Hostname: page-component-7479d7b7d-k7p5g Total loading time: 0 Render date: 2024-07-16T03:12:43.272Z Has data issue: false hasContentIssue false

High Resolution Transmission Electron Microscopy Study of Thermal Oxidation of Single Crystalline Aluminum Nitride

Published online by Cambridge University Press:  01 February 2011

Jharna Chaudhuri
Affiliation:
jharna.chaudhuri@ttu.edu, Texas Tech University, Mechanical Engineering, 7th Street & Boston Avenue, Lubbock, TX, 79409-1021, United States, (806) 742-3563 ext 224, (806) 742-3540
Rac Gyu Lee
Affiliation:
rac.lee@ttu.edu, Texas Tech University, Mechanical Engineering Department, 7th Street & Boston Ave, Lubbock, TX, 79409-1021, United States
Luke Owuor Nyakiti
Affiliation:
luke.nyakiti@ttu.edu, Texas Tech University, Mechanical Engineering Department, 7th Street & Boston Ave, Lubbock, TX, 79409-1021, United States
Zheng Gu
Affiliation:
Zheng Gu [guzheng@ksu.edu], Kansas State University, Chemical Engineering Department, Manhattan, KS, 66506, United States
James H Edgar
Affiliation:
edgarjh@ksu.edu, Kansas State University, Chemical Engineering Department, Manhattan, KS, 66506, United States
Peng Li
Affiliation:
Peng Li [pengli@unm.edu], Univ. of New Mexico, Earth and Planetary Science Department, Albuquerque, NM, 87131, United States
Get access

Abstract

The impact of process conditions and crystal properties on the structure of thermal oxides formed on AlN were determined by high resolution transmission electron microscopy (HRTEM). Oxidation for 2 hours at both 800 ° and 1000 °C produced mostly amorphous oxide layers whereas oxidation for 4 and 6 hours at 1000 °C produced partly crystalline and epitaxial oxide layers. The crystalline oxide was mostly single phase á-Al2O3 except at the surface where it was a mixture of γ-Al2O3 and á-Al2O3. The amorphous oxide layer first transformed to γ-Al2O3 and then to the stable á-Al2O3 as evidenced by the non-uniform thickness of the oxide and the existence of the γ-Al2O3 at the surface. The AlN crystal contained a high density of defects at the interface at 800 °C but it was nearly defect- and oxygen-free at 1000 °C. This could be due to the rapid diffusion of the nitrogen and aluminum interstitials at high temperatures leading to a point defect equilibrium throughout the nitride. A faceted interface between Al2O3 and AlN could be attributed to non-uniform out diffusion of aluminum.

Type
Research Article
Copyright
Copyright © Materials Research Society 2007

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. Rojo, J. C., Schowalter, L. J., Slack, G., Morgan, K., Barani, J., Schujman, S., Biswas, S., Raghothamachar, B., Dudley, M., Shur, M., Gaska, R., Johnson, N. M., and Kneissl, M., Mat. Res. Soc. Symp. Proc. 722 K1.1 (2002).Google Scholar
2. Kang, H. C., Seo, S. H., Jang, H. W., Kim, D. H., Kim, J. W., and Noh., D. Y. Appl. Phys. A 77, 627 (2003).Google Scholar
3. Chaowdhury, E. A., Kolozey, J., Olowolafe, J. O., Qiu, G., Katluka, G., Hitts, D., Dashiell, M., van der Weide, D., Swann, C. P., and Unruh, K. M., Appl. Phys. Lett 70, 2732 (1997).Google Scholar
4. Ho, J. K., Jong, C. S., Chiu, C. C., Huang, C. N., Shih, K. K., Chen, L. C., Chen, F. R., and Kai, J. J., J. Appl. Phys. 86, 4491(1999).Google Scholar
5. Chaudhuri, J., Nyakiti, L., Lee, R. G., Gu, Z., Edgar, J. H., and Wen, J. G., In press J. Mater. Charac., March, (2007).Google Scholar