and related methods
US7348603B2 (en) * 2005-10-17 2008-03-25 Luminus Devices, Inc. Anisotropic collimation devices and related methods
US7391059B2 (en) * 2005-10-17 2008-06-24 Luminus Devices, Inc. Isotropic collimation devices and related methods
US7388233B2 (en) 2005-10-17 2008-06-17 Luminus Devices, Inc. Patchwork patterned devices and related methods
US20080099777A1 (en) * 2005-10-19 2008-05-01 Luminus Devices, Inc. Light-emitting devices and related systems
CN101385145B (en) 2006-01-05 2011-06-08 伊鲁米特克斯公司 Separate optical device for directing light from an LED
JP5896442B2 (en) * 2006-01-20 2016-03-30 国立研究開発法人科学技術振興機構 Method for growing Iii nitride film
JP2009524251A (en) * 2006-01-20 2009-06-25 ザ リージェンツ オブ ザ ユニバーシティ オブ カリフォルニアThe Regents of The University of California Through the metal organic chemical vapor deposition semipolar (Al, In, Ga, B) a method for promoting the growth of N
US8193079B2 (en) * 2006-02-10 2012-06-05 The Regents Of The University Of California Method for conductivity control of (Al,In,Ga,B)N
KR20080104148A (en) * 2006-02-17 2008-12-01 더 리전츠 오브 더 유니버시티 오브 캘리포니아 Method for growth of semipolar (al,in,ga,b)n optoelectronic devices
KR101198763B1 (en) * 2006-03-23 2012-11-12 엘지이노텍 주식회사 Post structure and LED using the structure and method of making the same
KR100736623B1 (en) * 2006-05-08 2007-07-02 엘지이노텍 주식회사 Led having vertical structure and method for making the same
US7789531B2 (en) 2006-10-02 2010-09-07 Illumitex, Inc. LED system and method
US20090275266A1 (en) * 2006-10-02 2009-11-05 Illumitex, Inc. Optical device polishing
US8193020B2 (en) * 2006-11-15 2012-06-05 The Regents Of The University Of California Method for heteroepitaxial growth of high-quality N-face GaN, InN, and AlN and their alloys by metal organic chemical vapor deposition
EP2087507A4 (en) * 2006-11-15 2010-07-07 Univ California Method for heteroepitaxial growth of high-quality n-face gan, inn, and ain and their alloys by metal organic chemical vapor deposition
US7612362B2 (en) 2006-11-22 2009-11-03 Sharp Kabushiki Kaisha Nitride semiconductor light emitting device
JP2008130877A (en) * 2006-11-22 2008-06-05 Sharp Corp Method for fabricating nitride semiconductor light emitting element
US8110838B2 (en) * 2006-12-08 2012-02-07 Luminus Devices, Inc. Spatial localization of light-generating portions in LEDs
WO2008073414A8 (en) * 2006-12-12 2008-09-04 Univ California Crystal growth of m-plane and semipolar planes of(ai, in, ga, b)n on various substrates
US7663148B2 (en) * 2006-12-22 2010-02-16 Philips Lumileds Lighting Company, Llc III-nitride light emitting device with reduced strain light emitting layer
US8110425B2 (en) 2007-03-20 2012-02-07 Luminus Devices, Inc. Laser liftoff structure and related methods
US20080277682A1 (en) * 2007-03-29 2008-11-13 The Regents Of The University Of California Dual surface-roughened n-face high-brightness led
US7781779B2 (en) * 2007-05-08 2010-08-24 Luminus Devices, Inc. Light emitting devices including wavelength converting material
WO2009014707A9 (en) * 2007-07-23 2009-05-07 Qd Vision Inc Quantum dot light enhancement substrate and lighting device including same
US8022425B2 (en) * 2007-12-26 2011-09-20 Epistar Corporation Semiconductor device
KR20100122485A (en) * 2008-02-08 2010-11-22 일루미텍스, 인크. System and method for emitter layer shaping
US8807075B2 (en) * 2008-09-22 2014-08-19 Applied Materials, Inc. Shutter disk having a tuned coefficient of thermal expansion
US20100089315A1 (en) * 2008-09-22 2010-04-15 Applied Materials, Inc. Shutter disk for physical vapor deposition chamber
US8138518B2 (en) * 2008-09-22 2012-03-20 Industrial Technology Research Institute Light emitting diode, package structure and manufacturing method thereof
JP5530087B2 (en) * 2008-10-17 2014-06-25 ユー・ディー・シー アイルランド リミテッド The light-emitting element
JP2010114337A (en) * 2008-11-10 2010-05-20 Hitachi Cable Ltd Light-emitting device
