Reactive magnetron sputtered aluminum titanate high-κ dielectric films for MIM devices

Metal-insulator-metal (MIM) devices were fabricated with Al/Al2TiO5 stack on Pt/Ti coated SiO2/Si substrates and studied the effect of synthesized oxygen flow rate on their composition, structural and electrical properties. X-ray photoelectron spectroscopy revealed that the presence of aluminum, titanium and oxygen with the ratio 2:1:5, respectively in the projected mixed insulator Al2TiO5. XRD spectra showed that the Al2TiO5 high-k films were amorphous in nature. The average grain size observed from atomic force micrograph of the deposited high-k layer could be 25 nm. The capacitance-voltage curves showed reasonably accepted accumulation capacitance values. The films showed the dielectric constant of 19.3 and the leakage current density of 4 x 10(-7) A/cm(2) with good break down behavior. The leakage current in the films can be attributed to the Fowler-Nordheim mechanism due to tunneling of electron at higher electric field and Poole-Frenkel emission in the medium field region since the dielectric films contained the defects and traps.

Automated summary

Metal-insulator-metal (MIM) devices with Al/Al2TiO5 stack were fabricated and the effect of synthesized oxygen flow rate on their properties was studied. The results showed that the Al2TiO5 films exhibited good electrical properties, with high dielectric constant and low leakage current density.