Hostname: page-component-8448b6f56d-c47g7 Total loading time: 0 Render date: 2024-04-23T20:17:43.962Z Has data issue: false hasContentIssue false
  • English
  • Français

Determination of band gap in polycrystalline Si/Ge thin film multilayers

Published online by Cambridge University Press:  01 March 2006

S. Tripathi ,
R. Brajpuriya ,
C. Mukharjee  and
S.M. Chaudhari
S. Tripathi*
Affiliation:
University Grant Commission–Department of Atomic Energy Consortium for Scientific Research, University Campus, Indore-452017, India
R. Brajpuriya
Affiliation:
University Grant Commission–Department of Atomic Energy Consortium for Scientific Research, University Campus, Indore-452017, India
C. Mukharjee
Affiliation:
Centre for Advanced Technology (CAT), Indore–452013, India
S.M. Chaudhari
Affiliation:
University Grant Commission-Department of Atomic Energy Consortium for Scientific Research, University Campus, Indore–452017, India
*
a) Address all correspondence to this author. e-mail: shilpatr2@rediffmail.com
Get access

Abstract

The valence band (VB) photoemission supported by ultraviolet–visible–near infrared spectroscopy techniques were used to determine the band gap values of polycrystalline Si and Ge single layers as well as of Si/Ge multilayer structures. The band gap values obtained from VB photoemission measurements for these structures were found to be much larger than their corresponding bulks and to match well with those determined from standard optical absorption measurements. In each case, the VB offset values were obtained by considering the corresponding VB maximum as a reference. The increase in band gap in case of thin single layers of Si and Ge with respect to bulks were interpreted in terms of quantum confinement effect, while in case of multilayer sample, the effect of various factors such as (i) intermixing leading to the formation of SiGe alloy, (ii) roughness at the interface, (iii) particle size, and (iv) strain seem to play an important role in the observed change in band gap.

Keywords

FilmX-ray photoelectron spectroscopy (XPS)
Type
Articles
Information
Journal of Materials Research , Volume 21 , Issue 3 , March 2006 , pp. 623 - 631
Copyright
Copyright © Materials Research Society 2006

