TW200417066A - Semiconductor light emitting device and the manufacturing method thereof - Google Patents

Abstract

The subject of the present invention is to provide a light emitting diode device in high light emitting efficiency and high brightness. The solution of the present invention is to compose the cover layer at the anode, and the cover layer at the anode includes: undoped AlInP layer, which is connected with the active layer and grown in depth larger than 0.5 μm; and, a middle layer having a middle energy gap with the energy gap for the undoped AlInP layer and the energy gap for the window layer, and conducting the p-type doping for connecting with the window layer; furthermore, forming the distribution electrodes on part of the surface of the current diffusion layer, configuring the transparent conductive film covering the current diffusion layer and the distribution electrode, and configuring the bottom electrodes on the transparent conductive film.

Description

200417066 (1) 发明 Description of the invention [Technical field to which the invention belongs] The present invention relates to a light-emitting diode element capable of emitting visible light. [Prior art] Light-emitting diodes can be used for various purposes, mainly for display purposes. As is well known, in the order of short to long emission wavelengths, there are the use of indium gallium nitride (InGaN), aluminum gallium indium phosphide (A1G a I η P), aluminum gallium arsenide (GaAlAs), or indium gallium arsenide ( GalnAsP). Moreover, its brightness has been gradually improved in recent years. Recently, it has even been used in lighting or backlighting of liquid crystal display devices. Furthermore, research into improvement is also ongoing. Regarding LEDs with good light emission efficiency, Patent Document 1 or Patent Document 2 is known as an LED having a double heterostructure (DH) junction structure as shown in Fig. 5 or Fig. 6. The LED is characterized by having an active layer sandwiching an electron and a hole for recombination to emit light, and is provided with a sealing layer structure for sealing the electron or hole in the active layer. The encapsulation layer has a band gap larger than that of the active layer, and has a function of a cover layer that does not absorb its light emission. It is well known that the light emission wavelength of an LED configured as described above depends on the composition of the active layer. For example, using an AlGalnP with a double hetero (DH) junction structure as shown in Figure 7 as the active layer of the LED, when the composition is represented by (AUGan) G.5lnQ.5P, the band gap (Eg) of the active layer is 0 € The range of χ $ 0 · 6 is changed by Eg = 1.91 + 0.61x (eV) and 値 of x. Therefore, the emission wavelength of the LED is 65 Onm to 5 4 5 nm, and (2) (2) 200417066 is changed by the band gap of the active layer, that is, the composition of the active layer. It is also known that as the x increases, the output light of the LED becomes a short wavelength, and its intensity is greatly reduced. The reason for the decrease in the output light intensity can be understood from the following points. That is, in order to emit light at a short wavelength, it is necessary to increase the band gap of the active layer, so an active layer having a reduced composition ratio of gallium (Ga) is formed. However, a decrease in the composition ratio of gallium results in a decrease in the band gap difference between the active layer and the encapsulation layer. Therefore, when the hole is implanted into the active layer, the potential barrier will become larger, and the efficiency of hole implantation will decrease. In addition, the barrier layer for the electrons enclosed in the active layer is lowered, resulting in lowered electron-encapsulation properties. As a result, the recombination of electrons and holes is reduced, and the light output is reduced. Therefore, Non-Patent Document 1 discloses an LED in which a cover layer is used as AllnP to improve the hole implantation efficiency and the electron sealing effect. Further, Patent Document 3 discloses an LED in which an undoped layer is formed at a thickness of about 0.005 to 0.2 // m to a part of the p-cladding layer connected to the active layer. The present invention also has a structure similar to this undoped layer. However, for the sake of nature, a thick undoped layer must be formed, which is different from the above disclosure. In addition, Patent Document 4 discloses that in order to suppress a gap (notch) due to a discontinuous band between a p-GaP window layer and a p-AlGalnP layer, or between a p-AlGalnP cover layer and an AlGalnP active layer, A layer with a band gap is re-inserted between these layers to reduce the resistance of the current flowing in the forward direction. Patent Document 5 discloses a light-emitting diode element -6 which attaches importance to the structure of the cover layer. (3) 200417066 Active on the upper layer and connected to the carrier 2 layer. A hair cover of a cover layer, a cover, and the light emitting diode element are provided with a layer, an n-type cover layer disposed on one side of the active layer, and the other side of the active layer as shown in FIG. 8. The P-type cover layer is characterized in that the η cover layer has an η-type first cover layer adjacent to the active layer and an η-type second cover layer adjacent to the first cover layer; and the concentration of the first cover layer It is lower than the second cover layer and has a thickness smaller than that of the first cover layer, but a thickness thicker than that of the yield submechanical channel effect is formed by an electrical wall between the active layer of the valence electron band and the second cover layer. The height is higher than the potential barrier between the first covering layer formed in the active layer of the valence electron band; the first and second layers are composed of AlGalnP; The ratio is set lower than the second overlay In the cap layer, for InGa example. In addition, Patent Document 6 discloses a light-emitting diode element, which is laminated as shown in FIG. 9. The n-type cover layer made of an AlGalnP-based compound semiconductor, and an AlGalnP-based compound having a band gap smaller than that of the n-type cover layer. An electrode optical element is provided on a laminate of an active layer made of a semiconductor, a coating having a large band gap active layer made of a P-type AlGalnP-based compound semiconductor, and a P-type window layer made of GaP. The cover layer and the p-type window layer are provided with an interposer, and the interposer is composed of a material having a band gap smaller than that of the p-type layer. Patent Document 7 discloses a method for manufacturing a light-emitting diode device. As shown in FIG. 10, in a double heterojunction LED, in order not to diffuse (4) (4) 200417066 P-type impurities to undoped In the state where the luminous efficiency is reduced due to the active layer of the semiconductor, high characteristics can be obtained. Therefore, the semiconductor substrate has a method for manufacturing a double heterojunction light emitting diode composed of an n-type cover layer, an active layer, and a P-type cover layer. Wherein, the p-type cladding layer is located at a part of the active layer side, an undoped layer is substantially formed, and each semiconductor layer is sequentially laminated. Patent Document 1 discloses an LED structure in which a gallium phosphide (GaP) window layer is provided on an aluminum gallium phosphide (AlGalnP). Non-Patent Document 2 describes a method for manufacturing an LED. When this GaP window is laminated on AlGalnP to produce the LED shown in FIG. 11, it is grown in a high temperature environment of 800 ° C or higher. To suppress crystal defects. In general, it is known that the conductivity of p-AlGalnP or p-AllnP is relatively small. As a countermeasure against this problem, in order to enlarge the area of the light emitting portion and allow current to spread without being locally concentrated, a window layer (or a current diffusion layer) is used. However, when the resistance 値 of the window layer becomes larger, in order to flow the rated current in the LED, the required voltage must also become larger. Therefore, it is better to use a material with a small resistivity as much as possible for the window layer. Furthermore, conventionally, it is known that the following Patent Document 8 has a mixed crystal layer composed of (A1 x G a!