Optoelectronic semiconductor device
View Patent ↗An optoelectronic semiconductor component includes a layer stack based on a nitride compound semiconductor and has an n-type semiconductor region , a p-type semiconductor region and an active layer arranged between the n-type semiconductor region and the p-type semiconductor region. In order to form an electron barrier, the p-type semiconductor region includes a layer sequence having a plurality of p-doped layers composed of Al x In y Ga 1−x−y N where 0<=x<=1, 0<=y<=1 and x+y<=1. The layer sequence includes a first p-doped layer having an aluminum proportion x 1 >=0.5 and a thickness of not more than 3 nm, and the first p-doped layer, at a side facing away from the active layer, is succeeded by at least a second p-doped layer having an aluminum proportion x 2 <x 1 and a third p-doped layer having an aluminum proportion x 3 <x 2.
1. An optoelectronic semiconductor device formed from a layer stack based on a nitride compound semiconductor, the layer stack comprising:
an n-type semiconductor region;
an active layer overlying the n-type semiconductor region; and
a layer sequence comprising a plurality of p-doped layers of Al x In y Ga 1−x−y N overlying the active layer, where 0≦x≦1, 0≦y≦1 and x+y≦1, the layer sequence including a first p-doped layer with an aluminum content x 1 ≧0.5 and a thickness of no more than 3 nm overlying the active layer, a second p-doped layer with an aluminum content x 2 <x 1 overlying the first p-doped layer, and a third p-doped layer with an aluminum content x 3 <x 2 .
2. The optoelectronic semiconductor device according to claim 1 , wherein the plurality of p-doped layers form an electron barrier.
3. The optoelectronic semiconductor device according to claim 1 , wherein the first p-doped layer has an aluminum content x 1 ≧0.8.
4. The optoelectronic semiconductor device according to claim 1 , wherein the second p-doped layer has an aluminum content x 2 ≦0.4.
5. The optoelectronic semiconductor device according to claim 4 , wherein the second p-doped layer has an aluminum content x 2 ≦0.3.
6. The optoelectronic semiconductor device according to claim 1 , wherein the second p-doped layer has an aluminum content gradient at least in a sub-region, wherein the aluminum content x 2 decreases in a direction of the third p-doped layer.
7. The optoelectronic semiconductor device according to claim 1 , wherein the second p-doped layer has a thickness of less than 20 nm.
8. The optoelectronic semiconductor device according to claim 1 , wherein the third p-doped layer has an aluminum content x 3 ≦0.1.
9. The optoelectronic semiconductor device according to claim 1 , further comprising a fourth p-doped layer between the first p-doped layer and the second p-doped layer, the fourth p-doped layer having a thickness of less than 4 nm.
10. The optoelectronic semiconductor device according to claim 9 , wherein the fourth p-doped layer has an aluminum content x 4 , wherein x 4 <x 2 .
11. The optoelectronic semiconductor device according to claim 9 , wherein the fourth p-doped layer has an aluminum content x 4 having a gradient, wherein the aluminum content x 4 in the fourth p-doped layer has a minimum, at which x 4 <x 2 .
12. The optoelectronic semiconductor device according to claim 1 , wherein the first, second and third p-doped layers have an indium content, the indium content of each of the first, second and third p-doped layers being less than or equal to 0.1.
13. The optoelectronic semiconductor device according to claim 1 , wherein the first, second and third p-doped layers have a dopant concentration of 1×10 18 cm −3 to 1×10 20 cm −3 .
14. The optoelectronic semiconductor device according to claim 1 , further comprising an interlayer arranged between the active layer and the first p-doped layer, wherein the interlayer has a dopant concentration of no more than 5×10 17 cm −3 .
15. The optoelectronic semiconductor device according to claim 14 , wherein the interlayer is undoped.
16. The optoelectronic semiconductor device according to claim 14 , wherein the interlayer comprises Al x In y Ga 1−x−y N with 0≦x≦0.02 and 0≦y≦0.1.
17. The optoelectronic semiconductor device according to claim 14 , wherein the interlayer has an indium-content y<0.05.
18. An optoelectronic semiconductor device, comprising a layer stack based on a nitride compound semiconductor which comprises an n-type semiconductor region, a p-type semiconductor region and an active layer arranged between the n-type semiconductor region and the p-type semiconductor region;
wherein to form an electron barrier, the p-type semiconductor region comprises a layer sequence with a plurality of p-doped layers of Al x In y Ga 1−x−y N with 0≦x≦1, 0≦y≦1 and x+y≦1;
wherein the layer sequence has a first p-doped layer with an aluminum content x 1 ≧0.5 and a thickness of no more than 3 nm;
wherein the first p-doped layer is followed on a side remote from the active layer by at least one second p-doped layer with an aluminum content x 2 <x 1 and one third p-doped layer with an aluminum content x 3 <x 2 ;
wherein a fourth p-doped layer is arranged between the first p-doped layer and the second p-doped layer, the fourth p-doped layer having a thickness of less than 4 nm; and
wherein the fourth p-doped layer has an aluminum content x 4 having a gradient, wherein the aluminum content x 4 in the fourth p-doped layer has a minimum, at which x 4 <x 1 and x 4 <x 2 .