High-Performance Metal–Insulator–Metal Capacitors With HfTiO/Y₂O₃ Stacked Dielectric

TheHfTiO/Y₂O₃stacked dielectric is proposed as the dielectric of metal–insulator–metal (MIM) capacitor.Y₂O₃is more thermodynamically stable than HfTiO as contacting with TaN electrode. Interfacial layer thickness and leakage current density can be reduced by inserting a thinY₂O₃layer between HfTiO and TaN. The negative quadruple voltage coefficient of capacitance (VCC-α) ofY₂O₃cancels out the positive VCC-αof HfTiO to achieve low VCC-α. The MIM capacitor structure withHfTiO/Y₂O₃dielectric shows a capacitance density that is higher than 11fF/²and VCC-αthat is lower than 1222ppm/V². The leakage currents at$-$1 and$-$2 V are 6.4 and 14nA/cm², respectively. These results suggest that theHfTiO/Y₂O₃stacked dielectric is a promising candidate for MIM capacitors.