TW417308B - Light emitting diode - Google Patents

Abstract

There is disclosed a light emitting diode, wherein a semiconductor substrate is formed on a back electrode. A plurality of Bragg reflective layers are formed on the semiconductor substrate. A deposition layer structure is formed on the reflective layer. The deposition layer structure has a bottom restriction layer, an active layer, and a top restriction layer. A window layer is formed on the top restriction layer. A contact layer is formed on the window layer. A transparent conductive layer is formed on the contact layer to have an ohmic contact with the contact layer. A round through hole is formed in the center of the contact layer, and a round through hole is also formed in the center of the conductive layer. A front electrode passes through the round through hole in the center of the conductive layer and the round through hole in the center of the contact layer, so as to form on the window layer and contact with the conductive layer.

Description

Λ 5. Description of the invention (1) The present invention relates to a light-emitting diode, and more particularly to a light-emitting diode having a function of controlling electric current and current distribution. In the application filed on June 18, 1997 by the applicant of this case, the invention patent application No. 8 61 08537 for the invention name "" Light Emitting Diode ", disclosed the light emitting diode structure as shown in Fig. 1, where η A semiconductor base layer 12 made of GaAs is formed on the n-type rear electrode 10, and a multilayer Bragg reflection layer 30 is formed on the semiconductor base layer 12, and the multilayer Bragg reflection layer 30 is preferably composed of a series of materials such as AlGalnP or AlGaAs. The laminated structure 14 is formed on the reflective layer 30. The laminated structure 14 includes a ^ -type bottom tie layer 1 40 made of A1GaInP, an active layer 142 'made of AlGalnP, and a P-type top tie layer 144 made of AlGalnP. A p-type window layer 16 is formed on the top restraint f 144. This window layer 16 is preferably made of a transparent material such as Gap, GaAsP, GaInP, or AiGaAs. A P-type contact layer 7 is formed on the window layer 6. The contact layer 17 is preferably made of a material such as Gap, GaAsP, GaInP, or GaAs. A transparent conductive skin 19 is formed on the contact layer 1 and extends to the contact layer. The central hollow portion 17 'forms a Schottky barrier with the window layer 16, and this conductive layer 19 is preferably made of a transparent material such as indium oxide, tin oxide, or indium tin oxide. A P-type front electrode 20 is formed on the conductive layer IQ. This prior art light emitting diode is characterized in that the conductive layer 1 g and the contact surface of the contact layer 17 form an ohmic contact, and the contact surface of the conductive layer 19 and the window layer ^^ forms a Schottky barrier, so it is sent from the front electrode 20 After the current is distributed in the conductive layer 19, it passes through the ohmic contact, but does not pass through the Schottky barrier, and flows downward into the active layer 14 2 and encounters the current from the rear electrode 10 to generate a light-emitting effect.

V. Description of the invention (2) In the two technology light-emitting two-prong body, the current from the front electrode 2 passes through the ohmic contact, but does not pass, and the electric current catches the current directly below the electrode, thereby reducing the & The bad effect of the front electrode 20 blocking. . The light emitted though chrome / gold or chrome / ming is made before the electrode 20 is solid with the conductive layer M :. 'But the front electrode 2 made of titanium / gold or titanium / aluminum: "Combination: _In the actual manufacturing process, when the titanium / gold or the heart is advanced to make a gold wire operation, the front electrode 2 is easily detached from the conductive layer 1 9. At the moment, most manufacturers use titanium / gold or titanium / aluminum before 20 '. Only a few manufacturers use chromium / gold or chromium, and aluminum is made before electricity: so large numbers of manufacturers have The problem of the technology disclosed in the invention patent application cannot be used. Also, the prior art light emitting diode system is applied to the surface of the diode to emit light in the center. However, in the application of the connection between the diode and the optical fiber, the center of the diode must emit light. Therefore, there is also a problem that the technology of the invention patent application cannot be used. In view of the foregoing problems of the previous light emitting diode, an object of the present invention is to provide a light emitting diode, in which the previous electrode can communicate with The contact layer, the window layer, or the insulation layer is combined to avoid the problem of the stable combination of the front electrode and the conductor. Electricity increase ... Another object of the present invention is to provide a light-emitting diode that emits light on the central portion of the surface and the surface thereof. Peripheral Does not emit light, suitable to serve &.-Fiber connector of the case, with reference to the following drawings hereby ^ 'described in detail the preferred embodiment of the present invention e.g.

