Pulsed DC Magnetron Sputtered Rutile TiO₂ films for next generation DRAM capacitors

Abstract

In this study, synthesis and characterization of rutile-Titanium dioxide (TiO 2 ) thin films using pulsed DC Magnetron Sputtering at room temperature, along with the fabrication and characterization of MIM capacitors have been discussed. XPS and RBS data show that the films are stoichiometric and have compositional uniformity. The influence of electrode materials on electrical characteristics of the fabricated MIM capacitors has been studied. The Al/TiO 2 /Al based capacitors show low capacitance density (9 fF/µm 2 ) with low dielectric constant (K=25) and high EOT (3.67 nm) due to low dielectric constant TiO 2 phase formation on Al/Si substrate. On the other hand, Ru/TiO 2 /Ru based capacitors show high capacitance density (49 fF/µm 2 ) with high dielectric constant (K=130) and low EOT (0.7nm) values at high frequency (100 KHz) due to high dielectric constant phase (rutile) formation of TiO 2 , on Ru/Si substrate. Raman spectra confirm that the films deposited on Ru/Si substrate show the rutile phase.