US20080224158A1 - Light Emitting Device With Undoped Substrate And Doped Bonding Layer - Google Patents
Light Emitting Device With Undoped Substrate And Doped Bonding Layer Download PDFInfo
- Publication number
- US20080224158A1 US20080224158A1 US11/860,502 US86050207A US2008224158A1 US 20080224158 A1 US20080224158 A1 US 20080224158A1 US 86050207 A US86050207 A US 86050207A US 2008224158 A1 US2008224158 A1 US 2008224158A1
- Authority
- US
- United States
- Prior art keywords
- layer
- conductivity type
- doped
- electrical contact
- substrate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor 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
- H01L33/36—Semiconductor 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
- H01L33/38—Semiconductor 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 with a particular shape
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor 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
- H01L33/005—Processes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor 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
- H01L33/36—Semiconductor 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
- H01L33/40—Materials therefor
- H01L33/405—Reflective materials
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/0001—Technical content checked by a classifier
- H01L2924/0002—Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2933/00—Details relating to devices covered by the group H01L33/00 but not provided for in its subgroups
- H01L2933/0008—Processes
- H01L2933/0016—Processes relating to electrodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor 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
- H01L33/02—Semiconductor 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
- H01L33/20—Semiconductor 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
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor 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
- H01L33/36—Semiconductor 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
- H01L33/40—Materials therefor
- H01L33/42—Transparent materials
Definitions
- the present invention relates generally to light emitting diodes and more specifically to contacts for light emitting diodes.
- LEDs light emitting diodes
- III-V semiconductors particularly binary, ternary, and quaternary alloys of gallium, aluminum, indium, and nitrogen, also referred to as III-nitride materials; and binary, ternary, and quaternary alloys of gallium, aluminum, indium, and phosphorus, also referred to as III-phosphide materials.
- III-nitride devices are epitaxially grown on sapphire, silicon carbide, or III-nitride substrates and III-phosphide devices are epitaxially grown on gallium arsenide by metal organic chemical vapor deposition (MOCVD) molecular beam epitaxy (MBE) or other epitaxial techniques.
- MOCVD metal organic chemical vapor deposition
- MBE molecular beam epitaxy
- These LED device structures can also be transferred to a transparent substrate by wafer bonding.
- an n-type layer (or layers) is deposited on the substrate, then an active region is deposited on the n-type layers, then a p-type layer (or layers) is deposited on the active region. The order of the layers may be reversed such that the p-type layers are adjacent to the substrate by either epitaxial growth or wafer bonding.
- FIG. 1 illustrates a cross-sectional view of a conventional light emitting diode (LED) 10 .
- LED light emitting diode
- one or more p type layers are formed over a substrate 12 .
- a p-AlInP layer 16 may be formed over a p doped region 14 of a GaP substrate 10 by wafer bonding, and p-contacts 18 are formed on the p doped region 14 .
- An active region 20 is formed over the p type layer 16 and an n type layer 22 , e.g., an n-AlInP layer, is formed over the active region 20 .
- n type layer 22 e.g., an n-AlInP layer
- n contact 24 is formed over the n type layer 22 , but the contact area is minimized in order to increase the area of the reflective mirror 26 area for better light extraction through the substrate 10 .
- the LED 10 can be used in a flip chip configuration with the p-contacts 18 and n-contacts 24 formed on the same side of the device when flip-chipped on a submount and where the light is extracted through the substrate 12 , which is the top of the device.
- the design scheme of the flip chip LED 10 forces lateral current injection, which results in current crowding under the n-contact 24 and near the p contact area 18 as illustrated by the arrows in FIG. 1 .
- the current crowding results in non-uniform current injection as well as high series resistance and high forward voltage Vf compared to vertical injection LEDs.
- One manner of solving the non-uniform current injection problem in the n-side is to use full sheet n-metal contact.
- the n-metal contact has to be annealed at high temperature, e.g., greater than 420° C., to achieve a good ohmic contact, the metal surface is rough. As a result, the reflectively of the full sheet n-metal contact is poor and thus, decreases light extraction.
- a light emitting device includes a stack of layers bonded to an undoped substrate with a doped layer between the stack of layers and the undoped substrate.
- the stack of layers include a layer of first conductivity type over the doped layer, an active region overlying the layer of first conductivity type, and a layer of second conductivity type overlying the active region.
- the doped substrate is part of the stack of layers and is bonded to the undoped substrate.
- the doped layer and undoped substrate may be formed from the same semiconductor material, such as GaP.
- First and second electrical contacts are coupled to the device on a side opposite the undoped substrate.
- the doped layer may provide electrical contact between the first electrical contact and the layer of first conductivity type.
- a method of forming a light emitting device includes providing a transparent undoped substrate and forming a stack of layers including a layer of first conductivity type, an active region over the layer of first conductivity type, a layer of second conductivity type over the active region.
- the method includes bonding the stack of layers to the undoped substrate with a doped layer between the stack and the undoped substrate.
- the doped layer is part of the stack of layers and may be formed on a sacrificial substrate prior to bonding to the undoped substrate.
- the method further includes removing a portion of the layer of first conductivity type, the active region, and the layer of second conductivity type to expose the doped layer and forming a first electrical contact to contact the layer of first conductivity type and forming a second electrical contact to contact the exposed doped layer.
- the first and second electrical contacts are on the same side of the doped layer opposed the undoped substrate.
- FIG. 1 illustrates a cross-sectional view of a conventional light emitting diode.
- FIG. 2 illustrates a cross sectional view of a light emitting device that uses a full sheet contact with an omnidirectional high reflective mirror (ODRM) structure, in accordance with one embodiment of the present invention.
- ODRM omnidirectional high reflective mirror
- FIG. 3 illustrates a top view of a light emitting device with an ODRM structure and a distributed p-contact array, in accordance with another embodiment of the present invention.
- FIG. 4 illustrates a cross sectional view of a portion of light emitting device from FIG. 3 along line A-A.
- FIGS. 5A-5D illustrate an embodiment of the present invention at various stages during fabrication.
- FIG. 2 illustrates a cross sectional view of an light emitting device (LED) 100 , in accordance with one embodiment of the present invention, that uses a full sheet contact with an omnidirectional high reflective mirror (ODRM) structure 101 .
- LED light emitting device
- ODRM omnidirectional high reflective mirror
- LED 100 includes one or more p-type layers 106 formed over a substrate 102 .
- the p-type layer 106 e.g., may be P-AlInP layers formed over a p doped GaP layer 104 that is bonded to an undoped GaP substrate 102 .
- the p contacts 105 which may be formed from, e.g., AuZn, are formed over the p doped GaP layer 104 .
- An active region 108 is formed over the p type layer 106 and an n type layer 110 , e.g., n-AlInP, is formed over the active region 108 .
- the LED 100 may include one or more capping layers 112 , e.g., of n+GaAs and/or n+InGaP over the n type layer 110 .
- the ODRM structure 101 is formed over the capping layers 112 from a full sheet conductive transparent film 114 of, e.g., indium tin oxide (ITO), and a high reflective mirror 116 of, e.g., Ag or Au.
- transparent is used herein to indicate that an optical element so described, such as a “transparent film,” a “transparent layer,” or a “transparent substrate,” transmits light at the emission wavelengths of the LED with less than about 50%, preferably less than about 10%, single pass loss due to absorption or scattering.
