JP2009088160A - Light emitting diode and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting diode which has a double-heterojunction stack thick enough for handling even when a substrate is removed and is effectively reduced in contact resistance while maintaining light emission output, and to provide a manufacturing method of efficiently manufacturing the light emitting diode. <P>SOLUTION: In the light emitting diode having a pair of electrodes and the stack having an upper-side and a lower-side clad layer provided between the electrodes and an active layer provided between the upper-side and lower-side clad layers, the total thickness of the stack is 50 to 500 μm and a contact layer which is 0.001 to 1 μm thick is provided between at least one of the electrodes and the stack. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a light emitting diode used in, for example, an optical sensor, optical data transmission, an optical irradiation device, and the like, and a method for manufacturing the same, and in particular, has a thickness sufficient for handling even if a substrate is removed. The present invention relates to a technique for efficiently manufacturing a light-emitting diode having a double hetero laminate having a contact resistance effectively reduced while maintaining a light-emitting output.

  Conventionally, characteristics required for a light emitting diode include, for example, high output characteristics and low resistance characteristics. Generally, when a semiconductor and a metal are brought into contact with each other, a junction barrier is formed, and a high contact resistance is generated between the semiconductor and an electrode made of a metal material. As one of the basic structures of a light emitting diode, for example, a stacked body in which a layer having a small band gap called an active layer is sandwiched between p-type and n-type layers having a large band gap called a clad layer from both sides is paired. There is a so-called double heterostructure sandwiched between electrodes, but a light-emitting diode having such a structure has a contact resistance generated between a stacked body that is a semiconductor layer and an electrode when a voltage is applied between the pair of electrodes. The resulting power loss will occur.

In order to reduce the contact resistance generated between the semiconductor layer and the electrode, for example, Patent Document 1 discloses that a contact layer made of a material having a small band gap is interposed between the electrode and the semiconductor layer. Disclosed is a semiconductor light emitting device in which a semiconductor layer and a contact layer are formed by an MOCVD method, which prevents a large power loss between an electrode and a semiconductor layer by reducing a barrier difference and reducing a contact resistance. ing.
JP 2003-163365 A

  By the way, in general, an LPE (Liquid Phase Epitaxy) method and an MOCVD (Metal Organic Chemical Vapor Deposition) method are mainly used for manufacturing a light emitting diode.

  The LPE method has a high growth rate during epitaxial growth, and the growth rate is, for example, about 1.0 μm / min. On the other hand, the MOCVD method has a slow growth rate at the time of epitaxial growth, for example, about 0.05 μm / min, and there is a difference of about 20 times compared with that by the LPE method.

  In addition, since the LPE method is a structure in which a growth layer is sequentially formed by relatively moving the substrate with respect to a tank containing a melt such as Ga, the number of tanks is the same as the number of growth layers. In the MOCVD method, it is possible to easily form a desired composition and growth layer by exchanging source gases.

  From the above, the LPE method is unsuitable for controlling the uniformity of the thickness of the growth layer and generating a multilayer film because of its high growth rate, but has the advantage that a thick film crystal can be produced at low cost. On the other hand, the MOCVD method is unsuitable for forming a thick film because it takes more time and costs than the LPE method, but it is not suitable for thickness uniformity control and multilayer film formation. There are advantages.

  In addition, when a double hetero laminate is grown on a substrate using the LPE method, a thickness sufficient for handling can be secured only by the laminate itself even if the substrate is removed. When a double hetero laminate is grown on a substrate using a thin film, a structure having a thin double hetero laminate is usually provided on the substrate because the laminate alone is thin and a sufficient thickness cannot be secured. It is used as it is.

  Conventionally, even if the substrate is removed, sufficient thickness for handling can be secured, and moreover, emphasizing the feature that it is easy to increase the light emission output because there is no energy absorption by the substrate when it is made into a chip, It is considered preferable to use the LPE method for manufacturing high-power LEDs.

The contact resistance of the electrode part of the high power LED by the conventional LPE method is generally high due to the barrier difference between the semiconductor layer and the electrode. Therefore, as means for reducing the contact resistance, the conventional LPE method light emitting diode has good lattice matching with the AlGaAs semiconductor layer, and the band gap is an active layer Al _α Ga _1-α As layer (0 <α It is preferable to use Al _β Ga _1-β As (0 ≦ β <α ≦ 1, for example, GaAs) narrower than ≦ 1) for the contact layer. However, the contact layer, because of the band gap, there is a problem that absorbs luminescence generated from Al α Ga _1-α As active layer.