-X) y I ni — y P (0 $ XS 1, 0 < Y < 1) The light-emitting element having the light-emitting portion structure constitutes a light-emitting element such as a light-emitting diode (LED) or a laser diode (LD) that emits yellow-green to red-orange light. The light-emitting element disclosed in Patent Document 8, A transparent conductive film made of indium tin oxide is laminated on the surface of a light-emitting part composed of a (AlxGai_ x) yln 1-yP mixed crystal layer, and an upper surface is formed on the transparent conductive film -8- (5) ( 5) 200417066 electrode, with this structure, the current supplied by the upper electrode can be spread on the semiconductor surface as much as possible through the transparent conductive film. In the above-mentioned conventional light-emitting element, the ohmic contact between the transparent conductive film and the surface of the light-emitting portion cannot be sufficiently obtained, which is the main cause of the increase in forward voltage and the decrease in the life characteristics. Improvement countermeasures. The light-emitting element disclosed in Patent Document 9 is formed by forming a window layer on the surface of a light-emitting part, forming a contact layer on the window layer, and laminating a transparent conductive film (conductive light transmission) made of indium tin oxide on the contact layer. Oxide layer), formed by forming the upper electrode (upper electrode) on this transparent conductive film, so that the current supplied by the upper electrode can be diffused to the largest extent through the transparent conductive film, contact layer and window layer. Department surface. [Summary of the Invention] [Problems to be Solved by the Invention] In order to reduce the resistivity of the window layer (or the current diffusion layer), it is effective to improve the crystallinity of the window layer. However, if the growth temperature of the window layer is increased in order to improve the crystallinity of the window layer, the entire device will be exposed to a high temperature process, which will cause defects in parts other than the window layer and fail to achieve a light emitting diode with high output intensity. element. The present invention is proposed by the present invention in view of the above-mentioned problems. The window layer is formed at a higher temperature than in the past, and its conductivity is improved without changing due to the high temperature step. In this way, the structure is changed, and it is known The yellow-green wavelength band region with significantly reduced output intensity realizes a light-emitting diode-9- (6) (6) 200417066 element with greater brightness. In the light-emitting element described in the above-mentioned Patent Document 2, the ohmic contact between the transparent conductive film and the semiconductor layer can certainly be improved. However, the current problem is that, due to the contact layer, light emission is absorbed by the contact layer. Therefore, high-brightness light emission cannot be obtained, so light emission efficiency cannot be improved. In response to this problem, the inventor of the present invention proposes a light-emitting element described in Patent Document 10 below. By providing a distribution electrode on the surface of a semiconductor portion, the distribution electrode and the semiconductor can be reduced compared to the resistance between the transparent conductive film and the semiconductor layer. The resistance between the layers and the driving current supplied from most of the bottom electrode flow through the bottom electrode θ transparent conductive film-distribution electrode-semiconductor layer (light-emitting portion) with a lower resistance. In the light-emitting element disclosed in Patent Document 3, the light-emitting portion emits light around the distribution electrode, so no light is generated directly below the bottom electrode. Therefore, most of the light is not blocked by the bottom electrode, and can be directed toward the bottom electrode. Take out from the top to improve luminous efficiency. Furthermore, since no contact layer is provided, light emission can be prevented from being absorbed by the contact layer, and the light emission efficiency can be improved based on this point. However, it is known that the light-emitting element disclosed in the above-mentioned Patent Document 3 has a distributed electrode system in a dispersed state and a small area. When the light emitted directly below the distribution electrode is taken out upward, it may be blocked by the distribution electrode. This is one of the causes of the decrease in luminous efficiency. The present invention was proposed by the present invention in view of the above problems, and its object is to provide a -10 which can improve the luminous efficiency by achieving good ohmic contact between the electrode and the semiconductor layer, and the light emission of the light emitting portion is not shielded. -(7) 200417066 Light-emitting diode element and its manufacturing method. [Patent Document 1] US Patent US 5 0 0 8 7 1 8 [Patent Document 2] Japanese Patent Laid-Open No. 3 — 2 7 0 1 8 6 [Patent Document 3] Japanese Patent Laid-Open No. 8 — 3 2 1 6 3 3 [Patent Document 4] Japanese Patent No. 3 2 3 3 5 6 9 [Patent Document 5] Japanese Patent No. 3 0244 84 [Patent Document 6] Japanese Patent Laid-Open No. 2000-3 1 203 0 [ Patent Literature 7] Japanese Patent Laid-Open No. 8 — 293 62 [Patent Literature 8] Japanese Patent Laid-Open No. 8 — 8 3 927 [Patent Literature 9] Japanese Patent Laid-Open No. 1 1 — 1 7220 [Patent Literature 10] Japan Japanese Patent Laying-Open No. 20 0 1-1 8 9493 [Non-Patent Document Π

Light G.B.Stringfellow e t a 1. "High Brightness -11-(8) (8) 200417066

Emitting Diode ,,, pp. 108, pp. 162, and, pp. 168, 1 99 6.

[Non-Patent Document 2] J. Lin, et al., J. Crys. Growth, 142, pp. 15-20, 19 9 4 [Means for Solving the Problem] In order to achieve the above object, the first feature of the present invention is a light emitting device. A diode element includes: an AlGalnP active layer; and an anode-side cover layer and a cathode-side cover layer, and the active layer is sandwiched between the two, and the band gap between the anode-side cover layer and the cathode-side cover layer is larger than that. The active layer, and the band gap of the window layer is larger than the active layer formed on the anode side cover layer, which is characterized in that the anode side cover layer system includes: 1) an undoped AllnP layer, which is connected to the active layer and grows to 0.5 // thickness above m, 2) an intermediate layer having an intermediate band gap of the band gap of the undoped ΑΙιαα layer and the band gap of the window layer, and performing P-type doping connected to the window layer. A second feature of the present invention is a light-emitting diode element, comprising: an AlGalnP active layer; and an anode-side cover layer and a cathode-side cover layer, and the active layer is sandwiched between the two, and the anode-side cover layer and the cathode side The band gap of the cover layer is larger than that of the active layer, and the band gap of the window layer is larger than that of the active layer formed on the anode-side cover layer, which is characterized in that the window layer is a GaP layer grown at a temperature of 7 3 0 ° C or more. The constituent has a growth rate of more than 7 · 8 // m per hour, and its dopant is zinc. In addition, the third feature of the present invention is in addition to the second feature, wherein the anode-side covering layer system includes: 1) an undoped AllnP layer, which is connected to the active layer and grows to a thickness of 0.5 // m or more, 2 ) An intermediate layer having -12- (9) 200417066 the band gap of the undoped Allnp layer and the band gap of the window layer, and performing P-type doping connected to the window layer. The fourth feature of the present invention is a light emitting diode: an AlGaUP active layer; sandwiched between the anode side cover layer and the cathode active layer, and the band gap of the anode side cover layer is larger than the active layer, And the active layer on the anode side covering layer between the bands of the window layer is characterized in that the cathode includes a layer connected to the active layer and having a thickness of 0.1 μm A11 η P layer. Furthermore, in addition to the fourth feature of the fifth feature of the present invention, the cathode-side cover layer includes a n-type cover layer connected to the cathode by the cathode side, and the dopant of the n-type cover layer is: the sixth feature of the present invention is A light-emitting diode element system includes the following steps: a step of forming a layer on a gallium arsenide (GaAs) substrate J, and 2) a step of providing n as a reflective layer on the buffer layer, and 3) on the reflective layer Shi Xizhi's n-type cladding step, and 4) the step of placing an undoped AllnP layer on the n-type, and 5) the step of placing an AlGalnP active layer on the above, and 6) the step of setting an undoped Steps of the AllnP layer, and 7):? Steps of setting a P-type intermediate layer on the AllnP layer, and 8 on the intermediate layer, growing at a temperature of 7 3 0 ° C or higher, at a growth rate of 7 per hour, to grow zinc-doped P-type GaP layer, step. The intermediate band device has a side cover layer, and the gap between the cathode side and the cathode side cover is larger than the undoped layer formed on the side cover layer (except the undoped layer, in which the A11 n P layer is doped). : '1) Deposition of a slow-type reflective layer to' deposit a doped cover layer, and set the doped A 11 η P layer on the above active layer (above the undoped) above the above ρ type • 8 ν m or more -13- (10) (10) 200417066 as the window layer (1) The present invention is a light-emitting diode element, which is characterized by comprising: a semiconductor substrate having a first electrode formed on a back surface thereof; and formed on the semiconductor substrate, It includes a light-emitting portion made of A 11 n GaP, and a semiconductor layer having a window layer on the upper layer; and a distribution electrode formed on a part of the surface of the window layer and forming an ohmic contact with the window layer; and covering the surface of the window layer and the distribution A transparent conductive film formed by electrodes and in communication with the distribution electrode; and a bottom electrode formed on a part of the surface of the transparent conductive film and in communication with the transparent conductive film 0 (2) except for the structure described in (1) above Wherein, the above of the present invention Η-type substrate is a conductor, a p-type window layer. (3) In addition to the structure described in the above (1) or (2), the thickness