Improvement of C-V characteristics and control of interlayer growth of rare earth oxide stabilized zirconia epitaxial gate dielectrics

The effects of doping several rare earth oxides on the capacitance-voltage (C-V) characteristics and the SiO2 interlayer growth of ZrO2 based gate dielectrics on (001)Si were examined. The width of the C-V hysteresis window of La2O3 stabilized ZrO2 (LaSZ) gate dielectric was only 0.2V, on the other hands, that of Sc2O3 stabilized ZrO2 (SCSZ) gate dielectric was 1.4V. HRTEM analysis indicated that the growth Of SiO2 interlayer of RSZ (R=Sm,Nd,La) gate dielectric was about 1nm, which was less than half of the ScSZ one. These results indicate the advantage of the ZrO2 gate dielectric doped with rare earth oxide composed of larger ionic radius cation.