Semiconductor light emitting element and method for manufacturing the same

Abstract

A high-luminance light emitting element is manufactured by a method comprising: forming a light emitting layer on a first surface of a GaP substrate including the first surface and a second surface opposed to the first surface and having an area smaller than the first area, the light emitting layer emitting light of a wavelength λ permitted to pass through the GaP substrate; forming a plurality of side surfaces on the GaP substrate to be respectively aslant by substantially the same angle to become narrower toward the second surface; and forming a plurality of depressions and protrusions as high as 0.1λ to 3λ on the side surfaces.

1 - 6 . (canceled)  
   
   
       7 . A method for manufacturing a semiconductor light emitting element, comprising: 
 forming a light emitting layer on a first surface of a GaP substrate including the first surface and a second surface opposed to the first surface and having an area smaller than the first area, said light emitting layer emitting light of a wavelength λ permitted to pass through the GaP substrate;    forming a plurality of side surfaces on the GaP substrate to be respectively aslant by substantially the same angle to become narrower toward the second surface; and    forming a plurality of depressions and protrusions on the side surfaces by regrowing GaP thereon by MOCVD using source material gases of a group V source material including phosphorus and a group III source material including gallium at a growth temperature in a range from a lower limit equal to or higher than 350° C. to an upper limit equal to or lower than 700° C.    
   
   
       8 . A method for manufacturing a semiconductor light emitting element according to  claim 7  wherein the depressions and protrusions have a height in a range from a lower limit equal to or higher than 0.1λ to an upper limit equal to or lower than 3λ.  
   
   
       9 . A method for manufacturing a semiconductor light emitting element according to  claim 7  wherein the GaP substrate is an off-axis (100) GaP substrate with the off-axis angle of θ (5°≦θ≦20°) along the [011] direction.  
   
   
       10 . A method for manufacturing a semiconductor light emitting element, comprising: 
 forming a light emitting layer on a first surface of a GaP substrate including the first surface and a second surface opposed to the first surface and having an area smaller than the first surface, said light emitting layer emitting light of a wavelength λ permitted to pass through the GaP substrate;    forming a plurality of side surfaces on the GaP substrate to be respectively aslant by substantially the same angle to become narrower toward the second surface; and    forming a plurality of depressions and protrusions on the side surfaces by thermal decomposition of the side surfaces of the GaP substrate in a mixed gas of a group V source material including phosphorus with hydrogen, or hydrogen, used as the atmospheric gas, which is controlled in temperature in a range from a lower limit equal to or higher than 350° C. to an upper limit equal to or lower than 1000° C., and by removing droplets of gallium as residues of the thermal decomposition by etching with an etchant.    
   
   
       11 . A method for manufacturing a semiconductor light emitting element according to  claim 10  wherein the depressions and protrusions have a height in a range from a lower limit equal to or higher than 0.1λ to an upper limit equal to or lower than 3λ.  
   
   
       12 . A method for manufacturing a semiconductor light emitting element according to  claim 10  wherein the GaP substrate is an off-axis (100) GaP substrate with the off-axis angle of θ (5°≦θ≦20°) along the [011] direction.  
   
   
       13 . A method for manufacturing a semiconductor light emitting element, comprising: 
 forming a light emitting layer on a first surface of a GaP substrate including the first surface and a second surface opposed to the first surface and having an area smaller than the first surface, said light emitting layer emitting light of a wavelength λ permitted to pass through the GaP substrate;    forming a plurality of side surfaces on the GaP substrate to be respectively aslant by substantially the same angle to become narrower toward the second surface; and    forming a plurality of depressions and protrusions on the side surfaces by forming a metal layer of any of Al, Ti, Sn, Ag and Au by vapor deposition of sputtering and removing the metal layer by etching with an etchant.    
   
   
       14 . A method for manufacturing a semiconductor light emitting element according to  claim 13  wherein the depressions and protrusions have a height in a range from a lower limit equal to or higher than 0.1λ to an upper limit equal to or lower than 3λ.  
   
   
       15 . A method for manufacturing a semiconductor light emitting element, comprising: 
 forming a light emitting layer on a first surface of a GaP substrate including the first surface and a second surface opposed to the first surface and having an area smaller than the first surface, said light emitting layer emitting light of a wavelength λ permitted to pass through the GaP substrate;    forming a plurality of side surfaces on the GaP substrate to be respectively aslant by substantially the same angle to become narrower toward the second surface; and    forming a plurality of depressions and protrusions on the side surfaces by blasting the side surfaces with particles containing alumina adjusted in diameter in a range from a smaller limit equal to or larger than 2 μm to a larger limit equal to or smaller than 3 μm, and etching them with an etchant.    
   
