ZrO2 and ZrO2/Y2O3 gate dielectrics prepared by evaporation and annealing processes

The electrical characteristics of MOS capacitors with ZrO₂ gate dielectric prepared by e-beam evaporation of Zr or Yttrium Stabilized Zirconia (YSZ) and subsequent thermal treatment are reported. With this method dielectrics corresponding to an equivalent oxide thickness (EOT) of 1.9 nm and a relative dielectric constant of approximately 15 have been prepared. The effect of annealing on Zr incorporation into the Si substrate is investigated SIMS analysis showed no signs of Zr diffusion in the substrate at temperatures as high as 900°C and that significant diffusion from the dielectric layer occur only at 1100°C.