KR101471859B1 (en) * 2008-11-27 2014-12-11 삼성전자주식회사 A light emitting diode
US8115217B2 (en) * 2008-12-11 2012-02-14 Illumitex, Inc. Systems and methods for packaging light-emitting diode devices
KR101134732B1 (en) * 2009-02-17 2012-04-19 엘지이노텍 주식회사 Semiconductor light emitting device and fabrication method thereof
US8585253B2 (en) 2009-08-20 2013-11-19 Illumitex, Inc. System and method for color mixing lens array
US8449128B2 (en) * 2009-08-20 2013-05-28 Illumitex, Inc. System and method for a lens and phosphor layer
CN102054916B (en) * 2010-10-29 2012-11-28 厦门市三安光电科技有限公司 Reflector, manufacturing method thereof and luminescent device applying same
JP5117596B2 (en) * 2011-05-16 2013-01-16 株式会社東芝 Semiconductor light-emitting element, a wafer, and a manufacturing method of the nitride semiconductor crystal layer
KR101813934B1 (en) * 2011-06-02 2018-01-30 엘지이노텍 주식회사 A light emitting device and a light emitting devcie package
JP6042103B2 (en) 2012-05-30 2016-12-14 ユー・ディー・シー アイルランド リミテッド The organic electroluminescent device
US9000414B2 (en) * 2012-11-16 2015-04-07 Korea Photonics Technology Institute Light emitting diode having heterogeneous protrusion structures
US8896008B2 (en) 2013-04-23 2014-11-25 Cree, Inc. Light emitting diodes having group III nitride surface features defined by a mask and crystal planes
CN103811610A (en) * 2014-03-11 2014-05-21 中国科学院半导体研究所 Light emitting device inserted with current homogenizing structure and manufacturing method thereof
KR20160019622A (en) * 2014-08-11 2016-02-22 삼성전자주식회사 Semiconductor light emitting device and semiconductor light emitting device package
CN104538518B (en) * 2015-01-12 2017-07-14 厦门市三安光电科技有限公司 Nitride light emitting diode

Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4169997A (en) * 1977-05-06 1979-10-02 Bell Telephone Laboratories, Incorporated Lateral current confinement in junction lasers
US4732621A (en) * 1985-06-17 1988-03-22 Sanyo Electric Co., Ltd. Method for producing a transparent conductive oxide layer and a photovoltaic device including such a layer
US5365536A (en) * 1992-07-20 1994-11-15 Toyota Jidosha Kabushiki Kaisha Semiconductor laser
US5452316A (en) * 1993-09-24 1995-09-19 Toyota Jidosha Kabushiki Kaisha Semiconductor laser having stacked active layers with reduced drive voltage
US5990531A (en) * 1995-12-28 1999-11-23 Philips Electronics N.A. Corporation Methods of making high voltage GaN-AlN based semiconductor devices and semiconductor devices made
US6122103A (en) * 1999-06-22 2000-09-19 Moxtech Broadband wire grid polarizer for the visible spectrum
US6288840B1 (en) * 1999-06-22 2001-09-11 Moxtek Imbedded wire grid polarizer for the visible spectrum
US6309953B1 (en) * 1995-02-23 2001-10-30 Siemens Aktiengesellschaft Process for producing a semiconductor device with a roughened semiconductor surface
US6376580B1 (en) * 1996-08-06 2002-04-23 Daicel-Huels Ltd. Cement retarder and cement retardative sheet
US6449439B1 (en) * 1999-11-30 2002-09-10 3M Innovative Properties Company Unitary light diffusing cavity
US6486499B1 (en) * 1999-12-22 2002-11-26 Lumileds Lighting U.S., Llc III-nitride light-emitting device with increased light generating capability
US6526082B1 (en) * 2000-06-02 2003-02-25 Lumileds Lighting U.S., Llc P-contact for GaN-based semiconductors utilizing a reverse-biased tunnel junction
US6552905B2 (en) * 2001-09-13 2003-04-22 International Business Machines Corporation Heat sink retention apparatus
US6593657B1 (en) * 1997-03-03 2003-07-15 Micron Technology, Inc. Contact integration article
US6642618B2 (en) * 2000-12-21 2003-11-04 Lumileds Lighting U.S., Llc Light-emitting device and production thereof

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5376580A (en) 1993-03-19 1994-12-27 Hewlett-Packard Company Wafer bonding of light emitting diode layers

