The scaling of high-k gate stacks using an HF-last/NH3 anneal bottom interface was evaluated for EOT, Nit, and mobility effects on HfC2polysilicon and HfO2/metal gate transistors. TEM analysis of HF-last/NH3 bottom interface layers was also done, showing HF-Iast/NH3 and O3 bottom interface layer thickness to be identical within the resolution of the measurement. Electrical characterization showed that use of HF-last/NH3 anneal bottom interface reduces the EOT of high-k/polysilicon gate devices by 0.3 nm and high-k/metal gate devices by about 0.15-0.2 nm with respect to the corresponding ozonated (O3) interface sample. Charge pumping on the HF-last/NH3 anneal bottom interface indicated Nit density of ∼5×1010 cm-2, slightly greater than the O3 interface control, with mobilities nearly equivalent to those in corresponding O3 interface devices. These data show NH3 bottom interface chemistry to be highly effective in scaling the EOT of HfO 2/polysilicon and HfO2/metal gate stacks while giving nearly equivalent electrical characteristics in transistors fabricated using this method.
|Number of pages||7|
|State||Published - Oct 2003|
|Event||Cleaning Technology in Semiconductor Device Manufacturing VIII - Proceedings of the International Symposium - Orlando, FL., United States|
Duration: 12 Oct 2003 → 17 Oct 2003
|Conference||Cleaning Technology in Semiconductor Device Manufacturing VIII - Proceedings of the International Symposium|
|Period||12/10/03 → 17/10/03|