Method of producing a semiconductor laser and semiconductor laser
A semiconductor laser includes a substrate having a semiconductor layer sequence with an active layer that generates light during operation of the semiconductor laser, and a contact layer on a bottom side of the substrate opposite the semiconductor layer sequence, wherein the contact layer has at least one first partial region and at least one second partial region which are formed contiguously, the at least one first partial region is annealed, and the at least one second partial region is unannealed.
1. A semiconductor laser comprising:
a substrate having a semiconductor layer sequence with an active layer that generates light during operation of the semiconductor laser, and
a contact layer on a bottom side of the substrate opposite the semiconductor layer sequence,
wherein the contact layer has at least one first partial region and at least one second partial region which are formed contiguously,
the at least one first partial region is annealed, and
the at least one second partial region is unannealed.
2. The semiconductor laser according to claim 1 , wherein the bottom side of the substrate has a surface structure comprising a depression in the at least one first partial region.
3. The semiconductor laser according to claim 2 , wherein the at least one first partial region of the contact layer is arranged in the depression.
4. The semiconductor laser according to claim 1 , wherein the semiconductor layer sequence comprises a ridge waveguide structure and the at least one first partial region extends parallel to the ridge waveguide structure.
5. The semiconductor laser according to claim 4 , wherein the at least one first partial region overlaps with the ridge waveguide structure when viewed from the bottom side of the substrate.
6. The semiconductor laser according to claim 1 , wherein the contact layer comprises an adhesion promoting layer directly on the bottom side of the substrate.
7. The semiconductor laser according to claim 6 , wherein the adhesion promoting layer comprises Ti.
8. The semiconductor laser according to claim 1 , wherein the contact layer is arranged on an entire surface of the bottom side of the substrate.
9. The semiconductor laser according to claim 1 , wherein the contact layer covers an entire surface of the bottom side of the substrate except for an edge region.
10. The semiconductor laser according to claim 1 , wherein the contact layer comprises a plurality of layers.
11. The semiconductor laser according to claim 1 , wherein a further layer is applied at least to the first partial region.
12. The semiconductor laser according to claim 1 , wherein the contact layer has a plurality of first partial regions separated from one another by one or more second partial regions that are locally annealed.
13. The semiconductor laser according to claim 1 , wherein the at least one first partial region is arranged in an edge region of the first contact layer.
14. The semiconductor laser according to claim 1 , wherein the at least one first partial region has one or more geometric shapes selected from the group consisting of line, cross, circle, ellipse, spiral, grid, square, wavy line and meander.
15. The semiconductor laser according to claim 1 , wherein the substrate is electrically conductive.
16. The semiconductor laser according to claim 1 , wherein the substrate contains Ga.
17. The semiconductor laser according to claim 1 , wherein the first partial regions comprise stress-relaxing structures.
18. The semiconductor laser according to claim 1 , wherein the contact layer comprises one or more diffusion barrier layers comprising one or more materials selected from the group consisting of Pt, Pd, Ni, Cr and TiWN.