- an optical element so described such as a “transparent film,” a “transparent layer,” or a “transparent substrate,” transmits light at the emission wavelengths of the LED with less than about 50%, preferably less than about 10%, single pass loss due to absorption or scattering.
- the conditions “less than 50% single pass loss” and “less than 10% single pass loss” may be met by various combinations of transmission path length and absorption constant.
- the conductive transparent film 114 is sometimes referred to herein as an ITO layer 114 , but it should be understood that other conductive and transparent films may be used.
- the conductive transparent film 114 serves as the n contact for the LED 100 and the mirror 116 overlies the conductive transparent film 114 .
- the ITO layer 114 has a thickness that is, e.g., a quarter of the wavelength produced by the LED 100 .
- the ITO layer 114 is approximately 73 nm thick at a wavelength of 615 nm and has a refractive index of 2.1.
- the contact resistance of the ITO layer 114 is expected to be 1.5 e ⁇ 5 ⁇ cm 2 or lower, with a transmission of approximately 95% or better around 600 nm.
- the ODMR structure 101 provides high reflection for the light reaching the ODRM structure 101 over all incident angles.
- the ODRM structure 101 with a quarter wavelength ITO layer 114 and an Ag mirror 116 is expected to have a reflectively of over 90% for a wide range of incident angles.
- using the ITO layer 114 as a full sheet n-contact provides a uniform current injection from the n-side into the active region 108 , eliminating the current crowding problem at the n-layer 110 found in conventional devices. Accordingly, the ODMR structure 101 reduces the forward voltage Vf and series resistance while increasing the extraction efficiency of the LED 100 compared to conventional devices.
- the LED 100 of the present embodiment is described as a flip chip AlInGaP type device, the present ODRM structure may be used with difference devices if desired.
- the ODRM structure may be used with a flip chip InGaN LED devices.
- the ITO layer 114 can be used as a transparent contact on a p-GaN layer.
- the ITO layer 114 can also be applied on top of p-GaAs or P-InGaN contact layers.
- a uniform current injection is provided at the n side of the active region.
- the current injection at the p side of the active region may still be problematic due to the lateral contact scheme in a wide mesa structure such as that shown in FIG. 2 .
- four mesas are conventionally formed by etching to the p-GaP contact layer.
- the spacing between the p-contact and the center of the mesa for such a structure is over 100 ⁇ m. Due to the poor conductivity of the p-GaP, the hole injection on the p-side of the active region is not uniform across the mesa. Accordingly, current crowding may occur around the edges of the mesa.
- a distributed p-contact array is used, along with the ODRM structure 101 , to improve current spreading and increase the junction area of the LED.
- the distributed contact array may be similar to that disclosed in U.S. 2003/0230754, entitled “Contacting Scheme for Large and Small Area Semiconductor Light Emitting Flip-Chip Devices”, by Daniel A. Steigerwald et al., filed Jun. 13, 2002, which has the same assignee as the present disclosure and is incorporated herein by reference.
- FIG. 3 illustrates a top view of an LED 200 with an ODRM structure 201 that serves as the n-contact, and a distributed p-contact array, in accordance with an embodiment of the present invention.
- FIG. 4 illustrates a cross sectional view of a portion of LED 200 along line A-A in FIG. 3 .
- LED 200 includes one or more p-type layers 206 formed over p doped layer 204 that is bonded to a substrate 202 .
- the p doped layer 204 may be, e.g., 2 to 20 ⁇ m of p-GaP that is optimized for good current spreading.
- the thicker the p-doped layer 204 the larger the p-contact array spacing can be for uniform current spreading.
- a thicker p-doped layer 204 increases light absorption loss.
- the p-doped layer 204 should be kept as thin as possible with a small p-contact array pitch for uniform current spreading.
- the active region 208 and an n layer 210 are formed over the active region 208 and an n layer 210 .
- the ODRM 201 is formed over the capping layer 212 as a conductive transparent film 214 , such as a quarter wavelength thick ITO layer 214 , and an Ag or Au reflective mirror 216 formed over the ITO layer 214 .
- the LED 200 may be mounted to a submount (not shown) of silicon or ceramic and the cathode and the anode of the LED 200 can be connected to the corresponding contact pads on the submount through solder bumps or Au—Au stud bumps.
- the p-contact 205 is formed as a distributed array 116 by etching several vias 217 down to the p doped layer 204 , by etching away the ODRM 201 , the capping layer 212 , the n-type layer 210 , the active region 208 and the p-type layer 206 with, for example, a reactive ion etch; by ion implantation; by dopant diffusion; or by selective growth of the layers.
- the p doped layer 204 is exposed for the p contact 205 .
- a dielectric layer 218 such as SiN x or SiO 2 is formed over the LED epi structure, i.e., layers 206 , 208 , 210 , 212 , and 201 .
- the p-contacts 205 in the distributed array 216 are connected together by interconnect 222 , which is formed by the p contact layer 220 , as illustrated in FIG. 3 .
- the dielectric layer 218 isolates the p contact layer 220 from the reflective mirror 216 and ITO layer 214 in the ODRM 201 .
- a 4 ⁇ 4 distributed p-contact array is formed by etching vias 217 through the device and into the p-GaP layer 204 and depositing an AuZn p-contact layer 220 into the vias 217 .
- the via pitch (dimension P in FIG. 3 ) may be, for example, about 50 ⁇ m to about 1000 ⁇ m, and is usually about 50 ⁇ m to about 200 ⁇ m.
- the via diameter (dimension D in FIG. 3 ) may be, for example, between about 2 ⁇ m and about 100 ⁇ m, and is usually between about 10 ⁇ m and about 50 ⁇ m.
- the farthest current conduction path for holes is approximately 37.5 ⁇ m, which is the distance from the edge of a p-contact 205 to the center of two adjacent p-contacts 205 and approximately 58 ⁇ m on the diagonally between p contacts 205 .
- the total junction area is approximately 96 percent.
- a conventional LED of the same size with dual mesas and stripped p-contacts has a junction of approximately 75 percent assuming the mesa width is approximately 210 ⁇ m, the p-contact line around the mesa is 20 ⁇ m wide and the solder metal pad is 50 ⁇ m in diameter.
- FIG. 3 has a 4 ⁇ 4 rectangular array of vias, a rectangular array of a different size (for example, 6 ⁇ 6 or 9 ⁇ 9) may also be used, as well as a hexagonal array, a rhombohedral array, a face-centered cubic array, an arbitrary arrangement, or any other suitable arrangement.
- FIGS. 5A-5D illustrate an embodiment of the present invention at various stages during fabrication.
- Layers 212 , 210 , 208 , 206 , and 204 are epitaxially grown on an n-GaAs substrate (not shown) and then bonded to GaP substrate 202 .
- the capping layer 212 e.g., of n+GaAs or n+InGaP, is formed over the n-GaAs substrate.
- One or more n-type layers 210 are formed on the capping layer 212 .
- N-type layers 210 may include, for example, a buffer layer, a contact layer, an undoped crystal layer, and n-type layers of varying composition and dopant concentration.
- An active region 208 is then formed on the n-type layers 210 .
- Active region 208 may include, for example, a set of quantum well layers separated by a set of barrier layers.
- One or more p-type layers 206 are formed on the active region 208 .
