Hostname: page-component-848d4c4894-8kt4b Total loading time: 0 Render date: 2024-06-25T00:20:12.770Z Has data issue: false hasContentIssue false

Selective Suppression of Carrier-Driven Photochemical Etching: Raman Spectroscopy as a Diagnostic Tool

Published online by Cambridge University Press:  26 February 2011

C. I. H. Ashby
Affiliation:
Sandia National Laboratories, Albuquerque, New Mexico 87185
D. R. Myers
Affiliation:
Sandia National Laboratories, Albuquerque, New Mexico 87185
G. A. Vawter
Affiliation:
Sandia National Laboratories, Albuquerque, New Mexico 87185
R. M. Biefeld
Affiliation:
Sandia National Laboratories, Albuquerque, New Mexico 87185
J. F. Klem
Affiliation:
Sandia National Laboratories, Albuquerque, New Mexico 87185
Get access

Abstract

Carrier-driven photochemical etching of semiconductors can be selectively suppressed by altering the near-surface region to enhance carrier recombination, thereby reducing the supply of carriers that drive the surface etching reaction. Two methods for enhancing recombination and decreasing the etch rate at a given phonon flux include ion implantation and localized Zn diffusion. Raman spectroscopy can be employed to determine whether sufficient alteration of electronic properties has occurred to suppress etching.

Carrier-driven photochemical reactions, which require direct participation of free carriers for the chemical reaction to proceed, can be selectively suppressed by increasing the minority carrier recombination rate, thereby reducing the supply of carriers that drive the surface etching reaction. Two methods for enhancing recombination and decreasing the etching quantum yield, which is the number of atoms removed per incident photon, include ion implantation and localized Zn diffusion. For ion implantation, recombination-promoting defect concentrations depend on ion species, fluence, and annealing both during and after the implantation process. Other recombination processes related to carrier scattering from ionized impurities from in-diffusion of dopants or following implant activation can control etching.

Raman spectroscopy can be employed to detect changes in electronic properties that correlate with etching suppression. Changes that occur in the LO-phonon lineshape, such as those associated with phonon confinement and ionized impurity scattering, can be diagnostic of the carrier-driven etching behavior following a specific treatment. We have demonstrated two applications of Raman spectroscopy as a diagnostic for suppression of the carrier-driven photochemical etching of GaAs.

Type
Research Article
Copyright
Copyright © Materials Research Society 1991

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

1. Vawter, G. A., Omura, E., Wu, X. S., Merz, J. L., Coldren, L., and Hu, E., J Appl. Phys. 63, 5541 (1988).Google Scholar
2. Biefeld, R. M., Osbourn, G. C., Gourley, P. L., and Fritz, I. J., J. Electron. Mater. 12, 903 (1983).Google Scholar
3. Ashby, C. I. H., Myers, D. R., and Vook, F. L., J. Electrochem. Soc. 136, 782 (1989).Google Scholar
4. Ashby, C. I. H., Myers, D. R., Vawter, G. A., Biefeld, R. M., and Datye, A. K., J. Appl. Phys. 68. 2406 (1990).Google Scholar
5. Aspnes, D. E. and Studna, A. A., Phys. Rev. B 27, 985 (1983).Google Scholar
6. Sze, S. M., Semiconductor Devices: Physics and Technology (John Wiley & Sons, New York, 1985), p. 48.Google Scholar
7. Tiong, K. K., Amirtharaj, P. M., Pollak, F. H., and Aspnes, D. E., Appl. Phys. Lett. 44. 122 (1984).Google Scholar
8. Kinchin, G. H. and Pease, R. S., Repts. on Prog, in Physics 18, 1 (1955).Google Scholar
9. Peaker, A. R. and Hamilton, B., Chemtronics 3, 194 (1988).Google Scholar
10. Morgan, D. V. and Taylor, P. D., in Ion Implantation in Semiconductors 1976. edited by Chernow, F., Borders, J. A., and Brice, D. K., (Plenum Press, New York, 1977), p. 555.Google Scholar
11. Olego, D. and Cardona, M., Phys. Rev. B 24 7217 (1981).Google Scholar
12. Gogolin, A. A. and Rashba, E. I., in Physics of Semiconductors, edited by Funi, F. G., (North-Hoiland, New York, 1976), p. 284.Google Scholar