$hbox{ZrLaO}_{x}hbox{/ZrTiO}_{x}hbox{/ZrLaO}_{x}$ Laminate as Insulator for MIM Capacitors With High Capacitance Density and Low Quadratic Voltage Coefficient Using Canceling Effect

摘要

Metal–insulator–metal (MIM) capacitors with $hbox{ZrLaO}_{x} hbox{/ZrTiO}_{x}hbox{/ZrLaO}_{x}$ laminate as the insulator were explored in this work. Single $hbox{ZrTiO}_{x}$ dielectric was found to have a negative quadratic voltage coefficient of capacitance (VCC-$alpha$) with a high $kappa$ value of 22.5. By integrating this dielectric with $hbox{ZrLaO}_{x}$ which provides a positive VCC- $alpha$ and a high $kappa$ value of 25.8, the “canceling effect” of VCC-$ alpha$ can be achieved while a high capacitance density can be maintained. MIM capacitors with the laminated structure display desirable characteristics in terms of a capacitance density of 14.6 $hbox{fF}/muhbox{m}^{2}$, a low VCC- $alpha$ of 33 $ hbox{ppm/V}^{2}$, negligible frequency dispersion, and satisfactory leakage current of $hbox{1.6} times hbox{10}^{-6} hbox{A/cm}^{2}$ at $-$1.5 V. These results also well meet the International Technology Roadmap for Semiconductors requirement set for 2020.