Patent Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4169997A (en) * 1977-05-06 1979-10-02 Bell Telephone Laboratories, Incorporated Lateral current confinement in junction lasers
US4732621A (en) * 1985-06-17 1988-03-22 Sanyo Electric Co., Ltd. Method for producing a transparent conductive oxide layer and a photovoltaic device including such a layer
US5365536A (en) * 1992-07-20 1994-11-15 Toyota Jidosha Kabushiki Kaisha Semiconductor laser
US5452316A (en) * 1993-09-24 1995-09-19 Toyota Jidosha Kabushiki Kaisha Semiconductor laser having stacked active layers with reduced drive voltage
US6309953B1 (en) * 1995-02-23 2001-10-30 Siemens Aktiengesellschaft Process for producing a semiconductor device with a roughened semiconductor surface
US5990531A (en) * 1995-12-28 1999-11-23 Philips Electronics N.A. Corporation Methods of making high voltage GaN-AlN based semiconductor devices and semiconductor devices made
US6376580B1 (en) * 1996-08-06 2002-04-23 Daicel-Huels Ltd. Cement retarder and cement retardative sheet
US6593657B1 (en) * 1997-03-03 2003-07-15 Micron Technology, Inc. Contact integration article
US6122103A (en) * 1999-06-22 2000-09-19 Moxtech Broadband wire grid polarizer for the visible spectrum
US6288840B1 (en) * 1999-06-22 2001-09-11 Moxtek Imbedded wire grid polarizer for the visible spectrum
US6449439B1 (en) * 1999-11-30 2002-09-10 3M Innovative Properties Company Unitary light diffusing cavity
US6486499B1 (en) * 1999-12-22 2002-11-26 Lumileds Lighting U.S., Llc III-nitride light-emitting device with increased light generating capability
US6526082B1 (en) * 2000-06-02 2003-02-25 Lumileds Lighting U.S., Llc P-contact for GaN-based semiconductors utilizing a reverse-biased tunnel junction
US6642618B2 (en) * 2000-12-21 2003-11-04 Lumileds Lighting U.S., Llc Light-emitting device and production thereof
US6552905B2 (en) * 2001-09-13 2003-04-22 International Business Machines Corporation Heat sink retention apparatus

Cited By (47)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070023769A1 (en) * 2003-09-16 2007-02-01 Keiji Nishimoto Led lighting source and led lighting apparatus
US7099362B2 (en) * 2003-11-14 2006-08-29 Finisar Corporation Modulation doped tunnel junction
US20050105576A1 (en) * 2003-11-14 2005-05-19 Kim Jin K. Modulation doped tunnel junction
US20050236636A1 (en) * 2004-04-23 2005-10-27 Supernova Optoelectronics Corp. GaN-based light-emitting diode structure
US7943949B2 (en) * 2004-09-09 2011-05-17 Bridgelux, Inc. III-nitride based on semiconductor device with low-resistance ohmic contacts
US20060049417A1 (en) * 2004-09-09 2006-03-09 Elite Optoelectronics Inc. III-nitride based on semiconductor device with low-resistance ohmic contacts
US7875533B2 (en) * 2004-10-28 2011-01-25 Koninklijke Philips Electronics N.V. Package-integrated thin film LED
US20110084301A1 (en) * 2004-10-28 2011-04-14 Koninklijke Philips Electronics N.V. Package-integrated thin film led
US20100041170A1 (en) * 2004-10-28 2010-02-18 Philips Lumileds Lighting Company, Llc Package-Integrated Thin Film LED
US8455913B2 (en) 2004-10-28 2013-06-04 Phiips Lumileds Lighting Company LLC Package-integrated thin film LED
US7763904B2 (en) 2005-01-07 2010-07-27 Optogan Oy Semiconductor structure and method of manufacturing a semiconductor structure
US8062913B2 (en) 2005-07-01 2011-11-22 OptoGaN, Oy Semiconductor structure and method of manufacturing a semiconductor structure
US20090127574A1 (en) * 2005-07-01 2009-05-21 Bougrov Vladislav E Semiconductor Structure and Method of Manufacturing a Semiconductor Structure
US20100314662A1 (en) * 2005-07-01 2010-12-16 Optogan Oy Semiconductor structure and method of manufacturing a semiconductor structure
US8674375B2 (en) 2005-07-21 2014-03-18 Cree, Inc. Roughened high refractive index layer/LED for high light extraction
WO2007018789A1 (en) * 2005-07-21 2007-02-15 Cree, Inc. Blue led with roughened high refractive index surface layer for high light extraction
