Chemicophysical surface treatment and the experimental demonstration of Schottky-Mott rules for metalsemiconductor heterostructure interfaces

Journal of Chemical Physics

Volumn 123, Issue 19, 2005, Pages

  Motayed, Abhishek ^a   Mohammad, S Noor ^a,b,c  

^a School of Engineering   (United States)

^b UNIVERSITY OF MARYLAND   (United States)

^c NAVAL RESEARCH LABORATORY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

CHEMICOPHYSICAL SURFACE TREATMENT; DEPOSITION PARAMETERS; METALSEMICONDUCTOR (MS) HETEROSTRUCTURE; SCHOTTKY-MOTT RULES;

DEPOSITION; HETEROJUNCTIONS; INTERFACES (MATERIALS); PASSIVATION; POTASSIUM COMPOUNDS; SEMICONDUCTING ALUMINUM COMPOUNDS; SURFACE TREATMENT; TRANSMISSION ELECTRON MICROSCOPY; X RAY DIFFRACTION ANALYSIS;

PHYSICAL CHEMISTRY;

ALUMINUM; GALLIUM; METAL; NITROGEN;

ARTICLE; CHEMICAL MODEL; CHEMISTRY; CONFORMATION; CRYSTALLIZATION; DIFFUSION; ELECTROCHEMISTRY; ELECTRON; METHODOLOGY; PHYSICAL CHEMISTRY; SEMICONDUCTOR; STATISTICAL MODEL; TRANSMISSION ELECTRON MICROSCOPY; X RAY DIFFRACTION;

ALUMINUM; CHEMISTRY, PHYSICAL; CRYSTALLIZATION; DIFFUSION; ELECTROCHEMISTRY; ELECTRONS; GALLIUM; METALS; MICROSCOPY, ELECTRON, TRANSMISSION; MODELS, CHEMICAL; MODELS, STATISTICAL; MOLECULAR CONFORMATION; NITROGEN; SEMICONDUCTORS; X-RAY DIFFRACTION;

EID: 33746866233     PISSN: 00219606     EISSN: None     Source Type: Journal    
DOI: 10.1063/1.2102905     Document Type: Article

References (60)