of the window layer of the present invention is ψ or more than 3 // m. (0) In addition to the constitutions described in the above (1) to (3), φ, the product (N. d) of the thickness of the window layer and the carrier concentration N of the present invention (N.d) is 5 X 1 0 1 4 cm- 2 or more. (5) In addition to the structures described in (1) to (4) above, wherein the surface carrier concentration of the window layer of the present invention is 1 × 1018 cm-3 or more. (6) As described in (1) In addition to the structures described in (5) to (5), the window layer of the present invention is composed of a P-type GaP layer using zinc (Zn) or magnesium (Mg) as an impurity. (7) As described in (1) above In addition to the structures described in (6) to (6), when the present invention is viewed from a plane, the distribution electrode is formed on the surface of a semiconductor layer that does not overlap the cough electrode. -14- (11) (11) 200417066 (8) In addition to the structures described in the above (1) to (7), the area of the distribution electrode of the present invention is smaller than the area of the bottom electrode. (9) In addition to the structures described in the above (1) to (8) 'Among them, in the total flat area of the distribution electrode of the present invention, the effective light-emitting area is 3% or more and 30% or less. (10) As described in the above (1) to (9) In addition to the constitution, the distribution electrode of the present invention is a gold alloy. (11) In addition to the constitutions described in the above (1) to (10), the transparent conductive film of the present invention is indium tin oxide ( ITO). (1 2) In addition to the structures described in the above (1) to (1 1), in the present invention, when viewed from a plane, the bottom electrode is formed at the center of the element surface. (13) As described above ( 1) In addition to the structures described in (1 2), the surface of the bottom electrode of the present invention is gold. (1 4) In addition to the structures described in (1) to (1 3) above, wherein The above-mentioned bottom electrode of the present invention is composed of a multilayer film, and the layer connected to the transparent conductive film is chromium. (1 5) In addition to the structure described in the above (1) to (1 4), wherein The distribution electrode is a substantially quadrangular or substantially circular linear body surrounding the bottom electrode. (16) In addition to the structure described in the above (1) to (15), wherein the distribution electrode of the present invention has a line width It is a linear body below 20 " m. (17) The present invention is a manufacturing of a light emitting diode element Method 'its -15- (12) (12) 200417066 is characterized by having the following steps: the first step is to make a semiconductor layer including a light-emitting portion made of All n GaP on the single crystal substrate and a p-type window layer on the upper layer; Crystal growth; and a second step, forming a distribution electrode in ohmic contact with the window layer on the surface of the window layer portion formed in the above step; and a third step, covering the surface of the window layer and the distribution electrode, and forming a distribution electrode A transparent conductive film where the distribution electrode is conductive; and a fourth step, forming a bottom electrode where the transparent conductive film is conductive on a part of the surface of the transparent conductive film. (18) In addition to the structure described in the above (17), the semiconductor layer of the present invention is formed by an organometallic chemical vapor deposition method (MOCVD method). (19) In addition to the constitution described in (17) or (18) above, wherein the above-mentioned transparent conductive film of the present invention is formed by a sputtering method. (20) In addition to the constitution described in the above (17) or (19), wherein the above-mentioned bottom electrode of the present invention is formed by a sputtering method. [Embodiment] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of an exemplary embodiment of the present invention. The structure of FIG. 1 is formed on a gallium arsenide (GaAs) substrate 010 by a reduced pressure MOCVD growth method. The substrate 010 used is a silicon (Si) -doped gallium arsenide (GaAs) substrate (offset by 15 °). On this substrate, trimethylgallium (Ga (CH3) 3), trimethylindium (In (CH3) 3), trimethylaluminum (A1 (CH3) 3), and dimethylzinc (Zn (CH3) ) 2), Disilane (Si2H6), Samarium (AsH3), Phosphine (PH3), -16- (13) (13) 200417066 Film formation was performed as shown in Table 1. In addition, the AlGalnP layer and the AllnP layer are preferably formed on a GaAs substrate using a lattice integration method. Therefore, an example of the manufacturing steps of the present invention is as follows. 1) On the gallium substrate 0 1 0, a 0.5 // m silicon-doped n-type G a A s layer is deposited as a buffer layer 9. 2) Set η-type Si-Alo.5Gao.5As / Alo.9Gao.1As multilayer film as the reflective layer 08 (DBR: Distributed Bragg Reflector). When this reflective layer is not provided, the output light is reduced. 3) On the reflective layer 08, a silicon-doped AllnP layer is provided as the n-type cladding layer 07. 4) On the n-type capping layer 07, an undoped AllnP layer 06 is provided as an undoped capping layer 06. The thickness of the layer is preferably 0.1 μm or more. When this layer is not provided, the output light is reduced. The n-type cladding layer 07 and the undoped AllnP layer 06 constitute a cathode-side cladding layer. 5) On the undoped AllnP layer 06, an active layer 05 composed of undoped AlGalnP is provided. This active layer 05 is held between the undoped AllnP layer 06 and the undoped AllnP layer 04 described below to form a double heterostructure (DH) structure that contributes to light emission. 6) On the active layer 05, an undoped A11 η P layer 04 is provided as an undoped cover layer. The thickness of the layer is preferably 0.5 V η or more. On the undoped AllnP layer 04, a doped zinc (Zn) -17-(14) (14) 200417066 (Al 0.6Ga 0.4) p-type intermediate layer 03 composed of InP. Since this (AluGau) InP has a band gap between GaP and AllnP, two discontinuous small band gaps are formed between the window layer 02 and the undoped AllnP layer 04, Compared with the case where there is a discontinuous band gap, the resistance 抑制 generated by the discontinuous band gap can be suppressed. In addition, the composition of the P-type intermediate layer 03 is not limited to (Ai0.6GaGa.4) InP. As shown in Table 2, when the composition is (Al0.7GaGa.3) InP, it may be Get the output light. Compared with the use of AllnP, when (Al〇.6Ga〇.4) InP or (Al〇_7GaQ.3) InP is used in the intermediate layer, the forward voltage (Vf) can be reduced to about half, and the brightness can be doubled. . The data distribution leading to the results in Table 2 is shown in Figure 2 (a) and (b). In particular, compared to when (AlG.7Ga (). 3) InP is used, when (Al0.6.Ga0.4) InP is used, Vf is reduced by .15V and brightness is increased by 8.5%, which is an ideal case. In addition, the undoped AllnP layer 04 and the p-type intermediate layer 03 constitute an anode-side cover layer. 8) On the p-type intermediate layer 03, a window layer 02 made of zinc-doped p-type GaP is provided. The thickness of this layer is preferably 5 m or more. When this layer is grown, it is preferably performed at a temperature of 73 ° C. or higher. In addition, zinc is doped during film growth. However, in order to increase the density of the dopant, it is better to grow at a faster rate. As described below, by growing at a speed of more than 7.8 // m per hour, the brightness can be improved by 70%. 9) On the surface of the window layer 02, ρ-electrode 01 is formed; on the back surface of the GaAs substrate 010, η is formed. —Electrode 011. In addition, the dependence of V f and brightness on the structure of the cathode-side cladding layer will be described -18-(15) 200417066. Table 3 shows the time-varying Vf and brightness of the undoped AllnP layer on the cathode-side cladding layer. According to the table, compared with the case where there is no A 11 η P layer, when there is no chrysanthemum layer of 0.1 / 1 m or 0.2 μm, its Vf will be reduced by about 0.2V, and the brightness will be approximately 2. Compared with the formation of 0.1 m, when the undoped AllnP layer is formed, the brightness is improved by 6%. The data of the results derived from Table 3 are shown in Figure 3 (a) and (b). Explanation The dependence of Vf and brightness on the growth conditions of the window layer is Vf and brightness when the growth temperature of the window layer is changed. From this, when the window layer is grown at 700 ° C at a speed of 2.8 // m per hour at 700 ° C and at a speed of 7.8 // m per hour, the V f of the two is almost the same. However, when the window layer is grown at a speed of 730 ° C per hour, the Vf will decrease by about 0.16, and the brightness will increase at this time, although the non-doped All nP layer on the cathode side is 0.2 // m, but Table 3 It is known that the contribution caused by this difference is that even after the 6% is subtracted, the brightness can be improved by more than 80%. The data distribution of the result of 4 is as shown in Fig. 4 (a) and (b). Fig. 12 and Fig. 13 are schematic diagrams of the composition of the light-emitting diode element of the present invention, and Fig. 12 is a plan view thereof. 13 is a sectional view taken along the line I-I. In addition, in the present specification, the observation of the surface of the plane means to observe the plan view shown in FIG. 12.

