Claims
- 1. A heterojunction bipolar transistor comprising:
a) an n-doped collector; b) a base comprising a III-V material formed over the collector, wherein the III-V material includes indium and nitrogen, and wherein the base is doped with carbon at a concentration of about 1.5×1019 cm−3 to about 7.0 ×1019 cm−3; and c) an n-doped emitter formed over the base.
- 2. The transistor of claim 1, wherein the base comprises the elements gallium, indium, arsenic, and nitrogen.
- 3. The transistor of claim 2, wherein the collector is GaAs and the emitter is InGaP, AlInGaP, or AlGaAs and the transistor is a double heterojunction bipolar transistor.
- 4. The transistor of claim 3, wherein the base layer comprises a layer of the formula Ga1-xInxAs1-yNy, wherein x and y are each, independently, about 1.0×10−4 to about 2.0×10−1.
- 5. The transistor of claim 4, wherein x is about equal to 3y.
- 6. The transistor of claim 5, wherein x and 3y are about 0.01 at the collector and are graded to about zero at the emitter.
- 7. The transistor of claim 5, wherein the base layer is about 400 Å to about 1500 Å thick and has a sheet resistivity of about 100 Ω/square to about 400 Ω/square.
- 8. The transistor of claim 7, wherein the n-dopant in the emitter is present in a concentration of about 3.5×1017 cm−3 to about 4.5×1017 cm−3 and the concentration of the n-dopant in the collector is about 9×1015 cm−3 to about 2×10l6 cm−3.
- 9. The transistor of claim 8, wherein the emitter and the collector are doped with silicon.
- 10. The transistor of claim 9, wherein the emitter is about 500 Å to about 750 Å thick, and the collector is about 3500 Å to about 4500 Å thick.
- 11. The transistor of claim 10, further comprising a first transitional layer disposed between the base and the collector having a first surface contiguous with a first surface of the base, wherein the first transitional layer is composed of an n-doped material selected from GaAs, InGaAs and InGaAsN.
- 12. The transistor of claim 11, further comprising a second transitional layer having a first surface contiguous with a first surface of the emitter and a second surface contiguous with a second surface of the base, wherein the second transitional layer is composed of an n-doped material selected from GaAs, InGaAs and InGaAsN.
- 13. The transistor of claim 12, further comprising a lattice matched layer having a first surface contiguous with a first surface of the collector and a second surface contiguous with a second surface of the first transitional layer, wherein the lattice matched layer is a wide band gap material.
- 14. The transistor of claim 13, wherein the lattice matched layer is InGaP, AlInGaP or AlGaAs.
- 15. The transistor of claim 12, wherein the first and the second transitional layers are about 40 Å to about 60 Å thick.
- 16. The transistor of claim 13, wherein the first and the second transitional layers are about 40 Å to about 60 Å thick and the lattice matched layer is about 150 Å to about 250 Å.
- 17. A method of fabricating a heterojunction bipolar transistor comprising:
growing a base layer comprising gallium, indium, arsenic and nitrogen over an n-doped GaAs collector from a gallium, indium, arsenic, and nitrogen source, wherein the base layer is p-doped with carbon from an external carbon source; and growing an n-doped emitter layer over the base layer.
- 18. The method of claim 17, wherein the external carbon source is carbon tetrabromide or carbon tetrachloride.
- 19. The method of claim 18, wherein the gallium source is selected from trimethylgallium and triethylgallium.
- 20. The method of claim 19, wherein the nitrogen source is ammonia or dimethylhydrazine.
- 21. The method of claim 20, wherein the ratio of the arsenic source to the gallium source is about 2.0 to about 3.5.
- 22. The method of claim 21, wherein the base is grown at a temperature of less than 750° C.
- 23. The method of claim 22, wherein the base is grown at a temperature of about 500° C. to about 600° C.
- 24. The method of claim 22, wherein the base layer comprises a layer of the formula Ga1-xInxAs1-yNy, wherein x and y are each, independently, about 1.0×10−4 to about 2.0×10−1.
- 25. The method of claim 24, wherein x is about equal to 3y.
- 26. The method of claim 24, wherein the collector is GaAs and the emitter is InGaP, AlInGaP, or AlGaAs and the transistor is a double heterojunction bipolar transistor.
- 27. The method of claim 24, further comprising the step of growing an n-doped first transitional layer over the collector and disposed between the base and the collector, wherein the first transitional layer has a graded band gap or a band gap that is smaller than the band gap of the collector.
- 28. The method of claim 27, wherein the first transitional layer is selected from the group consisting of GaAs, InGaAs, or InGaAsN.
- 29. The method of claim 28, further comprising the step of growing an second transitional layer over the base, wherein the second transitional layer has a first surface contiguous with a surface of a first surface of the base and a second surface contiguous with a surface of the emitter, and wherein the second transitional layer has a doping concentration at least one order of magnitude less than the doping concentration of the emitter.
- 30. The method of claim 29, wherein the second transitional layer is selected from the group consisting of GaAs, InGaAs, or InGaAsN.
- 31. The method of claim 30, wherein the first transitional layer, the second transitional layer, or both the first and the second transitional layer have a doping spike.
- 32. The method of claim 30, further comprising the step of growing a latticed matched layer over the collector, wherein the lattice matched layer has a first surface contiguous with a first surface of the collector and a second surface contiguous with a second surface of the first transitional layer.
- 33. The method of claim 32, wherein the lattice matched layer is InGaP.
- 34. A material comprising gallium, indium, arsenic, and nitrogen, wherein the material is doped with carbon at a concentration of about 1.5×1019 cm−3 to about 7.0×1019 cm−3.
- 35. The material of claim 34, wherein the composition of the material can be represented by the formula Ga1-xInxAs1-yNy, wherein x and y are each, independently, about 1.0×10−4 to about 2.0×10−1.
- 36. The material of claim 35, wherein x is about equal to 3y.
- 37. The material of claim 36, wherein x and 3y are about 0.01.
- 38. The material of claim 37, wherein the carbon concentration is at least about 3.0 ×1019 cm−3.
RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application No. 60/253,159, filed on Nov. 27, 2000, the entire teachings of which are incorporated herein by reference.
Provisional Applications (1)
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Number |
Date |
Country |
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60253159 |
Nov 2000 |
US |