- P-type layers 206 may include, for example, may include, for example, a carrier confining layer, a contact layer, and other p-type layers of various composition and dopant concentration.
- the various layers may be deposited by, for example, MOCVD or other appropriate, well known techniques.
- the p-type layers 206 are then bonded to the GaP substrate 202 and the n-GaAs substrate is selectively removed.
- the ITO layer 214 is deposited over the capping layer 212 and the reflective mirror layer 216 of, e.g., Ag or Au, is deposited over the ITO layer 214 resulting in the structure shown in FIG. 5A .
- the ITO layer 214 and the reflective mirror layer 216 may be deposited by, e.g., e-beam evaporation or sputtering.
- the ITO layer 214 , mirror layer 216 and the capping layer 212 are patterned as shown in FIG. 5B , using for example photolithography along with etching, or a lift-off process.
- the patterning removes any of the ITO layer 214 , mirror layer 216 and capping layer 212 that will not be used as an n-contact.
- the patterning thus removes any of the n contact overlying vias 217 shown in FIGS. 3 and 4 .
- one or more etching steps are then performed to form vias 217 .
- a dielectric layer 218 such as for example silicon nitride or silicon oxide, is deposited, as shown in FIG. 5D to electrically isolate the ITO layer 214 and mirror layer 216 , which serve as the n-contact, from the p metal to be deposited in via 217 .
- Dielectric layer 218 may be any material that electrically isolates two materials on either side of dielectric layer 218 .
- Dielectric layer 218 is patterned to remove a portion of the dielectric material covering the p layer 204 at the bottom of via 217 and a portion of the top of the mirror layer 216 .
- Dielectric layer 218 must have a low density of pinholes to prevent short circuiting between the p- and n-contacts. In some embodiments, dielectric layer 218 is multiple dielectric layers.
- the p contact layer 220 is then deposited over the dielectric layer 218 and in via 217 .
- the interconnect 222 which connects the p-metal deposited in each via 217 , may also be deposited at this time.
- the p contact layer 220 is patterned to remove a portion of the material covering the mirror layer 216 as shown in FIG. 4 .
Abstract
Description
- The present application is a continuation of and claims priority to U.S. patent application Ser. No. 10/960,391, filed Oct. 6, 2004, entitled “Contact and Omnidirectional Reflective Mirror for Flip Chipped Light Emitting Devices”, by Decai Sun, which is incorporated herein by reference.
- The present invention relates generally to light emitting diodes and more specifically to contacts for light emitting diodes.
- Semiconductor light emitting devices such as light emitting diodes (LEDs) are among the most efficient light sources currently available. Material systems currently of interest in the manufacture of high brightness LEDs 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; and binary, ternary, and quaternary alloys of gallium, aluminum, indium, and phosphorus, also referred to as III-phosphide materials. Often III-nitride devices are epitaxially grown on sapphire, silicon carbide, or III-nitride substrates and III-phosphide devices are epitaxially grown on gallium arsenide by metal organic chemical vapor deposition (MOCVD) molecular beam epitaxy (MBE) or other epitaxial techniques. These LED device structures can also be transferred to a transparent substrate by wafer bonding. Often, an n-type layer (or layers) is deposited on the substrate, then an active region is deposited on the n-type layers, then a p-type layer (or layers) is deposited on the active region. The order of the layers may be reversed such that the p-type layers are adjacent to the substrate by either epitaxial growth or wafer bonding.
-
FIG. 1 illustrates a cross-sectional view of a conventional light emitting diode (LED) 10. As shown inFIG. 1 , one or more p type layers are formed over asubstrate 12. By way of example, a p-AlInP layer 16 may be formed over a p dopedregion 14 of aGaP substrate 10 by wafer bonding, and p-contacts 18 are formed on the p dopedregion 14. Anactive region 20 is formed over thep type layer 16 and ann type layer 22, e.g., an n-AlInP layer, is formed over theactive region 20. Ann contact 24 is formed over then type layer 22, but the contact area is minimized in order to increase the area of thereflective mirror 26 area for better light extraction through thesubstrate 10. Thus, theLED 10 can be used in a flip chip configuration with the p-contacts 18 and n-contacts 24 formed on the same side of the device when flip-chipped on a submount and where the light is extracted through thesubstrate 12, which is the top of the device. - The design scheme of the
flip chip LED 10 forces lateral current injection, which results in current crowding under the n-contact 24 and near thep contact area 18 as illustrated by the arrows inFIG. 1 . The current crowding results in non-uniform current injection as well as high series resistance and high forward voltage Vf compared to vertical injection LEDs. - One manner of solving the non-uniform current injection problem in the n-side is to use full sheet n-metal contact. However, because the n-metal contact has to be annealed at high temperature, e.g., greater than 420° C., to achieve a good ohmic contact, the metal surface is rough. As a result, the reflectively of the full sheet n-metal contact is poor and thus, decreases light extraction.
- Thus, it is highly desirable to improve the contacts used with LEDs reduce the non-uniform current injection problem without decreasing light extraction.
- In accordance with one embodiment, a light emitting device includes a stack of layers bonded to an undoped substrate with a doped layer between the stack of layers and the undoped substrate. The stack of layers include a layer of first conductivity type over the doped layer, an active region overlying the layer of first conductivity type, and a layer of second conductivity type overlying the active region. In one embodiment, the doped substrate is part of the stack of layers and is bonded to the undoped substrate. The doped layer and undoped substrate may be formed from the same semiconductor material, such as GaP. First and second electrical contacts are coupled to the device on a side opposite the undoped substrate. The doped layer may provide electrical contact between the first electrical contact and the layer of first conductivity type.
- In accordance with another embodiment, a method of forming a light emitting device includes providing a transparent undoped substrate and forming a stack of layers including a layer of first conductivity type, an active region over the layer of first conductivity type, a layer of second conductivity type over the active region. The method includes bonding the stack of layers to the undoped substrate with a doped layer between the stack and the undoped substrate. In one embodiment, the doped layer is part of the stack of layers and may be formed on a sacrificial substrate prior to bonding to the undoped substrate. The method further includes removing a portion of the layer of first conductivity type, the active region, and the layer of second conductivity type to expose the doped layer and forming a first electrical contact to contact the layer of first conductivity type and forming a second electrical contact to contact the exposed doped layer. The first and second electrical contacts are on the same side of the doped layer opposed the undoped substrate.