In these figures, the features of the light-emitting diode element of the present invention are: • a semiconductor substrate 1 having a first electrode 5 formed on its back surface; and a half 3 ′ formed on the semiconductor substrate 1 and including Alin GaP thickness Change the undoped I Alin? Times. Another 0.2 μ melon • cloth, Department. Table 4 shows that the brightness is 7.8 // m 8 8%. However, from 6%, the semiconductor system derived from the structure shown in Figure 12 is provided with a light-emitting portion 2a composed of a conductor layer and a light-emitting portion 2a (16) (16) 200417066, and a window layer 2b on the upper layer; and a distribution electrode 7 Which is formed on a portion of the surface of the window layer 2b (semiconductor layer 3) and forms an ohmic contact with the window layer 2b; and a transparent conductive film 4, which is formed by covering the surface of the window layer 2b and the distribution electrode 7, And is in communication with the distribution electrode 7; and the bottom electrode 6 is formed on a part of the surface of the transparent conductive film 4 and is in communication with the transparent conductive film 4. In addition, the light-emitting portion 2a preferably has a structure having a well-known double-height structure and a multiple quantum well (MQW) structure with high luminous efficiency. Here, as shown in FIG. 12, when the surface of the semiconductor layer 3 is viewed from a plane, the distribution electrode 7 is preferably arranged at a portion that does not overlap with the bottom electrode 6, and the portion that overlaps with the bottom electrode 6 is not arranged. More ideal. In addition, the bonding between the distribution electrode 7 and the window layer 2b forms a good ohmic contact, so the resistance between them is small; the bonding between the transparent conductive film 4 and the window layer 2b on the other side cannot obtain a sufficient ohmic contact, so The resistance between them is large. The light-emitting diode element 10 configured as described above is attached to a part of the surface of the window layer 2b and is provided on the distribution electrode 7 which forms an ohmic contact, thereby constituting a resistance which is smaller than that between the transparent conductive film 4 and the window layer 2b The resistance between the distribution electrode 7 and the window layer 2b can be greatly reduced. Most of the driving current supplied from the bottom electrode 6 is shown by the arrow in FIG. 13. 'With a lower resistance, it flows through the bottom electrode 6—the transparent conductive film distribution electrode 7—the window layer 2b—the light-emitting portion 2 The path of a. Since the current flowing from the distribution electrode 7 into the window layer 2b is appropriately diffused in the window layer 2b, the light emission of the light-emitting portion 2a is performed around the distribution electrode 7. Therefore, the light-emitting portion 2a emits less -20- (17) (17) 200417066 light, which is shielded by the distribution electrode 7, and most of the light emission can be taken upward. Therefore, the light emission efficiency can be improved. The window layer 2b described above, whether it is an n-type or a p-type, contributes to improving the light emitting efficiency. In general, although the ρ-type has a low degree of mobility, the current flowing from the distribution electrode 7 is difficult to diffuse, but the present invention has found that the P-type system meets certain conditions, such as by changing the layer thickness, the layer thickness, and The product of carrier concentration, surface carrier concentration, and material are most appropriately optimized, which can greatly contribute to localization. That is, it was found that when the window layer 2b is of a p-type, if the layer thickness is 3 μm or more, sufficient current diffusion will be caused. However, if the layer thickness is too thick, the surface state will be deteriorated. Therefore, the layer thickness is preferably formed below 20 # m, and in order to achieve low cost, it is more desirable to form a layer below 10 m. It is also known that the product of the thickness of the window layer 2 b and the carrier concentration is related to high brightness, and the larger range of the effect of high brightness is 5χ 1 014cm-2 or more. Furthermore, the carriers on the surface of the window layer 2b Concentration, formation! When the height is more than 8cm ~ 3, the resistance of the contact with the distribution electrode 7 will be reduced, which will cause the current to spread and achieve high brightness. The material of the window layer 2b is transparent to light and can be fully formed. The material of the diffusion current is preferred. For example, GaP can not only be grown by an organic metal vapor deposition method (M 0 CVD method), but also can be easily reduced in resistance and thickened. It is the most suitable material for the window layer. 1. In FIG. 12, the distribution electrode 7 is a linear body of a substantially circular shape -21-(18) (18) 200417066 surrounding the bottom electrode 6, and the linear body extends to four sides in a circular state. The linear body The width is preferably less than 20 μm. With this distribution of electricity 7 in the planar configuration, the current diffusion of the window layer 2b can be performed more effectively 'and the driving current from the bottom electrode 6 can be spread over a wide range of the surface of the window layer 2b. As described above, since the distribution electrode 7 is It is arranged so as not to overlap with the bottom electrode 6, so the light emission directly below the bottom electrode 6 is weak, and most of the light emission can be taken out from above without being shielded by the bottom electrode 6, so the light emission efficiency can be greatly improved. In addition, in terms of this luminous efficiency, since the area of the distribution electrode 7 is smaller than that of the bottom electrode 6, it is possible to make light more efficiently than in conventional light emitting diode elements. It is taken out to the outside, so that the luminous efficiency can be further improved. In addition, since the resistance between the distribution electrode 7 and the semiconductor layer 3 is reduced as described above by forming an ohmic contact, the light-emitting diode element can be suppressed. An increase in forward voltage of 10 can improve the life characteristics. The transparent conductive film 4 is made of, for example, indium tin oxide (I τ 〇) and has good light transmittance, especially ' The film formed by the sputtering method can produce a film having low resistance and good transmittance. The light emitted from the light emitting portion 2a will not be absorbed by the transparent conductive film 4 and can be efficiently conducted from the transparent conductive film. The film 4 is taken upward. The bottom electrode 6 is an electrode for wire bonding in order to connect the light-emitting diode element 10 and an external electrical circuit. Therefore, it must have an area of a certain size. -22- (19) 200417066 where the electrode 6 flows directly below the driving current will be shielded by the bottom electrode 6 and cannot be taken out to the outside. Therefore, the conventionally adopted countermeasure is to place the bottom electrode 6 and the light-emitting portion 2a. The insulating layer and the like forcibly prevent the driving current from flowing from the bottom electrode 6 directly below. However, in the present invention, the driving current can be distributed to the distribution electrode 7. Therefore, it is not necessary to provide an insulating layer. With a simpler structure, That is, the driving current can be prevented from flowing directly under the bottom electrode 6. Here, the area of the surface of the transparent conductive film 4 (or the surface of the semiconductor layer 3) that can make it effectively emit light (effective light-emitting surface) is the area of the transparent conductive film 4 and subtracts the area of the bottom electrode 6 ( Figure 12 shows the area obtained from the plane), and this area is called the effective light emitting area S. The phenomenon that the bottom electrode 6 interferes with the light emission immediately below it may also occur in the distribution electrode 7. Therefore, in the present invention, the total flat area (area viewed from the plane) of the distribution electrode 7 is 3% or more and 30% or less of the effective light emitting area S, which prevents excessive distribution of the area of the distribution electrode 7 when the area is too large. Obstructs the extraction of light. On the contrary, the area is too small, which causes the forward voltage (Vf) to increase and cause failure. In addition, as for the phenomenon that the distribution electrode 7 interferes with light emission extraction immediately below it, the better the diffusion state of the window layer 2b is, the more appropriate it is, and the probability of interference with light extraction can be reduced.

