Ultrathin EOT high- κ/metal gate devices for future technologies: Challenges, achievements and perspectives (invited)

Abstract

Ultrathin EOT-values are achieved by using optimized processing conditions and interface layer scavenging in metal-gated (TiN and TaN) HfO 2 based planar and bulk-FinFET devices. EOT values down to 4.5 Å ( T inv ∼ 8.5 Å ) in the planar devices and T inv < 11 Å in bulk-FinFETs are demonstrated. Improved EOT-leakage current scaling is observed with the use of chemical oxides as compared to thermally grown SiO 2 as interface layer for the HfO 2 . In contrast, the mobility is found independent of the compared interface layers, processing conditions and metal electrodes and follows one trend-line with EOT. The FinFET devices show decreased T inv -values and improved mobility for more narrow fin widths.