NiCr bottom electrodes for Ta2O5 high dielectric thin films in metal-insulator-metal capacitors

NiCr bottom electrodes are prepared onto p-type Si (100) substrates to replace Pt bottom electrode with a new one for integration of high dielectric constant materials. NiCr thin films deposited in Ni and Cr power of 80 and 30 W, respectively showed optimum properties in the composition of Ni7Cr3 . NiCr thin films were crystallized after annealing at high temperature. The resistivities of NiCr thin films annealed both at 600square for 30 min in O-2 and 700square for 3 min in 2x10(-5) torr were approximately 200squaresquare-cm. 30 nm-thick Ta2O5 thin films deposited at room temperature on NiCr bottom electrode (annealed at 700square for 3 min in 2x10(-5) torr) were annealed at 600 to 800square for 5min in an O-2 ambient. The dissipation factor and the leakage current of Ta2O5 thin films increased with increasing annealing temperature. The dielectric constant, the dissipation factor and leakage current density of Ta2O5 thin films annealed at 600square showed 18 and 2% at 100 kHz, and 1.9x10(-6) A/cm(2) at an applied field of 333 kV/cm, respectively.