Hostname: page-component-586b7cd67f-dlnhk Total loading time: 0 Render date: 2024-11-25T03:31:03.941Z Has data issue: false hasContentIssue false

Modification of a-Si(:H) by Thermally Generated Atomic Hydrogen: A Real Time Spectroscopic Ellipsometry Study of Si Bond Breaking

Published online by Cambridge University Press:  21 February 2011

Ilsin An
Affiliation:
Materials Research Laboratory, The Pennsylvania State University, University Park, PA 16802
Youming Li
Affiliation:
Materials Research Laboratory, The Pennsylvania State University, University Park, PA 16802
C.R. Wronski
Affiliation:
Materials Research Laboratory, The Pennsylvania State University, University Park, PA 16802
R.W. Collins
Affiliation:
Materials Research Laboratory, The Pennsylvania State University, University Park, PA 16802
Get access

Abstract

We have applied real time spectroscopie ellipsometry (2.5≤hv≤4.5 eV) to investigate in situ hydrogenation of thin film a-Si:H prepared by plasma-enhanced CVD. When a-Si:H is exposed to atomic H generated by a tungsten filament heated in H2, as many as ∼5×1021 Si-Si bonds/cm3 can be converted to Si-H bonds in the top ∼200 Å of the film. We have determined the spectroscopie characteristics of Si-H bonds from optical to near-uv photon energies through an analysis of the changes in the dielectric function of the near-surface of the film upon hydrogenation. The conversion of Si-Si bonds to Si-H bonds is identified as reaction-limited to a depth of ∼500 Å. We find that a surface oxide a few monolayers in thickness acts as an effective diffusion barrier to H-incorporation.

Type
Research Article
Copyright
Copyright © Materials Research Society 1992

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. Das, D., Shirai, H., Hanna, J., and Shimizu, I., Jpn. J. Appl. Phys. 30, L239 (1991).Google Scholar
2. Street, R.A., Phys. Rev. B 43, 2454 (1991).Google Scholar
3. Johnson, N.M., Nebel, C.E., Santos, P. V., Jackson, W.B., Street, R.A., Stevens, K.S., and Walker, J., Appl. Phys. Lett. 59, 1443 (1991).Google Scholar
4. Winer, K., Phys. Rev. B 41, 7952 (1990).Google Scholar
5. An, I. and Collins, R.W., Rev. Sci. Instrum. 62, 1904 (1991).Google Scholar
6. Li, Y.M., An, I., Gunes, M., Dawson, R.M., Collins, R.W., and Wronski, C.R., this volume.Google Scholar
7. An, I., Li, Y.M., Wronski, C.R., Nguyen, H.V., and Collins, R.W., Appl. Phys. Lett. 59, 2543 (1991).Google Scholar
8. Forouhi, A.R. and Bloomer, I., Phys. Rev. B 34, 7018 (1986).Google Scholar
9. Mui, K. and Smith, F.W., Phys. Rev. B 38, 10623 (1988).Google Scholar
10. Street, R.A., Tsai, C.C., Kakalios, J., and Jackson, W.B., Philos. Mag. B 56, 305 (1987).Google Scholar