_ ^ .1.; ： ≫ _ V. Description of the invention (3) ^ '---- After: a brief description of the figure: Figure 1 is a schematic sectional view of a light-emitting diode structure of the prior art; A schematic cross-sectional view of a light emitting diode structure according to the first preferred embodiment of the present invention; FIG. 3 is a top view of the light emitting diode structure according to the first preferred embodiment of the present invention; FIG. 4 is a light emitting diode structure according to the second preferred embodiment of the present invention Fig. 5 is a schematic sectional view of a light emitting diode structure according to a third preferred embodiment of the present invention; Fig. 6 is a schematic sectional view of a light emitting diode structure according to a fourth preferred embodiment of the present invention; 7 is a schematic cross-sectional view of a light-emitting diode structure according to a fifth preferred embodiment of the present invention; and FIG. 8 is a schematic cross-sectional view of a light-emitting diode structure according to a sixth preferred embodiment of the present invention; 'Detailed description of the present invention is as follows. FIG. 2 shows a light emitting diode structure according to the first preferred embodiment of the present invention, in which a semiconductor base layer 12 composed of π-type GaAs is formed on an n-type rear electrode 10, and a multilayer Bragg reflection layer 3 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 AiGaAs. The laminated structure 14 is formed on the reflective layer 30. The laminated structure ί4 includes an n-type bottom binding layer 40 made of AlGaluP, an active layer 142 made of A1GaInP, and a p-type top binding layer 144 made of AlGalnP. P-type

C: \ Program Files \ Patent \ pl0s0O1001.ptd page 6

The window layer 16 is formed on the top restraint layer 144, and this window layer μ —

Transparent materials such as GaAsP, GalnP, AlGalnP, or AlGaAs ^ 3 I. A layer of p-type contact layer 17 is formed on the window layer 16, and a circular perforation is formed in the contact layer & or wet etching. This contact layer 7 should be composed of hp, 6

It is made of a transparent material such as GaAsP, GaInP, or GaAS. A ^ transparent 3 thunder 19 is formed on the contact layer 17 and forms an ohmic contact with the contact layer 17. The center of the electrical layer 19 is formed by dry etching or wet etching-a circular perforation. The electrical layer 19 should be oxidized. Made of transparent materials such as indium tin, indium oxide, tin oxide, oxide, and magnesium. The front electrode 20 is in contact with the conductive layer 9 and passes through the circular perforation in the center of the electrical layer 19 and the circular perforation in the center of the contact layer 17 to contact the user layer 16. Since the front electrode 20 can be combined with the window layer 16 made of a semiconductor material, the front electrode 20 made of an appropriate material can be selected according to conventional techniques, so that the front electrode 20 is firmly combined with the window layer 16 and forms a small base with the window layer 16. Barrier 'for example' For the window layer 16 made of GaP, the front electrode 20 made of Ti / Al, Ti / Au, Cr / Al, or CrVAu can be selected. Because the ohmic contact is formed between the V electrical layer 19 and the contact layer 17 and the Schottky barrier is formed between the front electrode 20 and the window layer 16, the current sent from the front electrode 20 is dispersed in the electrical layer 19 and only Through the ohmic contact portion, but not through the Schottky barrier, it flows downward, so that the current sent from the front electrode 20 can be reduced, and in the active layer 142, a light emitting effect occurs directly below the front electrode 20, so The adverse effect of the front electrode 20 blocking light can be avoided as much as possible, and the luminous efficiency of the diode can be improved. Since the front electrode 20 can be combined with the window layer 丄 6 made of a semiconductor material, the front electrode 20 made of an appropriate material can be selected according to conventional techniques, so that

