MBE-grown high gate dielectrics of HfO2 and (Hf–Al)O2 for Si and III–V semiconductors nano-electronics

The MBE growth technique is employed to the intensively studied high κ gate dielectrics HfO2 (κ=20) and its alloy (Hf–Al)O2 in replacing conventional SiO2 for nano-CMOS applications. Typical 4.9 nm thick HfO2 films showed low leakage current density of ∼0.4 A/cm2 at 1 V, a dielectric constant κ of 20.7 and an EOT of 0.9 nm. Minor frequency dispersion is observed at C–V curves and is removed by an improved two-frequency method. An epitaxial order of (1 0 0) cubic HfO2 oxide is observed for the depositions on GaAs(1 0 0) at temperatures over 230 °C.