Optoelectronic semiconductor chip and method for producing an optoelectronic semiconductor chip
View Patent ↗In at least one embodiment, the optoelectronic semiconductor chip comprises a semiconductor layer sequence for generating an electromagnetic radiation, and also a silver mirror. The silver mirror is arranged at the semiconductor layer sequence. Oxygen is admixed with the silver of the silver mirror. A proportion by weight of the oxygen in the silver mirror is preferably at least 10 −5 and furthermore preferably at most 10%.
1. An optoelectronic semiconductor chip comprising:
a semiconductor layer sequence; and
a silver mirror,
wherein the silver mirror is arranged at the semiconductor layer sequence,
wherein oxygen is admixed with the silver of the silver mirror with a proportion by weight of at least 10 −5 and at most 10%,
wherein a covering layer is fitted directly to a side of the silver mirror which faces away from the semiconductor layer sequence, and
wherein the covering layer comprises a metal oxide or consists of one or more metal oxides.
2. The optoelectronic semiconductor chip according to claim 1 , wherein the silver mirror is fitted directly to the semiconductor layer sequence.
3. The optoelectronic semiconductor chip according to claim 1 , wherein the silver mirror comprises silver and oxygen, and wherein impurities of other substances amount to at most 100 ppm.
4. The optoelectronic semiconductor chip according to claim 1 , wherein the covering layer is formed by ZnO or by doped ZnO and has a thickness of at least 20 nm and of at most 500 nm.
5. The optoelectronic semiconductor chip according to claim 1 , wherein a boundary layer between the silver mirror and the semiconductor layer sequence has a thickness of at most 5 nm, and
wherein the boundary layer comprises GaN and at least one of silver, oxygen, aluminum, indium, and magnesium.
6. The optoelectronic semiconductor chip according to claim 1 , wherein a thickness of the silver mirror is between 70 nm and 300 nm inclusive.
7. The optoelectronic semiconductor chip according to claim 1 , wherein the proportion by weight of the oxygen in the silver mirror is between 0.01% and 1.0% inclusive.
8. The optoelectronic semiconductor chip according to claim 1 , wherein a partial layer of the semiconductor layer sequence which adjoins the silver mirror is formed from p-doped GaN or from p-doped InAlGaN.
9. The optoelectronic semiconductor chip according to claim 8 , wherein the partial layer has a thickness of between 2 nm and 20 nm inclusive, a dopant is magnesium and a dopant concentration is between 1×10 19 cm −3 and 2×10 20 cm −3 .
10. The optoelectronic semiconductor chip according to claim 8 , wherein an oxygen concentration in the partial layer is at most 1×10 16 cm −3 .
11. A method for producing an optoelectronic semiconductor chip comprising the following steps:
providing a semiconductor layer sequence; and
applying a silver mirror to the semiconductor layer sequence,
wherein oxygen is admixed with the silver of the silver mirror with a proportion by weight of at least 10 −5 and at most 10%, and
completing the semiconductor chip,
wherein a covering layer is fitted directly to a side of the silver mirror which faces away from the semiconductor layer sequence, and
wherein the covering layer comprises a metal oxide or consists of one or more metal oxides.
12. The method according to claim 11 ,
wherein
a thickness of the covering layer is between 20 nm and 500 nm inclusive,
the covering layer is exposed during the admixing of the oxygen,
during the admixing of the oxygen a temperature is between 100° C. and 550° C. inclusive,
the admixing is effected under an atmosphere having an oxygen partial pressure of between 2 mbar and 200 mbar inclusive, and
the admixing is effected over a time period of between 2 min and 40 min inclusive.
13. The method according to claim 11 ,
wherein during the admixing of the oxygen
the silver mirror is exposed,
a temperature is between 10° C. and 80° C. inclusive,
an oxygen partial pressure is between 100 mbar and 300 mbar inclusive, and
a duration of the admixing is between 10 h and 36 h inclusive.
14. An optoelectronic semiconductor chip comprising:
a semiconductor layer sequence; and
a silver mirror,
wherein the silver mirror is arranged at the semiconductor layer sequence,
wherein oxygen is admixed with the silver of the silver mirror with a proportion by weight of at least 10 −5 and at most 10%,
wherein a partial layer of the semiconductor layer sequence which adjoins the silver mirror is formed from p-doped GaN or from p-doped InAlGaN, and
wherein the partial layer has a thickness of between 2 nm and 20 nm inclusive, a dopant is magnesium and a dopant concentration is between 1×10 19 cm −3 and 2×10 20 cm −3 .