Continue with reference to Figures 14 to

Fig. 18 is a diagram for explaining the light emission of the present invention in sequence. Figs. 14 and 15 are diagrams showing a first configuration example of the light emitting diode element of the present invention. Fig. 14 is a plan view thereof. Fig. 15 is a view showing the 14th diagram. -Sectional view of line 11. In these figures, the light-emitting diode -23- (20) (20) 200417066 of the present invention is a light-emitting diode (LED) emitting yellow-green light. A semiconductor layer 23 is formed on a Si-doped n-type G a A s single crystal substrate 21 with a crystal plane orientation (0 0 1) shifted by 15 degrees. The semiconductor layer 23 is laminated on the substrate 21, and its structure sequentially includes: a buffer layer 231 composed of Si-doped n-type G a A s, and Si-doped n-type AlQ.5GaQ.5As / Al0. 9 DBR reflective layer 2 3 composed of Gao.iAs multilayer film, and a lower cover layer 2 3 3 ′ composed of Si-doped n-type and undoped AlG.5iri (). 5P, and undoped with adjusted composition Light-emitting layer 22 composed of AlGalnP mixed crystal and emitting wavelength of 570 nm, and an upper cover layer 2 3 4 composed of undoped AU.5lnG.5P and Zn-doped p-type AU.5Ga (). 5P, and Zn-doped Hetero-p-type GaP window layer 2 3 5. The layers 231, 232, 233, 22, 234, and 235 constituting the semiconductor layer 23 are made of trimethylaluminum ((CH3) 3 A1), trimethylgallium ((CH3) 3 Ga), and dimethylindium ((CH3 ) 3 In) is used as a raw material of the group III structural element, and is formed on the substrate 21 by a reduced pressure M 0 CVD method. On the doping material of zinc (Zη), dimethylzinc ((Ch3) 2Zη) was used. Disilane (Si2Η6) was used as the n-type doping material. As the raw material of the group ν element, phosphine (P Η3) or osmium (As Η3) is used. The film formation temperature of each layer 2 3 1, 2, 3 2, 2 3 3, 2 2, 2 3 4 and 2 3 5 was uniformly 7 3 5 ° C. The carrier concentration of the buffer layer 231 is about 2 × 1018 cm-3, and the layer thickness is about 0.5 // m. The carrier concentration of the reflective layer 2 3 2 is about 2 χ 丨 〇 1 8 c m-3, and the 'layer is about 1.2 // πm. The carrier concentration of the lower ρ 卩 cladding layer 2 3 3 is about 7 X 1 0 1 8 cm 'The layer thickness is on a Si-doped n-type layer of about 1.3 m, -24- (21) ( 21) 200417066 An undoped layer of 0 · 2 // m is formed. The thickness of the light-emitting layer 22 is about 1 // m. The layer thickness of the undoped layer of the upper cladding layer 234 is about 0.5 μm, and the layer thickness of the Zri-doped p-type layer above the undoped layer is about 0.5 μm. The carrier concentration of the Zn-doped P-type layer is about 6 × 1017 cm 3. The carrier concentration of the P-type window layer 2 3 5 is about 3 X 1018 cm—3, and the layer thickness is about 6 β m. In this case, the product of the thickness d of the window layer 2 3 5 and the carrier concentration N, N · d is approximately 1.8 X 1 0 15 c m-2. Here, the lower cladding layer 233, the light emitting layer 22, and the upper cladding layer 234 constitute a light emitting portion of the light emitting diode element 20. Therefore, the light emitting portion is a double hetero structure made of AlGaluP. In this light-emitting diode element 20, in order to form the distribution electrode 27, first, a gold-beryllium alloy (An 9.9 wt%-Be 1 wt%) film having a film thickness of about 5 Onm is formed by a general vacuum evaporation method. At one time, the entire surface of the window layer 235 was adhered, and then a gold (Au) film having a thickness of about 100 nm was attached to the surface of the gold-beryllium alloy film. Next, using a general photolithography mechanism, a multilayer film having a double-layer structure of the first film made of gold-beryllium alloy and the second film made of gold was patterned to form a distribution electrode 27. The distribution electrode 27 is a substantially square frame shape with a side of 1 5 0 // m formed by a linear body having a width of about 6 // m. The area of the distribution electrode 27 is about 0.36 × 10-4 cm-2. The distribution electrode 2 7 composed of the first film and the second film is a portion of the surface of the window layer 2 3 5 except the area directly below the bottom electrode 26 as shown in FIG. 14 to surround the bottom. The electrode 26 is formed in such a manner that, when viewed from a plane, the distribution electrode 27 has a substantially quadrangular shape which is symmetrical to the left and right. -25- (22) (22) 200417066 On the other hand, a gold-germanium alloy with a thickness of about 0.3 // m is laminated on the back surface of the single crystal substrate 21, and a thickness of 0.3 μm is laminated under the gold-germanium alloy. Of gold to form n-type ohmic electrodes 25. Then, in a nitrogen flow, an alloying heat treatment is performed at 45 ° C. for 10 minutes to form an ohmic contact between the distribution electrode 27 and the window layer 2 35, and the n-type ohmic electrode 25 and the single crystal substrate 2 1 ohmic contact. Next, a well-known magnetron sputtering method is used to attach an indium tin oxide (ITO) transparent conductive film 24 to the window layer 235 and the distribution electrode 27 on the surface thereof. The resistivity of the transparent conductive film 24 is 4 × 1 (T 4 Ω · Cm, the layer thickness is about 500 nm. The transmittance is about 95% of the good film quality for the emission wavelength. The well-known magnetron sputtering (magnetron A sputtering method is used to form a laminated film composed of 3 Onm of chromium (Cr) and 1 // m of gold on the transparent conductive film 24. After coating a general organic photoresist, a well-known photomicrograph is used. In the shadow technology, the area where the bottom electrode 26 is pre-set is patterned to form a circular bottom electrode 26 with a diameter of about 110 mm. The flat area of the bottom electrode 26 is about 4 × 10-4 cm2. When viewed from a plane as shown in FIG. 14, the predetermined setting area of the bottom electrode 26 is located at the center of the surface of the light emitting diode element, that is, an area including the diagonal focus of the surface of the quadrangular light emitting diode element. This is because when the bottom electrode 26 is located at the center of the surface of the light-emitting diode element, it is easier for the current to flow uniformly throughout the entire light-emitting diode element, and wire bonding (wi 1 · eb ο nding) is performed on the bottom electrode 2 6. ), The advantage of the chip is not easy to tilt. 26- ( 23) (23) 200417066 Then, using a general cutting method, cut one side at an interval of 230 gm to separate it into a square element shape to form a light emitting diode element 20. The flat area of the transparent conductive film 24 is about 4 X 1 (T 4 Cm2, the effective light-emitting area S obtained by subtracting the flat area of the bottom electrode 26 from the flat area of the transparent conductive film 24 is about 3 X 1 (T 4 Cm2. Furthermore, the total distribution electrode 27 The flat area is about 0.36 X 1 0_ 4 Cm2, and this area accounts for about 12% of the effective light-emitting area S. Current is passed through the light-emitting diode element 20 obtained in the above manner in the forward direction. Between the ohmic electrode 25 and the bottom electrode 26, yellow-green light with a wavelength of about 570 nm is emitted from the surface of the transparent conductive film 24. The forward voltage (Vf: 20mA when a current of 20 m A flows) Left and right), reflecting the good ohmic characteristics of each distribution electrode 27 and the diffusion effect of current in the window layer 2b, it is about 2 V. In addition, the distribution electrodes 27 having ohmic characteristics are arranged on the light-emitting diode element 2 The effect of the peripheral portion 0 and the effect of the window layer 2 b on the light emitting diode element 2 0 Luminescence can also be recognized in the peripheral area, and the luminous intensity measured in the wafer state is about 40 millicandles (me d). In addition, the driving current is formed by distributing the electrode 27 and the window layer 2b. Evenly distributed, therefore, the luminous intensity observed from the surface of the transparent conductive film 24 is approximately uniformly distributed. In the first configuration example described above, 'system uses Zn and Si as dopants, however, well-known magnesium ( MS), tellurium (Te), selenium (Se) and other dopants can also achieve the same effect. The light-emitting