TW488084B - High brightness LED - Google Patents

Abstract

A high brightness LED is disclosed, which comprises a first electrode; a semiconductor substrate associated with the first electrode; a first binding layer having the first conductivity formed on the semiconductor substrate; an active layer formed on the first binding layer; a second binding layer having the second conductivity formed on the active layer, whose upper surface comprises a central region and an exterior region located outside the central region; a contact layer formed on the exterior region of the second binding layer; a transparent conductive layer covering the contact layer and the central region, forming an Ohmic contact with the contact layer, and forming a Shottky barrier with the central region; a second electrode formed on the transparent conductive layer substantially on the central region.

Description

488084 V. Description of the invention (1) Field of the invention The present invention relates to a light-emitting diode, and more particularly to a high-brightness light-emitting diode. Explanation of related skills ^ The applicant of this case filed an application on February 9, 1999, and the invention name was “Nanjidu Light-Emitting Diode” No. 088 1 0 1 946 for the invention patent application 'Revelation according to its first preference Example of a high-brightness peripheral light-emitting diode, medium

^ The main technical content is to control the distribution of the current so that the current does not flow substantially to the area directly below the front electrode, so that substantially all the current sent from the front electrode is in the active layer at an appropriate distance from directly below the front electrode. It has a luminous effect, so the light emitted can avoid the blocking of the front electrode, and enhance the luminous effect of the diode, as shown in the figure! As shown in the figure, a semiconductor base layer 12 composed of ^ is formed on the n-type rear electrode 10, and a multilayer Bragg reflection layer 30 is formed on the semiconductor base layer 12. The multilayer Bragg reflection layer 30 is preferably composed of a series of materials such as AlGalnP or AlGaAs. The multilayer structure 4 is formed on the reflective layer 30. The multilayer structure 14 includes an n-type bottom binding layer 140 composed of A1GaInP, an active layer 142 composed of AlGaInP, and an AlGalnP structure.

成 至 P-shaped top binding layer 1 44. A p-type window layer 6 is formed on the top restraint layer 144. This window layer 16 is preferably made of GaP, GaASP, GalnP,

A transparent material such as AlGalnP or AlGaAs is formed, and the window layer 16 is formed into a ring-shaped groove of a predetermined depth by dry etching or wet etching at an appropriate distance from the front electrode 20 directly below. A P-type contact layer 17 is formed on the window 16 at an appropriate distance directly below the front electrode 20. This contact layer I?

It is made of a transparent material such as GaP, GaAsP, GalnP, or GaAs. A layer of transparency

V. Description of the invention (2) The layer 17 and the contact layer 17 are in contact with the window layer 16 and the window layer 19 should be composed of indium tin oxide and oxide transparent material. A p-type forms an ohmic contact and is arranged with the ring groove of the window, so after the front spreads, only the ohm is passed, so the chance of diffusion through the ohmic contact portion is reduced to all currents that are phased out in the active layer The light emitting effect is generated at an appropriate distance to improve the light emitting effect of the diode. The outer part of the electrical layer 19 is formed on the contact to form an ohmic contact, and the other parts directly form a Schottky barrier between the 16 layers. This conductive indium, tin oxide, Zinc oxide, or oxidation = front electrode 20 is formed on the conductive layer 19. The Schottky barrier is formed between the conductive layer 19 and the contact layer 17 and the layer 16 and the current sent by the circular electrode 20 contacts the conductive layer 19, but the current flowing downward through the Schottky barrier does not forward the electrode. 20 is just small, so that 142 out of the front electrode 20 are actually used directly below the front electrode 20, so the obstacle of the front electrode 20 can be avoided.-The inventor of the chase and chase case is thinking about how to reduce the When the previous high-brightness light was emitted, the inspiration for the # production cost was flashed. I thought that for the surface-mount device π, # ϋ 之 ^ light diode, because its lateral brightness is irrelevant_ j% & window layer 16 should It can be completely eliminated, so that not only the cost of growing the window layer 16 but also the cost of etching the window layer 16 can be saved. Summary of the invention: Lu Ying: The purpose of the present invention is to provide a high-brightness light emitting diode without a window layer, so as to achieve low manufacturing cost and material cost. To achieve the above objects, according to a first preferred embodiment of the present invention, 488084

