Implant damaged oxide insulating region in vertical cavity surface emitting laser
View Patent ↗Optical transmitters are disclosed, one example of which includes a vertical cavity surface emitting laser that includes a substrate upon which a lower mirror is disposed. In this example, a spacer is disposed between the lower mirror and an active region. Another spacer separates the active region and an upper mirror. The upper mirror includes an oxide insulating region that is damaged by ion implantation so that desirable effects are achieved with respect to lateral sheet resistance, and quantum well recombination centers in the active region.
1. A vertical cavity surface emitting laser, comprising:
a substrate;
a bottom mirror above the substrate;
an active region above the bottom mirror;
a top mirror located above the active region and including an oxide insulating region; and
a gain guide ion implant region extending at least into the oxide insulating region such that a portion of the oxide insulating region includes damage from implanted ions, and the gain guide ion implant region extending below the oxide insulating region and at least into an unoxidized portion of the top mirror.
2. The vertical cavity surface emitting laser as recited in claim 1 , wherein a substantial portion of the gain guide ion implant region is located below the oxide insulating region.
3. The vertical cavity surface emitting laser as recited in claim 1 , wherein the gain guide ion implant region extends completely through the oxide insulating region.
4. The vertical cavity surface emitting laser as recited in claim 1 , wherein the oxide insulating region defines a first central opening, and the gain guide ion implant region defines a second central opening.
5. The vertical cavity surface emitting laser as recited in claim 4 , wherein one of the following is larger than the other: a diameter of the first central opening; and, a diameter of the second central opening.
6. The vertical cavity surface emitting laser as recited in claim 1 , wherein the oxide insulating region and the gain guide ion implant region collectively define a current confinement region.
7. The vertical cavity surface emitting laser as recited in claim 1 , wherein the gain guide ion implant region extends at least partway into the active region such that a portion of the active region includes damage from implanted ions.
8. The vertical cavity surface emitting laser as recited in claim 1 , wherein the substrate substantially comprises n-doped GaAS.
9. The vertical cavity surface emitting laser as recited in claim 1 , wherein at least one of the following comprises a DBR: the bottom mirror; and, the top mirror.
10. The vertical cavity surface emitting laser as recited in claim 1 , wherein an unoxidized portion of the top mirror substantially comprises an aluminum-containing III–V compound semiconductor.
11. The vertical cavity surface emitting laser as recited in claim 1 , wherein the active region substantially comprises AlGaAs.
12. The vertical cavity surface emitting laser as recited in claim 1 , wherein the vertical cavity surface emitting laser has a lateral sheet resistance that is at least partially a function of energy and dose of implanted ions that form the gain guide ion implant region.
13. The vertical cavity surface emitting laser as recited in claim 1 , wherein the active region includes a plurality of quantum wells.
14. The vertical cavity surface emitting laser as recited in claim 1 , further comprising:
a bottom spacer interposed between the substrate and the bottom mirror; and
a top spacer interposed between the active region and the top mirror.
15. The vertical cavity surface emitting laser as recited in claim 14 , wherein the bottom spacer, active layer, and top spacer separate the top mirror and bottom mirror such that an optical cavity is defined that is resonant for at least one specific wavelength.
16. The vertical cavity surface emitting laser as recited in claim 14 , wherein the bottom spacer comprises an n-type spacer, and the top spacer comprises a p-type spacer.
17. A method for producing a vertical cavity surface emitting laser, comprising:
forming a bottom mirror on a substrate;
forming an active region above the bottom mirror;
forming a top mirror above the active region;
oxidizing at least a portion of the top mirror to form an oxide insulating region; and
defining a gain guide ion implant region that extends at least into the oxide insulating region of the top mirror and the gain guide ion implant region extending below the oxide insulating region and at least into an unoxidized portion of the top mirror, the gain guide ion implant region being defined by an ion implantation process that causes damage in areas to which the gain guide ion implant region extends.
18. The method as recited in claim 17 , wherein a substantial portion of the gain guide ion implant region is located below the oxide insulating region.
19. The method as recited in claim 17 , wherein the gain guide ion implant region extends completely through the oxide insulating region.
20. The method as recited in claim 17 , wherein the gain guide ion implant region extends at least partway into the active region.
21. The method as recited in claim 17 , wherein the gain guide ion implant region extends completely through the active region.
22. The method as recited in claim 17 , wherein ion implantation produces non-radiative recombination centers in the active region.
23. The method as recited in claim 17 , wherein the oxide insulating region is formed so as to define a first central opening, and the gain guide ion implant region is formed so as to define a second central opening, the first and second central openings having different sizes.
24. The method as recited in claim 17 , wherein an unoxidized portion of the top mirror substantially comprises an aluminum-containing III–V compound semiconductor.
25. The method as recited in claim 17 , wherein the active region comprises a plurality of quantum wells.
26. The method as recited in claim 17 , wherein an energy and dose of implanted ions of the gain guide ion implant region are tailored to independently control a lateral sheet resistance, and non-radiative centers within the active region.
27. The method as recited in claim 17 , wherein at least one of the following comprises a DBR: the bottom mirror; and, the top mirror.
28. The method as recited in claim 17 , further comprising:
forming a bottom spacer above the substrate and below the bottom mirror; and
forming a top spacer above the active region and below the top mirror.
29. The method as recited in claim 28 , wherein the gain guide ion implant region extends at least partway into the bottom spacer.