-
FIG. 1 illustrates a cross-sectional view of a conventional light emitting diode. -
FIG. 2 illustrates a cross sectional view of a light emitting device that uses a full sheet contact with an omnidirectional high reflective mirror (ODRM) structure, in accordance with one embodiment of the present invention. -
FIG. 3 illustrates a top view of a light emitting device with an ODRM structure and a distributed p-contact array, in accordance with another embodiment of the present invention. -
FIG. 4 illustrates a cross sectional view of a portion of light emitting device fromFIG. 3 along line A-A. -
FIGS. 5A-5D illustrate an embodiment of the present invention at various stages during fabrication. -
FIG. 2 illustrates a cross sectional view of an light emitting device (LED) 100, in accordance with one embodiment of the present invention, that uses a full sheet contact with an omnidirectional high reflective mirror (ODRM)structure 101. - As shown in
FIG. 2 ,LED 100 includes one or more p-type layers 106 formed over asubstrate 102. The p-type layer 106, e.g., may be P-AlInP layers formed over a p dopedGaP layer 104 that is bonded to anundoped GaP substrate 102. Thep contacts 105, which may be formed from, e.g., AuZn, are formed over the p dopedGaP layer 104. Anactive region 108 is formed over thep type layer 106 and ann type layer 110, e.g., n-AlInP, is formed over theactive region 108. TheLED 100 may include one or morecapping layers 112, e.g., of n+GaAs and/or n+InGaP over then type layer 110. - The
ODRM structure 101 is formed over thecapping layers 112 from a full sheet conductivetransparent film 114 of, e.g., indium tin oxide (ITO), and a highreflective mirror 116 of, e.g., Ag or Au. The term “transparent” is used herein to indicate that an optical element so described, such as a “transparent film,” a “transparent layer,” or a “transparent substrate,” transmits light at the emission wavelengths of the LED with less than about 50%, preferably less than about 10%, single pass loss due to absorption or scattering. One of ordinary skill in the art will recognize that the conditions “less than 50% single pass loss” and “less than 10% single pass loss” may be met by various combinations of transmission path length and absorption constant. The conductivetransparent film 114 is sometimes referred to herein as anITO layer 114, but it should be understood that other conductive and transparent films may be used. The conductivetransparent film 114 serves as the n contact for theLED 100 and themirror 116 overlies the conductivetransparent film 114. Where indium tin oxide is used as the conductivetransparent film 114, the ITOlayer 114 has a thickness that is, e.g., a quarter of the wavelength produced by theLED 100. By example, theITO layer 114 is approximately 73 nm thick at a wavelength of 615 nm and has a refractive index of 2.1. The contact resistance of theITO layer 114 is expected to be 1.5 e−5Ω cm2 or lower, with a transmission of approximately 95% or better around 600 nm. - The
ODMR structure 101 provides high reflection for the light reaching theODRM structure 101 over all incident angles. For example, theODRM structure 101 with a quarterwavelength ITO layer 114 and anAg mirror 116 is expected to have a reflectively of over 90% for a wide range of incident angles. Moreover, using theITO layer 114 as a full sheet n-contact provides a uniform current injection from the n-side into theactive region 108, eliminating the current crowding problem at the n-layer 110 found in conventional devices. Accordingly, theODMR structure 101 reduces the forward voltage Vf and series resistance while increasing the extraction efficiency of theLED 100 compared to conventional devices. - It should be understood that, while the
LED 100 of the present embodiment is described as a flip chip AlInGaP type device, the present ODRM structure may be used with difference devices if desired. For example, the ODRM structure may be used with a flip chip InGaN LED devices. It has been demonstrated that the ITOlayer 114 can be used as a transparent contact on a p-GaN layer. TheITO layer 114 can also be applied on top of p-GaAs or P-InGaN contact layers. - With the use of the
ODRM structure 101, a uniform current injection is provided at the n side of the active region. The current injection at the p side of the active region, however, may still be problematic due to the lateral contact scheme in a wide mesa structure such as that shown inFIG. 2 . By way of example, for a 1 mm×1 mm square red flip chip die, four mesas are conventionally formed by etching to the p-GaP contact layer. The spacing between the p-contact and the center of the mesa for such a structure is over 100 μm. Due to the poor conductivity of the p-GaP, the hole injection on the p-side of the active region is not uniform across the mesa. Accordingly, current crowding may occur around the edges of the mesa. - Thus, in accordance with another embodiment of the present invention, a distributed p-contact array is used, along with the
ODRM structure 101, to improve current spreading and increase the junction area of the LED. The distributed contact array may be similar to that disclosed in U.S. 2003/0230754, entitled “Contacting Scheme for Large and Small Area Semiconductor Light Emitting Flip-Chip Devices”, by Daniel A. Steigerwald et al., filed Jun. 13, 2002, which has the same assignee as the present disclosure and is incorporated herein by reference. -
FIG. 3 illustrates a top view of anLED 200 with anODRM structure 201 that serves as the n-contact, and a distributed p-contact array, in accordance with an embodiment of the present invention.FIG. 4 illustrates a cross sectional view of a portion ofLED 200 along line A-A inFIG. 3 . - As can be seen in
FIG. 4 , the formation ofLED 200 is similar to that ofLED 100 shown inFIG. 2 . For example,LED 200 includes one or more p-type layers 206 formed over p dopedlayer 204 that is bonded to asubstrate 202. The p dopedlayer 204 may be, e.g., 2 to 20 μm of p-GaP that is optimized for good current spreading. In general, the thicker the p-dopedlayer 204, the larger the p-contact array spacing can be for uniform current spreading. A thicker p-dopedlayer 204, however, increases light absorption loss. Therefore, the p-dopedlayer 204 should be kept as thin as possible with a small p-contact array pitch for uniform current spreading. Over the p-type layer 206 is formed theactive region 208 and ann layer 210. Acapping layer 212 of, e.g., of n+GaAs and/or n+InGaP, is formed over then layer 210. TheODRM 201 is formed over thecapping layer 212 as a conductivetransparent film 214, such as a quarter wavelengththick ITO layer 214, and an Ag or Aureflective mirror 216 formed over theITO layer 214. TheLED 200 may be mounted to a submount (not shown) of silicon or ceramic and the cathode and the anode of theLED 200 can be connected to the corresponding contact pads on the submount through solder bumps or Au—Au stud bumps. - As illustrated in