C: \ Program Files \ Patent \ pl0s001001.ptd Page 7 V. Description of the invention (5) It is firmly combined with the window layer 16; therefore, when performing gold wire work on the front electrode 20, avoid the front electrode 2 0 Get rid of the problem of light-emitting diodes. Figure 3 shows that the front electrode 20 has four extending fingers 31 extending from the center outward to transmit current to the conductive layer 19, and the probability that the front electrode 20 can block light is minimized. FIG. 4 shows a light-emitting diode structure according to a second preferred embodiment of the present invention, which is different from the first preferred embodiment in that: in this second preferred embodiment, the 'contact layer 17 is circular in the center The diameter of the perforation is larger than the diameter of the central circular perforation of the conductive layer 19. One part of the conductive layer 9 is formed on the contact layer 17 and the other is inside the central circular perforation of the contact layer 17 and is formed on the window layer. 16 The center of the circle has 17 obstacles, and the pole 20 sends the part of the light directly from the front of the electricity. The central circle of the fossil evening, the contact layer 17, the front electrode 20 is perforated, and makes ohmic contact with the window. The current from the front electrode 20 and the window is conductive but does not pass through the electricity sent from the electrode 20 to produce a bad effect of luminescence, and 5 shows that chaotic fossils, or oxygen and oxygen are formed within the second preferred shape of the perforation according to the present invention. The insulating layer 18 is in contact with the conductive layer 19, and the conductive layer 19 is in contact with the conductive layer 19 in the conductive layer 19, and the conductive layer 19 is dispersed in the electrical layer 19, which is in the active condition, so Improving the insulation layer of the third preferred embodiment of the diode Material. Conductive layer 19 Since the conductive layer 19, the contact layer, and the window layer 16 form a Schottky barrier to form a Xiaoji barrier, after the front electrical distribution, only the ohmic connection flows downwards, thereby reducing the number of layers 142 in the front electrode 2. The luminous efficiency of the front electrode 20 can be avoided as much as possible. The light-emitting diode structure of the embodiment is the same as that: in the contact layer 17, the insulating layer 18 can be made of oxygen, for example. A conductive layer 19 is formed in the center of the conductive layer for dry etching or wet etching.

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5. Description of the invention (6) '-~'-Carved into a circular perforation. The front electrode 20 is in contact with the conductive layer 丨 g and is formed on the insulating layer 18 through the circular perforation 'of the conductive layer 19. Because the front electrode 20 can be combined with an insulating layer 丨 8 made of a conventional insulating material, the front electrode 20 can be made of an appropriate material according to conventional technology, so that it can be firmly combined with the insulating layer 18. When the electrode 20 performs a gold wire operation, the problem that the front electrode 20 is separated from the light emitting diode can be avoided. FIG. 6 shows a light emitting diode structure according to the fourth preferred embodiment of the present invention, which is different from the first preferred embodiment in that a contact layer 7 is only a circular area of an appropriate size in the center of the window layer 16 Is formed on the window layer 16. A conductive layer 19 without a central perforation is formed on the contact layer 17 and the window layer 16. The front electrode 20 having a central perforation is formed on the conductive layer 9 and the diameter of the central perforation of the front electrode 20 is larger than the diameter of the circular region. Since the Schottky barrier is formed between the conductive layer 19 and the window layer 16, and the contact between the conductive layer 19 and the contact layer 17 is formed, after the current sent from the front electrode 20 passes through the conductive layer ig, it only passes through the ohmic contact portion, but Do not pass through the Schottky barrier, and the current flowing from the front electrode 20 flows down, so the current flows in the active layer! In 42, most of the light-emitting effect occurs directly under the contact layer 17, so the adverse effect of the front electrode 20 blocking light can be avoided as much as possible and the light-emitting efficiency of the diode can be improved. FIG. 7 shows a light-emitting diode structure according to a fifth preferred embodiment of the present invention, which is mainly different from the fourth preferred embodiment in that the light-emitting diode conductive layer 19 is the same as the fourth preferred embodiment. Form a location of the Xiaoji barrier with the window layer 丨 6, and add an insulating layer 丨 8 between the conductive layer 19 and the window layer 16. The Schottky barrier formed between the light emitting diode conductive layer 19 and the window layer 16 as in the fourth preferred embodiment is not enough to resist the voltage drop between the front electrode 20 and the rear electrode.

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Claims (1)

