Hostname: page-component-7479d7b7d-jwnkl Total loading time: 0 Render date: 2024-07-11T09:22:59.007Z Has data issue: false hasContentIssue false

Thermal Annealing Study of Variable Band-Gap a-SiN:H Alloy Films

Published online by Cambridge University Press:  17 March 2011

N. Banerji
Affiliation:
Dpto. Física Aplicada, Univ. de Vigo, Lagoas-Marcosende, 36200 Vigo, Spain
E. Faro
Affiliation:
Dpto. Matemática Aplicada, Univ. de Vigo, Lagoas-Marcosende, 36200 Vigo, Spain
J. Serra
Affiliation:
Dpto. Física Aplicada, Univ. de Vigo, Lagoas-Marcosende, 36200 Vigo, Spain
Get access

Abstract

A study of the effects of thermal annealing on the bond structure, optical properties, morphology and stoichiometry of variable band gap a-SixNyHz alloy films deposited by ArF LCVD has been made. These films were generated through two different photochemical pathways resulting from the use of either SiH4/NH3 or Si2H6/NH3 as precursor gases. Thermal annealing study of these films which span a wide compositional (0.22 < x/y < 1.44) and band-gap (Eg) range (1.7–5.2 eV) has led to the analysis of the stability of different bond configurations. We report here hydrogen bond stability and rearrangement of the near-neighbor environment of SiN bonds analyzed through FTIR, refractive index variations measured by ellipsometry and surface morphological changes observed through AFM during to the process of annealing. Results indicate that in the SiH4/NH3 deposited nitrogen-rich SiN:H films, SiHn bonds persist even upto 900°C and SiH bonds are less thermally stable than SiH2. Also, while the total bonded hydrogen decreases, the extent of SiN bond increases through a reaction mechanism involving: SiH + NH → SiN + H2. In the Si2H6/NH3 deposited silicon-rich film, whose initial spectra shows Si-H stretching and Si-H wagging bands, a rapid loss of Si-H bonds occurs at T ≤ 650°C. Based on the bond configurational interpretations of the Random bonding model proposed by Bustarret, we calculate the variations in film stoichiometry and density with the annealing temperature.

Type
Research Article
Copyright
Copyright © Materials Research Society 2001

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. Demichellis, F., Crovini, G., Giorgis, F., Pirri, C. F. and Tresso, E., J. Appl. Phys. 79(3), 17301735 (1996).Google Scholar
2. Williams, M. J., Cho, S. M., He, S.S. and Lucovsky, G., Journal of Non-Crystalline Solids 164–166, 6770 (1993).Google Scholar
3. Giorgis, F., Pirri, C.F., and Tresso, E., Thin Solid Films 307, 298305 (1997).Google Scholar
4. Banerji, N., Serra, J., Chiussi, S., León, B., Applied Surface Science 6424, 15 (2000)Google Scholar
5. Robertson, J., Philosophical Magazine B 69, 307326 (1994).Google Scholar
6 Stafast, H., J. Appl. Phys. A 45, 93102 (1988).Google Scholar
7. Serra, J., Szörényi, T., Fernández, D., González, P., Garcia, E., Pou, J., León, B., érez Amor, M.P, Surf.Coat.Technol. 80, 211 (1996).Google Scholar
8. Bustarret, E., Bensouda, M., Habrard, M.C., Poulin, S., and Gujrathi, S.C., Phys. Rev. B 38, 8171 (1988).Google Scholar
9. Yin, Z. and Smith, F. W., Physical Rev. Vol 42 Number 6, 366367 (1990).Google Scholar
10. Banerji, N., Serra, J., Lusquiños, F., Chiussi, S., León, B., Peréz-Amor, M. Proceedings of 9th Cimtec World Forum on New Materials, Symposium III, Surface Engineering, 399–406 (1999).Google Scholar
11. Hasegawa, S., Lee, L., Amano, Y., Inokuma, T., Physical Rev B 48, 5313 (1993).Google Scholar
12. Martínez, F.L., Mártil, I., González-Díaz, G., Selle, B., Sieber, I., Journal of Non-Crystalline Solids 227–230, 523527 (1998)Google Scholar
13. Makino, T., Journal of Electrochem. Soc. 130, 450 (1983).Google Scholar