Investigation of the electrical properties of metal–oxide–metal structures formed from RF magnetron sputtering deposited MgTiO3 films

Thin films of MgTiO3 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 MgTiO3 metal–insulator–metal (MIM) capacitors were investigated at various deposition temperatures, Pt/MgTiO3/Pt/SiO2/n-Si, were studied. It is shown that the MgTiO3 (210 nm) MIM capacitor fabricated at 200 °C shows an overall high performance, such as a high capacitance density of ∼1.2 nF/um2, a low leakage current of 1.51 × 10−9 A/cm2 at 5 V, low-voltage coefficients of capacitance, and good frequency dispersion properties. All of these indicate that the MgTiO3 MIM capacitors are very suitable for use in Si analog circuit application or dynamic random access memory (DRAM) cell.

► MgTiO3 MIM capacitor can provide a higher capacitance density than the Si3N4 and SiO2 MIM.
► A low leakage current of 1.51 × 10−9/cm2 at 5 V, low-voltage coefficients of capacitance.
► Good frequency dispersion property was found the MgTiO3 MIM capacitor fabricated at 200 °C.
► All of these make the MgTiO3 MIM capacitor very suitable for use in silicon RF and mixed-signal IC applications.