6. Scope of Patent Application 1 An additional light-emitting diode (1) includes:-a first electrode; a semiconductor base layer formed on the first electrode; a first binding layer having a first conductivity formed on the semiconductor On the base layer; an active layer formed on the first tie layer; a second tie layer with second conductivity formed on the active layer; a window layer with second conductivity formed on the second On the restraint layer; a contact layer formed on the window layer; a transparent conductive layer formed on the contact layer and forming an ohmic contact with the contact layer; a predetermined shape of a perforation is formed in the center of the transparent conductive layer; and a first Two electrodes are formed on the contact layer through a hole in the center of the transparent conductive layer, and are in contact with the transparent conductive layer. 2—An additional type of light-emitting diode (1) includes: a first electrode; a semiconductor base layer formed on the first electrode; a first binding layer having a first conductivity formed on the semiconductor base layer; An active layer is formed on the first binding layer; a second binding layer having a second conductivity is formed on the active layer; a window layer having a second conductivity is formed on the second binding layer; A contact layer is formed on the window layer, and a predetermined shape perforation is formed in the center of the contact layer; C: \ ProgramFiles \ Patent \ pl0s001001.ptd page 11 Formed on the contact layer, and in the transparent conductive layer-the scope of six patent applications-the transparent conductive layer forms a predetermined shape of a perforation; and #-the second electrode, the pot passes through the central perforation of the transparent conductive layer and the contact layer A central perforation is formed on the window layer and is in contact with the transparent conductive layer. 3 According to one of the light-emitting diodes (2) in the scope of the patent application, a Schottky barrier is formed between the second electrode and the window layer. 4—An additional type of light emitting diode (1) includes:-a first electrode; a semiconductor base layer formed on the first electrode;-a first tie layer having a first conductivity formed on the semiconductor base layer; An active layer is formed on the first tethering layer;-a second tethering layer having a second conductivity is formed on the active layer;-a window layer having a second conductivity is formed on the second tethering layer; A contact layer is formed on the window layer, and a predetermined shape of a perforation is formed in the center of the contact layer; a transparent conductive layer, a part of which is formed on the contact layer and forms an ohmic contact with the contact layer, and the other part Is formed on the window layer inside the central perforation of the contact layer, and a pre-shaped perforation is formed in the center of the transparent conductive layer; and a second electrode is formed on the window layer through the central tooth hole of the conductive layer. And in contact with the conductive layer. Please add a new type of light-emitting diode in item 4 of the patent scope, which "the transparent conductive layer and the window layer form a Schottky barrier, the second Sixth, the scope of patent application Xiaoji obstacles have also formed between the pole and the window layer. 6—An additional type of light-emitting diode (1) includes: a first electrode; a semiconductor base layer formed on the first electrode; a first binding layer having a first conductivity formed on the semiconductor base layer; An active layer is formed on the first binding layer; a second binding layer having a second conductivity is formed on the active layer; a window layer having a second conductivity is formed on the second binding layer; A contact layer is formed on the window layer, and a center-shaped perforation is formed in the center of the contact layer; an insulating layer is formed in the central perforation of the contact layer; a transparent conductive layer is formed on the contact layer and the On the insulating layer, a hole of a predetermined shape is formed in the center of the conductive layer; and a second electrode is formed on the insulating layer through the central hole of the conductive layer and is in contact with the conductive layer. 7 —An additional type of light emitting diode (1) includes: — a first electrode; a semiconductor base layer formed on the first electrode; a first binding layer having a first conductivity formed on the semiconductor base layer — an active layer Is formed on the first binding layer; a second binding layer having a second conductivity is formed on the active layer; a window layer having a second conductivity is formed on the second binding layer; C: \ Program Fiies \ Patent \ plOs0D1001.p1: d Page 13 M \ '* ί' «^-** 1 41 ..: Six 'patent application scope a contact layer formed in a predetermined shape in the center of the window layer Area; a transparent conductive layer formed on the window layer and the contact layer and forming an ohmic contact with the contact layer; and a second electrode formed on the conductive layer, the second electrode being positive on the contact layer There is a central perforation above. 8 Add (1) according to a light-emitting diode in item 7 of the scope of the patent application, in which a Schottky barrier is formed between the transparent conductive layer and the window layer. 9 The polar body addition (1) includes a first electrode; a semiconductor base layer formed on the first electrode; a first binding layer having a first conductivity formed on the semiconductor base layer; an active layer formed on On the first tethering layer; a second tethering layer having a second conductivity is formed on the active layer; a window layer having a second conductivity is formed on the second tethering layer; a contact layer is formed On an area of a predetermined shape in the center of the window layer; an insulating layer formed on the window layer outside the area of the predetermined shape in the center of the window layer; a transparent conductive layer formed on the insulating layer and the contact layer, An ohmic contact is formed with the contact layer; and a second electrode is formed on the conductive layer, and the second electrode has a central perforation directly above the contact layer. Item (1) of a light-emitting diode, wherein the active layer includes AlGalnP, and the window layer package Page 15 6. The scope of the patent application includes a material selected from the group consisting of GaP, GaAsP, GaInP, AlGaInP, and AlGaAs. The contact layer includes a material selected from GaP, GaAsP, GaInP, and GaAs. Each material in the group 'The conductive layer includes a material selected from the group consisting of indium tin oxide, indium oxide, tin oxide, zinc oxide, and magnesium oxide, and the base layer includes GaAs', the first bond The layer includes AlGalnP, the second tie layer includes AlGalnP, the insulating layer includes a material selected from the group consisting of stone oxide, silicon nitride, and aluminum oxide, and the semiconductor base layer and the laminated structure are more A reflective layer is formed. The reflective layer is composed of multiple distributed Braggreflectors. The multilayer Bragg reflective layer includes a material selected from the group consisting of AlGalnP and AlGaAs. Page 16