  In Patent Document 1, by setting the thickness of the contact layer as thin as 0.01 to 0.03 μm, most of the light generated in the vicinity of the interface between the p-type semiconductor layer and the n-type semiconductor layer is generated inside the contact layer. However, since the MOCVD method is used not only for the formation of the contact layer but also for the formation of the laminate, the laminate cannot be manufactured into a thick film. Since the laminate cannot be removed because the laminate is thin, light is absorbed within the substrate unless a complicated structure such as a reflecting mirror that causes an increase in element resistance is used, resulting in inferior luminous efficiency. is there.

  Further, in the conventional LPE method, a method is known in which a clean growth surface (with no oxide or the like attached) is exposed by meltback, and a semiconductor layer is epitaxially grown thereon. Since this meltback phenomenon is liable to occur in the LPE method, the contact layer formed on the substrate is formed with a thin film having a thickness of 1 μm or less, and the laminate is thinly formed on the contact layer by the LPE method advantageous for thick film formation When a thick semiconductor layer is epitaxially grown on the contact layer, as shown in FIG. 6, the contact layer itself tends to disappear or deteriorate due to meltback, and therefore, a double layer with a thin uniform contact layer of 1 μm or less remains. It was difficult to grow a hetero laminate by a conventional LPE method. Due to these problems, it has been difficult to achieve both high luminous efficiency and reduction in contact resistance due to the contact layer.

  An object of the present invention is to manufacture at least one contact layer and a laminated body in contact with the one contact layer using a suitable forming method, so that the thickness is sufficient to handle even if the substrate is removed. It is an object of the present invention to provide a light emitting diode having a double hetero laminated body having a thickness and effectively reducing contact resistance while maintaining light emission output, and a method for efficiently manufacturing the light emitting diode.

In order to achieve the above object, the gist of the present invention is as follows.
(1) In a light-emitting diode comprising a pair of electrodes and a laminate having at least an upper and lower cladding layer provided between the electrodes and an active layer provided between the upper and lower cladding layers, A total thickness of the laminated body is 50 to 500 μm, and a contact layer having a thickness of 0.001 to 1 μm is provided between at least one of the electrodes and the laminated body. .

(2) The stacked body includes a lower clad layer made of _a first conductivity type Al _a Ga _1-a As material (where 0 <a ≦ 1), an Al _b Ga _1-b As material (where 0 ≦ b ≦ 1 and b <a) and an upper clad layer made of Al _c Ga _1-c As material of the second conductivity type (provided that 0 <c ≦ 1 and b <c) The light-emitting diode according to (1) above.

  (3) The light emitting device according to (1) or (2), wherein the stacked body is formed using a liquid phase growth method, and the contact layer is formed using a vapor phase growth method. diode.

  (4) A method of manufacturing a light-emitting diode comprising a pair of electrodes and a laminate having at least an upper and lower cladding layer provided between the electrodes and an active layer provided between the upper and lower cladding layers. A step of sequentially growing a lower clad layer, an active layer and an upper clad layer on a substrate using a liquid phase growth method to form the laminate having a total thickness of 50 to 500 μm; And a step of forming a lower contact layer having a thickness of 0.001 to 1 μm by a vapor phase growth method before the step of forming the stacked body.

  (5) A method of manufacturing a light-emitting diode comprising a pair of electrodes and a laminate having at least an upper and lower cladding layer provided between the electrodes and an active layer provided between the upper and lower cladding layers. A step of sequentially growing a lower clad layer, an active layer and an upper clad layer on a substrate using a liquid phase growth method to form the laminate having a total thickness of 50 to 500 μm; And a step of forming an upper contact layer having a thickness of 0.001 to 1 μm by a vapor phase growth method after the step of forming the stacked body.

  (6) A method for manufacturing a light-emitting diode comprising a pair of electrodes and a laminate having at least an upper and lower cladding layer provided between the electrodes and an active layer provided between the upper and lower cladding layers. A step of sequentially growing a lower clad layer, an active layer and an upper clad layer on a substrate using a liquid phase growth method to form the laminate having a total thickness of 50 to 500 μm; And a step of forming a lower contact layer and an upper contact layer having a thickness of 0.001 to 1 μm by vapor phase epitaxy before and after the step of forming the laminated body, respectively.

