Structural and electrical properties of HfLaOx films for an amorphous high-k gate insulator

Abstract

Thin HfLaOx films on Si(100) have been investigated as an alternative gate insulator. The introduction of La2O3 into HfO2 causes an increase of crystallization temperature. Furthermore, unlike other Hf-based amorphous materials such as HfSiOx or HfAlOx, the permittivity of HfLaOx keeps a high value (>20). The capacitance-voltage curve of metal oxide semiconductor capacitor using the HfLaOx dielectric film has shown a negligible hysteresis and no frequency dispersion, indicating very small degradations of both interface and bulk properties. In addition, a very low fixed charge density in HfLaOx films is demonstrated from a very small film thickness dependence of the flatband voltage.

Hafnium-based High-k Gate Dielectrics

“…In addition, varying the La concentrations in the TaN/HfLaO or HfN/HfLaO gate stack can effectively tune the metal work function for N-MOSFETs [43]. In the capacitance-voltage curve of metal oxide semiconductor capacitor, Yamamoto et al [46] have shown that the HfLaO x dielectric film exhibits very small degradation in both the interface and bulk properties, as shown in Fig. 19.…”

“…17). Furthermore, unlike other Hf-based amorphous materials such as HfSiO x or HfAlO x , the permittivity of HfLaO x still yields a high k value (>20) [ 46] (Fig. 18).…”

Crystallization resistance of barium titanate zirconate ultrathin films from aqueous CSD: a study of cause and effect

“…After having reduced the thickness of the traditional SiO x gate dielectric to its limits, the downscaling has continued lately by replacing the SiO x with alternative high-k dielectrics such as Hf based materials [1][2][3][4] , among other efforts. After successful implementation of these second generation gate dielectrics in commercial applications, research has turned towards the identification of a third generation alternative "higher-k" dielectric, to keep up with the ever increasing demands imposed by the ITRS roadmap.…”

Impacts of crystal orientation of GaAs on the interfacial structures and electrical properties of Hf0.6La0.4Ox films

“…1,2 HfO 2 is one of the most promising high-k candidates for future CMOS devices, however, HfO 2 on GaAs showed abnormal capacitance-voltage (C-V) characteristics with no accumulation observed, 3 which is attributed to the native oxides induced interface pining between GaAs substrate and HfO 2 . 4 Fortunately, by doping La into HfO 2 to form HfLaO x the performance of gate dielectrics can be enhanced considerably due to its high permittivity, 5 relatively large conduction band (CB) offset, 6,7 high crystallization temperature, 8 and less Fermi-level pinning. 9,10 GaAs has a zinc blende structure with double fcc cubic lattice of Ga atoms and As atoms.…”