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1.Peressi, M., Binggeli, N., Baldereschi, A.: Band engineering at interfaces: Theory and numerical experiments. J. Phys. D: Appl. Phys. 31, 1273 (1998).CrossRefGoogle Scholar
2.Wilks, S.P.: Engineering and investigating the control of semiconductor surfaces and interfaces. J. Phys. D: Appl. Phys. 35, R77 (2002).CrossRefGoogle Scholar
3.Sun, Q.C., Pan, L.K., Fu, Y.Q., Tay, B.K., Li, S.: Size dependence of the 2p-level shift of nanosolid silicon. J. Phys. Chem. B 107, 5113 (2003).CrossRefGoogle Scholar
4.Kim, M., Osten, H.J.: X-ray photoelectron spectroscopic evaluation of valence band offsets for strained Si1−xGex, Si1−yCy and Si1−x−yGexCy on Si(001). Appl. Phys. Lett. 70, 2702 (1997).CrossRefGoogle Scholar
5.Pan, M., Wilks, S.P., Dunstan, P.R., Pritchard, M., Williams, R.H., Cammack, D.S., Clark, S.A.: Modification of band offsets by a ZnSe intralayer at the Si/Ge(111) interface. Appl. Phys. Lett. 72, 2707 (1998).CrossRefGoogle Scholar
6.Sze, S.M.: Physics of Semiconductor Devices, 2nd ed. (Wiley-Interscience, Hoboken, NJ, 1981).Google Scholar
7.Miller, R.C., Kleinman, D.A., Gossard, A.C.: Energy-gap discontinuities and effective masses for GaAs-AlxGa1−xAs quantum wells. Phys. Rev. B 29, 7085 (1984).CrossRefGoogle Scholar
8.Kraut, E.A., Grant, R.W., Waldrop, J.R., Kowalczyk, S.P.: Semiconductor core-level to valence band maximum binding-energy differences: Precise determination by x-ray photoelectron spectroscopy. Phys. Rev. B 28, 1965 (1983).CrossRefGoogle Scholar
9.Weber, J., Alonso, M.I.: Near-band gap photoluminescence of Si-Ge alloys. Phys. Rev. B 40, 5683 (1989).CrossRefGoogle ScholarPubMed
10.Braunstein, R., Moore, A.R., Herman, F.: Intrinsic optical absorption in germanium-silicon alloys. Phys. Rev. 109, 695 (1958).CrossRefGoogle Scholar
11.Rieger, M.M., Vogl, P.: Electronic-band parameters in strained Si1−xGex alloys on Si1−yGey substrates. Phys. Rev. B 48, 14276 (1993).CrossRefGoogle ScholarPubMed
12.People, R., Bean, J.C.: Band alignments of coherently strained GexSi1−x/Si heterostructures on 〈001〉 GeySi1−y substrates. Appl. Phys. Lett. 48, 538 (1986).CrossRefGoogle Scholar
13.Theodorou, G., Kelires, P.C., Tserbak, C.: Structural, electronic, and optical properties of strained Si1−xGex alloys. Phys. Rev. B 50, 18355 (1994).CrossRefGoogle ScholarPubMed
14.Van Walle, G.C. de, Martin, R.M.: Theoritical study of Si/Ge interfaces. J. Vac. Sci. Technol. B 3, 1256 (1985).CrossRefGoogle Scholar
15.Colombo, L., Resta, R., Baroni, S.: Valence band offsets at strained Si/Ge interfaces. Phys. Rev. B 44, 5572 (1991).CrossRefGoogle ScholarPubMed
16.Di Gaspare, L., Capellini, G., Sebastiani, M., Chudoba, C., Evangelisti, F.: Ge/Si(100) heterostructures: a photoemission and low-energy yield spectroscopy investigation. Appl. Surf. Sci. 102, 94 (1996).CrossRefGoogle Scholar
17.Zachai, R., Eberl, K., Abstreiter, G., Kasper, E., Kibbel, H.: Photoluminescence in short-period Si/Ge strained-layer superlattices. Phys. Rev. Lett. 64, 1055 (1990).CrossRefGoogle ScholarPubMed
18.Schwartz, G.P., Hybertsen, M.S., Bevk, J., Nuzzo, R.G., Mannaerts, J.P., Gualtieri, G.J.: Core-level photoemission measurements of valence-band offsets in highly strained heterojunctions: Si–Ge system. Phys. Rev. B 39, 1235 (1989).CrossRefGoogle ScholarPubMed
19.Chaudhari, S.M., Suresh, N., Phase, D.M., Gupta, A., Dasannacharya, B.A.: Design and performance of an ultrahigh vacuum system for metallic multilayers. J. Vac. Sci. Technol. A 17, 242 (1999).CrossRefGoogle Scholar
20.Chaudhari, S.M., Phase, D.M., Wadikar, A.D., Ramesh, G.S., Hegde, M.S., Dasannacharya, B.A.: Photoelectron spectroscopy beamline on INDUS-1 synchrotron source. Curr. Sci. 82, 305 (2002).Google Scholar
21.Laine, A.D., Cepek, C., Goldoni, A., Vandre, S., DeSeta, M., Franco, N., Avila, J., Asensio, M.C., Sancrotti, M.: Photoemission of Ge (110) at room and high temperature. Surf. Sci. 402–404, 875 (1998).CrossRefGoogle Scholar
22.Grobman, W.D., Eastman, D.E.: Absolute conduction- and valence-band positions for Ge from an anisotropic model of photoemission. Phys. Rev. Lett. 33, 1034 (1974).CrossRefGoogle Scholar
23.Williamson, A.J., Bostedt, C., van Buuren, T., Willey, T.M., Terminello, L.J., Galli, G.: Probing the electronic density of states of germanium nanoparticles: A method for determining atomic structure. Nano Lett. 4, 1041 (2004).CrossRefGoogle Scholar
