It is shown that the work function of Ta1-x Alx Ny depends on the electrode and gate dielectric compositions. Specifically, the work function of Ta1-x Alx Ny increased with Si O2 content in the gate dielectric, reaching as high as 5.0 eV on Si O2; the work function was nearly 400 mV smaller on Hf O2. In addition, the work function decreased with increasing nitrogen content in the Ta1-x Alx Ny metal gate. Increasing Al concentration increased the work function up to about 15% Al, but the work function decreased for higher Al concentrations. Chemical analysis shows that Al-O bonding at the interface correlates with the observed work function values.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)