Hostname: page-component-848d4c4894-x24gv Total loading time: 0 Render date: 2024-05-12T23:45:14.435Z Has data issue: false hasContentIssue false

Reliability of InP-based HBTs at High Current Density

Published online by Cambridge University Press:  31 January 2011

Yoshino Fukai*
Affiliation:
fukai@aecl.ntt.co.jp, NTT Photonics Labs., Atsugi, Japan
Get access

Abstract

InP-based HBTs for ultrahigh speed optical communications systems operation at over 40 GHz require a long-term stability under high current injection conditions, such as current densities of 2 or 5 mA/μm2. We achieved high reliability by suppressing surface recombination and emitter-metal-related crystalline degradation.

Changes in the electric properties of devices due to temperature and bias stress were evaluated. The reduction in DC current gain due to surface recombination had the activation energy of 1.7 eV without current density dependence, and the lifetime of HBTs for this degradation mode is predicted to be over 1×108 hours at 125°C. The emitter metal diffusion and disruption of uniformity of the atomic composition were observed by transmission electron microscopy and energy dispersive X-ray spectroscopy in HBTs with the conventional Ti/Pt/Au emitter, whereas suppression of those degradations was observed in HBTs with refractory metal of Mo and W. The emitter resistance was estimated to evaluate the contact layer degradation. The critical time was one order larger for HBTs with refractory metal than for HBTs with conventional metal. The activation energies for resistance increases were 2.0 and 1.65 eV for the current density of 2 and 5 mA/μm2, respectively, for all types of emitter electrodes.

The effectiveness of the refractory metal electrode for improving device reliability was confirmed, especially in high-current-density operation, which is essential for applying InP HBTs in high-speed ICs.

Type
Research Article
Copyright
Copyright © Materials Research Society 2010

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

[1] Sano, K. et. al., 2004 SSDM.; Tsunashima, S., et. al., 2003 GaAs IC Symposium Technical Digest, pp.284287.Google Scholar
[2] Kamitsuna, H., Kurishima, K., Ida, M., and Sano, K., Electronics Letters, 40 (2004) 139.10.1049/el:20040067Google Scholar
[3] Hafizi, M., Stanchina, W. E., Williams, F. Jr , and Jensen, J.F., IEEE Trans. on Microwave Theory and Techn. Vol. 43 (1995) pp. 30483054.10.1109/22.475673Google Scholar
[4] Kurishima, K., Kobayashi, T., and Ito, H., J. Appl. Phys., 79(8) (1996) pp. 40174023.10.1063/1.361830Google Scholar
[5] Chen, C.-Y., Fu, S.-I., Chang, C. Y., Tsai, C.-H., Yen, C.-H., Tsai, S.-F., Liu, R.-C., and Liu, W.-C., IEEE Trans. ED 51 (2004) pp.19631971.10.1109/TED.2004.839121Google Scholar
[6] Yan, B. P., Yang, Y. F., Hsu, C. C., Lo, H. B., Yang, E. S., Microelectronics Reliability 41 (2001) pp.19591963.10.1016/S0026-2714(01)00222-0Google Scholar
[7] Yamabi, R., Kotani, K., Kawasaki, K., Yaegashi, M., and Yano, H., Indium Phosphide Related Materials (IPRM), 122125, 2003.10.1109/ICIPRM.2003.1205328Google Scholar
[8] Fukai, Y. K., Kurishima, K., Ida, M., Yamahata, S., and Enoki, T.,”Electronics and Communication in Japan, part 2, vol. 90, no. 4, 18, 2007.Google Scholar
[9] Kashio, N., Kurishima, K., Fukai, Y. K., Yamahata, S., and Miyamoto, Yasuyuki, Indium Phosphide Related Materials (IPRM), 44214424, 2007.Google Scholar
[10] Kashio, N., Kurishima, K., Fukai, Y. K., and Yamahata, S., “Highly Reliable submicron InP-based HBTs with over 300-GHz fT”, IEICE Trans. Electron. Vol. E91–C, No. 7, pp. 10841090, 2008 Google Scholar
[11] Fukai, Y. K., Kurishima, K., Kashio, N., Ida, M., Yamahata, S., and Enoki, T., Microelectronics Reliability, Vol. 49, 357364, 2009.10.1016/j.microrel.2009.01.005Google Scholar
[12] Lyu, Y. T., Jaw, K. L., Lee, C. T., Tsui, C. D., Lin, Y. J., and Cheng, T. T., Mater. Chem. Phys., 63 (2000) 122126.10.1016/S0254-0584(99)00208-4Google Scholar
[13] Ivey, D.G., Ingtrey, S., Noel, J.-P., Lau, W. M., Materials Science and Engineering, B49 (1997) 6673.10.1016/S0921-5107(97)00114-1Google Scholar
[14] Huang, J. S., and Vartuli, C.B., J. Appl. Phys. 93 (2003) 51965200.10.1063/1.1565187Google Scholar
[15] Gösele, U. and Morehead, F., J. Appl. Phys. 52 (1981) 46174619.10.1063/1.329340Google Scholar
[16] Piotrowska, A., Auvray, P., Guivarc'h, A., and Pelous, G., J. Appl. Phys. 52 (1981) 51125117.10.1063/1.329410Google Scholar
[17] Seki, M., Fukuda, M., and Wakita, K., Appl. Phys. Lett. 40, (1982) 115117.10.1063/1.93027Google Scholar