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Microstructure of highly p-type doped GaN sub-contact layers for low-resistivity contacts

Published online by Cambridge University Press:  01 February 2011

R. Kröger ,
J. Dennemarck ,
T. Böttcher ,
S. Figge  and
D. Hommel
R. Kröger
Affiliation:
Institute of Solid State Physics, University of Bremen, P.O. Box 330440, 28334 Bremen, Germany
J. Dennemarck
Affiliation:
Institute of Solid State Physics, University of Bremen, P.O. Box 330440, 28334 Bremen, Germany
T. Böttcher
Affiliation:
Institute of Solid State Physics, University of Bremen, P.O. Box 330440, 28334 Bremen, Germany
S. Figge
Affiliation:
Institute of Solid State Physics, University of Bremen, P.O. Box 330440, 28334 Bremen, Germany
D. Hommel
Affiliation:
Institute of Solid State Physics, University of Bremen, P.O. Box 330440, 28334 Bremen, Germany
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Abstract

The effect of a highly Mg doped subcontact layer on top of GaN grown by metal organic vapor phase epitaxy and its interface to a Pd/Au contact layer was investigated by means of transmission electron microscopy and electrical characterization techniques. Use was made of prior investigations of the Mg doping characteristics, which showed the existence of a segregation related defect free layer even for doping levels as high as 5×10−19cm−3, which thickness depends on the Mg to Ga molar precursor flow ratio. For a given subcontact layer thickness of 15 nm a critical precursor molar flow ratio of 0.035 resulted in a smooth surface showing an interfacial layer indicating a Pd/Ga alloying. This layer resulted in a contact resistivity as low as 2×10−5 Ωcm2. For a flow ratio of 0.070 the surface was found to be rough due to defect formation resulting in a contact resistivity as high as 10−3 Ωcm2 similar to the value obtained without subcontact layer. Moreover, the metallization layer showed in all cases a texture of the {111} lattice planes with respect to the {0002} planes of the GaN.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 831: Symposium E – GaN, AlN, InN, and Their Alloys , 2004 , E8.10
Copyright
Copyright © Materials Research Society 2005

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References

REFERENCES

1. Böttcher, T., Zellweger, Ch., Figge, S., Kröger, R., Petter, Ch., Bühlmann, H.-J., Ilegems, M., Ryder, P.L., Hommel, D., phys. stat. sol. (a) 191, R3 (2002).Google Scholar
2. Liliental-Weber, Z., Benamara, M., Swider, W., Washburn, J., Grzegory, , Porowski, S., Lambert, D.J.H., Eiting, C.J., and Dupuis, R.D., Appl. Phys. Lett. 75, 26, 4159 (1999).Google Scholar
3. Vennéguès, P., Benaissa, M., Beaumont, B., Feltin, E., De Mierry, P., Dalmasso, S., Leroux, M., and Gibart, P., Appl. Phys. Lett. 77, 6, 880 (2000).Google Scholar
4. Dennemarck, J., Böttcher, T., Figge, S., Einfeldt, S., Kröger, R., Hommel, D., Kaminska, E., Wiatroszak, W., Piotrowska, A., phys. stat. sol. (c), 1, 2537 (2004).Google Scholar
5. Kumakura, K., Makimoto, T., Kobayashi, N., Jpn. J. Appl. Phys. 42, 2254 (2003).Google Scholar
6. Figge, S., Kröger, R., Böttcher, T., Ryder, P.L., Hommel, D., Appl. Phys. Lett. 81, 4748 (2002).Google Scholar
7. Kröger, R., Figge, S., Böttcher, T., Ryder, P., and Hommel, D., Mat. Res. Soc. Proc. 693, 615 (2002).Google Scholar