   
       16 . A method for manufacturing a semiconductor light emitting element according to  claim 15  wherein the depressions and protrusions have a height in a range from a lower limit equal to or higher than 0.1λ to an upper limit equal to or lower than 3λ.  
   
   
       17 . A method for manufacturing a semiconductor light emitting element, comprising: 
 forming a light emitting layer on a first surface of a GaP substrate including the first surface and a second surface opposed to the first surface and having an area smaller than the first surface, said light emitting layer emitting light of a wavelength λ permitted to pass through the GaP substrate;    forming a plurality of side surfaces on the GaP substrate to be respectively aslant by substantially a same angle to become narrower toward the second surface by using a dicing blade having depressions and protrusions on an outer surface thereof; and    forming a plurality of depressions and protrusions on the side surfaces by etching them with an etchant.    
   
   
       18 . A method for manufacturing a semiconductor light emitting element, comprising: 
 forming a light emitting layer on a first surface of a GaP substrate including the first surface and a second surface opposed to the first surface and having an area smaller than the first surface, said light emitting layer emitting light of a wavelength λ permitted to pass through the GaP substrate;    forming a plurality of side surfaces on the GaP substrate to be respectively aslant by substantially a same angle to become narrower toward the second surface; and    forming a plurality of depressions and protrusions on the side surfaces by etching with an etchant while irradiating halogen light.    
   
   
       19 . A method for manufacturing a semiconductor light emitting element, comprising: 
 forming a light emitting layer on a first surface of a GaP substrate including the first surface and a second surface opposed to the first surface and having an area smaller than the first surface, said light emitting layer emitting light of a wavelength λ permitted to pass through the GaP substrate;    forming a plurality of side surfaces on the GaP substrate to be respectively aslant by substantially a same angle to become narrower toward the second surface; and    forming a plurality of depressions and protrusions on the side surfaces by heating them to a softening point of the GaP crystal and pressing a die defining depressions and protrusions onto the heated side surfaces.    
   
   
       20 . A method for manufacturing a semiconductor light emitting element according to  claim 7 , wherein, in the step of forming the plurality of side surfaces, a first to a fourth side surfaces are formed, the first side surface being (1-11) oriented, the second side surface being slanted at a predetermined angle from the (111) orientation, the third side surface being (11-1) oriented, and the fourth side surface being slanted at a predetermined angle from the (1-1-1) orientation.  
   
   
       21 . A method for manufacturing a semiconductor light emitting element according to  claim 10 , wherein, in the step of forming the plurality of side surfaces, a first to a fourth side surfaces are formed, the first side surface being (1-11) oriented, the second side surface being slanted at a predetermined angle from the (111) orientation, the third side surface being (11-1) oriented, and the fourth side surface being slanted at a predetermined angle from the (1-1-1) orientation.  
   
   
       22 . A method for manufacturing a semiconductor light emitting element according to  claim 13 , wherein, in the step of forming the plurality of side surfaces, a first to a fourth side surfaces are formed, the first side surface being (1-11) oriented, the second side surface being slanted at a predetermined angle from the (111) orientation, the third side surface being (11-1) oriented, and the fourth side surface being slanted at a predetermined angle from the (1-1-1) orientation.  
   
   
       23 . A method for manufacturing a semiconductor light emitting element according to  claim 15 , wherein, in the step of forming the plurality of side surfaces, a first to a fourth side surfaces are formed, the first side surface being (1-11) oriented, the second side surface being slanted at a predetermined angle from the (111) orientation, the third side surface being (11-1) oriented, and the fourth side surface being slanted at a predetermined angle from the (1-1-1) orientation.  
   
   
       24 . A method for manufacturing a semiconductor light emitting element according to  claim 17 , wherein, in the step of forming the plurality of side surfaces, a first to a fourth side surfaces are formed, the first side surface being (1-11) oriented, the second side surface being slanted at a predetermined angle from the (111) orientation, the third side surface being (11-1) oriented, and the fourth side surface being slanted at a predetermined angle from the (1-1-1) orientation.  
   
   
       25 . A method for manufacturing a semiconductor light emitting element according to  claim 18 , wherein, in the step of forming the plurality of side surfaces, a first to a fourth side surfaces are formed, the first side surface being (1-11) oriented, the second side surface being slanted at a predetermined angle from the (111) orientation, the third side surface being (11-1) oriented, and the fourth side surface being slanted at a predetermined angle from the (1-1-1) orientation.  
   
   
       26 . A method for manufacturing a semiconductor light emitting element according to  claim 19 , wherein, in the step of forming the plurality of side surfaces, a first to a fourth side surfaces are formed, the first side surface being (1-11) oriented, the second side surface being slanted at a predetermined angle from the (111) orientation, the third side surface being (11-1) oriented, and the fourth side surface being slanted at a predetermined angle from the (1-1-1) orientation.