IP Library › Granted Patent US 7,085,298
Granted Patent B2
US 7,085,298 · App. 10/697,028 · Granted Aug 1, 2006

Tunnel junction utilizing GaPSb, AlGaPSb

View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 7,085,298
App. No.
10/697,028
Granted
Aug 1, 2006
Kind
B2
Abstract

A vertical cavity surface emitting laser (VCSEL) includes a substrate; a first mirror stack over the substrate; an active region having a plurality of quantum wells over the first mirror stack; a tunnel junction over the active region, a p-layer of the tunnel junction including GaPSb or AlGaPSb; and a second mirror stack over the tunnel junction. The p-layer including GaPSb or AlGaPSb can be used to form a tunnel junction with an n-doped layer of InP or AlInAs, or with a lower bandgap material such as InGaAs, AlInGaAs or InGaAsP. Such tunnel junctions are especially useful for a long wavelength VCSEL.

Claims (36)

1. A vertical cavity surface emitting laser, comprising:

a substrate;

a first mirror stack over the substrate;

an active region having a plurality of quantum wells over the first mirror stack;

a tunnel junction over the active region, a p-layer of the tunnel junction including GaPSb or AlGaPSb; and

a second mirror stack over the tunnel junction.

2. A vertical cavity surface emitting laser according to claim 1 , wherein an n-layer of the tunnel junction further includes a compound selected from the group consisting of InP, AlInAs, AlInGaAs, InGaAs and InGaAsP.

3. A vertical cavity surface emitting laser according to claim 1 , further including an n-type spacer adjacent the active region, and wherein the first mirror stack is an n-type DBR.

4. A vertical cavity surface emitting laser according to claim 1 , further including an p-type spacer adjacent the tunnel junction, and wherein the second mirror stack is an n-type DBR.

5. A vertical cavity surface emitting laser according to claim 1 , further including:

an n-type bottom spacer adjacent the active region, and wherein the first mirror stack is an n-type DBR; and

an p-type top spacer adjacent the tunnel junction,

wherein the first and second mirror stacks are each an n-type DBR.

6. A vertical cavity surface emitting laser according to claim 1 , wherein the p-layer is grown by MOCVD or MBE.

7. A vertical cavity surface emitting laser according to claim 6 , wherein the MOCVD grows the p-layer of the tunnel junction using TMAI, TMGa, TMSb and PH 3 in a temperature range between about 400° C. and about 900° C.

8. A vertical cavity surface emitting laser according to claim 6 , wherein the MBE grows the p-layer of the tunnel junction at a condition where the Equivalent Beam Pressures of group V sources are in a range of about 1×10 −7 to about 1×10 −3 torr and the growth rates of group III sources are less than about 10 μm/hour.

9. A vertical cavity surface emitting laser according to claim 6 , wherein the p-layer is doped with carbon with a concentration greater than about 2×10 18 cm −3 .

10. A vertical cavity surface emitting laser according to claim 1 , wherein the active region includes one of InGaAs, InGaAsP and AlInGaAs.

11. A vertical cavity surface, emitting laser according to claim 1 , wherein the first and second mirror stacks are lower and upper mirror stacks, respectively.

12. A tunnel junction having a p-layer including GaPSb or AlGaPSb.

13. A tunnel junction according to claim 12 , wherein the p-layer is doped with carbon with a concentration greater than about 2×10 18 cm −3 .

14. A tunnel junction according to claim 12 , further including an n-doped layer of a compound in the group consisting of InP, AlInAs, InGaAs, AlInGaAs, and InGaAsP.

15. A tunnel junction according to claim 14 , wherein the n-doped layer is doped with a concentration greater than about 2×10 18 cm −3 .

16. A tunnel junction according to claim 14 , wherein the n-doped layer is less than about 100 nanometers thick.

17. A tunnel junction according to claim 14 , wherein the n-doped layer is doped with a concentration greater than about 2×10 18 cm −3 and the n-doped layer is less than about 100 nanometers thick.

18. A long wavelength VCSEL, comprising:

an indium-based semiconductor substrate;

a first mirror stack over the substrate;

an active region having a plurality of quantum wells over the first mirror stack;

a tunnel junction over the active region, wherein a p-layer of the tunnel junction includes GaPSb or AlGaPSb; and

a second mirror stack over the tunnel junction.

19. A long wavelength VCSEL according to claim 18 , wherein an n-layer of the tunnel junction further includes a compound selected from the group consisting of InP, AlInAs, InGaAs, AlInGaAs and InGaAsP.

20. A long wavelength VCSEL according to claim 18 , further including an n-type spacer adjacent the active region, and wherein the first mirror stack is an n-type DBR.

21. A long wavelength VCSEL according to claim 18 , further including an p-type spacer adjacent the tunnel junction, and wherein the second mirror stack is an n-type DBR.

22. A long wavelength VCSEL according to claim 18 , further including: an n-type bottom spacer adjacent the active region, and wherein the first mirror stack is an n-type DBR;

and an p-type top spacer adjacent the tunnel junction, wherein the first and second mirror stacks are each an n-type DBR.