Semiconductor light emitting element

Abstract

The present invention provides a light emitting element capable or realizing at least one of lower resistance, higher output, higher power efficiency (1 m/W), higher mass productivity and lower cost of the element using a light transmissive electrode for an electrode arranged exterior to the light emitting structure. A semiconductor light emitting element includes a light emitting section, a first electrode and a second electrode on a semiconductor structure including first and second conductive type semiconductor layers, the first and the second electrodes respectively including at least two layers of a first layer of a light transmissive conductive film conducting to the first and the second conductive type semiconductor and a second layer arranged so as to conduct with the first layer. First and second light transmissive insulating films are respectively arranged so as to overlap at least one part of the first and the second layers.

We claim: 
     
       1. A semiconductor light emitting element comprising:
 a first conductive type semiconductor layer;   a second conductive type semiconductor layer;   a first electrode being arranged on the first conductive type semiconductor layer;   a second electrode being arranged on the second conductive type semiconductor layer; and   a light transmissive insulating film being positioned to overlap at least a part of the first electrode or the second electrode,   wherein at least the first electrode or the second electrode includes both a first layer and a second layer, the first layer and the second layer being laminated in this order from the first conductive type semiconductor layer side or from the second conductive type semiconductor layer side,   the second layer comprises an external connecting part and an electrode elongated part which extends from the external connecting part, and   the light transmissive insulating film has the similar shape as the second layer, in a plan view of the semiconductor light emitting element.   
     
     
       2. The semiconductor light emitting element according to  claim 1 ,
 wherein the light transmissive insulating film is located along the electrode elongated part of the second layer, in a plan view of the semiconductor light emitting element.   
     
     
       3. The semiconductor light emitting element according to  claim 2 ,
 wherein an arrangement of at least the external connecting part or the electrode elongated part is inside an area where the light transmissive insulating film is located, in a plan view of the semiconductor light emitting element.   
     
     
       4. The semiconductor light emitting element according to  claim 2 ,
 wherein an arrangement of a part of at least the external connecting part or the electrode elongated part is out of an area where the light transmissive insulating film is located, in a plan view of the semiconductor light emitting element.   
     
     
       5. The semiconductor light emitting element according to  claim 4 ,
 wherein the first layer and the second layer are laminated outside the light transmissive insulating film.   
     
     
       6. The semiconductor light emitting element according to  claim 1 ,
 a width of the electrode elongated part is formed to be narrower than a width of the light transmissive insulating film, in a plan view of the semiconductor light emitting element.   
     
     
       7. The semiconductor light emitting element according to  claim 1 ,
 wherein the first electrode and the external connecting part of the second electrode are arranged diagonally, in a plan view of the semiconductor light emitting element.   
     
     
       8. The semiconductor light emitting element according to  claim 1 ,
 wherein the first conductive type semiconductor layer is an n-type layer, and the second conductive type semiconductor layer is a p-type layer, respectively.   
     
     
       9. The semiconductor light emitting element according to  claim 1 ,
 further comprising a substrate on which the semiconductor structure is deposited thereon,   wherein a recess/protrusion structure is formed between the semiconductor structure and the substrate.   
     
     
       10. The semiconductor light emitting element according to  claim 1 ,
 wherein the light transmissive insulating film is positioned between the second conductive type semiconductor layer and the second layer of the second electrode, in a cross sectional view of the semiconductor light emitting element.   
     
     
       11. The semiconductor light emitting element according to  claim 1 ,
 wherein a thickness of the first layer is smaller than a thickness of the light transmissive insulating film, in a cross sectional view of the semiconductor light emitting element.   
     