(7) Prior to the step of forming the lower contact layer, an Al _d Ga _1-d As material (provided that 0.5 <d ≦ 1.0) is applied to the substrate by vapor phase growth. The method for producing a light-emitting diode according to (4) or (6) above, further comprising the step of forming an etching stop layer.

(8) After the step of forming the upper contact layer and before the step of forming the electrode layer, an Al _d Ga _1-d As material (provided that 0.5 < The method for producing a light-emitting diode according to the above (5) or (6), further comprising a step of forming an etching stop layer comprising d ≦ 1.0).

(9) An Al _e Ga _1-e As material (provided that 0 <e ≦ 1) on the lower contact layer between the step of forming the lower contact layer and the step of forming the stacked body. The method for producing a light-emitting diode according to the above (4), (6) or (7), further comprising a step of growing a sacrificial layer comprising:

(10) The laminate includes a lower clad layer made of _a first conductivity type Al _a Ga _1-a As material (where 0 <a ≦ 1), an Al _b Ga _1-b As material (where 0 ≦ b). ≦ 1 and b <a) and an upper clad layer made of Al _c Ga _1-c As material of the second conductivity type (provided that 0 <c ≦ 1 and b <c) The manufacturing method of the light emitting diode as described in any one of said (4)-(9).

  According to the present invention, at least one contact layer and a laminate formed on the one contact layer are manufactured by using suitable forming methods, respectively, so that even if the substrate is removed, handling is possible. It is possible to provide a light-emitting diode having a double hetero laminate having a sufficient thickness, effectively reducing the contact resistance while maintaining a light-emitting output, and a method for efficiently manufacturing the light-emitting diode.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 schematically shows a cross-sectional structure of a light-emitting diode according to the present invention.

  The light-emitting diode 1 shown in FIG. 1 includes a pair of lower and upper electrodes 11 and 12, at least lower and upper cladding layers 5 and 7 provided between the electrodes 11 and 12, and lower and upper cladding layers. And a laminated body 10 having an active layer 6 provided on the substrate. The contact layers 4 and 8 are formed between at least one of the electrodes 11 and 12, respectively, between the electrodes 11 and 12 and the laminate 10 in FIG. The active layer 6 emits light from a region other than the electrode.

  The total thickness of the laminate 10 is 50 to 500 μm. When the total thickness is less than 50 μm, handling is not easy when the substrate is removed, and mounting is difficult, so that it is not suitable for a substrate-removable light emitting diode. Further, if the total thickness exceeds 500 μm, the effect of improving the extraction efficiency is small as compared with the manufacturing cost, and the thickness of the light emitting diode is not realistic. More preferably, it is 100-350 micrometers. Within this range, a light emitting diode with high luminous efficiency and high productivity can be obtained.

  The contact layers 4 and 8 have a thickness of 0.001 to 1 μm. If the thickness is less than 0.001 μm, the contact resistance cannot be effectively reduced by the contact layer. If the thickness exceeds 1 μm, the contact layer absorbs light emitted from the active layer. This is because the luminous efficiency deteriorates.

  The thickness of the contact layers 4 and 8 is more preferably 0.5 μm or less. This is because when the thickness is 0.5 μm or less, the influence of light absorption by the contact layers 4 and 8 is very small, and light emission efficiency almost equal to that obtained when no contact layer is provided can be obtained.

  The in-plane variation in the thickness of the contact layers 4 and 8 causes variation in the resistance value and output value of the light emitting diode, and therefore it is preferably within 10%, and more preferably within 1%. is there. Examples of means for forming a contact layer with an in-plane thickness variation of 1% or less include MOCVD and MBE (Molecular Beam Epitaxy).

As a suitable composition that constitutes each layer of the stacked body 10, for example, the lower cladding layer 5 is made of a p-type Al _a Ga _1-a As material (provided that 0 <a ≦ 1) as a first conductivity type, The active layer 6 is made of an Al _b Ga _1-b As material (where 0 ≦ b ≦ 1 and b <a), and the upper cladding layer 7 is made of a second conductivity type and is an n-type Al _c Ga _1-c As material. (However, 0 <c ≦ 1 and b <c). Conversely, the first conductivity type may be n-type and the second conductivity type may be p-type.