layer 22 has a double heterostructure. However, when a multi-quantum well (M Qw) structure is formed, the same effect can be obtained as -27- (24) (24) 200417066. As described above, the light-emitting diode element 20 obtained in the first configuration example is as described above, and the layer thickness of the window layer 2 3 5 is approximately 6 / zm, and the carrier concentration is approximately 3 X 1 0 18 cm-3, the product of the layer thickness d and the carrier concentration N, n · d is about 1 · 8 X 1 0 15 cm ~ 2, and the light emitting diode device 20 is used as an example 1 ° as shown in Table 5 As shown in the figure, the layer thickness and carrier concentration of the window layer are variously changed. Other conditions are the same as in Example 1. In this way, five other types of light-emitting diode elements are formed, and this light-emitting diode element is used as Examples 2, 3, 4, 5, 6. The results shown in Table 5 were obtained by testing V f 値 and the luminous intensity of each of the light-emitting diode elements of Examples 1 to 6. (Comparative Example) In order to compare with the Vf 値 and light emission intensity of the light-emitting diode elements of Examples 1 to 6 described above, the light-emitting diode element of the comparative example is not provided with a window layer. The other parts are the same as the examples. A light-emitting diode element (LED) configured in this manner is used as a comparison element. The comparison results are shown in Table 5. In Table 5, the Vf 値 (about 20 mA) of the comparative example is about 2.2 V, which is higher than the Vf 値 of the light-emitting diode element 20 of Examples 1 to 6 from 1.99 V to 2.02 V. On the other hand, the light emission of the 'comparative example' occurred only under the ohmic characteristic electrode and its surroundings, and a considerable proportion of the light emission was blocked by the electrode, making it impossible to take out the outside. Therefore, the brightness is extremely low, less than 15mcd. In contrast, the brightness of Examples 1 to 6 is from 30 mcd to 4 2 mcd ° -28- (25) 200417066 In comparison with this comparative example and the embodiment of the present invention, it is known that the light-emitting diode element of the present invention can be used in various applications. High brightness is achieved with an increase in Vf.

Figures 16 to 19 are diagrams illustrating other arrangement examples of the distribution electrodes viewed from a plane. In the above description, the distribution electrodes are linearly distributed around the bottom electrode. However, as shown in FIG. 16, the distribution electrodes 7 may be individually and separately arranged around the bottom electrode 6. Alternatively, as shown in FIG. 17, a distribution electrode 7 in which the linear bodies are combined into a pattern may be formed. Alternatively, as shown in FIG. 18, the linear bodies may be arranged in a grid to form the distribution electrode 7. Further, as shown in Fig. 19, the distribution electrode 7 may be constituted by a combination of a linear body and an independent individual electrode. As described above, the distribution electrodes 7 can be arranged not only in a discrete manner but also in a continuous configuration in a band-like or linear configuration, and it can also be configured in a planar configuration.

In addition, when the distribution electrodes 7 are arranged individually and dispersedly, or when they are formed into continuous strips or lines, their shapes can be formed into arbitrary shapes such as squares, rectangles, circles, ovals, and polygons, and dispersed. The pattern at this time can also be formed into radial, circumferential, spiral, or other arbitrary patterns. (Example 7) On the window layer of the element of Sample 1, a distribution electrode, a transparent conductive film, and a substrate were formed under the conditions of Example 1. The electrode was used to measure Vf, brightness, and emission wavelength using conditions similar to those of sample 1. The results are shown in the table. Compared to Sample 1, further improvement in brightness and reduction in Vf can be obtained. -29- (26) (26) 200417066 [Effects of the Invention] Since the present invention is constituted as described above, the effects described below can be obtained. As described above, the 'anode-side covering layer system of the double hetero-type light-emitting monolithic element with the A 1 G a I η P active layer of the present invention includes: 1) an undoped A11 η P layer, which is connected to the active layer And grow to a thickness of 0.5 or more from ❿ '2) an intermediate layer having an intermediate band gap of the undoped AllnP layer band gap and a window layer band gap, and performing a p-type connection with the window layer Doping, so Vf can be about half, and the brightness can be doubled. In addition, the window layer can be grown in a high temperature environment to improve its crystallinity. At the same time, by doping and growing at a high speed, Vf can be reduced by about 0.1 6V, and the brightness can be improved by 80%. By providing an undoped layer on the active layer side of the cathode-side cladding layer, Vf can be reduced by about 0.2V, and the brightness can be approximately doubled. Furthermore, by using silicon as a dopant for the semiconductor layer on the cathode side, problems caused by temperature rise during the manufacturing process can be suppressed without occurring. In addition, in the light-emitting diode element of the present invention, a distribution electrode forming an ohmic contact is provided on a part of the surface of the window layer, so the resistance between the distribution electrode and the window layer is higher than that between the transparent conductive film and the window layer Can be greatly reduced. Further, most of the driving current 'supplied from the bottom electrode is passed through the bottom electrode-transparent conductive film-distribution electrode-window layer-light-emitting section at a lower power. In addition, the current flowing from the distribution electrode into the window layer will be appropriately diffused in the window layer. Therefore, the light emission of the light-emitting part is performed around the distribution electrode as a center -30- (27) 200417066. Therefore, since the light emission from the light emitting portion is less covered by the distribution electrode ', most of the light emission can be taken upward, and therefore, the efficiency can be improved. When the window layer is a P-type, the layer thickness is formed to be 3 μm to generate sufficient current diffusion. When the window layer is a P-type, the product of the layer thickness and the carrier concentration is more than 10 4 cm −2, so it can effectively help the window layer to have higher brightness. When the window layer is P-type, its carrier concentration on the surface is 1x or more, so the resistance of the contact with the distribution electrode will be reduced, which will promote the dispersion and increase the density. This window layer is made of p-type GaP with Zn or Mg as an impurity, so that it is transparent to the light-emission system and can sufficiently expand the current. The resistance can be easily reduced, the thickness can be increased, and the window layer can be easily optimized. [Brief description of the drawings] FIG. 1 is a schematic diagram showing an implementation example of the present invention. FIG. 2 is a diagram showing the composition of the intermediate layer of the LED of the present invention. Thick dependency graph. Fig. 4 is a graph showing the growth conditions of the window layer of the LED of the present invention. Fig. 5 shows the pattern of the cross section of the conventional light-emitting diode to improve the luminescence, so it can form 5 X 1 0 1 8cm ~ 3 into the current spreading, spread, and then the window layer has the most existence. Figure 11 A diagram of the dependence of the η P layer. -31-(28) (28) 200417066 Fig. 6 is a schematic diagram showing a cross section of a conventional light emitting diode. Fig. 7 is a schematic view showing a cross section of a conventional light emitting diode. Fig. 8 is a schematic view showing a cross section of a conventional light emitting diode. Fig. 9 is a schematic view showing a cross section of a conventional light emitting diode. Fig. 10 is a schematic view showing a cross section of a conventional light emitting diode. Fig. 11 is a schematic view showing a cross section of a conventional light emitting diode. Fig. 12 is a schematic plan view of a schematic