FIG. 3 and 4 , however, the p-contact 205 is formed as a distributedarray 116 by etchingseveral vias 217 down to the p dopedlayer 204, by etching away theODRM 201, thecapping layer 212, the n-type layer 210, theactive region 208 and the p-type layer 206 with, for example, a reactive ion etch; by ion implantation; by dopant diffusion; or by selective growth of the layers. Thus, the p dopedlayer 204 is exposed for thep contact 205. Adielectric layer 218, such as SiNx or SiO2, is formed over the LED epi structure, i.e., layers 206, 208, 210, 212, and 201. Ap contact layer 220 of, e.g., AuZn, is formed over thedielectric layer 218 and is in electrical contact with the underlying p dopedlayer 204 to form thep contact 205. The p-contacts 205 in the distributedarray 216 are connected together byinterconnect 222, which is formed by thep contact layer 220, as illustrated inFIG. 3 . Thedielectric layer 218 isolates thep contact layer 220 from thereflective mirror 216 andITO layer 214 in theODRM 201. - By way of example, for a 500 μm×500 μm square LED chip, a 4×4 distributed p-contact array, such as that shown in
FIG. 3 , is formed by etchingvias 217 through the device and into the p-GaP layer 204 and depositing an AuZn p-contact layer 220 into thevias 217. The via pitch (dimension P inFIG. 3 ) may be, for example, about 50 μm to about 1000 μm, and is usually about 50 μm to about 200 μm. The via diameter (dimension D inFIG. 3 ) may be, for example, between about 2 μm and about 100 μm, and is usually between about 10 μm and about 50 μm. Where the via pitch is 100 μm and the via diameter is 25 μm, the farthest current conduction path for holes is approximately 37.5 μm, which is the distance from the edge of a p-contact 205 to the center of two adjacent p-contacts 205 and approximately 58 μm on the diagonally betweenp contacts 205. Moreover, the total junction area is approximately 96 percent. By way of comparison, a conventional LED of the same size with dual mesas and stripped p-contacts has a junction of approximately 75 percent assuming the mesa width is approximately 210 μm, the p-contact line around the mesa is 20 μm wide and the solder metal pad is 50 μm in diameter. - It should be understood, that the other dimensions or other materials may be used with the present invention if desired. Moreover, while the device illustrated in
FIG. 3 has a 4×4 rectangular array of vias, a rectangular array of a different size (for example, 6×6 or 9×9) may also be used, as well as a hexagonal array, a rhombohedral array, a face-centered cubic array, an arbitrary arrangement, or any other suitable arrangement. -
FIGS. 5A-5D illustrate an embodiment of the present invention at various stages during fabrication.Layers FIG. 5A , are epitaxially grown on an n-GaAs substrate (not shown) and then bonded toGaP substrate 202. Thus, thecapping layer 212, e.g., of n+GaAs or n+InGaP, is formed over the n-GaAs substrate. One or more n-type layers 210 are formed on thecapping layer 212. N-type layers 210 may include, for example, a buffer layer, a contact layer, an undoped crystal layer, and n-type layers of varying composition and dopant concentration. Anactive region 208 is then formed on the n-type layers 210.Active region 208 may include, for example, a set of quantum well layers separated by a set of barrier layers. One or more p-type layers 206 are formed on theactive region 208. P-type layers 206 may include, for example, may include, for example, a carrier confining layer, a contact layer, and other p-type layers of various composition and dopant concentration. The various layers may be deposited by, for example, MOCVD or other appropriate, well known techniques. The p-type layers 206 are then bonded to theGaP substrate 202 and the n-GaAs substrate is selectively removed. TheITO layer 214 is deposited over thecapping layer 212 and thereflective mirror layer 216 of, e.g., Ag or Au, is deposited over theITO layer 214 resulting in the structure shown inFIG. 5A . TheITO layer 214 and thereflective mirror layer 216 may be deposited by, e.g., e-beam evaporation or sputtering. - The
ITO layer 214,mirror layer 216 and thecapping layer 212 are patterned as shown inFIG. 5B , using for example photolithography along with etching, or a lift-off process. The patterning removes any of theITO layer 214,mirror layer 216 andcapping layer 212 that will not be used as an n-contact. The patterning thus removes any of the ncontact overlying vias 217 shown inFIGS. 3 and 4 . As shown inFIG. 5C , one or more etching steps are then performed to formvias 217. - A
dielectric layer 218, such as for example silicon nitride or silicon oxide, is deposited, as shown inFIG. 5D to electrically isolate theITO layer 214 andmirror layer 216, which serve as the n-contact, from the p metal to be deposited in via 217.Dielectric layer 218 may be any material that electrically isolates two materials on either side ofdielectric layer 218.Dielectric layer 218 is patterned to remove a portion of the dielectric material covering thep layer 204 at the bottom of via 217 and a portion of the top of themirror layer 216.Dielectric layer 218 must have a low density of pinholes to prevent short circuiting between the p- and n-contacts. In some embodiments,dielectric layer 218 is multiple dielectric layers. - The
p contact layer 220 is then deposited over thedielectric layer 218 and in via 217. Theinterconnect 222, which connects the p-metal deposited in each via 217, may also be deposited at this time. Thep contact layer 220 is patterned to remove a portion of the material covering themirror layer 216 as shown inFIG. 4 . - Although the present invention is illustrated in connection with specific embodiments for instructional purposes, the present invention is not limited thereto. Various adaptations and modifications may be made without departing from the scope of the invention. Therefore, the spirit and scope of the appended claims should not be limited to the foregoing description.
Claims (25)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/860,502 US20080224158A1 (en) | 2004-10-06 | 2007-09-24 | Light Emitting Device With Undoped Substrate And Doped Bonding Layer |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/960,391 US7274040B2 (en) | 2004-10-06 | 2004-10-06 | Contact and omnidirectional reflective mirror for flip chipped light emitting devices |
US11/860,502 US20080224158A1 (en) | 2004-10-06 | 2007-09-24 | Light Emitting Device With Undoped Substrate And Doped Bonding Layer |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/960,391 Continuation US7274040B2 (en) | 2004-10-06 | 2004-10-06 | Contact and omnidirectional reflective mirror for flip chipped light emitting devices |
Publications (1)
Publication Number | Publication Date |
---|---|
US20080224158A1 true US20080224158A1 (en) | 2008-09-18 |
Family
ID=35636892
