Manufacturing method of light emitting device

a manufacturing method and light-emitting technology, applied in semiconductor devices, lasers, semiconductor lasers, etc., can solve problems such as difficulty in achieving larger luminous intensity, and achieve the effects of reducing luminous intensity, improving luminous intensity, and reducing luminous intensity

Inactive Publication Date: 2011-01-25
EPISTAR CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0013]In the light emitting device of the invention, formation of the cap layer on the active layer suppresses elimination of constituent elements such as indium from the active layer. This provides increased luminous intensity.
[0037]The growth temperature for the cap layer is preferably set to a temperature which allows crystal growth of the active layer. The active layer is preferably formed at a growth temperature not lower than 700° C. and not higher than 950° C. The cap layer is preferably formed at a growth temperature not lower than 700° C. and not higher than 950° C. The formation of the cap layer on the active layer at a low growth temperature suppresses elimination of constituent elements such as indium from the active layer.

Problems solved by technology

This causes difficulty in achieving larger luminous intensity with the light emitting diode.

Method used

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  • Manufacturing method of light emitting device
  • Manufacturing method of light emitting device
  • Manufacturing method of light emitting device

Examples

Experimental program
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Effect test

first embodiment

[0052]A light emitting diode composed of III-V group nitride system semiconductors according to the present invention will now be described in detail referring to FIG. 1.

[0053]In FIG. 1, formed in order on a sapphire insulating substrate 1 are a 110-Å-thick undoped AlxGa1−xN (x=0.5) buffer layer 2, a 0.2-μm-thick undoped GaN underlayer 3, a 4-μm-thick Si-doped n-type GaN contact layer 4 also serving as an n-type cladding layer, and a 0.2-μm-thick Zn- and Si-doped InqGa1−qN (q=0.05) active layer 5. Formed in order on the InGaN active layer 5 are a 200-Å-thick undoped GaN cap layer 6 for preventing crystal deterioration of the active layer 5, a 0.15-μm-thick Mg-doped p-type AlzGa1−zN (z=0.2) cladding layer 7, and a 0.3-μm-thick Mg-doped p-type GaN contact layer 8.

[0054]The part from the p-type GaN contact layer 8 to a certain position in the n-type GaN contact layer 4 is removed, so that the n-type GaN contact layer 4 is exposed. A p electrode 9 composed of Au is formed on the upper s...

second embodiment

[0081]Next, a light emitting diode formed of III-V group nitride system semiconductors in the present invention will be described.

[0082]This embodiment differs from the first embodiment in that it uses a 200-Å-thick undoped AluGa1−uN layer as the cap layer 6 in place of the undoped GaN layer. The value of u is approximately 0.1 and 0.2. This AluGa1−uN layer, too, is formed by MOCVD at the same temperature as the growth temperature for the active layer 5, at 860° C. in this embodiment. H2 and N2 are used as carrier gas and ammonia, trimethylgallium (TMG) and trimethylaluminum (TMA) are used as material gas. Triethylgallium (TEG) may be used instead of trimethylgallium (TMG).

[0083]It was seen that the light emitting diode of this embodiment also provides remarkably larger luminous intensity than a light emitting diode having no cap layer 6.

[0084]However, as compared with the 200-Å-thick undoped GaN cap layer 6 in the first embodiment regarded as providing a luminous intensity of 450 (...

third embodiment

[0087]Next, a light emitting diode composed of III-V group nitride system semiconductors in the invention will be described referring to FIG. 2.

[0088]This embodiment differs from the first embodiment in that it uses no GaN underlayer 3, whose manufacturing method is the same as that in the first embodiment except that it excludes the process step for forming the GaN underlayer 3.

[0089]While the light emitting diode of this embodiment provides lower yield than the light emitting diode of the first embodiment, it achieves larger luminous intensity than a light emitting diode having no cap layer 6.

[0090]Although the light emitting diodes of the above-described embodiments have the active layer 5 on the n-type contact layer 4, an n-type AlGaN cladding layer may be provided between the n-type contact layer 4 and the active layer 5. An n-type AlGaN cladding layer and an n-type InGaN layer may be provided between the n-type contact layer 4 and the active layer 5.

[0091]The aforementioned em...

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Abstract

A method of manufacturing a light emitting device, including the steps of: forming an active layer composed of a compound semiconductor containing indium by a vapor phase growth method; and forming a cap layer composed of a compound semiconductor on said active layer by a vapor phase growth method at a growth temperature approximately equal to or lower than a growth temperature for said active layer.

Description

[0001]This application is a divisional of prior application Ser. No. 08 / 847,471, filed Apr. 25, 1997 now U.S. Pat. No. 5,990,496.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a light emitting device and a manufacturing method thereof.[0004]2. Description of the Background Art[0005]Light emitting devices such as light emitting diodes and semiconductor laser devices which are formed of III-V group nitride system semiconductors such as GaN, AlGaN, InGaN and InAlGaN are receiving a great deal of attention because they are capable of, by direct transition, light emission in the yellow to ultraviolet region, especially in the blue region, with large luminous intensity.[0006]FIG. 8 is a schematic cross-sectional view showing a conventional light emitting diode composed of III-V group nitride system semiconductors.[0007]In FIG. 8, formed in order on a sapphire substrate 101 are a GaN buffer layer 102, an n-type GaN contact layer 103 also se...

Claims

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Application Information

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Patent Type & AuthorityPatents(United States)
IPC IPC(8): H01L21/00H01L33/00H01L33/06H01L33/12H01L33/32H01L33/34H01S5/00H01S5/323H01S5/343
CPCH01L33/007H01L33/32H01L33/02H01S5/0213H01S5/221H01S5/32341H01S2301/173H01S2304/04H01S5/2231H01S5/321H01S5/2202
InventorKUNISATO, TATSUYAKANO, TAKASHIUEDA, YASUHIROMATSUSHITA, YASUHIKOYAGI, KATSUMI
OwnerEPISTAR CORP