     
       12. The semiconductor light emitting element according to  claim 1 ,
 wherein the first layer includes Indium Tin Oxide.   
     
     
       13. The semiconductor light emitting element according to  claim 1 ,
 wherein the second layer includes Au.   
     
     
       14. A semiconductor light emitting element comprising:
 a first conductive type semiconductor layer;   a second conductive type semiconductor layer;   a first electrode being arranged on the first conductive type semiconductor layer;   a second electrode being arranged on the second conductive type semiconductor layer; and   a light transmissive insulating film being positioned to overlap at least a part of the first electrode or the second electrode,   wherein, the light transmissive insulating film has a larger film thickness at an inner area than a film thickness at a perimeter area, in a cross sectional view of the semiconductor light emitting element,   at least the first electrode or the second electrode includes both a first layer and a second layer, the first layer and the second layer being laminated in this order from the first conductive type semiconductor layer or from the second conductive type semiconductor layer,   the second layer comprises an external connecting part, and   the external connecting part is positioned to overlap at least a part of the light transmissive insulating film in a plan view of the semiconductor light emitting element.   
     
     
       15. The semiconductor light emitting element according to  claim 14 ,
 wherein the first electrode and the second electrode are arranged on a same plane side of the semiconductor structure, in a plan view of the semiconductor light emitting element.   
     
     
       16. The semiconductor light emitting element according to  claim 14 ,
 wherein the first conductive type semiconductor layer is an n-type layer, and the second conductive type semiconductor layer is a p-type layer, respectively.   
     
     
       17. A semiconductor light emitting element comprising:
 a semiconductor structure comprising:
 a n-type semiconductor layer, and 
 a p-type semiconductor layer; 
   a first electrode arranged on the n-type semiconductor layer;   a second electrode arranged on the p-type semiconductor layer, wherein the second electrode includes a first layer and a second layer, the first layer and the second layer being laminated in this order from a p-type semiconductor layer side; and   a light transmissive insulating film positioned to overlap at least a part of the second layer of the second electrode, the light transmissive insulating film being positioned between the p-type semiconductor layer and the second electrode, and the light transmissive insulating film being made of a material that is transmissive to light generated in the semiconductor structure, wherein:   the first layer is arranged on the p-type semiconductor layer and the light transmissive insulating film,   the first layer comprises a light-transmissive conductive metal oxide,   the second layer comprises a metal,   in a plan view of the semiconductor light emitting element, an outer perimeter of the first layer is located outward of an outer perimeter of the second layer and outward of an outer perimeter of the light transmissive insulating film,   the second layer comprises an external connecting part and an electrode elongated part that extends from the external connecting part,   in the plan view of the semiconductor light emitting element, a shape of the light transmissive insulating film is similar to a shape of the second layer, and   a refractive index of the light transmissive insulating film is smaller than a refractive index of the p-type semiconductor layer, such that the light generated in the semiconductor structure is reflected by the light transmissive insulating film.   
     
     
       18. The semiconductor light emitting element according to claim 17, wherein, in the plan view of the semiconductor light emitting element, the light transmissive insulating film is located along the electrode elongated part of the second layer. 
     
     
       19. The semiconductor light emitting element according to claim 18, wherein, in the plan view of the semiconductor light emitting element, the electrode elongated part is entirely inside an area of the light transmissive insulating film. 
     
     
       20. The semiconductor light emitting element according to claim 19, wherein, in the plan view of the semiconductor light emitting element, the first electrode and the external connecting part of the second electrode are arranged diagonally. 
     
     
       21. The semiconductor light emitting element according to claim 19, further comprising a substrate on which the semiconductor structure is disposed, the substrate comprising a recess/protrusion structure at a surface of the substrate that contacts the semiconductor structure. 
     
     
       22. The semiconductor light emitting element according to claim 19, wherein, in a cross sectional view of the semiconductor light emitting element, a thickness of the first layer is smaller than a thickness of the light transmissive insulating film. 
     
     
       23. The semiconductor light emitting element according to claim 19, wherein the light-transmissive insulating conductive metal oxide includes Indium Tin Oxide. 
     
     
       24. The semiconductor light emitting element according to claim 19, wherein the metal of the second layer includes Au. 
     
     
       25. The semiconductor light emitting element according to claim 19, wherein, in a cross sectional view of the semiconductor light emitting element, a width of the external connecting part is larger than a width of the electrode elongated part. 
     