1. J. S. Foresi and T. D. Moustakas, Appl. Phys. Lett. 62, 2859 (1993).
2. S. K. Noh and P. K. Bhattacharya, Appl. Phys. Lett. 78, 3642 (2001).
3. N. Newman, M. van Schilfgaarde, and W. Spicer, Phys. Rev. B 0163-1829 10.1103/PhysRevB.35.6298 35, 6298 (1987); J. Nogami, T. Kendelewicz, I. Lindau, and W. E. Spicer, Phys. Rev. B 34, 669 (1986); S. M. Sze, Physics of Semiconductor Devices, 2nd ed. (Wiley, New York, 1981), p. 273; The thickness of the interfacial layer δ is of atomic dimension, and hence is different for different MS interface. While Spicer and co-workers assigned it a value of about 0.5 Å, Sze assumed it to be around 4.0-5.0 Å.
4. N. Newman, M. van Schilfgaarde, and W. Spicer, Phys. Rev. B 0163-1829 10.1103/PhysRevB.35.6298 35, 6298 (1987); J. Nogami, T. Kendelewicz, I. Lindau, and W. E. Spicer, Phys. Rev. B 34, 669 (1986); S. M. Sze, Physics of Semiconductor Devices, 2nd ed. (Wiley, New York, 1981), p. 273; The thickness of the interfacial layer δ is of atomic dimension, and hence is different for different MS interface. While Spicer and co-workers assigned it a value of about 0.5 Å, Sze assumed it to be around 4.0-5.0 Å.
5. N. Newman, M. van Schilfgaarde, and W. Spicer, Phys. Rev. B 0163-1829 10.1103/PhysRevB.35.6298 35, 6298 (1987); J. Nogami, T. Kendelewicz, I. Lindau, and W. E. Spicer, Phys. Rev. B 34, 669 (1986); S. M. Sze, Physics of Semiconductor Devices, 2nd ed. (Wiley, New York, 1981), p. 273; The thickness of the interfacial layer δ is of atomic dimension, and hence is different for different MS interface. While Spicer and co-workers assigned it a value of about 0.5 Å, Sze assumed it to be around 4.0-5.0 Å.
6. N. Newman, M. van Schilfgaarde, and W. Spicer, Phys. Rev. B 0163-1829 10.1103/PhysRevB.35.6298 35, 6298 (1987); J. Nogami, T. Kendelewicz, I. Lindau, and W. E. Spicer, Phys. Rev. B 34, 669 (1986); S. M. Sze, Physics of Semiconductor Devices, 2nd ed. (Wiley, New York, 1981), p. 273; The thickness of the interfacial layer δ is of atomic dimension, and hence is different for different MS interface. While Spicer and co-workers assigned it a value of about 0.5 Å, Sze assumed it to be around 4.0-5.0 Å.
7. H. S. Venugopalan, S. E. Mohney, B. P. Luther, S. D. Wolter, and J. M. Redwing, Appl. Phys. Lett. 82, 650 (1997).
8. A. Ruini, R. Resta, and S. Baroni, Phys. Rev. B 56, 14921 (1997).
9. S. J. Pearton, J. W. Lee, J. D. McKenzie, C. R. Abernathy, and R. J. Shul, Appl. Phys. Lett. 67, 2329 (1995).
10. A. Motayed, A. K. Sharma, K. A. Jones, M. A. Derenge, A. A. Iliadis, and S. N. Mohammad, J. Appl. Phys. 96, 3286 (2004).
11. T. Gessmann, J. W. Graff, Y. L. Li, E. L. Waldron, and E. F. Schubert, J. Appl. Phys. 92, 3740 (2002).
12. S. Chang, L. Brillson, Y. Kime, D. Rioux, P. D. Kirchner, G. D. Pettit, and J. M. Woodall, Phys. Rev. Lett. 64, 2551 (1990).
13. T. Ytterdal, M. S. Shur, M. Hurt, and W. C. B. Peatman, Appl. Phys. Lett. 70, 441 (1997).
14. F. Braun, Ann. Phys. Chem. 153, 556 (1874).
15. Walter Schottky, Naturwiss. 26, 843 (1938).
16. N. F. Mott, Proc. Cambridge Philos. Soc. 34, 568 (1938).
17. Y. Koide, H. Itoh, M. R. H. Khan, K. Hiramatsu, N. Sawaki, and I. Akasaki, J. Appl. Phys. 61, 4540 (1987).
18. H. Jang, J. H. Lee, and J. L. Lee, Appl. Phys. Lett. 80, 3955 (2002).
19. T. Kozawa, T. Mori, T. Ohwaki, Y. Taho, and N. Sawaki, Jpn. J. Appl. Phys., Part 2 39, L772 (2000).
20. C. I Wu and A. Kahn, J. Vac. Sci. Technol. B 16, 2218 (1998).
21. D. Qiao, L. S. Yu, S. S. Lau, J. M. Redwing, J. Y. Lin, and X. H. Jiang, Appl. Phys. Lett. 87, 801 (2000).
22. V. Heine, Phys. Rev. 138, A1689 (1965).
23. Y. Chang, Y. Hwu, J. Hansen, F. Zanini, and G. Margaritondo, Phys. Rev. Lett. 63, 1845 (1989).
24. M. Schluter, Phys. Rev. B 17, 5044 (1987).
25. J. Tersoff, Phys. Rev. Lett. 52, 465 (1984).
26. P. Masri, Phys. Rev. Lett. 64, 208 (1990).
27. W. Mönch, Phys. Rev. Lett. 0031-9007 10.1103/PhysRevLett.58.1260 58, 1260 (1987); W. Mönch, J. Vac. Sci. Technol. B 0734-211X 10.1116/1.590839 17, 1867 (1999); W. Mönch, J. Appl. Phys. 80, 5076 (1996); In line with the present study, these ones emphasize that the experimental conditions during the preparation of Schottky contacts must be controlled to ensure the lowest possible defect density at the interface, and thus to achieve an ordered chemical trend of the barrier heights as a function of virtual gap states.
