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Selective Removal of Silicon-Germanium: Chemical and Reactive Ion Etching

Published online by Cambridge University Press:  25 February 2011

F. Scott Johnson ,
Veena Misra ,
J. J. Wortman ,
Leanne R. Martin ,
Gari A. Harris  and
Dennis M. Maher
F. Scott Johnson
Affiliation:
North Carolina State University, Department of Electrical and Computer Engineering, Raleigh, NC 27695-7911
Veena Misra
Affiliation:
North Carolina State University, Department of Electrical and Computer Engineering, Raleigh, NC 27695-7911
J. J. Wortman
Affiliation:
North Carolina State University, Department of Electrical and Computer Engineering, Raleigh, NC 27695-7911
Leanne R. Martin
Affiliation:
North Carolina State University, Department of Materials Science and Engineering, Raleigh, NC 27695-7916
Gari A. Harris
Affiliation:
North Carolina State University, Department of Materials Science and Engineering, Raleigh, NC 27695-7916
Dennis M. Maher
Affiliation:
North Carolina State University, Department of Materials Science and Engineering, Raleigh, NC 27695-7916
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Abstract

The use of both chemical and reactive ion etching for the selective removal of SixGe1-x alloys with respect to both silicon and silicon dioxide has been investigated. We have found that a solution of NH4OH:H2O2:H2O is effective in selectively etching the SixGe1-x films with respect to both of these materials. The chemical composition of the substrate surface after removal of insitu doped SixGe1-x films was evaluated using EDS and SIMS. Diffusion from insitu doped Si0.7Ge0.3, followed by selective removal, was used to demonstrate self-aligned npn dopant profiles with narrow base widths. Reactive ion etching of SixGe1-x alloys was investigated using SF6, CF4, and Cl2 based chemistries. Pressure, power, and gas flow ratios were optimized to provide the least isotropic etch possible for SixGe1-x films containing approximately 40% Ge. Selectivity and degree of anisotropic etching were determined as a function of Ge content for samples with 0% to 100% Ge. Samples were analyzed using SEM and ellipsometry. Highest selectivities were achieved using SF6 and O2.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 298: Symposium B – Silicon-Based Optoelectronic Materials , 1993 , 157
Copyright
Copyright © Materials Research Society 1993

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References

1. Grider, D. T., Ozturk, M. C., and Wortman, J. J., submitted to Transactions on Electron Devices, Nov. 1992.Google Scholar
2. Johnson, F. S., Miller, R. M., Ozturk, M. C., and Wortman, J. J., Materials Research Symposium Proceedings, 146, p. 345, (1989).CrossRefGoogle Scholar
3. Sanganeria, M., Oztuirk, M. C., Harris, G., Maher, D. M., Batchelor, D., Wortman, J. J., Zhang, B., and Zhong, Y. L., Presented at 1991 Electrochemical Society Third International Symposium on Ultra Large Scale Integration, Washington DC (1991).Google Scholar
4. Johnson, F. S., Miles, D. S., Grider, D. T., and Wortman, J. J., J. Elect. Mat., 21, p. 805, (1992).CrossRefGoogle Scholar
5. Oehrlein, G. S., Zhang, Y., Kroesen, G. M. W., Fresart, E. D., and Bestwick, T. D., Appl. Phys. Lett., 58, p. 2252, (1991).CrossRefGoogle Scholar
6. Oehrlein, G. S., Bestwick, T. D., Jones, P. L., Jaso, M. A., and Lindstrom, J. L., J. Electrochem. Soc., 138, p. 1443, (1991).CrossRefGoogle Scholar
7. Porkolab, G. A. and Wolf, E. D., Appl. Phys. Lett., 56, p. 2319, (1990).CrossRefGoogle Scholar
8. Oehrlein, G. S., Kroesen, G. M. W., Fresart, E. D., Zhang, Y. and Bestwick, T. D., J. Vac. Sci. Technol., 9, p. 768, (1991).CrossRefGoogle Scholar