     
       26. The semiconductor light emitting element according to claim 19, wherein the n-type semiconductor layer and the p-type semiconductor layer are made of a nitride gallium-based compound semiconductor material represented by a general formula In x Al y Ga 1-x-y N (wherein 0≤x≤1, 0≤y≤1, and 0≤x+y≤1). 
     
     
       27. The semiconductor light emitting element according to claim 26, wherein a refractive index n1 of the first layer, a refractive index n2 of the light transmissive insulating film, and a refractive index ns of the semiconductor structure, satisfy a relationship ns>n1>n2. 
     
     
       28. The semiconductor light emitting element according to claim 19, wherein the first electrode and the second electrode are located on a same side of the semiconductor structure. 
     
     
       29. The semiconductor light emitting element according to claim 19, wherein, in the plan view of the semiconductor light emitting element, the semiconductor light emitting element has a rectangular shape having longitudinal sides and lateral sides, the longitudinal sides being longer than the lateral sides, and the electrode elongated part extends from the external connecting part in a direction parallel to the longitudinal sides. 
     
     
       30. The semiconductor light emitting element according to claim 19, wherein, in a cross sectional view of the semiconductor light emitting element, the second layer has a trapezoidal shape with a wider width on a first layer side. 
     
     
       31. The semiconductor light emitting element according to claim 19, wherein a thickness of the first layer is in a range of about 10 to 500 nm. 
     
     
       32. The semiconductor light emitting element according to claim 19, wherein the light transmissive insulating film is made of SiO 2 . 
     
     
       33. The semiconductor light emitting element according to claim 19, wherein a thickness of the light transmissive insulating film is in a range of about 10 nm to 1 μm. 
     
     
       34. The semiconductor light emitting element according to claim 19, wherein a thickness of the second layer is in a range of about 0.3 to 1.5 μm. 
     
     
       35. A semiconductor light emitting element comprising:
 a semiconductor structure comprising:
 a n-type semiconductor layer, and 
 a p-type semiconductor layer; 
   a first electrode arranged on the n-type semiconductor layer;   a second electrode arranged on the p-type semiconductor layer, wherein the second electrode includes a first layer and a second layer, the first layer and the second layer being laminated in this order from a p-type semiconductor layer side; and   a light transmissive insulating film positioned to overlap at least a part of the second layer of the second electrode, the light transmissive insulating film being positioned between the p-type semiconductor layer and the second electrode, and the light transmissive insulating film being made of a material that is transmissive to light generated in the semiconductor structure, wherein:   in a cross sectional view of the semiconductor light emitting element, a film thickness of the light transmissive insulating film at an inner area of the light transmissive insulating film is larger than a film thickness of the light transmissive insulating film at a perimeter area of the light transmissive insulating film,   the first layer is arranged on the p-type semiconductor layer and the light transmissive insulating film,   the first layer comprises a light-transmissive conductive metal oxide,   the second layer comprises a metal,   in a plan view of the semiconductor light emitting element, an outer perimeter of the first layer is located outward of an outer perimeter of the second layer and outward of an outer perimeter of the light transmissive insulating film,   the second layer comprises an external connecting part and an electrode elongated part that extends from the external connecting part,   in the plan view of the semiconductor light emitting element, the external connecting part is positioned to overlap at least a part of the light transmissive insulating film,   the electrode elongated part is positioned on the light transmissive insulating film,   in the plan view of the semiconductor light emitting element, the electrode elongated part is entirely inside an area of the light transmissive insulating film, and   a refractive index of the light transmissive insulating film is smaller than a refractive index of the p-type semiconductor layer, such that the light generated in the semiconductor structure is reflected by the light transmissive insulating film.   
     
     
       36. The semiconductor light emitting element according to claim 35, wherein the first electrode and the second electrode are located on a same side of the semiconductor structure.