28. W. Mönch, Phys. Rev. Lett. 0031-9007 10.1103/PhysRevLett.58.1260 58, 1260 (1987); W. Mönch, J. Vac. Sci. Technol. B 0734-211X 10.1116/1.590839 17, 1867 (1999); W. Mönch, J. Appl. Phys. 80, 5076 (1996); In line with the present study, these ones emphasize that the experimental conditions during the preparation of Schottky contacts must be controlled to ensure the lowest possible defect density at the interface, and thus to achieve an ordered chemical trend of the barrier heights as a function of virtual gap states.
29. W. Mönch, Phys. Rev. Lett. 0031-9007 10.1103/PhysRevLett.58.1260 58, 1260 (1987); W. Mönch, J. Vac. Sci. Technol. B 0734-211X 10.1116/1.590839 17, 1867 (1999); W. Mönch, J. Appl. Phys. 80, 5076 (1996); In line with the present study, these ones emphasize that the experimental conditions during the preparation of Schottky contacts must be controlled to ensure the lowest possible defect density at the interface, and thus to achieve an ordered chemical trend of the barrier heights as a function of virtual gap states.
30. W. Mönch, Phys. Rev. Lett. 0031-9007 10.1103/PhysRevLett.58.1260 58, 1260 (1987); W. Mönch, J. Vac. Sci. Technol. B 0734-211X 10.1116/1.590839 17, 1867 (1999); W. Mönch, J. Appl. Phys. 80, 5076 (1996); In line with the present study, these ones emphasize that the experimental conditions during the preparation of Schottky contacts must be controlled to ensure the lowest possible defect density at the interface, and thus to achieve an ordered chemical trend of the barrier heights as a function of virtual gap states.
31. L. J. Brillson, C. F. Brucker, N. G. Stoffel, A. D. Katnani, and G. Margaritondo, Phys. Rev. Lett. 46, 838 (1981).
32. D. E. Eastman and J. L. Freeouf, Phys. Rev. Lett. 34, 1624 (1975).
33. Q. Z. Liu and S. S. Lau, Solid-State Electron. 43, 677 (1998); This article presents a good review of the scattered experimental values of the Schottky barrier heights in III-V nitrides, and difficulties encountered to obtain good Schottky contacts to III-V nitrides.
34. Q. Z. Liu and S. S. Lau, Solid-State Electron. 43, 677 (1998); This article presents a good review of the scattered experimental values of the Schottky barrier heights in III-V nitrides, and difficulties encountered to obtain good Schottky contacts to III-V nitrides.
35. G. D. Widdill, I. M. Vitomirov, C. M. Aldao, S. G. Anderson, C. Capasso, and J. M. Weaver, Phys. Rev. B 0163-1829 10.1103/PhysRevB.41.5293 41, 5293 (1990); G. D. Waddill, C. M. Aldao, I. M. Vitomirov, Y. Gao, and J. H. Weaver, Phys. Rev. Lett. 0031-9007 10.1103/PhysRevLett.62.1568 62, 1568 (1989); G. D. Widdill, C. M. Aldao, I. M. Vitomirov, S. G. Anderson, C. Capasso, and J. H. Weaver, J. Vac. Sci. Technol. B 7, 950 (1989).
36. G. D. Widdill, I. M. Vitomirov, C. M. Aldao, S. G. Anderson, C. Capasso, and J. M. Weaver, Phys. Rev. B 0163-1829 10.1103/PhysRevB.41.5293 41, 5293 (1990); G. D. Waddill, C. M. Aldao, I. M. Vitomirov, Y. Gao, and J. H. Weaver, Phys. Rev. Lett. 0031-9007 10.1103/PhysRevLett.62.1568 62, 1568 (1989); G. D. Widdill, C. M. Aldao, I. M. Vitomirov, S. G. Anderson, C. Capasso, and J. H. Weaver, J. Vac. Sci. Technol. B 7, 950 (1989).
37. G. D. Widdill, I. M. Vitomirov, C. M. Aldao, S. G. Anderson, C. Capasso, and J. M. Weaver, Phys. Rev. B 0163-1829 10.1103/PhysRevB.41.5293 41, 5293 (1990); G. D. Waddill, C. M. Aldao, I. M. Vitomirov, Y. Gao, and J. H. Weaver, Phys. Rev. Lett. 0031-9007 10.1103/PhysRevLett.62.1568 62, 1568 (1989); G. D. Widdill, C. M. Aldao, I. M. Vitomirov, S. G. Anderson, C. Capasso, and J. H. Weaver, J. Vac. Sci. Technol. B 7, 950 (1989).
38. J. Bardeen, Phys. Rev. 71, 717 (1947).
39. Y.-J. Lin and C.-T. Lee, Appl. Phys. Lett. 0003-6951 10.1063/1.1332827 77, 3986 (2000); See also, J.-K. Kim, J.-L. Lee, J.-W. Lee, Y. J. Park, and T. Kim, J. Vac. Sci. Technol. B 17, 497 (1999).
