Semiconductor light emitting device, nitride semiconductor layer growth substrate, and nitride semiconductor wafer

Abstract

According to one embodiment, a semiconductor light emitting device includes a first semiconductor layer of a first conductivity type and having a major surface, a second semiconductor layer of a second conductivity type, and a light emitting layer provided between the first and second semiconductor layers. The major surface is opposite to the light emitting layer. The first semiconductor layer has structural bodies provided in the major surface. The structural bodies are recess or protrusion. A centroid of a first structural body aligns with a centroid of a second structural body nearest the first structural. hb, rb, and Rb satisfy rb/(2·hb)≦0.7, and rb/Rb<1, where hb is a depth of the recess, rb is a width of a bottom portion of the recess, and Rb is a width of the protrusion.

1 . (canceled) 
     
     
         2 : A substrate,
 the substrate having a substrate surface, the substrate surface including a plurality of protrusions,   the protrusions including a first apical face and a second apical face nearest to the first apical face,   the first apical face having a first centroid, the second apical face having a second centroid, the first centroid aligning with the second centroid along a second axis; and   ha and ra satisfying
     ra /(2· ha )<0.7,
 
   where
 ha is a height of the protrusion, and 
 ra is a width of the first apical face along the second axis. 
   
     
     
         3 : The substrate according to  claim 2 , wherein a ratio of a total surface area of apical faces of the protrusions per unit surface area of the substrate surface to a total surface area of a bottom face of the substrate surface per the unit surface area of the substrate surface is less than 0.17. 
     
     
         4 : The substrate according to  claim 2 , wherein ha/(Ta−Ra−ra) is not more than 0.6, where Ta is a distance between the first centroid and the second centroid along the second axis and Ra is a width of the bottom face along the second axis. 
     
     
         5 : The substrate according to  claim 2 , wherein the substrate includes at least one of sapphire, silicon carbide (SiC), silicon (Si), and gallium arsenide (GaAs). 
     
     
         6 : The substrate according to  claim 2 , wherein
 Ra is a width of the bottom face along the second axis,   the ha is 0.5 micrometers or more and 3 micrometers or less,   the ra is 0.5 micrometers or more and 4 micrometers or less, and   the Ra is 0.5 micrometers or more and 4 micrometers or less.   
     
     
         7 : The substrate according to  claim 2 ,
 wherein the ra/Ra is not more than 0.6, and   where Ra is a width of the bottom face along the second axis.   
     
     
         8 : The substrate according to  claim 7 , wherein the ra/Ra is not less than 0.25. 
     
     
         9 : The substrate according to  claim 3 , the ratio of the total surface area of the apical faces per the unit surface area of the substrate surface to the total surface area of the bottom face per the unit surface area of the substrate surface is not more than 0.11. 
     
     
         10 : The substrate according to  claim 7 , wherein ha/(Ta−Ra−ra) is not more than 0.6, where Ta is a distance between the first centroid and the second centroid along the second axis. 
     
     
         11 : The substrate according to  claim 4 , wherein the ha/(Ta−Ra−ra) is not more than 0.59. 
     
     
         12 : The substrate according to  claim 10 , wherein the ha/(Ta−Ra−ra) is not more than 0.59. 
     
     
         13 : The substrate according to  claim 4 , wherein the ha/(Ta−Ra−ra) is not more than 0.5. 
     
     
         14 : The substrate according to  claim 10 , wherein the ha/(Ta−Ra−ra) is not more than 0.5. 
     
     
         15 : The substrate according to  claim 2 , wherein each of the first apical face and the second apical face is hexagonal. 
     
     
         16 : The substrate device according to  claim 15 , wherein a side of the first apical face is parallel to a side of the second apical face. 
     
     
         17 : The substrate according to  claim 2 , wherein each of the first apical face and the second apical face is regular hexagonal. 
     
     
         18 : The substrate according to  claim 2 , wherein each of the first apical face and the second apical face is triangular. 
     
     
         19 : The substrate according to  claim 18 , wherein a side of the first apical face is parallel to a side of the second apical face. 
     
     
         20 : The substrate according to  claim 2 , wherein each of the first apical face and the second apical face is regular triangular. 
     
     
         21 : The substrate according to  claim 2 , wherein each of the first apical face and the second apical face is triangular, and
 a side of the first apical face located on an extension of a side of the second apical face.   
     
     
         22 : The substrate according to  claim 21 , wherein each of the first apical face and the second apical face is right regular triangular.