Hostname: page-component-78c5997874-dh8gc Total loading time: 0 Render date: 2024-11-19T07:31:30.223Z Has data issue: false hasContentIssue false

Impurity Effects in the Growth of 4H-SiC Crystals by Physical Vapor Transport

Published online by Cambridge University Press:  10 February 2011

V. Balakrishna
Affiliation:
Northrop Grumman Science & Technology Center, 1350 Beulah Road, Pittsburgh, PA 15235
G. Augustine
Affiliation:
Northrop Grumman Science & Technology Center, 1350 Beulah Road, Pittsburgh, PA 15235
R. H. Hopkins
Affiliation:
Northrop Grumman Science & Technology Center, 1350 Beulah Road, Pittsburgh, PA 15235
Get access

Abstract

SiC is an important wide bandgap semiconductor material for high temperature and high power electronic device applications. Purity improvements in the growth environment has resulted in a two-fold benefit during growth: (a) minimized inconsistencies in the background doping resulting in high resistivity (>5000 ohm-cm) wafer yield increase from 10–15% to 70-85%, and (b) decrease in micropipe formation. Growth parameters play an important role in determining the perfection and properties of the SiC crystals, and are extremely critical in the growth of large diameter crystals. Several aspects of growth are vital in obtaining highly perfect, large diameter crystals, such as: (i) optimized furnace design, (ii) high purity growth environment, and (iii) carefully controlled growth conditions. Although significant reduction in micropipe density has been achieved by improvements in the growth process, more stringent device requirements mandate further reduction in the defect density. In-depth understanding of the mechanisms of micropipe formation is essential in order to devise approaches to eliminate them. Experiments have been performed to understand the role of growth conditions and ambient purity on crystal perfection by intentionally introducing arrays of impurity sites on one half of the growth surface. Results clearly suggest that presence of impurities or second phase inclusions during start or during growth can result in the nucleation of micropipes. Insights obtained from these studies were instrumental in the growth of ultra-low micropipe density (less than 2 micropipes cm−2 ) in 1.5 inch diameter boules.

Type
Research Article
Copyright
Copyright © Materials Research Society 1999

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. Tairov, Y. M. and Tsvetkov, V. F., Journal Cryst. Growth, 43, 209(1978).10.1016/0022-0248(78)90169-0Google Scholar
2. Ziegler, G., Lanig, P., Theis, D., and Weyrich, C., IEEE Transactions on Electron Devices, ED- 30, 277(1983).Google Scholar
3. Hobgood, H. Mc D., Barrett, D. L., McHugh, J. P., Clarke, R. C., Sriram, S., Burk, A. A., Greggi, J., Brandt, C. D., Hopkins, R. H., and Choyke, W. J., Journal of Crystal Growth, 137, 181(1994).10.1016/0022-0248(94)91269-6Google Scholar
4. Balakrishna, V.. Hopkins, R. H., Augustine, G., Dunne, G. T., and Thomas, R. N., Inst. Phys. Ser. No 60, DRIP-VII, Berlin, pp. 321330 (1997)Google Scholar
5. Jenny, J. R., Skowronski, M., Mitchel, W. C., Hobgood, H. Mc D., Glass, R. C., Augustine, G., and Hopkins, R. H., Appl. Phys. Lett., 68(14), p1963 (1996).10.1063/1.115640Google Scholar
6. Glass, R. C,, Augustine, G., Balakrishna, V., Hobgood, H. Mc D., Hopkins, R. H., Jenny, J., Skowronski, M., and Choyke, W. J., SiC and Related Materials, Inst. Of Phys. Ser. 142, p 3740 (1995)Google Scholar
7. Sriram, S., Augustine, G., Burk, A. A. Jr, Glass, R. C., Hobgood, H. Mc D., Orphanos, P. A., Rowland, L. B., Smith, T. J., Brandt, C. D., Driver, M. C., and Hopkins, R. H., IEEE Electron Device Letters, 17, 369(1996).10.1109/55.506370Google Scholar
8. Clarke, R. C., Siergiej, R. R., Agarwal, A. K., Brandt, C. D., Burk, A. A. Jr, Morse, A., and Orphanos, P. A., Proceedings IEEE/Cornell Conference on Advanced Concepts in High Speed Semiconductor Devices and Circuits, 47 (1995).Google Scholar
9. Palmour, J. W., Allen, S. T., Singh, R., Lipkin, L. A., and Waltz, D. G., Technical Digest of the International Conference on Silicon Carbide and Related Materials, Kyoto Japan, 813 (1995).Google Scholar
10. Tsvetkov, V. F., Henshall, D. N., Brady, M. F, Glass, R. C., and Carter, C. H. Jr, Mat. Res. Soc. Sym. Proc. Vol. 512, p89 (1998)10.1557/PROC-512-89Google Scholar