Optoelectronic component, semiconductor structure and method
A semiconductor structure comprises an n-doped first layer, a p-doped second layer doped with a first dopant, and an active layer disposed between the n-doped first layer and the p-doped second layer and having at least one quantum well. The active layer of the semiconductor structure is divided into a plurality of first optically active regions, at least one second region, and at least one third region. Here, the plurality of first optically active regions are arranged in a hexagonal pattern spaced apart from each other. The at least one quantum well in the active region comprises a larger band gap in the at least one second region than in the plurality of first optically active regions and the at least one third region, the band gap being modified, in particular, by quantum well intermixing. The at least one second region encloses the plurality of first optically active regions.
1. A method of manufacturing an optoelectronic device, in particular a light-emitting diode, comprising:
providing a semiconductor structure comprising an n-doped layer, a p-doped layer, and an active layer disposed therebetween having at least one quantum well, wherein the p-doped layer comprises a first dopant;
depositing and patterning of a mask on the semiconductor structure; and
doping the p-doped layer with a second dopant, including Zn or Mg, so that quantum well intermixing is produced in regions of the active layer over which there is no region of patterned mask;
wherein the doping of the p-doped layer with the second dopant is performed by a gas phase diffusion using a precursor with the second dopant and comprises:
depositing the second dopant on a surface of the p-doped layer by decomposing the precursor at a first temperature selected such that substantially no diffusion of the second dopant occurs into the p-doped layer occurs; and
diffusing the deposited second dopant into the p-doped layer at a second temperature higher than the first temperature.
2. The method of claim 1 , wherein an amount of the deposited second dopant is selected such that it diffuses substantially completely into the p-doped layer during diffusion.
3. The method of claim 1 , wherein an amount of the second dopant is selected such that, in regions of the active layer not covered by a region of the patterned mask, a lateral diffusion barrier of charge carriers created by the second dopant is greater than a barrier created by quantum well intermixing.
4. The method of claim 1 , wherein the doping of the p-doped layer with the second dopant comprises annealing the semiconductor structure after diffusion of the second dopant into the p-doped layer at a third temperature higher than the second temperature.
5. The method of claim 4 , wherein the mask is locally formed by a suitable layer of the semiconductor structure by patterning.
6. The method of claim 4 , wherein the annealing comprises:
providing a further precursor comprising an element from a fifth main group, including P or As; and/or
depositing a layer of a III-V semiconductor material on the surface of the p-doped layer.
7. The method of claim 4 , wherein, during the depositing, the diffusing, and the annealing, at least one parameter is selected differently, the at least one parameter comprising at least one of:
a temperature change over a first defined period of time during one of the depositing, the diffusing, and the annealing;
a pressure;
a pressure change over a second defined period of time during one of the depositing, the diffusing, and the annealing;
a composition of a gas; or
a combination thereof.
8. A semiconductor structure, comprising:
an n-doped layer;
a p-doped layer doped with a first dopant; and
an active layer disposed between the n-doped layer and the p-doped layer and having at least one quantum well, wherein the active layer of the semiconductor structure is divided into a plurality of first optically active regions, at least one second region, and at least one third region;
wherein the plurality of first optically active regions are spaced apart in a hexagonal pattern;
wherein the at least one quantum well in the active layer comprises a larger band gap in the at least one second region than in the plurality of first optically active regions and the at least one third region;
wherein the larger band gap is modified by quantum well intermixing;
wherein the at least one second region encloses the plurality of first optically active regions; and
wherein the at least one third region is disposed in spaces between the plurality of first optically active regions.
9. The semiconductor structure of claim 8 , wherein the at least one second region and the at least one third region comprise a plurality of second regions and a plurality of third regions, respectively, wherein at least one of the plurality of first optically active regions, the plurality of second regions, and each of the plurality of third regions are substantially circular in shape.
10. The semiconductor structure of claim 8 , wherein the at least one second region comprises a plurality of second regions, wherein the plurality of second regions each concentrically surrounds one of the plurality of first optically active regions.
11. The semiconductor structure of claim 10 , wherein the at least one third region comprises a plurality of third regions, wherein the plurality of third regions are arranged such that each of the plurality of third regions is located at a center of exactly three of the plurality of first optically active regions.
12. The semiconductor structure of claim 8 , wherein the at least one second region and the at least one third region comprise a plurality of second regions and a plurality of third regions, respectively, wherein each of the plurality of third regions maps substantially to a shape of a deltoid curve formed by exactly three of the plurality of second regions, respectively, which are substantially circular in shape.
13. The semiconductor structure of claim 8 , further comprising a second dopant substantially uniformly disposed in the at least one second region.
14. The semiconductor structure of claim 13 , wherein the second dopant is present in at least a second region in the p-doped layer and/or in the active layer and/or at least partially in a region of the n-doped layer adjacent to the active layer.
15. The semiconductor structure of claim 13 , wherein the second dopant is different from the first dopant.
16. The semiconductor structure of claim 13 , wherein the second dopant is formed from a group comprising at least one of Mg, Zn, and/or Cd.
17. The semiconductor structure of claim 8 , wherein the at least one second region comprises a substantially uniform bandgap modified by quantum well intermixing.
18. The semiconductor structure of claim 8 , wherein the plurality of first optically active regions and the at least one third region comprise a substantially identical bandgap.
19. The semiconductor structure of claim 8 , wherein the plurality of first optically active regions comprises substantially no quantum well intermixing and/or the at least one third region comprises substantially no quantum well intermixing.
20. The semiconductor structure of claim 8 , wherein quantum well intermixing decreases in a defined transition region from the at least one second region to the plurality of first optically active regions.
21. A method of manufacturing a semiconductor structure, comprising:
providing a semiconductor structure having an n-doped layer, a p-doped layer doped with a first dopant, and an active layer disposed therebetween;
applying a mask to the p-doped layer to define a plurality of first optically active regions in the active layer surrounded by at least one second region of the active layer and to define at least one third region disposed in interstices between the plurality of first optically active regions; and
generating quantum well intermixing in the at least one second region of the active layer.
22. The method of claim 21 , wherein generating quantum well intermixing comprises diffusing a second dopant into the p-doped layer, into the active layer in the at least one second region, and at least partially into a region of the n-doped layer adjacent to the active layer.
23. The method of claim 21 , wherein quantum well intermixing occurs only in the at least one second region due to application of the mask to the p-doped layer and due to diffusion of the first dopant into the p-doped layer, into the active layer in the at least one second region, and at least partially in a region of the n-doped layer adjacent to the active layer.
24. The method of claim 22 , wherein the second dopant is different from the first dopant and is formed from a group comprising at least one of Mg, Zn, or Cd.
25. The method of claim 21 , further comprising separating, including by an etching process, of individual optoelectronic components.