Characterizing Voltage Linearity and Leakage Current of High Density <formula formulatype="inline"><tex Notation="TeX">Al₂O₃/HfO₂/Al₂O₃</tex> </formula> MIM Capacitors

It was found that the quadratic voltage coefficient of the capacitance (VCC) of Al2O3-based metal-insulator-metal (MIM) capacitors is inversely proportional to the square of the insulator thickness, i.e., ~t-2, whereas HfO2-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 Al2O3/HfC2/Al2O3(A/H/A)-structured MIM capacitors, with various thickness ratios of the Al2O3and HfO2insulators, could be well estimated. A large portion of the HfO2insulators 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.