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/960,391 Active US7274040B2 (en) | 2004-10-06 | 2004-10-06 | Contact and omnidirectional reflective mirror for flip chipped light emitting devices |
US11/860,502 Abandoned US20080224158A1 (en) | 2004-10-06 | 2007-09-24 | Light Emitting Device With Undoped Substrate And Doped Bonding Layer |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/960,391 Active US7274040B2 (en) | 2004-10-06 | 2004-10-06 | Contact and omnidirectional reflective mirror for flip chipped light emitting devices |
Country Status (5)
Country | Link |
---|---|
US (2) | US7274040B2 (en) |
EP (1) | EP1646092B1 (en) |
JP (1) | JP2006108698A (en) |
DE (1) | DE602005012207D1 (en) |
TW (1) | TW200627676A (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20100151612A1 (en) * | 2007-03-16 | 2010-06-17 | Toyoda Gosei Co., Ltd. | Group III-V semiconductor device and method for producing the same |
CN104217927A (en) * | 2014-09-29 | 2014-12-17 | 圆融光电科技有限公司 | Graphical method of multi-layer insulating film and multi-layer insulating film of chip |
JP2015173294A (en) * | 2015-06-05 | 2015-10-01 | ローム株式会社 | Light-emitting element, light-emitting element unit, and light-emitting element package |
WO2018129428A1 (en) * | 2017-01-09 | 2018-07-12 | Danesh Fariba | Light emitting diodes with integrated reflector for a direct view display and method of making thereof |
US10998465B2 (en) | 2017-01-09 | 2021-05-04 | Glo Ab | Light emitting diodes with integrated reflector for a direct view display and method of making thereof |
Families Citing this family (75)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR100987451B1 (en) * | 2003-12-04 | 2010-10-13 | 엘지전자 주식회사 | Flat luminescence device |
KR100624448B1 (en) * | 2004-12-02 | 2006-09-18 | 삼성전기주식회사 | Semiconductor light emitting device and method thereof |
EP1974389A4 (en) | 2006-01-05 | 2010-12-29 | Illumitex Inc | Separate optical device for directing light from an led |
KR100736623B1 (en) * | 2006-05-08 | 2007-07-09 | 엘지전자 주식회사 | Led having vertical structure and method for making the same |
KR100812736B1 (en) | 2006-06-29 | 2008-03-12 | 삼성전기주식회사 | High brightness nitride semiconductor light emitting device |
JP2010505250A (en) * | 2006-09-29 | 2010-02-18 | オスラム オプト セミコンダクターズ ゲゼルシャフト ミット ベシュレンクテル ハフツング | Optoelectronic element |
JP2010506402A (en) | 2006-10-02 | 2010-02-25 | イルミテックス, インコーポレイテッド | LED system and method |
KR100818466B1 (en) * | 2007-02-13 | 2008-04-02 | 삼성전기주식회사 | Light emitting devices |
US9484499B2 (en) * | 2007-04-20 | 2016-11-01 | Cree, Inc. | Transparent ohmic contacts on light emitting diodes with carrier substrates |
DE102007022947B4 (en) * | 2007-04-26 | 2022-05-05 | OSRAM Opto Semiconductors Gesellschaft mit beschränkter Haftung | Optoelectronic semiconductor body and method for producing such |
US8212273B2 (en) | 2007-07-19 | 2012-07-03 | Photonstar Led Limited | Vertical LED with conductive vias |
US20090173956A1 (en) * | 2007-12-14 | 2009-07-09 | Philips Lumileds Lighting Company, Llc | Contact for a semiconductor light emitting device |
US7985979B2 (en) | 2007-12-19 | 2011-07-26 | Koninklijke Philips Electronics, N.V. | Semiconductor light emitting device with light extraction structures |
US8118447B2 (en) | 2007-12-20 | 2012-02-21 | Altair Engineering, Inc. | LED lighting apparatus with swivel connection |
DE102008011809A1 (en) | 2007-12-20 | 2009-06-25 | Osram Opto Semiconductors Gmbh | Optoelectronic component |
EP2240968A1 (en) | 2008-02-08 | 2010-10-20 | Illumitex, Inc. | System and method for emitter layer shaping |
US7791101B2 (en) * | 2008-03-28 | 2010-09-07 | Cree, Inc. | Indium gallium nitride-based ohmic contact layers for gallium nitride-based devices |
US8360599B2 (en) | 2008-05-23 | 2013-01-29 | Ilumisys, Inc. | Electric shock resistant L.E.D. based light |
US8653984B2 (en) | 2008-10-24 | 2014-02-18 | Ilumisys, Inc. | Integration of LED lighting control with emergency notification systems |
US7938562B2 (en) | 2008-10-24 | 2011-05-10 | Altair Engineering, Inc. | Lighting including integral communication apparatus |
US8901823B2 (en) | 2008-10-24 | 2014-12-02 | Ilumisys, Inc. | Light and light sensor |
US8324817B2 (en) | 2008-10-24 | 2012-12-04 | Ilumisys, Inc. | Light and light sensor |
US8214084B2 (en) | 2008-10-24 | 2012-07-03 | Ilumisys, Inc. | Integration of LED lighting with building controls |
KR101543328B1 (en) * | 2008-11-18 | 2015-08-11 | 삼성전자주식회사 | Light emitting device and method of fabricating light emitting device |
TW201034256A (en) | 2008-12-11 | 2010-09-16 | Illumitex Inc | Systems and methods for packaging light-emitting diode devices |
US8556452B2 (en) | 2009-01-15 | 2013-10-15 | Ilumisys, Inc. | LED lens |
US8362710B2 (en) | 2009-01-21 | 2013-01-29 | Ilumisys, Inc. | Direct AC-to-DC converter for passive component minimization and universal operation of LED arrays |
US8664880B2 (en) | 2009-01-21 | 2014-03-04 | Ilumisys, Inc. | Ballast/line detection circuit for fluorescent replacement lamps |
JP2010245366A (en) * | 2009-04-08 | 2010-10-28 | Fujifilm Corp | Electronic device, method of manufacturing the same, and display device |
US8330381B2 (en) | 2009-05-14 | 2012-12-11 | Ilumisys, Inc. | Electronic circuit for DC conversion of fluorescent lighting ballast |
US8299695B2 (en) | 2009-06-02 | 2012-10-30 | Ilumisys, Inc. | Screw-in LED bulb comprising a base having outwardly projecting nodes |
EP2446715A4 (en) | 2009-06-23 | 2013-09-11 | Ilumisys Inc | Illumination device including leds and a switching power control system |
US9437785B2 (en) * | 2009-08-10 | 2016-09-06 | Cree, Inc. | Light emitting diodes including integrated backside reflector and die attach |
US8449128B2 (en) | 2009-08-20 | 2013-05-28 | Illumitex, Inc. | System and method for a lens and phosphor layer |
US8585253B2 (en) | 2009-08-20 | 2013-11-19 | Illumitex, Inc. | System and method for color mixing lens array |
WO2011119907A2 (en) | 2010-03-26 | 2011-09-29 | Altair Engineering, Inc. | Led light tube with dual sided light distribution |
CA2792940A1 (en) | 2010-03-26 | 2011-09-19 | Ilumisys, Inc. | Led light with thermoelectric generator |
US8540401B2 (en) | 2010-03-26 | 2013-09-24 | Ilumisys, Inc. | LED bulb with internal heat dissipating structures |
AU2011268135B2 (en) | 2010-06-18 | 2014-06-12 | Glo Ab | Nanowire LED structure and method for manufacturing the same |
US8454193B2 (en) | 2010-07-08 | 2013-06-04 | Ilumisys, Inc. | Independent modules for LED fluorescent light tube replacement |
US8395079B2 (en) * | 2010-07-12 | 2013-03-12 | Lawrence Livermore National Security, Llc | Method and system for high power reflective optical elements |
EP2593714A2 (en) | 2010-07-12 | 2013-05-22 | iLumisys, Inc. | Circuit board mount for led light tube |
CN103222073B (en) * | 2010-08-03 | 2017-03-29 | 财团法人工业技术研究院 | Light-emitting diode chip for backlight unit, package structure for LED and to form above-mentioned method |
DE102010035966A1 (en) * | 2010-08-31 | 2012-03-01 | Osram Opto Semiconductors Gmbh | Optoelectronic semiconductor chip and method for producing an optoelectronic semiconductor chip |
