Hostname: page-component-586b7cd67f-2brh9 Total loading time: 0 Render date: 2024-11-25T17:59:56.575Z Has data issue: false hasContentIssue false

Improvement of Recovery Time of Bipolar Power Devices by Si1-xGex Misfit Dislocations

Published online by Cambridge University Press:  25 February 2011

Ali S.M. Salih*
Affiliation:
General Instrument Corp., Power Semiconductor Division, R&D Engineering Department, Hicksville, NY 11802
Get access

Abstract

A new technique for improving the recovery time of bipolar power devices by misfit dislocations to fast switching speed levels is described. Misfit dislocations formed in situ at abrupt SiGe/Si heteroepitaxial interfaces are used as recombination centers in the space charge regions of devices. The density of misfit dislocations was varied over a wide range by controlling the Ge concentration and the number of Ge-containing layers in both <111> and <100> orientations. The structural properties of misfit dislocations were studied by optical microscopy, TEM, and X-ray topography. Power rectifier recovery and electrical parameters, DLTS, and minority carrier lifetime were employed to evaluate the electrical behavior of dislocations with and without gold diffusion. Fast recovery times with low leakage current and forward voltage drop were achieved by the introduction of misfit dislocations. Monotonically decreasing recovery times were obtained with increasing dislocation density. For the same recovery time, introduction of misfit dislocations produced about 50% reduction in high-temperature leakage current and similar forward voltage drop compared to devices subjected to Au diffusion. The combination of dislocations and metal impurities is also investigated and found to provide an excellent mechanism for further tailoring of the recovery characteristics of power devices. In this application the metals were preferentially accumulated in the depletion region at the misfit dislocations from small background metal concentrations leading to additional reduction of recovery time, while maintaining small leakage current and forward voltage drop.

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

REFERENCES

1. Shockley, W. and Read, W.T., Phys. Rev. 87, 835 (1952).Google Scholar
2. Hall, R.H., Phys.Rev., 87, 387 (1952).Google Scholar
3. Cornu, J., Sittig, R., and Zimmermann, W., Solid State Electron., 17 1099 (1974).CrossRefGoogle Scholar
4. Baliga, B.J., and Krishna, S., Solid State Electron., 20, 225 (1976).CrossRefGoogle Scholar
5. Zimmerman, W., Electron. Lett., 9, 378 (1973).CrossRefGoogle Scholar
6. Baliga, B.J., “Modem Power Devices” Ch. 2. p. 36, Wiley, NY (1987).Google Scholar
7. Pals, J.A., Solid State Electron., 17, 1139 (1974).CrossRefGoogle Scholar
8. Bondos, E., Research and Development, p. 108, May (1985).Google Scholar
9. Evwaraye, A.O. and Sun, E., J. Appl. Phys., 47, 3776 (1976).CrossRefGoogle Scholar
10. Salih, A.S.M., Kim, H.J., Davis, R.F., and Rozgonyi, G.A., Appl. Phys. Lett., 46, 419 (1985)Google Scholar
11. Salih, A.S.M., Ryu, J.S., Rozgonyi, G.A., and Bean, K.E., J.Electrochem. Soc., 133, 475 (1986).Google Scholar
12. Salih, A.S.M., Radzimski, Z., Honeycutt, J., Rozgonyi, G.A., Bean, K.E., and Lindberg, K., Appl. Phys. Lett., 50, 1678 (1987).Google Scholar
13. Rozgonyi, G.A., Salih, A.S.M., Radzimski, Z., Kola, R.R., and Honeycutt, J., J. Crystal Growth, 85, 300 (1987).Google Scholar
14. Glaenzer, R.H. and Jordan, A.G., Solid State Electron., 12, 247 (1969).Google Scholar
15. Matthews, J.W., “Epitaxial Growth,” Matthews, J. W., Editor, Ch. 8, p. 559, Academic Press, New York (1975).Google Scholar
16. Kimerling, L.C., Patel, J.R., Appl. Phys. Lett., 34, 73 (1979).Google Scholar
17. Patel, J.R. and Kimerling, L.C., Cryst. Res. and Tech., 16, 2, 187 (1981).Google Scholar
18. Salih, A.S.M., Maszara, W., Kim, H.J., and Rozgonyi, G.A., Mat. Res. Soc. Symp. Proc., 36, 61 (1985).Google Scholar