Si/SiGe interband tunneling diode structures including SiGe diffusion barriers

1. A silicon-based interband tunneling diode comprising:

a degenerate p-type doping of acceptors;

a degenerate n-type doping of donors disposed on a first side of the degenerate p-type doping; and

a barrier silicon-germanium layer disposed on a second side of the degenerate p-type doping opposite the first side, the barrier silicon-germanium layer suppressing diffusion of acceptors away from a p/n junction defined by the degenerate p-type and n-type dopings.

2. The silicon-based interband tunneling diode as set forth in claim 1 , wherein the acceptors of the degenerate p-type doping are selected from a group consisting of boron, aluminum and gallium.

3. The silicon-based interband tunneling diode as set forth in claim 2 , wherein the donors of the degenerate n-type doping are selected from a group consisting of lithium, antimony, phosphorus, arsenic and bismuth.

4. The silicon-based interband tunneling diode as set forth in claim 1 , further comprising:

one or more interposed group IV semiconductor layers interposed between the degenerate p-type doping and the degenerate n-type doping.

5. The silicon-based interband tunneling diode as set forth in claim 4 , wherein the one or more interposed group IV semiconductor layers include at least one of a silicon layer and a silicon-germanium layer.

6. The silicon-based interband tunneling diode as set forth in claim 4 , wherein the one or more interposed group IV semiconductor layers comprise:

an interposed silicon-germanium layer adjacent the barrier silicon-germanium layer and the degenerate p-type doping, the interposed silicon-germanium layer and the barrier silicon-germanium layer defining a unitary silicon-germanium layer substantially containing the degenerate p-type doping.

7. The silicon-based interband tunneling diode as set forth in claim 6 , wherein the interposed silicon-germanium layer and the barrier silicon-germanium layer have the same germanium fraction.

8. The silicon-based interband tunneling diode as set forth in claim 1 , wherein the barrier silicon-germanium layer has a germanium fraction of at least about 0.1.

9. The silicon-based interband tunneling diode as set forth in claim 1 , wherein the barrier silicon-germanium layer has a germanium fraction of at least about 0.4.

10. The silicon-based interband tunneling diode as set forth in claim 1 , wherein the barrier silicon-germanium layer has a thickness of about one nanometer or thicker.

11. The silicon-based interband tunneling diode as set forth in claim 1 , wherein the barrier silicon-germanium layer has a uniform germanium concentration.

12. The interband tunneling diode as set forth in claim 1 , wherein the acceptors of the degenerate p-type doping have a concentration distribution along a direction transverse to the barrier silicon-germanium layer corresponding to a post-growth anneal of greater than about 800° C.

13. The silicon-based interband tunneling diode as set forth in claim 1 , wherein the degenerate n-type doping is a delta doping forming a degenerate two-dimensional electron gas.

14. The silicon-based interband tunneling diode as set forth in claim 13 , wherein the degenerate p-type doping is a delta doping forming a degenerate two-dimensional hole gas.

15. An interband tunneling diode comprising:

one or more semiconductor layers selected from a group consisting of (i) a silicon layer and (ii) a silicon-germanium layer;

a degenerate p-type doping of acceptors substantially disposed within a containing silicon-germanium layer of the one or more semiconductor layers, the containing silicon-germanium layer suppressing diffusion of the acceptors out of the containing silicon-germanium layer; and

a degenerate n-type doping of donors substantially disposed within or between one or more of the semiconductor layers other than the containing silicon-germanium layer.

16. The interband tunneling diode as set forth in claim 15 , wherein the degenerate n-type doping of donors is substantially disposed within a silicon layer of the one or more semiconductor layers.

17. The interband tunneling diode as set forth in claim 15 , wherein the acceptors of the degenerate p-type doping have a concentration distribution along a direction transverse to the plane of the containing silicon-germanium layer corresponding to a post-growth anneal of greater than about 800° C.

18. A semiconductor device made by a process comprising:

forming an interband tunneling structure by successively forming one of:

a barrier silicon-germanium layer, a degenerate p-type doping, and a degenerate n-type doping, in that order, and

a degenerate n-type doping, a degenerate p-type doping, and a barrier silicon-germanium layer, in that order.

19. The semiconductor device as set forth in claim 18 , wherein the forming is by one of low temperature molecular beam epitaxy, solid phase epitaxy, low pressure chemical vapor deposition or ultra-high vacuum chemical vapor deposition.

20. The semiconductor device as set forth in claim 18 , wherein the process further comprises:

after the forming, annealing the formed interband tunneling structure at a temperature greater than 500° C., the barrier silicon-germanium layer suppressing outdiffusion of acceptors of the degenerate p-type doping away from a p/n junction during the annealing.

21. The semiconductor device as set forth in claim 18 , wherein the process further comprises:

after the forming, annealing the formed interband tunneling structure at a thermal budget corresponding to an anneal temperature greater than or about 750° C. and an anneal time of about one minute.