Title :
Laminate as Insulator for MIM Capacitors With High Capacitance Density and Low Quadratic Voltage Coefficient Using C
Author :
Chen, Lun Lun ; Wu, Yung-Hsien ; Lin, Yu-Bo ; Lin, Chia-Chun ; Wu, Min-Lin
Author_Institution :
Dept. of Eng. & Syst. Sci., Nat. Tsing Hua Univ., Hsinchu, Taiwan
Abstract :
Metal-insulator-metal (MIM) capacitors with ZrLaOx/ZrTiOx/ZrLaOx 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/μm2, a low VCC-α of 33 ppm/V2, negligible frequency dispersion, and satisfactory leakage current of 1.6 × 10-6 A/cm2 at -1.5 V. These results also well meet the International Technology Roadmap for Semiconductors requirement set for 2020.
Keywords :
MIM devices; composite insulating materials; high-k dielectric thin films; laminates; lanthanum compounds; leakage currents; thin film capacitors; titanium compounds; zirconium compounds; MIM capacitors; ZrLaOx-ZrTiOx-ZrLaOx; canceling effect; high capacitance density; high-κ dielectric; insulator; laminate; laminated structure; leakage current; low quadratic voltage coefficient; metal-insulator-metal capacitors; negative quadratic voltage coefficient of capacitance; Annealing; Capacitance; Capacitors; Laminates; Leakage current; MIM capacitors; $hbox{ZrLaO}_{x}hbox{/ZrTiO}_{x} hbox{/ZrLaO}_{x}$ laminate; Canceling effect; metal–insulator–metal (MIM) capacitors; negative quadratic voltage coefficient of capacitance (VCC-$alpha$ );
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2012.2209396