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

Abstract

Metal-insulator-metal (MIM) capacitors with ZrLaO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> /ZrTiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> /ZrLaO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> laminate as the insulator were explored in this work. Single ZrTiOx dielectric was found to have a negative quadratic voltage coefficient of capacitance (VCC-α) with a high κ value of 22.5. By integrating this dielectric with ZrLaOx which provides a positive VCC-α and a high κ value of 25.8, the “canceling effect” of VCC-α 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 fF/μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , a low VCC-α of 33 ppm/V <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , negligible frequency dispersion, and satisfactory leakage current of 1.6 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-6</sup> A/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at -1.5 V. These results also well meet the International Technology Roadmap for Semiconductors requirement set for 2020.