Semiconductor light emitting element

Abstract

Is provided a resonant cavity type light emitting diode having excellent humidity durability and a light output unsaturated even several 10 mA., which is suitable for mass production. The semiconductor light emitting element has a resonator formed by one set of multi-layer reflecting films disposed at a constant distance on a GaAs substrate inclined at an angle of not less than 2 degrees in the direction [011] or [0-1-1] from the plane (100) and a light emitting layer disposed at a loop position of a standing wave in the resonator, wherein a multi-layer reflecting film disposed on the GaAs substrate side is composed of plural layers of Al x Ga 1-x As (0≦x≦1) and a multi-layer reflecting film disposed on the opposite side of the GaAs substrate is composed of plural layers of Al y Ga z In 1-y-z P (0≦y≦1, 0≦z≦1), thereby achieving an improved humidity durability and an increased reflection factor by increasing the number of the reflection layers.

1 . A semiconductor light emitting element, comprising: 
 a substrate;    a light emitting layer;    a resonator comprising first and second reflecting films disposed on opposite sides of the light emitting layer, wherein the first reflecting film comprises Al x Ga 1-x As (0≦x≦1) and the second reflecting film comprises Al y Ga z In 1-y-z P (0≦y≦1,0≦z≦1);    a contact layer formed on the side of the light emitting layer opposite the side on which the substrate is provided;    an insulating layer formed on the contact layer and provided with an opening therein which exposes a portion of the contact layer; and    a patterned electrode formed on the insulating layer and the exposed portion of the contact layer,    wherein the first reflecting film is disposed on the same side of the light emitting layer as the substrate.    
     
     
         2 . A semiconductor light emitting element as defined in  claim 1 , wherein the light emitting layer comprises one or more films of Al y Ga z In 1-y-z P (0≦y≦1,0≦z≦1).  
     
     
         3 . A semiconductor light emitting element as defined in  claim 1 , wherein the substrate comprises a GaAs substrate having a surface inclined at about 2 degrees in the direction [011] or [0-1-1] from the plane (100).  
     
     
         4 . A semiconductor light emitting element as defined in  claim 1 , wherein the resonator has a resonant wavelength of 650 nm.  
     
     
         5 . A semiconductor light emitting element as defined in  claim 1 , wherein the length of the resonator is 1.5 times the resonant wavelength of the resonator.  
     
     
         6 . A semiconductor light emitting element as defined in  claim 1 , wherein the opening in the insulating layer is circular.  
     
     
         7 . A semiconductor light emitting element as defined in  claim 1 , further comprising: 
 first and second cladding layers respectively formed on opposite sides of the light emitting layer.    
     
     
         8 . A semiconductor light emitting element as defined in  claim 1 , further comprising: 
 a buffer layer formed between the substrate and the first reflecting film.    
     
     
         9 . A semiconductor light emitting element as defined in  claim 1 , wherein the first and second reflecting layer each comprises a distributed Bragg reflector.  
     
     
         10 . A semiconductor light emitting element as defined in  claim 1 , incorporated in an optical communication network.  
     
     
         11 . A semiconductor light emitting element, comprising: 
 a substrate;    a light emitting layer;    a resonator comprising first and second reflecting films disposed on opposite sides of the light emitting layer, wherein the first reflecting film comprises Al x Ga 1-x As (0≦x≦1) and the second reflecting film comprises Al y Ga z In 1-y-z P (0≦y≦1,0≦z≦1);    an n-type layer formed on the side of the light emitting layer opposite the side on which the substrate is provided and having an opening formed therein;    a current diffusion layer formed on the n-type layer; and    an electrode formed on the current diffusion layer,    wherein the first reflecting film is disposed on the same side of the light emitting layer as the substrate.    
     
     
         12 . A semiconductor light emitting element as defined in  claim 11 , wherein the light emitting layer comprises one or more films of Al y Ga z In 1-y-z P (0≦y≦1,0≦z≦1).  
     
     
         13 . A semiconductor light emitting element as defined in  claim 11 , wherein the substrate comprises a GaAs substrate having a surface inclined at about 15 degrees in the direction [011] or [0-1-1] from the plane (100).  
     
     
         14 . A semiconductor light emitting element as defined in  claim 11 , wherein the resonator has a resonant wavelength of 650 nm.  
     
     
         15 . A semiconductor light emitting element as defined in  claim 11 , wherein the length of the resonator is 1.5 times the resonant wavelength of the resonator.  
     
     
         16 . A semiconductor light emitting element as defined in  claim 11 , further comprising: 
 first and second cladding layers respectively formed on opposite sides of the light emitting layer.    
     
     
         17 . A semiconductor light emitting element as defined in  claim 11 , further comprising: 
 a buffer layer formed between the substrate and the first reflecting film.    
     
     
         18 . A semiconductor light emitting element as defined in  claim 11 , wherein the first and second reflecting layer each comprises a distributed Bragg reflector.  
     
     
         19 . A semiconductor light emitting element as defined in  claim 11 , incorporated in an optical communication network.  
     
     
         20 . A semiconductor light emitting element, comprising: 
 a substrate;    a light emitting layer;    a resonator comprising first and second reflecting films disposed on opposite sides of the light emitting layer, wherein the first reflecting film comprises Al x Ga 1-x As (0≦x≦1) and the second reflecting film comprises Al y Ga z In 1-y-z P (0≦y≦1,0≦z≦1);    a contact layer formed on the side of the light emitting layer opposite the side on which the substrate is provided;    an insulating layer formed on the contact layer and provided with an opening therein which exposes a portion of the contact layer; and    an ITO film formed on the insulating layer and the exposed portion of the contact layer,    wherein the first reflecting film is disposed on the same side of the light emitting layer as the substrate.    
     
     
         21 . A semiconductor light emitting element as defined in  claim 20 , wherein the light emitting layer comprises one or more films of Al y Ga z In 1-y-z P (0≦y≦1,0≦z≦1).  
     
     
         22 . A semiconductor light emitting element as defined in  claim 20 , wherein the substrate comprises a GaAs substrate having a surface inclined at about 15 degrees in the direction [011] from the plane (100).  
     
     
         23 . A semiconductor light emitting element as defined in  claim 20 , wherein the resonator has a resonant wavelength of 650 nm.  
     
     
         24 . A semiconductor light emitting element as defined in  claim 20 , further comprising: 
 first and second cladding layers respectively formed on opposite sides of the light emitting layer.    
     
     
         25 . A semiconductor light emitting element as defined in  claim 20 , further comprising: 
 a buffer layer formed between the substrate and the first reflecting film.    
     
     
         26 . A semiconductor light emitting element as defined in  claim 20 , wherein the first and second reflecting layer each comprises a distributed Bragg reflector.  
     
     
         27 . A semiconductor light emitting element as defined in  claim 20 , incorporated in an optical communication network.