Semiconductor light emitting device

Abstract

There is provided a semiconductor light emitting device that minimizes reflection or absorption of emitted light, maximizes luminous efficiency with the maximum light emitting area, enables uniform current spreading with a small area electrode, and enables mass production with high reliability and high quality. A semiconductor light emitting device according to an aspect of the invention includes first and second conductivity type semiconductor layers, an active layer formed therebetween, first electrode layer, and a second electrode part electrically connecting the semiconductor layers. The second electrode part includes an electrode pad unit, an electrode extending unit, and an electrode connecting unit connecting the electrode pad unit and electrode extending unit.

1 - 19 . (canceled) 
     
     
         20 . An optoelectronic semiconductor body that is provided for emitting electromagnetic radiation from a front side of the semiconductor body, the optoelectronic semiconductor body comprising:
 a semiconductor layer sequence which has an active layer suitable for generating electromagnetic radiation,   a first electrical connecting layer arranged at a rear side of semiconductor layer sequence, the rear side opposite the front side,   a second electrical connecting layer arranged at the rear side of the semiconductor layer sequence, and   a separating layer, wherein the first and second electrical connecting layers are electrically insulated from one another by the separating layer,   wherein the first electrical connecting layer, the second electrical connecting layer and the separating layer overlap laterally,   wherein a partial region of the second electrical connecting layer extends from the rear side through a breakthrough in the active layer in a direction of the front side, and   wherein the first electrical connecting layer has an electrical contact area which is suitable for electrically contacting the semiconductor body from the front side and/or the second electrical connecting layer has an electrical contact area which is suitable for electrically contacting the semiconductor body from the front side.   
     
     
         21 . The optoelectronic semiconductor body according to  claim 20 , wherein the first and/or the second electrical connecting layer reflect in the direction of the front side a part of the electromagnetic radiation emitted in a direction of the rear side by the active layer. 
     
     
         22 . The optoelectronic semiconductor body according to  claim 20 , wherein the semiconductor layer sequence is free of a growth substrate. 
     
     
         23 . The optoelectronic semiconductor body according to  claim 20 , further comprising a carrier substrate at the rear side. 
     
     
         24 . The optoelectronic semiconductor body according to  claim 20 , further comprising a semiconducting or electrically insulating mirror layer arranged at least in places between the semiconductor layer sequence and the first and/or the second electrical connecting layer, the semiconducting or electrically insulating mirror layer having a plurality of openings and the first and/or the second electrical connecting layer extending through the openings to the semiconductor layer sequence. 
     
     
         25 . The optoelectronic semiconductor body according to  claim 20 , wherein the semiconductor layer sequence has a current spreading layer adjacent to the rear side, the current spreading layer containing a transparent conducting oxide. 
     
     
         26 . The optoelectronic semiconductor body according to  claim 20 , wherein the first and/or the second electrical connecting layer has a multi-layer structure with an adhesion promoting layer, a reflector layer and/or a current distribution layer. 
     
     
         27 . The optoelectronic semiconductor body according to  claim 20 , wherein the electrical contact area or areas which are suitable for electrically contacting the semiconductor body from the front side are arranged alongside the semiconductor layer sequence. 
     
     
         28 . The optoelectronic semiconductor body according to  claim 20 , wherein the semiconductor layer sequence is removed in places in order to expose the electrical contact area or areas which are suitable for electrically contacting the semiconductor body from the front side. 
     
     
         29 . The optoelectronic semiconductor body according to  claim 20 , wherein the first or the second electrical connecting layer has an electrical contact area which is suitable for electrically contacting the semiconductor body from the rear side. 
     
     
         30 . The optoelectronic semiconductor body according to  claim 20 , wherein the semiconductor layer sequence has a buffer layer arranged at the front side, the buffer layer having a low electrical conductivity and being undoped or weakly n-doped. 
     
     
         31 . A method for producing an optoelectronic semiconductor body that is provided for emitting electromagnetic radiation from a front side of the semiconductor body, the method comprising:
 epitaxially growing a semiconductor layer sequence on a growth substrate, the semiconductor layer sequence comprising an active layer suitable for generating electromagnetic radiation;   forming a first electrical connecting layer over a rear side of the semiconductor layer sequence, the rear side opposite the front side;   forming a breakthrough in the active layer;   forming a separating layer over the rear side of the semiconductor layer sequence;   forming a second electrical connecting layer over the rear side of the semiconductor layer sequence; and   forming an electrical contact area of the first electrical connecting layer in such fashion that it is suitable for electrically contacting the semiconductor body from its front side and/or forming an electrical contact area of the second electrical connecting layer in such fashion that it is suitable for electrically contacting the semiconductor body from its front side;   wherein the first electrical connecting layer, the separating layer and the second electrical connecting layer are formed in a laterally overlapping fashion,   wherein a partial region of the second electrical connecting layer is formed in the breakthrough, and   wherein the second electrical connecting layer is electrically insulated from the first electrical connecting layer by the separating layer.   
     