A shell-shaped light-emitting diode including a first electrode; > a semiconductor substrate bonded to the first electrode; a first binding layer having a first conductivity formed on the semiconductor substrate; an active layer, Formed on the first tethering layer; a second tethering layer having second conductivity is formed on the active layer; the upper surface of the second tethering layer includes a central region and a peripheral region located on the periphery of the central region; A contact layer formed on the peripheral region of the second tie layer; a transparent conductive layer covering the contact layer and the central region, and forming an ohmic contact with the contact layer, and forming a Xiao with the central region; A base barrier; and a second electrode formed on the transparent conductive layer substantially above the central region. Detailed description. Referring to FIG. 2, in a high-brightness light emitting diode according to the first preferred embodiment of the present invention, an n-type rear electrode 10 is bonded to a lower surface of an nSGaAs semiconductor substrate 12, and the semiconductor substrate 12 is formed on the semiconductor substrate 12. Multi-layer Bragg reflection layer 30 'This multilayer Bragg reflection layer 30 should preferably be made of a series of materials such as A1GaInP or A1GaAs. A ρ-η junction layer (p —n junction stack) 14 is formed on the reflective layer 30. The p —n junction layer η includes an η-type bottom binding layer 140 composed of AlGalnP, an active layer 142 composed of AlGa InP, And a p-type top tie layer 144 made of AlGalnP. A p-type contact layer 17 is formed on the P-type top confinement layer 1 4 4 and then is etched to form a central circular through hole 'exposing the portion of the surface of the P-type top confinement layer 1 4 4 below the central circular through hole. 'Then a transparent conductive layer 9 is covered on the p-type contact layer 17 and the exposed p-type top tie layer 144. A p-type front electrode 20 is formed on the transparent conductive layer 19 above the central circular through hole. Contact layer 1

Page 6 488084 V. Description of the invention (4) GaP composed of erbium-doped carbon, whose doping concentration can reach 102G / cffl3. Since the ohmic contact is formed between the transparent conductive layer 19 and the!) Type contact layer 17 and the Schottky barrier is formed between the top binding layer 144, the flow from the front electrode 20 passes through the ohmic contact portion only, but does not pass through the Xiaoji Obstacles, all currents sent from the Ke electrode 20 on Bebe generate light emission in the active layer 142, and areas directly below the front electrode 20, so it can avoid the barrier of the thorium electrode 20 and obtain a good luminous effect. f 3 shows one of the second preferred embodiment of the present invention; the difference between the body and its first-best. embodiment of the high-brightness light-emitting diode f is: replacing the first with a P-type GaAs contact layer 17 In the preferred embodiment, the second-degree GaP contact layer 17 is formed, and a thin top beam of the GaAs contact layer = layer "4" is added to a thin layer (thickness, for example), transparent 15 = a stop layer when the GaAs contact layer 17 is etched ΐ5. The stop layer is doped with magnesium, and its doping concentration is, for example, lOiVcm3. The high-brightness light emission of each of the foregoing preferred embodiments. In the prior art, the window layer usually has a thickness of several tens of microns, so it can; Someone should understand that the concept of the present invention can also be applied to the case where the base barrier is formed on the light-emitting surface at f, the above-mentioned P-η buildup layer is located below the electric pole in the central area of the surface, but not The ones that are necessarily formed in the μ Π Π X are only the preferred embodiments of the present invention, and the modifications of the present invention are all subject to any changes in the application of the invention. For example, the semiconductor is eliminated. Substrate 488084 V. Description of the invention (5) Multi-layer cloth on 12 Grid reflective layer 30, obviously without departing from the spirit and scope of the invention.

