Martin L. Green, Kao-Shuo Chang, Ichiro Takeuchi, T Chikyow
Combinatorial methodology is a rapid technique for surveying new gate dielectrics and gate metal electrodes for the very complex advanced CMOS gate stack. Here, we report on a typical metal gate electrode alloy system, the Ni-Ti-Pt ternary. We have fabricated this metal gate thin film library on HfO2 using magnetron co-sputtering, to investigate flat-band voltage shift (?Vfb) and leakage current density (JL) variations. Wavelength dispersive spectroscopy (WDS) results show that over 90% 1% of Ni and Ti, and 75% 1% of Pt were attained in the library. A more negative ?Vfb is observed close to the Ti-rich corner than close to the Ni- and Pt-rich corners, implying smaller Fm near Ni- and Pt-rich corners. In addition, measured JL values are consistent with the observed ?Vfb variations.
advanced gate stack, combinatorial materials science, metal gate electrodes, sputtering