Characterizing Voltage Linearity and Leakage Current of High Density $\hbox{Al}_{2}\hbox{O}_{3}/\hbox{HfO}_{2}/\hbox{Al}_{2}\hbox{O}_{3}$ MIM Capacitors

It was found that the quadratic voltage coefficient of the capacitance (VCC) of Al 2 O 3 -based metal-insulator-metal (MIM) capacitors is inversely proportional to the square of the insulator thickness, i.e., ~t -2 , whereas HfO 2 -based MIM capacitors exhibit the inverse cube relationship, i.e., ~t -3 . Using each of their voltage linearity characteristics in combination with the VCC calculation method, the quadratic VCC of Al 2 O 3 /HfC 2 /Al 2 O 3 (A/H/A)-structured MIM capacitors, with various thickness ratios of the Al 2 O 3 and HfO 2 insulators, could be well estimated. A large portion of the HfO 2 insulators in the A/H/A structures improved the voltage linearity of the MIM capacitors, whereas it deteriorated the dielectric breakdown and the leakage current characteristics.