structure of a light-emitting diode element of the present invention. Fig. 13 is a schematic view of a schematic structure of a light-emitting diode element of the present invention. Section view. Fig. 14 is a plan view showing an embodiment of a light emitting diode element according to the present invention. Fig. 15 is a view showing an embodiment of a light emitting diode element according to the present invention, and is a cross-sectional view taken along line 11-11 of Fig. 14; Fig. 16 is a diagram showing another arrangement example of the distribution electrode of the present invention. Fig. 17 is a diagram showing another arrangement example of the distribution electrode of the present invention. Fig. 18 is a diagram showing another arrangement example of the distribution electrode of the present invention. Fig. 19 is a diagram showing another arrangement example of the distribution electrode of the present invention. [Comparison table of main components] 0 1 ρ-electrode 02 window layer 03 ρ-type intermediate layer 04 undoped AllηP layer-32, (29) (29) 200417066 〇5 active layer 06 undoped AllnP layer 0 7 n-type cover Layer 08 reflective layer 09 buffer layer 0 substrate 0 n-electrode 1 semiconductor substrate 2 a light-emitting portion 2 b window layer 3 semiconductor layer 4 transparent conductive film 5 first electrode 6 bottom electrode 7 distribution electrode 1 light-emitting diode Body element 2 0 Light-emitting diode element 2 1 Single crystal substrate 2 2 Light-emitting layer 23 Semiconductor layer 2 3 1 Buffer layer 2 3 2 Reflective layer 2 3 3 Lower cover layer 234 Upper cover layer (30) (30) 200417066 235 window Layer 24 Transparent conductive film 25 η-type ohmic electrode 2 6 Bottom electrode 2 7 Distribution electrode -34 (31) 200417066 [Table 1] Name Film thickness (μιη) CV carrier density (c3) Chemical formula window layer 5 ^ 2 ~ 4x10 丨8 p (Zn) -GaP P-type intermediate layer 0.5 5 to 10x10 " p (Zn)-(Al0.6Ga0.4) InP undoped AllnP layer 0.5-u η-A 11 η P active layer 1.0 un- AlGalnP undoped A11 η P layer 0.2-un-A 11 np η-type cladding layer 1.3 0.5 to 3χ1〇ΐ8 n (Si) -AllnP reflective layer 1.0 to 1.5 0.5 to 3x1018 n (Si-Al .5Ga〇.5As / Al〇.9Ga〇iAs) Buffer layer 0.5 0.5 ~ 3χ1018 n (S i)-G a A s Substrate 280 Si-doped GaAs (biased 15.) [Table 2] [Vf, brightness for p Dependence of Type Intermediate Layer 3] Sample Growth Conditions Vf (V @ 20mA) Brightness (mcd @ 20mA) Luminous Wavelength A u η-A 11 η P 3.99 4.9 574 B pAl0.7.GaIn.2InP 2.14 9.4 573 C pAl〇 6G ^ o.4lnP 1.99 10.2 5 73 Window layer: GaP thickness = 5μιη, carrier density = 2xl018 Undoped AllnP layer: layer thickness = 0.5μΓη -35- (32) (32) 200417066 [Table 3] [ Dependence of Vf and brightness on the composition of the cathode-side cladding layer] Sample growth conditions VF (V @ 20mA) Brightness (mcd @ 20mA) Emission wavelength D No undoped layer AllnP layer 2.32 5.1 573 E Undoped layer AllnP layer 0.1 // m 2.13 10.8 574 F undoped layer AΠηP layer 0.2 // m 2.14 11.5 573 growth temperature: ri-type cladding layer 7 = 700 ° C, undoped AllnP layers 6, 4 and active layer 5 = 730 ° C, P-type intermediate layer 3 = 700 ° C p-type intermediate layer 3 layers: composition Al0.77Ga0.3InP, thickness = 0.5 " m, carrier density = 7xl017cm-3 Undoped AllnP layer on anode side: thickness = 0.5 // m Window layer: Composition Ga P, thickness =, carrier density = 2.5xl018cm—3 -36- (33) 200417066 [Table 4] Sample growth conditions VF (V @ 20mA) Brightness (mcd @ 20mA) Luminous wavelength G GaP 700 ° C 2.8 // m / h 2.14 9.4 573 Η GaP700 ° C 7.8 ^ m / h 2.14 9.0 573 I GaP 730 ° C 7.8 // m / h 1.98 16.9 573 Growth temperature: n-type cladding layer 7 = 700 ° C, undoped AlkiP layer 6 , 4 layers and active layer 5 = 730 ° C, P-type intermediate layer 3 = 700 ° C Undoped AllnP layer on the cathode side cover layer: thickness = 0.1 / zm (I series 0.2 vm) P-type intermediate layer: composition Ala7Gaa3InP , Thickness =, carrier density = 7xl017cm-3 window layer: composition GaP, thickness = 5 ^ 01, carrier density = 2.5xlOI8cm_3 [dependence of V f and brightness on the growth conditions of the window layer] [Table 5] Current diffusion Layer characteristics Thickness Carrier concentration N · d Brightness Vf (V) @ 2 0mA (μπι) Degree (cm-3) (cm · 2) (mcd) 6 3.0E + 1 8 1 .8E + 1 5 40 1.99 Implementation Example 1 3 3.0E + 1 8 9E + 1 4 〇o JJ 2.02 Example 2 10 3.0E + 1 8 3E + 1 5 42 1 .99 Example 3 6 1 .0E + 1 8 6E + 1 4 32 2.02 Example 4 10 1.0 E + 1 8 1E + 15 39 1.99 Example 5 10 5.0E + 1 7 5E + 1 4 30 2.02 Example 6 _- 1 2 2.24 Comparative Example Comparison between the present invention and a conventional example -37- 200417066 (34) [Table 6] Brightness (mcd) Wavelength (n m) Vf (V) Example 7 5 1 573 1.94 -38-

Claims (1)

(1) (1) 200417066 Scope of patent application 1. A light emitting diode device comprising: an aluminum gallium indium phosphide (AlGalnP) active layer; and an anode side cover layer and a cathode side cover layer, and the active layer system Sandwiched between the two, and the band gap between the anode side cover layer and the cathode side cover layer is larger than the active layer, and the window layer band gap is larger than the active layer formed on the anode side cover layer, which is characterized by: The cover layer system includes: 1) an undoped aluminum indium phosphorus (AllnP) layer 'which is connected to the active layer' and grown to a thickness of 0.5 m or more, 2) an intermediate layer 'which has the undoped aluminum indium phosphorus The (AllnP) layer band gap and the middle band gap of the window layer band gap are P-type doped connected to the window layer. 2 · A light-emitting diode element, comprising: an active layer of aluminum gallium indium (AlGalnP); and an anode-side cover layer and a cathode-side cover layer, and the active layer is sandwiched between the two, and the anode-side cover The band gap between the layer and the cathode side cover layer is larger than the active layer, and the window layer band gap is larger than the active layer formed on the anode side cover layer, which is characterized in that: the window layer is formed by gallium phosphide (GaP) layer to It is composed by growing at a temperature above 7 3 0 ° C, its growth rate is above 7.8 // m per hour, and its dopant is zinc. 3. The light-emitting diode element as described in item 2 of the scope of the patent application, wherein the anode-side cover layer includes: 1) an undoped aluminum indium phosphorus (Alin P) layer, which is connected to the active layer and grows into A thickness of 0.5 // m or more, 2) an intermediate layer having an intermediate band gap between the band gap of the undoped aluminum indium phosphorus (AllnP) layer and the band gap of the window layer, and connecting the window layer P -39- (2) (2) 200417066 type doping. 4. A light-emitting diode element comprising: AlGalnP: and an anode-side covering layer and a cathode-side covering layer, and an active layer is sandwiched between the two, and the anode-side covering layer and the cathode The band gap of the side cover layer is larger than the active layer, and the band gap of the window layer is larger than the active layer formed on the anode side cover layer, which is characterized in that the cathode side cover layer includes: connected to the active layer, and has a thickness of 0. . Undoped aluminum indium phosphorus (a 11 η P) layer above 1 V m. 5. The light-emitting diode element as described in item 4 of the scope of the patent application, wherein the 'cathode-side cover layer includes an n-type cover layer connected to the aforementioned undoped aluminum indium phosphorus (AllnP) layer by the cathode side, and the The dopant of the ^ -type capping layer is silicon. 6. A method for manufacturing a light-emitting diode element, which is characterized by the following steps: on a gallium arsenide (GaAs) substrate, 1) a step of depositing a buffer layer, and 2) setting an n-type reflection on the buffer layer Layer, as a reflective layer step, and 3) a step of depositing a silicon-doped n-type cover layer on the reflective layer, and 4) on the n-type cover layer, disposing an undoped aluminum indium phosphorus ( ah ηρ) step, and 5) a step of disposing an aluminum gallium indium (A 1 G a I η ρ) active layer on the undoped aluminum indium phosphorus (a 11 η P) layer, and -40 -(3) (3) 200417066 6) on the above active layer, a step of arranging unidentified phosphorous (a 11 η P) _, and 7) on the above undoped aluminum indium phosphorus (AllnP) layer, Steps of setting a p-type intermediate layer, and 8) On the above P-type intermediate layer, grow p-type gallium phosphide doped with zinc at a temperature of 73 (TC or higher and a growth rate of 7.8 // m per hour or more) (GaP) layer as a step of the window layer. 