UBI Page 8 488084 Brief description of the diagram Brief description of the diagram: Fig. 1 shows a high-brightness light-emitting diode of the prior art; and Fig. 2 schematically shows a high-brightness light-emitting diode 2 according to the first preferred embodiment of the present invention. Polar body. Fig. 3 schematically shows a high-brightness light emitting diode according to a second preferred embodiment of the present invention. DESCRIPTION OF SYMBOLS 10 Back electrode 12 Semiconductor substrate 14 Laminated structure 15 Stop layer 30 Bragg reflector 140 Bottom tie layer 142 Active layer 144 Top tie layer 17 Contact layer 19 Transparent conductive layer 20 Front electrode

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Claims (1)

488084 々 、 Scope of patent application 1. A high-brightness light-emitting diode, comprising: a P-η build-up layer having a first major surface and a second major surface, the second major surface including a central region and located on the A peripheral region on the periphery of the central region; a contact layer formed over the peripheral region of the ρ-η junction layer; and a transparent conductive layer covering the contact layer and the central region and forming an ohmic contact with the contact layer , And essentially formed a Schottky barrier in this central area. 2. A high-brightness light-emitting diode, comprising: an electrode; a ρ-η junction layer formed below the electrode, the ρ-η junction layer having a first major surface and a second major surface, the first The two main surfaces are composed of a masked area that is substantially directly below the electrode and a non-masked area that is substantially not directly below the electrode, and the unmasked area is located on the periphery of the masked area; a contact layer on the Below the electrode is formed above the unshielded area of the ρ-η junction layer; and a transparent conductive layer covers the contact layer and the shielded area under the electrode, and forms an ohmic contact with the contact layer, A Schottky barrier is essentially formed on the covered area. 3. —A kind of high-brightness light-emitting diode, including: Page 10 488084 VI. Application scope: a first electrode; a semiconductor substrate bonded to the first electrode; a first binding layer having a first conductivity formed over the semiconductor substrate; an active layer formed On the first tethering layer; a second tethering layer having a second conductivity is formed on the active layer, and the upper surface of the second tethering layer includes a central region and a peripheral region located on the periphery of the central region; A contact layer is formed on the peripheral region of the second east-bound layer. A transparent conductive layer covers the contact layer and the central region, forms an ohmic contact with the contact layer, and forms a contact with the central region. A base barrier; and a second electrode formed on the transparent conductive layer substantially above the central region. 4. The high-brightness light-emitting diode according to item 3 of the patent application scope, wherein a multilayer Bragg reflector is further included between the semiconductor substrate and the first restraint layer. 5. A high-brightness light-emitting diode comprising: a P-η buildup layer having a first major surface and a second major surface, the second major surface including a central region and one of the periphery of the central region Peripheral region; a stop layer formed above the ρ-η accumulation layer; Page 11 488084 VI. Patent application scope A contact layer is formed on the stop layer above the peripheral area; and a transparent conductive layer located on the η build-up layer covers the contact layer to form an ohmic contact with the contact layer, and It is above the central area and is in obstacle with Xiao Ji. @ 贝 forms 6 ·· high-brightness light-emitting diodes on the central region, including: an electrode; a ρ-η build-up layer formed under the electrode, a first major surface and a second major surface, The ρ-η buildup layer has a masked area whose main surface is directly below the electrode, and its main surface is composed of a non-blocked area directly below the electrode. A stop layer in the masked area is formed above the ρ-η buildup layer. A contact layer is formed below the electrode above the non-shielded area of the P-η buildup layer; and: on the stop layer And is located: a transparent conductive layer, under the electrode, covering the contact layer and the masked layer, and forming an ohmic contact with the contact layer, and substantially forming a Schottky barrier on the cross-shielded region. A 1¾¾ degree light-emitting diode includes a first electrode; a semiconductor substrate bonded to the first electrode; a first binding layer having a first conductivity formed on the semiconductor substrate Page 12 488084 6. Above the scope of the patent application; an active layer is formed on the first tethering layer; a second tethering layer having a second conductivity is formed on the active layer and above the second tethering layer The surface includes a central region and a peripheral region located on the periphery of the central region; a stop layer formed on the second tie layer; a contact layer formed on the stop layer and located on the second tie layer On the peripheral region; a transparent conductive layer covering the contact layer and the central region, forming an ohmic contact with the contact layer, and forming a Schottky barrier with the central region; and a second electrode substantially in the central region A region is formed on the transparent conductive layer. 8. The high-brightness light-emitting diode according to item 7 of the scope of patent application, wherein a multilayer Bragg reflection layer is further included between the semiconductor substrate and the first tie layer ° Page 13