Radiation-emitting semiconductor chip and light-emitting diode
View Patent ↗Proposed for high-performance light-emitting diodes are semiconductor chips ( 1 ) whose longitudinal sides are substantially longer than their transverse sides. Light extraction can be substantially improved in this manner.
1. A radiation-emitting semiconductor chip comprising an active layer ( 2 ) that includes a region emitting electromagnetic radiation, and a substrate ( 3 ) which is transparent to the radiation and on which said active layer is arranged, said semiconductor chip having transverse sides ( 9 ) and longitudinal sides ( 6 ) that delimit it in the directions of extent of said active region and through which at least a portion of the radiation is extracted,
characterized in that
at least one longitudinal side ( 6 ), serving as the extraction surface, is longer in the direction of extent of said active region than a transverse side ( 9 ).
2. The semiconductor chip as recited in claim 1 ,
characterized in that
said semiconductor chip has a multilayer structure ( 27 ) that includes said active layer ( 2 ) and on which said substrate ( 3 ) is arranged.
3. The semiconductor chip as recited in claim 1 , characterized in that said longitudinal sides ( 6 ) and said transverse sides ( 9 ) delimit said active layer ( 2 ) in its lateral extent.
4. The semiconductor chip as recited in any of claim 1 , characterized in that said longitudinal side ( 6 ) serving as the extraction surface is at least twice as long, in the direction of extent of said active layer ( 2 ), as a transverse side ( 9 ).
5. The semiconductor chip as recited in any of claim 1 , characterized in that said longitudinal side ( 6 ) serving as the extraction surface has, in the direction of extent of said active layer ( 2 ), at least ten times the length of a transverse side ( 9 ).
6. The semiconductor chip as recited in any of claim 1 , characterized in that said substrate ( 3 ) is realized as a parallelepiped.
7. The semiconductor chip as recited in any of claim 1 , characterized in that said substrate ( 3 ) tapers to a base surface disposed opposite said active layer ( 2 ).
8. The semiconductor chip as recited in claim 7 ,
characterized in that
said substrate ( 3 ) comprises a lateral surface which is inclined with respect to the direction of extent of said active layer ( 2 ) and which is disposed after, in the direction of the base surface, a lateral surface that is perpendicular to said direction of extent of said active layer.
9. The semiconductor chip as recited in any of claim 1 , characterized in that provided on one of its surfaces are current-spreading lands ( 24 ) that originate from a connection surface ( 23 ).
10. The semiconductor chip as recited in claim 9 ,
characterized in that
stub lines ( 25 ) branch off from said current-spreading lands ( 24 ).
11. The semiconductor chip as recited in any of claim 2 , characterized in that the refractive index of said substrate is greater than the refractive index of said multilayer structure.
12. The semiconductor chip as recited in any of claim 2 , characterized in that said multilayer structure contains GaN, InGaN, AlGaN or InAlGaN.
13. The semiconductor chip as recited in claim 1 , characterized in that said active layer contains GaN, InGaN, AlGaN or InAlGaN.
14. The semiconductor chip as recited in any of claim 1 , characterized in that said substrate is an SiC substrate ( 3 ).
15. The semiconductor chip as recited in any of claim 2 , characterized in that said multilayer structure ( 27 ) is fabricated epitaxially.
16. The semiconductor chip as recited in claim 15 ,
characterized in that
the substrate ( 3 ) is fabricated from an epitaxial substrate used for the epitaxial fabrication of said multilayer structure ( 27 ).
17. A light-emitting diode, characterized in that said light-emitting diode includes a semiconductor chip as recited in any of claim 1 .
18. The light-emitting diode as recited in claim 17 ,
characterized in that
reflectors ( 11 ) extend along the longitudinal sides ( 6 ) of said semiconductor chip.
19. The semiconductor chip as recited in claim 2 , characterized in that
said longitudinal sides ( 6 ) and said transverse, sides ( 9 ) delimit said active layer ( 2 ) in its lateral extent.
20. The semiconductor chip as recited in claim 12 , characterized in that
said active layer contains GaN. InGaN, AlGaN or InAlGaN.