40. Y.-J. Lin and C.-T. Lee, Appl. Phys. Lett. 0003-6951 10.1063/1.1332827 77, 3986 (2000); See also, J.-K. Kim, J.-L. Lee, J.-W. Lee, Y. J. Park, and T. Kim, J. Vac. Sci. Technol. B 17, 497 (1999).
41. A. Koma, Thin Solid Films 0040-6090 10.1016/0040-6090(92)90872-9 216, 72 (1992); A. Koma, J. Cryst. Growth 201202, 236 (1999); See also W. Mönch, Electronic Properties of Semiconductor Interfaces (Springer, Berlin, 2004), Sec. 3.9.2, p. 70; The most striking observation of the van der Waals procedure is that it leads to a drastic relaxation of the lattice-matching condition at the interface usually encountered during heteroepitaxial growth. As articulated by Mönch, depending on growth parameters (for example, substrate temperature, metal evaporation rate, etc.), the deviation of the metal deposition from van der Waals epitaxy may lead to one or more of three growth modes, viz., Frank-van der Merwe, Volmer-Weber, and Stranski-Krastanov growth modes. Criteria for the occurrence of one or the other of these growth modes may depend on equilibrium conditions and be obtained from the principle of minimum free energy.
42. A. Koma, Thin Solid Films 0040-6090 10.1016/0040-6090(92)90872-9 216, 72 (1992); A. Koma, J. Cryst. Growth 201202, 236 (1999); See also W. Mönch, Electronic Properties of Semiconductor Interfaces (Springer, Berlin, 2004), Sec. 3.9.2, p. 70; The most striking observation of the van der Waals procedure is that it leads to a drastic relaxation of the lattice-matching condition at the interface usually encountered during heteroepitaxial growth. As articulated by Mönch, depending on growth parameters (for example, substrate temperature, metal evaporation rate, etc.), the deviation of the metal deposition from van der Waals epitaxy may lead to one or more of three growth modes, viz., Frank-van der Merwe, Volmer-Weber, and Stranski-Krastanov growth modes. Criteria for the occurrence of one or the other of these growth modes may depend on equilibrium conditions and be obtained from the principle of minimum free energy.
43. A. Koma, Thin Solid Films 0040-6090 10.1016/0040-6090(92)90872-9 216, 72 (1992); A. Koma, J. Cryst. Growth 201202, 236 (1999); See also W. Mönch, Electronic Properties of Semiconductor Interfaces (Springer, Berlin, 2004), Sec. 3.9.2, p. 70; The most striking observation of the van der Waals procedure is that it leads to a drastic relaxation of the lattice-matching condition at the interface usually encountered during heteroepitaxial growth. As articulated by Mönch, depending on growth parameters (for example, substrate temperature, metal evaporation rate, etc.), the deviation of the metal deposition from van der Waals epitaxy may lead to one or more of three growth modes, viz., Frank-van der Merwe, Volmer-Weber, and Stranski-Krastanov growth modes. Criteria for the occurrence of one or the other of these growth modes may depend on equilibrium conditions and be obtained from the principle of minimum free energy.
44. A. Koma, Thin Solid Films 0040-6090 10.1016/0040-6090(92)90872-9 216, 72 (1992); A. Koma, J. Cryst. Growth 201202, 236 (1999); See also W. Mönch, Electronic Properties of Semiconductor Interfaces (Springer, Berlin, 2004), Sec. 3.9.2, p. 70; The most striking observation of the van der Waals procedure is that it leads to a drastic relaxation of the lattice-matching condition at the interface usually encountered during heteroepitaxial growth. As articulated by Mönch, depending on growth parameters (for example, substrate temperature, metal evaporation rate, etc.), the deviation of the metal deposition from van der Waals epitaxy may lead to one or more of three growth modes, viz., Frank-van der Merwe, Volmer-Weber, and Stranski-Krastanov growth modes. Criteria for the occurrence of one or the other of these growth modes may depend on equilibrium conditions and be obtained from the principle of minimum free energy.
45. For the selective etch capability of KOH, see J. L. Rouviere, J. L. Weyher, M. Seelman-Eggebery, and S. Porowski, Appl. Phys. Lett. 0003-6951 10.1063/1.121942 73, 668 (1998); D.-S. Li, K. Yoshimura, Y. Suzuki, Y. Fukuda, and S. Fuke, Phys. Status Solidi A 0031-8965 10.1002/1521-396X(200007)180: 1<357::AID-PSSA357>3.0.CO;2-F 180, 357 (2000); A. R. Smith, R. M. Feenstra, D. W. Grieve, M.-S. Shin, M. Skowronski, J. Neugebauer, and J. F. Northrup, Appl. Phys. Lett. 72, 2114 (1998).
