Heterojunction semiconductor devices having a doping interface dipole

• US 4,686,550 A
• Filed: 12/04/1984
• Issued: 08/11/1987
• Est. Priority Date: 12/04/1984
• Status: Expired due to Term

• Current Assignee: Bell Telephone Laboratories, Inc. (Nokia Corporation)
• Original Assignee: American Telephone & Telegraph Company (AT&T, Inc.)
• Inventors: Capasso, Federico, Cho, Alfred Y.
• Primary Examiner(s): James, Andrew J.
• Assistant Examiner(s): Crane, S. W.
• Application Number:
  US06/677,795
• Time in Patent Office: 980 Days
• Field of Search: 357/4 SL, 357/16, 357/22 A, 357/13, 357/14, 357/17, 357/4, 357/89, 357/20, 357/58
• US Class Current: 257/12
• CPC Class Codes: H01L 29/365 Planar doping, e.g. atomic-plane doping, delta-doping
• CPC Class Codes: H01L 29/7371 Vertical transistors
• CPC Class Codes: H01S 5/305 characterised by the doping materials used in the laser structure
• CPC Class Codes: H01S 5/3211 characterised by special cladding layers, e.g. details on band-discontinuities

Abstract

Heterojunction devices having doping interface dipoles near the heterojunction interface are disclosed. The doping interface dipoles comprise two charge sheets of different conductivity type which are positioned within a carrier mean free path of the heterojunction interface.

Claims

1. A heterojunction device comprising at least a first region of a first semiconductor material and at least a second region of a second semiconductor material, said first and said second regions having a first heterojunction interface, and a first interface dipole, said dipole comprising a first charge sheet and a second charge sheet, said first and second charge sheets being spatially separated from each other and comprising ionized donors and acceptors, respectively, at least one of said charge sheets being a heavily doped region, said charge sheets being within the lesser of a carrier mean free path or a thermal de Broglie wavelength of said interface.

2. A device as recited in claim 1 in which said charge sheets are in the same region.

3. A device as recited in claim 1 in which said charge sheets are in different regions.

4. A device as recited in claim 2 or 3 in which said charge sheets are less than the thermal de Broglie wavelength from said interface.

5. A device as recited in claim 4 in which said charge sheets are less than approximately 10 atomic layers from said interface.

6. A device as recited in claim 1 in which said first region has a bandgap greater than the bandgap of said second region.

7. A device as recited in claim 6 comprising a two-dimensional carrier gas at said interface.

8. A device as recited in claim 7 comprising first and second electrical contacts to said second region and a third electrical contact to said first region.

9. A device as recited in claim 6 further comprising a third region of a third semiconductor material, said third region and said second region having a second interface.

10. A device as recited in claim 9 in which said first and said second regions have opposite conductivity types.

11. A device as recited in claim 10 in which said third region has the conductivity type of said first region.

12. A device as recited in claim 11 further comprising first, second and third electrical contacts to said first, second and third regions, respectively.

13. A device as recited in claim 6 in which said first and said second regions have the same conductivity type.

14. A device as recited in claim 13 further comprising a third region, said third region and said first region having a second interface.

15. A device as recited in claim 14 in which said third region has a bandgap greater than the bandgap of said second region.

16. A device as recited in claim 15 in which said third region has a conductivity type opposite to said conductivity type of said region.

17. A device as recited in claim 16 further comprising first and second electrical contacts to said second and third regions, respectively.

18. A device as recited in claim 9 in which said third region has a bandgap greater than the bandgap of said second region.

19. A device as recited in claim 18 further comprising a second doping interface dipole, said second dipole comprising a third charge sheet and a fourth charge sheet, said third and fourth charge sheets being spatially separated from each other and comprising ionized donors and acceptors, respectively, at least one of said charge sheets being a heavily doped region, being within the lesser of a carrier mean free path or a thermal de Broglie wavelength of said second interface.

20. A device as recited in claim 19 in which said first and third regions have opposite conductivity types.

21. A device as recited in claim 1 further comprising means for establishing an electric field parallel to said interface.

22. A device as recited in claim 1 further comprising means for establishing an electric field perpendicular to said interface.

23. A device as recited in claim 1 in which said charge sheets have thicknesses less than approximately 100 Angstroms.

24. A device as recited in claim 1 in which said charge sheets having doping concentrations within the range from approximately 10¹⁷ /cm³ to approximately 10¹⁹ /cm³.

25. A device as recited in claim 1 in which said semiconductor materials are selected from the group consisting of Group IV, Group III-V and Group II-VI semiconductors.

26. A device as recited in claim 25 in which at least one of said semiconductor materials comprises a Group IV element.

27. A device as recited in claim 25 in which at least one of said semiconductor materials comprises a Group III-V compound semiconductor.

28. A device as recited in claim 27 in which said Group III-V semiconductors are selected from the group consisting of InGaAsP, AlGaAsSb, and AlInGaAs.

29. A device as recited in claim 6 in which the conduction band of said first region is below the conduction band of said second region.