  The laminate 10 is preferably formed using a liquid phase growth method that allows easy formation of a thick film, and the contact layers 4 and 8 are preferably formed using a vapor phase growth method that facilitates film thickness control. Forming a laminated body having a total thickness of 50 μm or more on the substrate by a vapor phase growth method is not easy and requires an enormous amount of time and source gas. The reason why the contact layer of the thin film in the range of 001 to 1 μm is formed by the liquid phase growth method within 10% of the in-plane variation is that the growth rate is high and the control is very difficult and is not easy.

  Examples of the liquid phase growth method include an LPE method, and examples of the vapor phase growth method include an MOCVD method and an MBE method.

Furthermore, when manufacturing a light emitting diode, in order to prevent the contact layers 4 and 8 from being etched or scraped during device fabrication such as removing the substrate or forming an electrode, the contact layers 4 and 8 are formed outside the contact layers 4 and 8. Etching stop layer (for example, Al _d Ga _1-d As layer having a high Al composition, 0.5 <d ≦ 1.0) having a composition different from that of the contact layers 4 and 8 (more specifically, having different etching properties) Can be formed as needed.

Next, an example of a method for manufacturing a typical light emitting diode according to the present invention will be described below.
2 to 5 show the main steps of the method for manufacturing a light emitting diode according to the present invention. At least one of the upper contact layer and the lower contact layer formed by this method may be formed. The case where both contact layers are formed will be described.

In the illustrated method, first, as shown in FIG. 2, the lower contact layer 4 having a thickness of 0.001 to 1 μm is formed above the substrate 2 (lower contact layer forming step). The lower contact layer 4 is preferably made of, for example, a GaAs material.
FIG. 2 shows a case where the etching stop layer 3 is formed using a vapor phase growth method prior to the step of forming the lower contact layer 4. Can be provided as appropriate.

  Next, as shown in FIG. 3, a lower clad layer 5, an active layer 6 and an upper clad layer 7 are sequentially grown on the lower contact layer 4 by using a liquid phase growth method to obtain a total thickness t. Form a laminated body 10 having a thickness of 50 to 500 μm (laminated body forming step). If the GaAs raw material / Ga melt ratio during liquid phase growth is less than 0.01, so-called meltback may occur in which the thin lower contact layer 4 melts and disappears or deteriorates at the start of crystal growth. (FIG. 6). In order to prevent this meltback, for example, the GaAs raw material / Ga melt ratio is preferably 0.01 or more, and more preferably 0.03 or more in order to effectively prevent meltback. FIG. 7 shows the lower contact layer and the lower cladding layer of the present invention in which the contact layer does not disappear or deteriorate when the melt ratio is 0.01. The upper limit of the GaAs raw material / Ga melt ratio is preferably set to 0.12 or less from the viewpoint that excessive GaAs raw material may remain undissolved and cause a problem. Here, the melt ratio is a mass ratio of a GaAs raw material (solid) to a Ga melt (liquid 40 ° C.) at room temperature (25 ° C.) and atmospheric pressure.

  In order to prevent the meltback, the growth start temperature is preferably 500 to 900 ° C, and more preferably 800 to 870 ° C. If the temperature is lower than 500 ° C., a large amount of polycrystals are generated in the tank containing the raw material melt, causing a problem. Because. Moreover, although a cooling rate is set with start temperature, Suitably, the range of 3-60 degrees C / s is good.

Thereafter, as shown in FIG. 4, the upper contact layer 8 having a thickness of 0.001 to 1 μm is formed on the stacked body 10 (upper contact layer forming step). The carrier concentration of the contact layers 4 and 8 is preferably a high concentration with a large amount of charge carriers, specifically, more preferably 1 × 10 ^{19 to} 5 × 10 ²¹ cm ⁻³ . One or both of the lower and upper contact layers 4 and 8 are formed by a vapor phase growth method.

  Examples of the liquid phase growth method include an LPE method, and examples of the vapor phase growth method include an MOCVD method and an MBE method.