46. For the selective etch capability of KOH, see J. L. Rouviere, J. L. Weyher, M. Seelman-Eggebery, and S. Porowski, Appl. Phys. Lett. 0003-6951 10.1063/1.121942 73, 668 (1998); D.-S. Li, K. Yoshimura, Y. Suzuki, Y. Fukuda, and S. Fuke, Phys. Status Solidi A 0031-8965 10.1002/1521-396X(200007)180: 1<357::AID-PSSA357>3.0.CO;2-F 180, 357 (2000); A. R. Smith, R. M. Feenstra, D. W. Grieve, M.-S. Shin, M. Skowronski, J. Neugebauer, and J. F. Northrup, Appl. Phys. Lett. 72, 2114 (1998).
47. For the selective etch capability of KOH, see J. L. Rouviere, J. L. Weyher, M. Seelman-Eggebery, and S. Porowski, Appl. Phys. Lett. 0003-6951 10.1063/1.121942 73, 668 (1998); D.-S. Li, K. Yoshimura, Y. Suzuki, Y. Fukuda, and S. Fuke, Phys. Status Solidi A 0031-8965 10.1002/1521-396X(200007)180: 1<357::AID-PSSA357>3.0.CO;2-F 180, 357 (2000); A. R. Smith, R. M. Feenstra, D. W. Grieve, M.-S. Shin, M. Skowronski, J. Neugebauer, and J. F. Northrup, Appl. Phys. Lett. 72, 2114 (1998).
48. The mechanism of GaN etching by KOH treatment has been discussed at length by D.-S. Li, M. Sumiya, S. Fuke, D. Yang, D. Que, Y. Suzuki, and Y. Fukuda, J. Appl. Phys. 90, 4219 (2001).
49. The capability of KOH treatment to remove oxides to produce good MS contacts has been demonstrated by M.-S. Chung, W.-T. Lin, and J.-R. Gong, J. Vac. Sci. Technol. B 1071-1023 10.1116/1.1406157 19, 1976 (2001); J.-L. Lee and J. K. Kim, J. Electrochem. Soc. 147, 2297 (2000).
50. The capability of KOH treatment to remove oxides to produce good MS contacts has been demonstrated by M.-S. Chung, W.-T. Lin, and J.-R. Gong, J. Vac. Sci. Technol. B 1071-1023 10.1116/1.1406157 19, 1976 (2001); J.-L. Lee and J. K. Kim, J. Electrochem. Soc. 147, 2297 (2000).
51. W. E. Spicer, I. Lindau, P. Skeath, C. Y. Su, and P. Chye, Phys. Rev. Lett. 44, 420 (1980).
52. M. O. Aboelfotoh, C. Fröjdh, and C. S. Petersson, Phys. Rev. B 67, 075312 (2003).
53. S. N. Mohammad, J. Appl. Phys. 97, 063703 (2005); This paper has critically examined various design rules and contact mechanisms for Schottky contacts, and has presented extensive discussions of the mechanisms required to produce both Schottky and Ohmic contacts. The fundamental causes distinguishing the Schottky contacts from the Ohmic contacts have also been elucidated. In fact, the present study provides an experimental support of the arguments put forth in this article for differences between the Ohmic and Schottky contacts.
54. S. N. Mohammad, J. Appl. Phys. 97, 063703 (2005); This paper has critically examined various design rules and contact mechanisms for Schottky contacts, and has presented extensive discussions of the mechanisms required to produce both Schottky and Ohmic contacts. The fundamental causes distinguishing the Schottky contacts from the Ohmic contacts have also been elucidated. In fact, the present study provides an experimental support of the arguments put forth in this article for differences between the Ohmic and Schottky contacts.
55. S. N. Mohammad, J. Appl. Phys. 0021-8979 10.1063/1.1664029 95, 4856 (2004); S. N. Mohammad, J. Appl. Phys. 0021-8979 10.1063/1.1712016 95, 7940 (2004); S. N. Mohammad, Philos. Mag. 84, 2559 (2004).
56. S. N. Mohammad, J. Appl. Phys. 0021-8979 10.1063/1.1664029 95, 4856 (2004); S. N. Mohammad, J. Appl. Phys. 0021-8979 10.1063/1.1712016 95, 7940 (2004); S. N. Mohammad, Philos. Mag. 84, 2559 (2004).
57. S. N. Mohammad, J. Appl. Phys. 0021-8979 10.1063/1.1664029 95, 4856 (2004); S. N. Mohammad, J. Appl. Phys. 0021-8979 10.1063/1.1712016 95, 7940 (2004); S. N. Mohammad, Philos. Mag. 84, 2559 (2004).
58. J. Spradlin, S. Dogan, M. Mikkelson, D. Huang, L. He, D. Johnstone, and H. Morko̧, Appl. Phys. Lett. 82, 3556 (2003).
59. J. Alam, R. Bathe, R. D. Vispute, J. M. Zavada, C. W. Litton, A. Iliadis, and S. N. Mohammad, J. Vac. Sci. Technol. B 22, 624 (2004).
60. Jahangir Alam and S. N. Mohammad (unpublished).