     
         32 . The method according to  claim 31 , further comprising removing at least a part of the growth substrate and forming a carrier substrate at the rear side. 
     
     
         33 . The method according to  claim 31 , further comprising: forming a semiconducting or electrically insulating mirror layer in places on the rear side of the semiconductor layer sequence, and
 forming a plurality of openings in the semiconducting or electrically insulating mirror layer,   wherein the first and/or the second electrical connecting layer are formed in such a manner that they extend through the openings.   
     
     
         34 . The method according to  claim 31 , wherein epitaxially growing the semiconductor layer sequence comprises growing a buffer layer which has a low electrical conductivity, the method further comprising removing at least a part of the growth substrate so that the buffer layer is exposed when the growth substrate is removed. 
     
     
         35 . The method according to  claim 31 , wherein the electrical contact area or areas which are suitable for electrically contacting the semiconductor body from its front side are formed such that they are arranged alongside the semiconductor layer sequence. 
     
     
         36 . The method according to  claim 31 , wherein forming the electrical contact area or areas comprises removing the semiconductor layer sequence in places in order to expose the electrical contact area or areas which are suitable for electrically contacting the semiconductor body from its front side. 
     
     
         37 . An optoelectronic semiconductor body that is provided for emitting electromagnetic radiation from a front side of the semiconductor body, the optoelectronic semiconductor body comprising:
 a semiconductor layer sequence which has an active layer suitable for generating electromagnetic radiation,   a first electrical connecting layer arranged at a rear side of the semiconductor layer sequence, the rear side opposite the front side,   a second electrical connecting layer arranged at the rear side of the semiconductor layer sequence,   a separating layer, and   a semiconducting or electrically insulating mirror layer having a plurality of openings,   wherein the first and second electrical connecting layers are electrically insulated from one another by the separating layer,   wherein the first electrical connecting layer, the second electrical connecting layer and the separating layer overlap laterally,   wherein a partial region of the second electrical connecting layer extends from the rear side through a breakthrough in the active layer in a direction of the front side, and   wherein the semiconducting or electrically insulating mirror layer is arranged in places between the semiconductor layer sequence and the first electrical connecting layer, and the first electrical connecting layer extends through the openings to the semiconductor layer sequence.   
     
     
         38 . The optoelectronic semiconductor body of  claim 37 , wherein the mirror layer is arranged in places between the semiconductor layer sequence and the second electrical connecting layer, and the second electrical connecting layer extends through at least one further opining in the mirror layer to the semiconductor layer sequence. 
     
     
         39 . The optoelectronic semiconductor body of  claim 37 , wherein the mirror layer contains at least one pair of layers with alternating high and low refractive indices. 
     
     
         40 . The optoelectronic semiconductor body of  claim 37 , wherein the mirror layer covers at least 50% of a main face at the rear side of the semiconductor layer stack. 
     
     
         41 . The optoelectronic semiconductor body of  claim 37 , wherein the first electrical connecting layer, the second electrical connecting layer and the mirror layer are provided to reflect 80% or more of the electromagnetic radiation emitted in the direction of the rear side by the active layer back in the direction of the front side. 
     
     
         42 . An optoelectronic semiconductor body that is provided for emitting electromagnetic radiation from a front side of the semiconductor body, the optoelectronic semiconductor body comprising:
 a semiconductor layer sequence which has an active layer suitable for generating electromagnetic radiation,   a first electrical connecting layer arranged at a rear side of the semiconductor layer sequence, the rear side opposite the front side,   a second electrical connecting layer arranged at the rear side of the semiconductor layer sequence, and   a separating layer, wherein the first and second electrical connecting layers are electrically insulated from one another by the separating layer,   wherein the first electrical connecting layer, the second electrical connecting layer and the separating layer overlap laterally,   wherein a partial region of the second electrical connecting layer extends from the rear side through a breakthrough in the active layer in a direction of the front side, and   wherein the first and/or the second electrical connecting layer has a multi-layer structure with an adhesion promoting layer and a reflector layer, the adhesion promoting layer being provided for improving adhesion of the reflector layer to the semiconductor layer sequence and/or the separating layer.   
     
     
         43 . The optoelectronic semiconductor body of  claim 42 , wherein the adhesion promoting layer has a thickness of 1 nm or less. 
     
     
         44 . The optoelectronic semiconductor body of  claim 43 , wherein the reflector layer has a thickness of between 50 nm and 200 nm. 
     
     
         45 . The optoelectronic semiconductor body of  claim 42 , wherein the adhesion promoting layer has titanium and/or platinum. 
     
     
         46 . The optoelectronic semiconductor body of  claim 42 , wherein the reflector layer adjoins the adhesion promoting layer on its side remote from the semiconductor layer sequence. 
     
     
         47 . The optoelectronic semiconductor body of  claim 46 , wherein the multi-layer structure additionally has a current distribution layer on the side of the reflector layer which is remote from the adhesion promoting layer. 
     
     
         48 . The optoelectronic semiconductor body of  claim 47 , wherein the current distribution layer comprises gold and the reflector layer comprises a metal with a high reflection coefficient such as silver.