DE102010044738A1 (en) | 2010-09-08 | 2012-03-08 | Osram Opto Semiconductors Gmbh | Thin-film encapsulation, optoelectronic semiconductor body with a thin-layer encapsulation and method for producing a thin-layer encapsulation |
TW201216517A (en) * | 2010-10-06 | 2012-04-16 | Chi Mei Lighting Tech Corp | Light-emitting diode device and manufacturing method thereof |
CN102456793A (en) * | 2010-10-25 | 2012-05-16 | 佛山市奇明光电有限公司 | Light-emitting diode component and manufacturing method for same |
WO2012058556A2 (en) | 2010-10-29 | 2012-05-03 | Altair Engineering, Inc. | Mechanisms for reducing risk of shock during installation of light tube |
US8870415B2 (en) | 2010-12-09 | 2014-10-28 | Ilumisys, Inc. | LED fluorescent tube replacement light with reduced shock hazard |
WO2013028965A2 (en) | 2011-08-24 | 2013-02-28 | Ilumisys, Inc. | Circuit board mount for led light |
CN103828073B (en) * | 2011-09-16 | 2016-09-21 | 首尔伟傲世有限公司 | Light emitting diode and the method manufacturing this light emitting diode |
US8350251B1 (en) | 2011-09-26 | 2013-01-08 | Glo Ab | Nanowire sized opto-electronic structure and method for manufacturing the same |
CN102403425A (en) * | 2011-11-25 | 2012-04-04 | 俞国宏 | Method for manufacturing inverted LED chip |
WO2013131002A1 (en) | 2012-03-02 | 2013-09-06 | Ilumisys, Inc. | Electrical connector header for an led-based light |
KR101887942B1 (en) * | 2012-05-07 | 2018-08-14 | 삼성전자주식회사 | Light emitting device |
KR101669641B1 (en) | 2012-06-28 | 2016-10-26 | 서울바이오시스 주식회사 | Light Emitting Diode for Surface Mount Technology, Method of manufacturing the same and Method of manufacturing of Light Emitting Diode Module |
US8816383B2 (en) * | 2012-07-06 | 2014-08-26 | Invensas Corporation | High performance light emitting diode with vias |
WO2014008463A1 (en) | 2012-07-06 | 2014-01-09 | Ilumisys, Inc. | Power supply assembly for led-based light tube |
US9271367B2 (en) | 2012-07-09 | 2016-02-23 | Ilumisys, Inc. | System and method for controlling operation of an LED-based light |
US9285084B2 (en) | 2013-03-14 | 2016-03-15 | Ilumisys, Inc. | Diffusers for LED-based lights |
EP3022778B1 (en) * | 2013-07-18 | 2019-06-26 | Lumileds Holding B.V. | A highly reflective led chip |
US9267650B2 (en) | 2013-10-09 | 2016-02-23 | Ilumisys, Inc. | Lens for an LED-based light |
EP3097748A1 (en) | 2014-01-22 | 2016-11-30 | iLumisys, Inc. | Led-based light with addressed leds |
EP2942815B1 (en) * | 2014-05-08 | 2020-11-18 | Nexperia B.V. | Semiconductor device and manufacturing method |
US9510400B2 (en) | 2014-05-13 | 2016-11-29 | Ilumisys, Inc. | User input systems for an LED-based light |
CN113035850B (en) * | 2014-06-18 | 2022-12-06 | 艾克斯展示公司技术有限公司 | Micro-assembly LED display |
KR101888608B1 (en) * | 2014-10-17 | 2018-09-20 | 엘지이노텍 주식회사 | Light emitting device package and lighting apparatus |
US10161568B2 (en) | 2015-06-01 | 2018-12-25 | Ilumisys, Inc. | LED-based light with canted outer walls |
US10998478B2 (en) * | 2015-08-18 | 2021-05-04 | Lg Innotek Co., Ltd. | Light-emitting element, light-emitting element package comprising light-emitting element, and light-emitting device comprising light-emitting element package |
JP6974324B2 (en) * | 2015-12-29 | 2021-12-01 | ルミレッズ ホールディング ベーフェー | Flip chip LED with side reflector and phosphor |
DE102016112587A1 (en) | 2016-07-08 | 2018-01-11 | Osram Opto Semiconductors Gmbh | Radiation-emitting semiconductor chip |
US10804436B2 (en) | 2017-10-06 | 2020-10-13 | Glo Ab | Light emitting diode containing oxidized metal contacts |
US11362238B2 (en) | 2017-10-06 | 2022-06-14 | Nanosys, Inc. | Light emitting diode containing oxidized metal contacts |
CN110379801A (en) * | 2019-07-04 | 2019-10-25 | 南京宇丰晔禾信息科技有限公司 | LED lamp bead, display screen |
US11600656B2 (en) | 2020-12-14 | 2023-03-07 | Lumileds Llc | Light emitting diode device |
Citations (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20020055003A1 (en) * | 1998-08-03 | 2002-05-09 | The Curators Of The University Of Missouri | Zinc oxide films containing p-type dopant and process for preparing same |
US20020141006A1 (en) * | 2001-03-30 | 2002-10-03 | Pocius Douglas W. | Forming an optical element on the surface of a light emitting device for improved light extraction |
US6530991B2 (en) * | 1999-12-14 | 2003-03-11 | Riken | Method for the formation of semiconductor layer |
US20030057434A1 (en) * | 1998-10-22 | 2003-03-27 | Masayuki Hata | Semiconductor device having improved buffer layers |
US6583443B1 (en) * | 2001-12-26 | 2003-06-24 | United Epitaxy Co., Ltd. | Light emitting diode and method of making the same |
US20030230754A1 (en) * | 2002-06-13 | 2003-12-18 | Steigerwald Daniel A. | Contacting scheme for large and small area semiconductor light emitting flip chip devices |
US6667529B2 (en) * | 2001-05-07 | 2003-12-23 | Mitsubishi Denki Kabushiki Kaisha | Semiconductor device |
US20040125838A1 (en) * | 2002-12-26 | 2004-07-01 | Wen-Huang Liu | Light emitter with a voltage dependent resistor layer |
US6784462B2 (en) * | 2001-12-13 | 2004-08-31 | Rensselaer Polytechnic Institute | Light-emitting diode with planar omni-directional reflector |
US6784463B2 (en) * | 1997-06-03 | 2004-08-31 | Lumileds Lighting U.S., Llc | III-Phospide and III-Arsenide flip chip light-emitting devices |
US20050167680A1 (en) * | 2004-02-02 | 2005-08-04 | Shih-Chang Shei | Light-emitting diode structure with electrostatic discharge protection |
US20050173724A1 (en) * | 2004-02-11 | 2005-08-11 | Heng Liu | Group III-nitride based LED having a transparent current spreading layer |
US7019330B2 (en) * | 2003-08-28 | 2006-03-28 | Lumileds Lighting U.S., Llc | Resonant cavity light emitting device |
US20060097278A1 (en) * | 2002-06-20 | 2006-05-11 | Osamu Goto | Gan semiconductor device |
US20060145177A1 (en) * | 2003-02-28 | 2006-07-06 | Kazunori Hagimoto | Light emitting device and process for fabricating the same |
Family Cites Families (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5779685A (en) * | 1980-11-05 | 1982-05-18 | Ricoh Co Ltd | Light emitting diode device |
JPS5853873A (en) * | 1981-09-25 | 1983-03-30 | Nec Corp | Surface illuminating type light emitting diode |
CA1267716A (en) * | 1984-02-23 | 1990-04-10 | Frederick W. Scholl | Edge-emitting light emitting diode |
JPH06151955A (en) * | 1992-10-29 | 1994-05-31 | Victor Co Of Japan Ltd | Semiconductor light emitting element |
GB9524414D0 (en) * | 1995-11-29 | 1996-01-31 | Secr Defence | Low resistance contact semiconductor device |
JP3447527B2 (en) * | 1996-09-09 | 2003-09-16 | 株式会社東芝 | Semiconductor light emitting device and method of manufacturing the same |
US20020047131A1 (en) * | 1999-12-22 | 2002-04-25 | Ludowise Michael J. | Selective placement of quantum wells in flipchip light emitting diodes for improved light extraction |
US6486499B1 (en) * | 1999-12-22 | 2002-11-26 | Lumileds Lighting U.S., Llc | III-nitride light-emitting device with increased light generating capability |
