Investigation of the electrical properties of metal-oxide-metal structures formed from RF magnetron sputtering deposited MgTiO ₃ films

Thin films of MgTiO ₃ high-k dielectric have been prepared by RF magnetron sputtering deposition at various substrate temperatures. X-ray diffraction, atomic force microscopy were used to characterize the deposited films. Experimental results show that substrate temperature has little effect on the stoichinometry. The electrical properties of MgTiO ₃ metal-insulator-metal (MIM) capacitors were investigated at various deposition temperatures, Pt/MgTiO ₃/Pt/SiO ₂/n-Si, were studied. It is shown that the MgTiO ₃ (210 nm) MIM capacitor fabricated at 200°C shows an overall high performance, such as a high capacitance density of ∼1.2 nF/um ², a low leakage current of 1.51 × 10 ^-9 A/cm ² at 5 V, low-voltage coefficients of capacitance, and good frequency dispersion properties. All of these indicate that the MgTiO ₃ MIM capacitors are very suitable for use in Si analog circuit application or dynamic random access memory (DRAM) cell.