24.Bostedt, C., van Buuren, T., Willey, T.M., Franco, N., Moller, T., Terminello, L.J.: Photoemission spectroscopy of germanium nanocrystal films. J. Elec. Spec. Relat. Phenom. 126, 117 (2002).CrossRefGoogle Scholar
25.Sato, S., Nozaki, S., Morisaki, H.: Density of states of the tetragonal-phase germanium nanocrystals using x-ray photoelectron spectroscopy. Appl. Phys. Lett. 72, 2460 (1998).CrossRefGoogle Scholar
26.Yeh, J.J. In Atomic Calculations of Photoionization Cross-Sections and Asymmetry Parameters (Gordon and Breach Science Publishers, Langhorne, PA, 1993).Google Scholar
27.Ley, L., Kowalczyk, S., Pollak, R., Shirley, D.A.: X-ray photoemission spectra of crystalline and amorphous Si and Ge valence bands. Phys. Rev. Lett. 29, 1088 (1972).CrossRefGoogle Scholar
28.Chambers, S.A., Droubay, T., Kaspar, T.C., Gutowski, M.: Experimental determination of valence band maxima for SrTiO3, TiO2, and SrO and the associated valence band offsets with Si(001). J. Vac. Sci. Technol. B 22, 2205 (2004).CrossRefGoogle Scholar
29.Van Buuren, T., Dinh, L.N., Chase, L.L., Siekhaus, W.J., Terminello, L.J.: Changes in the electronic properties of Si nanocrystals as a function of particle size Phys. Rev. Lett. 80, 3803 (1998).CrossRefGoogle Scholar
30.Wang, S.J., Huan, A.C.H., Foo, Y.L., Chai, J.W., Pan, J.S., Li, Q., Dong, Y.F., Feng, Y.P., Ong, C.K.: Energy-band alignments at ZrO2/Si, SiGe and Ge interfaces. Appl. Phys. Lett. 85, 4418 (2004).CrossRefGoogle Scholar
31.Ogut, S., Chelikowsky, J.R., Louie, S.G.: Quantum confinement and optical gaps in Si nanocrystals. Phys. Rev. Lett. 79, 1770 (1997).CrossRefGoogle Scholar
32.Sun, Q.C., Chen, T.P., Tay, B.K., Li, S., Haung, H., Zhang, Y.B., Pan, L.K., Lau, S.P., Sun, X.W.: An extended quantum confinement theory: Surface-coordination imperfection modifies the entire band structure of a nanosolid. J. Phys. D: Appl. Phys. 34, 3470 (2001).CrossRefGoogle Scholar
33.Niquet, Y.M., Allan, G., Delerue, C., Lannoo, M.: Quantum confinement in germanium nanocrystals. Appl. Phys. Lett. 77, 1182 (2000).CrossRefGoogle Scholar
34.Marsen, B., Lonfat, M., Scheier, P., Sattler, K.: Energy gap of silicon clusters studied by scanning tunneling spectroscopy. Phys. Rev. B 62, 6892 (2000).CrossRefGoogle Scholar
35.Delley, B., Steigmeier, E.F.: Size dependence of bandgaps in silicon nanostructures. Appl. Phys. Lett. 67, 2370 (1995).CrossRefGoogle Scholar
36.VanBuuren, T., Tiedje, T., Dahn, J.R., Way, B.M.: Photoelectron spectroscopic measurements of the band gap in porous silicon. Appl. Phys. Lett. 63, 2911 (1993).CrossRefGoogle Scholar
37.Ishikawa, Y., Wada, K., Cannon, D.D., Liu, J., Luan, H-C., Kimerling, L.C.: Strain-induced bandgap shrinkage in Ge grown on Si substrate. Appl. Phys. Lett. 82, 2044 (2003).CrossRefGoogle Scholar
38.Beke, D.L., Langer, G.A., Kis-Varga, M., Dudas, A., Nemes, P., Daroczi, L., Kerekes, Gy., Erdelyi, Z.: Thermal stability of amorphous and crystalline multilayers produced by magnetron sputtering. Vacuum 50, 373 (1998).CrossRefGoogle Scholar
39.Veprek, S., Sarott, F.A., Iqbal, Z.: Effect of grain boundaries on the Raman spectra, optical absorption and elastic light scattering in nanometer-sized crystalline silicon. Phys. Rev. B 36, 3344 (1987).CrossRefGoogle ScholarPubMed
40.Kumar, S., Trodahl, H.J.: Raman spectroscopy studies of progressively annealed amorphous Si/Ge superlattices. J. Appl. Phys. 70, 3088 (1991).CrossRefGoogle Scholar
41.Persans, P.D., Ruppert, A.F., Wu, Y.J., Abeles, B., Lanford, W., Pantoias, V.: Stability of tetrahedrally bonded amorphous semiconductor multilayers. J. Non-Cryst. Solids 114, 771 (1989).CrossRefGoogle Scholar
42.Olivares, J., Martin, P., Rodriguez, A., Sangrador, J., Jimenez, J., Rodriguez, T.: Raman spectroscopy study of amorphous SiGe flms deposited by low pressure chemical vapor deposition and polycrystalline SiGe flms obtained by solid-phase crystallization. Thin Solid Films 358, 56 (2000).CrossRefGoogle Scholar
43.Pearsall, T.P., Colace, L., DiVergilio, A., Jager, W., Stenkamp, D., Theodorou, G., Presting, H., Kasper, E., Thonke, K.: Spectroscopy of band-to-band optical transitions in Si-Ge alloys and superlattices. Phys. Rev. B 57, 9128 (1998).CrossRefGoogle Scholar
44.Tamizhmani, G., Cocivera, M., Oakley, R.T., Fischer, C., Fujimoto, M.: Physical characterization of a-Si thin films deposited by thermal decomposition of iodosilanes. J. Phys. D: Appl. Phys. 24, 1015 (1991).CrossRefGoogle Scholar