A high-density MIM capacitor (13 fF/μm2) using ALD HfO2 dielectrics

Abstract

Metal-insulator-metal (MIM) capacitors with a different thickness of HfO2 have been investigated. The results show that both the capacitance density and voltage coefficients of capacitance (VCCs) increase with decreasing the HfO2 thickness. In addition, it is also found that the VCCs decrease logarithmically with increasing the thickness of HfO2. Furthermore, the MIM capacitor with 10-nm HfO2 shows a record high capacitance density of 13 fF/μm2 and a VCC of 607 ppm/V, which can meet the requirement of the International Technology Roadmap for Semiconductors. It can also provide a low leakage current of 5.95 × 10-8A/cm2 at room temperature at 1 V, low tangent values below 0.05, and a small frequency dependence as well. All these indicate that it is very suitable for use in silicon integrated circuit applications.