  Finally, as shown in FIG. 5, the substrate 2 is removed by etching, and electrodes are formed on both the contact layers 4 and 8, or on any of the formed contact layers and the surface of the laminate corresponding thereto. Layers 11 and 12 are formed. The etching is preferably performed by wet etching using an etching solution such as sulfuric acid, phosphoric acid, hydrochloric acid, nitric acid, citric acid, ammonia, or Br-methanol, but can also be performed by dry etching. Further, the substrate can be removed by grinding and laser lift-off. Further, for example, the portion of the lower contact layer 4 other than the portion in contact with the electrode layer 11 is removed as shown in FIG. 5 so as not to absorb light, but is left for reasons of current diffusion or the like. It doesn't matter. Further, the removal surface of the substrate 2 can be a light emission surface, and the opposite surface can be a light emission surface.

As a suitable composition for constituting each layer of the stacked body 10, for example, the lower cladding layer 5 is made of a p-type Al _a Ga _1-a As material (provided that 0 <a ≦ 1) as the first conductivity type, The active layer 6 is made of an Al _b Ga _1-b As material (where 0 ≦ b ≦ 1 and b <a), and the upper cladding layer 7 is made of a second conductivity type, which is an n-type Al _c Ga _1-c As material. (However, 0 <c ≦ 1 and b <c). Conversely, the first conductivity type may be n-type and the second conductivity type may be p-type.

Prior to the step of forming the lower contact layer 4, the substrate 2 is made of an Al _d Ga _1-d As material (provided that 0.5 <d ≦ 1.0) by using a vapor phase growth method. It is preferable to form the etching stop layer 3. This is to prevent the lower contact layer 4 from being etched or scraped during the device fabrication such as removing the substrate 2. The thickness of the etching stop layer 3 is preferably set to a thickness that allows easy control of the etching end time with the etchant, and specifically, 0.01 to 10 μm is preferable.

After the step of forming the upper contact layer 8 and before the step of forming the electrode layer 12, an Al _d Ga _1-d As material (however, 0.5 V is formed on the upper contact layer 8 by vapor phase growth). It is preferable to form an etching stop layer 9 made of <d ≦ 1.0). This is to prevent the upper contact layer 8 from being etched or scraped during the device formation such as forming the electrode 12. The thickness of the etching stop layer 9 is preferably set to a thickness that allows easy control of the etching end time with the etchant, and specifically, 0.01 to 10 μm is preferable.

Between the step of forming the lower contact layer 4 and the step of forming the stacked body 10, an Al _e Ga _1-e As material (provided that 0 < A sacrificial layer (not shown) made of e ≦ 1) may be grown. More preferably, the sacrificial layer has the same Al composition as that of the lower cladding layer 5 or an Al composition between the lower cladding layer 5 and the active layer 6 (b <e ≦ a). By forming the sacrificial layer, the contact layer can be protected even if meltback occurs, and when the contact layer alone is transferred from the MOCVD apparatus to the LPE apparatus, the contact layer surface is contaminated and LPE growth occurs. Oxides and the like can sometimes be taken into the interface, so the surface of the contact layer can be protected by the sacrificial layer (the oxide on the surface of the sacrificial layer is cleaned by meltback), and the carrier of the sacrificial layer The contact resistance can be further reduced by increasing the concentration.

Example 1
In Example 1, an etching stop layer 3 made of a p-type Al _0.7 Ga _0.3 As material is grown on a p-type GaAs substrate 2 by MOCVD, as shown in FIGS. A lower contact layer 4 made of Zn-doped p-type GaAs material having a carrier concentration of 2 × 10 ¹⁹ cm ⁻³ is formed on the lower contact layer 4 by MOCVD, and then LPE is used. A p-type Al _x Ga _1-x As (0.03 <x <0.3) material is formed on the lower contact layer 4 in a melt having a GaAs raw material / Ga melt ratio of 0.01 or more. Lower clad layer 5, active layer 6 made of p-type Al _0.03 Ga _0.97 As material, and upper clad made of n-type Al _x Ga _1-x As (0.03 <x <0.5) material Layer 7 is grown sequentially at a growth temperature of 830 ° C. The thickness t to form a stack of 160 .mu.m, then, by MOCVD, on the laminate 10, composed of a Zn-doped n-type GaAs material having a carrier concentration 2 × ¹⁰ 19 ^{cm -3,} thickness 0. An upper contact layer 8 having a thickness of 1 μm is formed, an etching stop layer 9 made of a p-type Al _0.7 Ga _0.3 As material is further grown, and wet etching using a mixed solution of ammonia and hydrogen peroxide water is performed. After the substrate 2 is removed, the etching stop layers 3 and 9 are removed using hydrofluoric acid, and gold alloy electrodes 11 and 12 for taking a power supply are formed, whereby 350 μm × 350 μm × 162 μm (vertical × horizontal × A light emitting diode 1 having a height) was obtained. The composition was adjusted so that the emission wavelength generated from the active layer was about 850 nm.