7. A light emitting diode device, comprising: a semiconductor substrate having a first electrode formed on a back surface thereof; And a semiconductor layer formed on the semiconductor substrate and containing a light-emitting portion composed of aluminum gallium indium phosphide (AlGalnP) and having a window layer on the upper layer; and a portion of the surface formed on the window layer and forming an ohmic layer with the window layer A contacting distribution electrode; and a transparent conductive film formed by covering the surface of the window layer and the distribution electrode and communicating with the distribution electrode; and a bottom electrode formed on a part of the surface of the transparent conductive film and communicating with the transparent conductive film. 8 · The light-emitting diode device described in item 7 of the scope of patent application, wherein the semiconductor substrate is of an n-type and the current diffusion layer is p-type. 9. The light-emitting diode described in item 7 or 8 of the scope of patent application. A device in which the thickness of the window layer is 3 // m or more. 1 0 · The light-emitting diode device described in item 7 or 8 of the scope of patent application, wherein the thickness of the window layer and the carrier concentration N The product (N. -41-(4) (4) 200417066 d) is 5 x 1 0 1 4 cm — 2 or more. 1 1 · The light-emitting diode element as described in item 7 or 8 of the scope of patent application, where The surface of the window layer The sub-concentration is 1 × 1018 cm-3 or more. 1 2 · The light-emitting diode device as described in item 7 or 8 of the scope of patent application, wherein the current diffusion layer is made of zinc (Z η) or magnesium (Mg) It is composed of a P-type gallium phosphide (GaP) layer as an impurity. 1 3 · The light-emitting diode device as described in item 7 or 8 of the scope of patent application, wherein the distribution electrode is formed on a surface when viewed from a plane. The surface of the semiconductor layer overlapping the bottom electrode. 1 4 · The light-emitting diode element according to item 7 or 8 of the scope of patent application, wherein the area of the distribution electrode is smaller than the area of the bottom electrode. 15. The light-emitting diode element according to item 7 or 8 of the scope of patent application, wherein the effective light-emitting area of the total flat area of the distribution electrode is 3% or more and 30% or less. 16. The light-emitting diode element according to item 7 or 8 of the scope of patent application, wherein the distribution electrode is a gold alloy. 17 · The light-emitting diode device according to item 7 or 8 of the scope of patent application, wherein the transparent conductive film is indium tin oxide (ITO). 18 · The light-emitting diode device according to item 7 or 8 of the scope of patent application, wherein the bottom electrode is formed at the center of the surface of the device when viewed from a plane. 19. The light-emitting diode element according to item 7 or 8 of the scope of the patent application, wherein the surface of the bottom electrode is gold. -42- (5) (5) 200417066 20 · The light-emitting diode element described in item 7 or 8 of the scope of the patent application, wherein the bottom electrode is composed of a multilayer film, and the layer connected to the transparent conductive film is chromium. 21. The light-emitting diode element according to item 7 or 8 of the scope of patent application, wherein 'the distribution electrode is a substantially quadrangular or substantially circular linear body surrounding the bottom electrode. 22. The light-emitting diode element as described in item 7 or 8 of the scope of the patent application, wherein 'the distribution electrode is a linear body having a line width of 20 / m or less. 23. A method for manufacturing a light-emitting diode device, comprising the following steps: Step 1 'On a single crystal substrate, a light-emitting portion composed of aluminum gallium indium phosphide (AlGalnP) is provided, and the upper layer has epitaxial growth of the semiconductor layer of the p-type window layer; and step 2 'forming a distribution electrode forming an ohmic contact with the window layer on the surface of the window layer portion formed in the above step 1; and step 3' covering the surface of the window layer And a distribution electrode to form a transparent conductive film in communication with the distribution electrode; and a fourth step 'forming a bottom electrode in which the transparent conductive film is conductive on a part of the surface of the transparent conductive film. 2 4 · The method for manufacturing a light-emitting diode device according to item 23 of the scope of the patent application, wherein the above-mentioned semiconductor layer is formed by an organic metal chemical vapor deposition method (MOCVD method). 2 5 · The manufacturing method of the light-emitting diode -43- (6) (6) 200417066 as described in item 23 or 24 of the scope of patent application, wherein the transparent conductive film is formed by a sputtering method. . 26. The method for manufacturing a light-emitting diode device as described in claim 23 or 24, wherein the bottom electrode is formed by a sputtering method. 2 7. The light-emitting diode element according to any one of claims 1 to 5 in the patent application scope, wherein the light-emitting diode element includes a distribution electrode that is formed on a part of the surface of the window layer and forms an ohmic contact with the window layer. A transparent conductive film formed by covering the surface of the window layer and the distribution electrode and communicating with the distribution electrode; and a bottom electrode formed on a part of the surface of the transparent conductive film and communicating with the transparent conductive film. 28. The light-emitting diode element as described in item 27 of the scope of patent application, wherein the thickness of the window layer is greater than or equal to. 29. The light-emitting diode device as described in item 27 or 28 of the scope of patent application, wherein the product (N.d) of the thickness of the window layer and the carrier concentration N is 5xl014cm-2 or more. 3 0 · The light-emitting diode element described in item 27 or 28 of the scope of patent application, wherein the carrier concentration on the surface of the window layer is lxl018cm_3 or more. 3 · As item 27 or 28 of the scope of patent application In the light-emitting diode element according to the description, the distribution electrode is formed on a surface of the semiconductor layer that does not overlap the bottom electrode when viewed from a plane. -44- (7) (7) 200417066 3 2. The light-emitting diode element described in item 27 or 28 of the patent application scope, wherein the area of the distribution electrode is smaller than the area of the bottom electrode. 3 3. The light-emitting diode element described in item 27 or 28 of the scope of patent application, wherein the effective light-emitting area of the total flat area of the distribution electrode is 3% or more and 30% or less. 34. The light-emitting diode element as described in item 27 or 28 of the scope of patent application, wherein the distribution electrode is a gold alloy. 3 5 · The light-emitting diode device as described in item 27 or 28 of the patent application scope, wherein the transparent conductive film is indium tin oxide (ITO). 36. The light-emitting diode element as described in claim 27 or 28, wherein the bottom electrode is formed at the center of the surface of the element when viewed from a plane. 37. The light-emitting diode element according to item 27 or 28 in the scope of patent application, wherein the surface of the bottom electrode is gold. 38. The light-emitting diode element described in item 27 or 28 of the scope of patent application, wherein the bottom electrode is composed of a multilayer film, and the layer connected to the transparent conductive film is chromium. 39. The light-emitting diode element described in item 27 or 28 of the scope of the patent application, wherein the distribution electrode is a substantially quadrangular or substantially circular linear body surrounding the bottom electrode. 40. The light-emitting diode element according to item 27 or 28 of the scope of patent application, wherein the distribution electrode is a linear body having a line width of 20 m or less. -45-