Journal of the Korean Physical Society

pISSN 0374-4884 eISSN 1976-8524


J. Korean Phy. Soc. 2011; 58(5(1)): 1393-1397

Published online May 13, 2011

Copyright © The Korean Physical Society.

Effect of Ultraviolet Irradiation on the Defect States and the Charge Transport Properties of Low-k SiOC(-H) Dielectric Films Deposited by Using UV-assisted PECVD

A. S. Zakirov, T. W. Kang, R. Navamathavan, C. Y. Kim, C. K. Choi


Low-k SiOC(-H) films with different structural orders were fabricated by using UV-assisted PECVD, and the influence of the replacement of Si-O bonds by (Si-C) bonds on the structural and the electro-physical properties was investigated. FT-IR spectrum shows that the SiOC(-H) films deposited at a RF power of 400 W have a cross-linking structure with nano-pores due to the combined Si-CHn-Si bond and Si-O-Si network, and there relative ratio changed with increasing RF power. From current transients, as well as the C-V characteristics, we estimated the trap and the positive charge densities in the low-k films. They were found to be on the order of 1016 traps/cm3 and 1011 cm?2eV?1, having a tendency to increase with increasing UV irradiation. We also found that the barrier heights for electrons at the interfaces of low-k insulators with metals were almost insensitive to the metal¡?s Fermi energy, suggesting that the current injection was determined by some localized state in the insulator gap. The results were substantiated and directly correlated with the changes in transport properties and with the bond structure characteristics of SiOC(-H) films.

Keywords: low-k SiOC(-H) films, UV irradiation, C-V characteristics, Defect states, ,