Examples 2 to 4 were carried out except that the carrier concentrations of both contact layers 4 and 8 were 2 × 10 ²¹ cm ⁻³ , 2 × 10 ¹⁸ cm ⁻³ , and 2 × 10 ¹⁷ cm ⁻³ , respectively. A light emitting diode was obtained in the same manner as in Example 1. Examples 5, 6, 7 and 8 are the same as Example 1 except that the thicknesses of both contact layers 4 and 8 are 1 μm, 0.2 μm, 0.001 μm and 0.5 μm, respectively. Thus, a light emitting diode was obtained. Further, in Examples 9 and 10, light emitting diodes were obtained in the same manner as in Example 1 except that the melt ratios were 0.10 and 0.001, respectively.

  In Comparative Example 1, a light emitting diode was obtained in the same manner as in Example 5 except that both contact layers 4 and 8 and the laminate were formed using the LPE method.

  Comparative Example 2 and Comparative Example 3 are conventional light emitting diodes in which a contact layer is not provided for a double hetero laminate formed using only the LPE method and the MOCVD method, respectively. Note that the thickness of the stacked body formed by the MOCVD method of Comparative Example 3 is 330 μm (including the substrate), and the substrate is not removed.

(Performance evaluation 1)
For each of the light emitting diodes of Examples 1 to 10 and Comparative Examples 1 to 3, the light emission output, the standard deviation of the light emission output, and the resistance value when a current of 20 mA (constant) was passed were measured. These measurement results are shown in Table 1. This resistance value indicates the sum of the specific resistance and the contact resistance. If the specific resistance is constant, the increase or decrease in the resistance value can be regarded as the increase or decrease in the contact resistance.

From the results in Table 1, it can be seen that Examples 1 to 10 effectively reduce the contact resistance while maintaining the light emission output. It can also be seen that the resistance value decreases as the carrier concentration increases, becomes a substantially constant minimum value at 10 ¹⁹ cm ⁻³ or more, and the light emission output is larger as the contact layer is thinner. In Example 10, it was confirmed that the (lower) contact layer was impaired by meltback.

  Although low resistance can be obtained even in Comparative Example 1, the in-plane distribution of the contact layer thickness is poor, and a distribution of about 0.3 to 1.5 μm is obtained (variation distribution 30%) to stably produce the contact layer. I couldn't. Further, the light output was as low as about 70 to 90% of the light emitting diode of the present invention, and the standard deviation indicating the variation was large.

  Since neither Comparative Example 2 nor Comparative Example 3 has a contact layer, it can be seen that both the maintenance of the light emission output and the reduction of the contact resistance cannot be realized.

  In this example, the case where the contact layer is provided on both sides of the laminated body is described. However, the present invention is not limited to this embodiment, and even when the contact layer is added on one side, the light emission output is maintained and the contact resistance It is obvious that the effect of reducing the above can be obtained.

  The light-emitting diode of the present invention can be handled even when the substrate is removed by manufacturing at least one contact layer and a laminate formed on the one contact layer using suitable forming methods. The double hetero laminate having a sufficient thickness can be effectively reduced while maintaining the light emission output, and the contact resistance can be effectively reduced. The light emitting diode manufacturing method of the present invention uses the MOCVD method. A double hetero laminated body can be formed on this contact layer using the LPE method without the thin contact layer formed disappearing.