TW556253B (en) * | 2002-01-15 | 2003-10-01 | United Epitaxy Co Ltd | High efficiency light emitting diode and method of making the same |
JP4122785B2 (en) * | 2002-01-30 | 2008-07-23 | 日亜化学工業株式会社 | Light emitting element |
JP2003249682A (en) * | 2002-02-22 | 2003-09-05 | Toshiba Corp | Semiconductor light emitting device |
TW577178B (en) * | 2002-03-04 | 2004-02-21 | United Epitaxy Co Ltd | High efficient reflective metal layer of light emitting diode |
JP4123828B2 (en) * | 2002-05-27 | 2008-07-23 | 豊田合成株式会社 | Semiconductor light emitting device |
JP2004056010A (en) * | 2002-07-23 | 2004-02-19 | Toyota Central Res & Dev Lab Inc | Nitride semiconductor light emitting device |
JP4121551B2 (en) * | 2002-10-23 | 2008-07-23 | 信越半導体株式会社 | Light emitting device manufacturing method and light emitting device |
-
2004
- 2004-10-06 US US10/960,391 patent/US7274040B2/en active Active
-
2005
- 2005-09-27 DE DE602005012207T patent/DE602005012207D1/en active Active
- 2005-09-27 EP EP05108919A patent/EP1646092B1/en active Active
- 2005-10-03 TW TW094134441A patent/TW200627676A/en unknown
- 2005-10-06 JP JP2005321479A patent/JP2006108698A/en active Pending
-
2007
- 2007-09-24 US US11/860,502 patent/US20080224158A1/en not_active Abandoned
Patent Citations (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6784463B2 (en) * | 1997-06-03 | 2004-08-31 | Lumileds Lighting U.S., Llc | III-Phospide and III-Arsenide flip chip light-emitting devices |
US20020055003A1 (en) * | 1998-08-03 | 2002-05-09 | The Curators Of The University Of Missouri | Zinc oxide films containing p-type dopant and process for preparing same |
US20030057434A1 (en) * | 1998-10-22 | 2003-03-27 | Masayuki Hata | Semiconductor device having improved buffer layers |
US6530991B2 (en) * | 1999-12-14 | 2003-03-11 | Riken | Method for the formation of semiconductor layer |
US20020141006A1 (en) * | 2001-03-30 | 2002-10-03 | Pocius Douglas W. | Forming an optical element on the surface of a light emitting device for improved light extraction |
US6667529B2 (en) * | 2001-05-07 | 2003-12-23 | Mitsubishi Denki Kabushiki Kaisha | Semiconductor device |
US6784462B2 (en) * | 2001-12-13 | 2004-08-31 | Rensselaer Polytechnic Institute | Light-emitting diode with planar omni-directional reflector |
US6583443B1 (en) * | 2001-12-26 | 2003-06-24 | United Epitaxy Co., Ltd. | Light emitting diode and method of making the same |
US20030230754A1 (en) * | 2002-06-13 | 2003-12-18 | Steigerwald Daniel A. | Contacting scheme for large and small area semiconductor light emitting flip chip devices |
US20060097278A1 (en) * | 2002-06-20 | 2006-05-11 | Osamu Goto | Gan semiconductor device |
US20040125838A1 (en) * | 2002-12-26 | 2004-07-01 | Wen-Huang Liu | Light emitter with a voltage dependent resistor layer |
US20060145177A1 (en) * | 2003-02-28 | 2006-07-06 | Kazunori Hagimoto | Light emitting device and process for fabricating the same |
US7019330B2 (en) * | 2003-08-28 | 2006-03-28 | Lumileds Lighting U.S., Llc | Resonant cavity light emitting device |
US20050167680A1 (en) * | 2004-02-02 | 2005-08-04 | Shih-Chang Shei | Light-emitting diode structure with electrostatic discharge protection |
US20050173724A1 (en) * | 2004-02-11 | 2005-08-11 | Heng Liu | Group III-nitride based LED having a transparent current spreading layer |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20100151612A1 (en) * | 2007-03-16 | 2010-06-17 | Toyoda Gosei Co., Ltd. | Group III-V semiconductor device and method for producing the same |
US8420502B2 (en) * | 2007-03-16 | 2013-04-16 | Toyoda Gosei Co., Ltd. | Group III-V semiconductor device and method for producing the same |
CN104217927A (en) * | 2014-09-29 | 2014-12-17 | 圆融光电科技有限公司 | Graphical method of multi-layer insulating film and multi-layer insulating film of chip |
JP2015173294A (en) * | 2015-06-05 | 2015-10-01 | ローム株式会社 | Light-emitting element, light-emitting element unit, and light-emitting element package |
WO2018129428A1 (en) * | 2017-01-09 | 2018-07-12 | Danesh Fariba | Light emitting diodes with integrated reflector for a direct view display and method of making thereof |
US10553767B2 (en) | 2017-01-09 | 2020-02-04 | Glo Ab | Light emitting diodes with integrated reflector for a direct view display and method of making thereof |
US10998465B2 (en) | 2017-01-09 | 2021-05-04 | Glo Ab | Light emitting diodes with integrated reflector for a direct view display and method of making thereof |
Also Published As
Publication number | Publication date |
---|---|
US7274040B2 (en) | 2007-09-25 |
EP1646092A3 (en) | 2006-12-06 |
TW200627676A (en) | 2006-08-01 |
US20060071228A1 (en) | 2006-04-06 |
DE602005012207D1 (en) | 2009-02-26 |
EP1646092A2 (en) | 2006-04-12 |
EP1646092B1 (en) | 2009-01-07 |
JP2006108698A (en) | 2006-04-20 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7274040B2 (en) | Contact and omnidirectional reflective mirror for flip chipped light emitting devices | |
US8679869B2 (en) | Contact for a semiconductor light emitting device | |
US8319243B2 (en) | Nitride semiconductor light-emitting device and method of manufacturing the same | |
EP2033238B1 (en) | Semiconductor light emitting device including porous layer | |
US6800500B2 (en) | III-nitride light emitting devices fabricated by substrate removal | |
US6992331B2 (en) | Gallium nitride based compound semiconductor light-emitting device | |
EP1608030A2 (en) | Light emitting device with transparent submount having backside vias | |
US8823049B2 (en) | Light-emitting diode with current-spreading region | |
EP1511137A2 (en) | Resonant cavity light emitting device | |
US20230024651A1 (en) | Light-emitting diode | |
CN115566036A (en) | Light emitting element | |
US6777717B1 (en) | LED reflector for improved light extraction | |
TW201817033A (en) | III-P light emitting device with a superlattice | |
CN111490140A (en) | Light emitting element | |
US20110121358A1 (en) | P-type layer for a iii-nitride light emitting device | |
KR20220140748A (en) | Micro-LED and method for making same | |
JP6697020B2 (en) | Light emitting diode having light emitting layer containing nitrogen and phosphorus | |
US20240030387A1 (en) | Light-emitting device and method for manufacturing the same | |
KR102189614B1 (en) | III-P light emitting device with super lattice | |
CN115548187A (en) | Light emitting diode and light emitting device | |
JP2004304050A (en) | Light emitting diode |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |
|
AS | Assignment |
Owner name: LUMILEDS LIGHTING, U.S. LLC, CALIFORNIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SUN, DECAI;REEL/FRAME:045499/0366 Effective date: 20041001 |
|
AS | Assignment |
Owner name: PHILIPS LUMILEDS LIGHTING COMPANY LLC, CALIFORNIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:LUMILEDS LIGHTING, U.S. LLC;REEL/FRAME:045530/0395 Effective date: 20110215 |
|
AS | Assignment |
Owner name: LUMILEDS LLC, CALIFORNIA Free format text: CHANGE OF NAME;ASSIGNOR:PHILIPS LUMILEDS LIGHTING COMPANY LLC;REEL/FRAME:046623/0038 Effective date: 20150326 |