Temperature dependence of the work function of ruthenium-based gate electrodes Academic Article uri icon


  • The effect of device fabrication temperature on the work function of ruthenium (Ru) metal gate and its bilayers was investigated. The work function shows strong temperature dependence when Ru electrodes are deposited on silicon oxide, SiO2, but not on hafnium silicates (HfSiOx). Specifically, the work function of Ru on SiO2 increased from 4.5eV at 500C to 5.0eV at 700C. On further annealing to 900C or higher, the work function dropped to about 4.4eV. In the case of HfSiOx, the work function of Ru changed by less than 100mV over the same temperature range. Identical temperature dependence was observed using hafnium (Hf)/Ru and tantalum (Ta)/Ru bilayers. However, the peak values of the work function decreased with increasing Hf/Ru and Ta/Ru thickness ratios. Materials analysis suggests that these trends are driven by interactions at the Ru metal gate-dielectric interface. 2006 Elsevier B.V. All rights reserved.

published proceedings

  • Thin Solid Films

author list (cited authors)

  • Alshareef, H. N., Wen, H. C., Luan, H. F., Choi, K., Harris, H. R., Senzaki, Y., ... Lian, G.

citation count

  • 9

complete list of authors

  • Alshareef, HN||Wen, HC||Luan, HF||Choi, K||Harris, HR||Senzaki, Y||Majhi, P||Lee, BH||Foran, B||Lian, G

publication date

  • January 2006