1 is a cross-sectional view of a light emitting diode according to the present invention. 4 shows a lower contact layer forming step of a method for manufacturing a light emitting diode according to the present invention. The laminated body formation process of the manufacturing method of the light emitting diode according to this invention is shown. 4 shows an upper contact layer forming step of a method for manufacturing a light emitting diode according to the present invention. The electrode layer formation process of the manufacturing method of the light emitting diode according to this invention is shown. The presence state of the lower side contact layer immediately after forming a laminated body by the conventional LPE method is shown. Fig. 4 shows the presence state of the lower contact layer of a light emitting diode according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light emitting diode 2 Substrate 3, 9 Etching stop layer 4 Lower contact layer 8 Upper contact layer 5 Lower cladding layer 7 Upper cladding layer 6 Active layer 10 Laminate 11, 12 Electrode layer t Total thickness of laminate 10

Claims (10)

In a light emitting diode comprising a pair of electrodes and a laminate having at least an upper and lower cladding layer provided between the electrodes and an active layer provided between the upper and lower cladding layers,
The total thickness of the laminated body is 50 to 500 μm, and a contact layer having a thickness of 0.001 to 1 μm is provided between at least one of the electrodes and the laminated body. diode. The stacked body includes a lower clad layer made of an Al _a Ga _1-a As material (where 0 <a ≦ 1), an Al _b Ga _1-b As material (where 0 ≦ b ≦ 1). And an active layer made of b <a) and an upper clad layer made of Al _c Ga _1-c As material of the second conductivity type (where 0 <c ≦ 1 and b <c). Item 2. A light emitting diode according to item 1.   The light emitting diode according to claim 1, wherein the stacked body is formed using a liquid phase growth method, and the contact layer is formed using a vapor phase growth method. A method of manufacturing a light emitting diode comprising a pair of electrodes, and a laminate having at least an upper and lower cladding layer provided between the electrodes and an active layer provided between the upper and lower cladding layers,
A step of sequentially growing a lower clad layer, an active layer and an upper clad layer on the substrate using a liquid phase growth method to form the laminate having a total thickness of 50 to 500 μm;
And a step of forming a lower contact layer having a thickness of 0.001 to 1 μm by a vapor phase growth method before the step of forming the stacked body. A method of manufacturing a light emitting diode comprising a pair of electrodes, and a laminate having at least an upper and lower cladding layer provided between the electrodes and an active layer provided between the upper and lower cladding layers,
A step of sequentially growing a lower clad layer, an active layer and an upper clad layer on the substrate using a liquid phase growth method to form the laminate having a total thickness of 50 to 500 μm;
And a step of forming an upper contact layer having a thickness of 0.001 to 1 μm by a vapor phase growth method after the step of forming the stacked body. A method of manufacturing a light emitting diode comprising a pair of electrodes, and a laminate having at least an upper and lower cladding layer provided between the electrodes and an active layer provided between the upper and lower cladding layers,
A step of sequentially growing a lower clad layer, an active layer and an upper clad layer on the substrate using a liquid phase growth method to form the laminate having a total thickness of 50 to 500 μm;
And a step of forming a lower contact layer and an upper contact layer having a thickness of 0.001 to 1 μm by vapor phase epitaxy before and after the step of forming the laminated body, respectively. . Prior to the step of forming the lower contact layer, an etching stop made of Al _d Ga _1-d As material (provided that 0.5 <d ≦ 1.0) is applied to the substrate by vapor phase growth. The method for producing a light-emitting diode according to claim 4, further comprising a step of forming a layer. After the step of forming the upper contact layer and before the step of forming the electrode layer, an Al _d Ga _1-d As material (provided that 0.5 <d ≦ 1) is formed on the upper contact layer using a vapor deposition method. The method of manufacturing a light emitting diode according to claim 5 or 6, further comprising a step of forming an etching stop layer made of. Between the step of forming the lower contact layer and the step of forming the stacked body, a sacrifice made of an Al _e Ga _1-e As material (where 0 <e ≦ 1) is formed on the lower contact layer. The method for manufacturing a light-emitting diode according to claim 4, further comprising a step of growing a layer. The stacked body includes a lower clad layer made of an Al _a Ga _1-a As material (where 0 <a ≦ 1), an Al _b Ga _1-b As material (where 0 ≦ b ≦ 1). And an active layer made of b <a) and an upper clad layer made of Al _c Ga _1-c As material of the second conductivity type (where 0 <c ≦ 1 and b <c). Item 10. A method for producing a light-emitting diode according to any one of Items 4 to 9.