US20070029541A1 (en) * 2005-08-04 2007-02-08 Huoping Xin High efficiency light emitting device
US8168995B2 (en) * 2005-10-17 2012-05-01 Samsung Led Co., Ltd. Nitride based semiconductor light emitting diode
US20070085095A1 (en) * 2005-10-17 2007-04-19 Samsung Electro-Mechanics Co., Ltd. Nitride based semiconductor light emitting diode
US8124957B2 (en) 2006-02-22 2012-02-28 Cree, Inc. Low resistance tunnel junctions in wide band gap materials and method of making same
US8324637B2 (en) * 2006-02-23 2012-12-04 Cree, Inc. High efficiency LEDs with tunnel junctions
US7737451B2 (en) * 2006-02-23 2010-06-15 Cree, Inc. High efficiency LED with tunnel junction layer
US20070194330A1 (en) * 2006-02-23 2007-08-23 Cree, Inc. High efficiency LEDs with tunnel junctions
WO2007106220A1 (en) * 2006-02-23 2007-09-20 Cree, Inc. High efficiency leds with tunnel junctions
US20100224860A1 (en) * 2006-02-23 2010-09-09 Cree, Inc. High efficiency leds with tunnel junctions
JP2009527920A (en) * 2006-02-23 2009-07-30 クリー インコーポレイテッドCree Inc. Light emitting diode having a tunnel junction
US20070201134A1 (en) * 2006-02-24 2007-08-30 Seiko Epson Corporation Optical device and method for manufacturing optical device
US7593076B2 (en) * 2006-02-24 2009-09-22 Seiko Epson Corporation Optical device and method for manufacturing optical device
US8476643B2 (en) 2006-04-13 2013-07-02 Osram Opto Semiconductors Gmbh Radiation-emitting body and method for producing a radiation-emitting body
US8877529B2 (en) 2006-04-13 2014-11-04 Osram Opto Semiconductors Gmbh Radiation-emitting body and method for producing a radiation-emitting body
EP1845564A3 (en) * 2006-04-13 2012-02-29 OSRAM Opto Semiconductors GmbH Radiation emitting body and method for manufacturing a radiation emitting body
EP1845564A2 (en) * 2006-04-13 2007-10-17 Osram Opto Semiconductors GmbH Radiation emitting body and method for manufacturing a radiation emitting body
US20080173863A1 (en) * 2006-04-13 2008-07-24 Osram Opto Semiconductors Gmbh Radiation-emitting body and method for producing a radiation-emitting body
US20100254129A1 (en) * 2006-04-18 2010-10-07 Cree, Inc. Saturated yellow phosphor converted led and blue converted red led
GB2453464B (en) * 2006-05-23 2011-08-31 Univ Meijo Light-emitting semiconductor device
US20090065763A1 (en) * 2006-05-23 2009-03-12 Meijo University Light-emitting semiconductor device
US7985964B2 (en) 2006-05-23 2011-07-26 Meijo University Light-emitting semiconductor device
US20080179608A1 (en) * 2007-01-30 2008-07-31 Sharp Kabushiki Kaisha Nitride semiconductor light-emitting device
US7893446B2 (en) * 2007-01-30 2011-02-22 Sharp Kabushiki Kaisha Nitride semiconductor light-emitting device providing efficient light extraction
US20100295076A1 (en) * 2007-12-14 2010-11-25 Ralph Wirth Semiconductor Component Emitting Polarized Radiation
DE102007060202A1 (en) * 2007-12-14 2009-06-25 Osram Opto Semiconductors Gmbh Polarized radiation-emitting semiconductor component
US8063410B2 (en) * 2008-08-05 2011-11-22 Sharp Kabushiki Kaisha Nitride semiconductor light emitting device and method of manufacturing the same
US20100032701A1 (en) * 2008-08-05 2010-02-11 Sharp Kabushiki Kaisha Nitride semiconductor light emitting device and method of manufacturing the same
US8319243B2 (en) 2008-08-05 2012-11-27 Sharp Kabushiki Kaisha Nitride semiconductor light-emitting device and method of manufacturing the same
US20110220871A1 (en) * 2008-09-05 2011-09-15 Sharp Kabushiki Kaisha Nitride semiconductor light-emitting device and semiconductor light-emitting device
JP2015503849A (en) * 2012-01-10 2015-02-02 コーニンクレッカ フィリップス エヌ ヴェ led light output which is controlled by the selective regions roughening
CN102891232A (en) * 2012-09-29 2013-01-23 中国科学院半导体研究所 The semiconductor light emitting device and manufacturing method thereof

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