Atomic vapour deposited HfO2 and Sr4Ta2O9 layers for metal-insulator-metal applications

Sr4Ta2O9 and HfO2 films were prepared on 200 mm TiN/Si(100) substrates by Atomic Vapour Deposition (AVD). Depositions were carried out within a thermal budget of CMOS back end of line. Electrical properties have been investigated in metal-insulator-metal capacitors after sputter deposition of Au top electrodes. Both Sr4Ta2O9 and HfO2 dielectrics show excellent electrical perfonnances. Oxides possess high capacitance densities of 3.5 fF/mu m(2) (HfO2) and 4.5 fF/mu m(2) (Sr4Ta2O9) in combination with high voltage linearity (alpha< 100ppm/V-2). Sr4Ta2O9 MIM capacitors provide lower leakage currents at 2 V, while HfO2 MIMS offer higher operating voltage values for 10 years lifetime than Sr4Ta2O9 based capacitors. The dielectric breakdown fields of HfO2 (5.8 MV/cm) and Sr4Ta2O9 (3.2 MV/cm) were obtained from I(V) characteristics.