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Effects of Silicon Doping and Threading Dislocation Density on Stress Evolution in AlGaN Films

Published online by Cambridge University Press:  08 February 2012

Joan M. Redwing
Affiliation:
Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA 16802 USA Materials Research Institute, The Pennsylvania State University, University Park, PA 16802 USA
Ian C. Manning
Affiliation:
Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA 16802 USA
Xiaojun Weng
Affiliation:
Materials Research Institute, The Pennsylvania State University, University Park, PA 16802 USA
Sarah M. Eichfeld
Affiliation:
Electro-Optics Center, The Pennsylvania State University, University Park, PA 16802 USA
Jeremy D. Acord
Affiliation:
Electro-Optics Center, The Pennsylvania State University, University Park, PA 16802 USA
Mark A. Fanton
Affiliation:
Electro-Optics Center, The Pennsylvania State University, University Park, PA 16802 USA
David W. Snyder
Affiliation:
Electro-Optics Center, The Pennsylvania State University, University Park, PA 16802 USA
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Abstract

In-situ wafer curvature measurements were used to study the effect of Si doping on intrinsic growth stress during the metalorganic chemical vapor deposition (MOCVD) growth of AlxGa1-xN (x=0-0.62) layers on SiC substrates. Post-growth transmission electron microscopy (TEM) characterization was used to correlate measured changes in stress with changes in film microstructure. Si doping was found to result in the inclination of edge-type threading dislocations (TDs) in AlxGa1-xN which resulted in a relaxation of compressive stress and generation of tensile stress. The experimentally measured stress gradient was similar to that predicted by an effective climb model. Dislocation inclination resulted in a reduction in the TD density for Si-doped layers compared to undoped AlxGa1-xN likely due to increased opportunities for dislocation interaction and annihilation. The TD density, which increased with increasing Al-fraction, was found to significantly alter the stress gradients in the films. Film stress was also observed to play a role in TD inclination. In undoped AlxGa1-xN, TD inclination was observed only when the film grew under a compressive stress while in Si-doped AlxGa1-xN, TD inclination was observed independent of the sign or magnitude of the film stress. Si dopants are believed to alter the concentration of surface vacancies which gives rise to dislocation jog via a surface-mediated climb mechanism.

Type
Research Article
Copyright
Copyright © Materials Research Society 2012

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References

REFERENCES

1. Monemar, B. and Pozina, G., Prog. Quantum Electron. 24, 239 (2000).Google Scholar
2. Polyakov, A.Y., Smirnov, N.B., Govorkov, A.V., Mil’vidskii, M.G., Redwing, J.M., Shin, M., Skowronski, M., Greve, D.W. and Wilson, R.G., Solid State Electron. 42, 627 (1998).Google Scholar
3. Terao, S., Iwaya, M., Nakamura, R., Kamiyama, S., Amano, H. and Akasaki, I., Jpn. J. Appl. Phys. Part 2, 40, L195 (2001).Google Scholar
4. Zhang, J.P., Wang, H.M., Gaevski, M.E., Chen, C.Q., Fareed, Q., Yang, J.W., Simin, G. and Khan, M.A., Appl. Phys. Lett. 80, 3542 (2002).Google Scholar
5. Nix, W.D. and Clemens, B.M., J. Mater. Res. 14, 3467 (1999).Google Scholar
6. Romanov, A.E. and Speck, J.S., Appl. Phys. Lett. 83, 674 (2003).Google Scholar
7. Stoney, G. G., Proc. R. Society of London 82, 172175 (1909).Google Scholar
8. Wang, J.F., Yao, D.Z., Chen, J., Zhu, J.J., Zhao, D.G., Jiang, D.S., Yang, H. and Liang, J.W., Appl. Phys. Lett. 89, 152105 (2006).Google Scholar
9. Acord, J.D., Manning, I.C., Weng, X.J., Snyder, D.W. and Redwing, J.M., Appl. Phys. Lett. 93, 111910 (2008).Google Scholar
10. Cantu, P., Wu, F., Waltereit, P., Keller, S., Romanov, A. E., Mishra, U. K., DenBaars, S. P., and Speck, J. S., Appl. Phys. Lett. 83, 674 (2003).Google Scholar
11. Hull, D. and Bacon, D.J., Introduction to Dislocations, 4th ed. (Butterworth Heinemann, New York, 2002).Google Scholar
12. Follstaedt, D.M., Lee, S.R., Allerman, A.A. and Floro, J.A., J. Appl. Phys. 105, 083507 (2009).Google Scholar
13. Manning, I.C., Weng, X., Acord, J.D., Fanton, M.A., Snyder, D.W. and Redwing, J.M., J. Appl. Phys. 106, 023506 (2009).Google Scholar
14. Manning, I.C., Weng, X., Fanton, M.A., Snyder, D.W. and Redwing, J.M., J. Crystal Growth 312, 1301 (2010).Google Scholar
15. Follstaedt, D.M., Lee, S.R., Provencio, P.P., Allerman, A.A., Floro, J.A. and Crawford, M.H., Appl. Phys. Lett. 87, 121112 (2005).Google Scholar
16. Dadgar, A., Veit, P., Schulze, F., Blasing, J., Krtschil, A., Witte, H., Diez, A., Hempel, T., Christen, J., Clos, R. and Krost, A., Thin Solid Films 515, 4356 (2007).Google Scholar
17. Dadgar, A., Blasing, J., Diez, A. and Krost, A., Appl. Phys. Express. 4, 011001 (2011).Google Scholar
18. Xie, J.Q., Mita, S., Hussey, L., Rice, A., Tweedie, J., LeBeau, J., Collazo, R. and Sitar, Z., Appl. Phys. Lett. 99, 141916 (2011).Google Scholar
19. Xie, J.Q., Seiji, M., Ricke, A., Tweedie, J., Hussey, L., Collazo, R. and Sitar, Z., Appl. Phys. Lett. 98, 202101 (2011)Google Scholar
20. Wright, A.F. and Grossner, U., Appl. Phys. Lett. 73, 2751 (1998).Google Scholar