Fully integrated tantalum pentoxide metal-insulator-metal capacitors for Si and SiGe RF-BiCMOS technologies

We report fully integrated Metal-Insulator-Metal (MIM) capacitors (>5fF/mum(2)) developed for the advanced Si and SiGe RF BiCMOS technologies. MIM capacitor consists of two metal plates separated by an amorphous Tantalum pentoxide (Ta2O5) with high dielectric constant of 24. The integration into existing technology requires only one additional mask. The characterization of the tantalum pentoxide MIM capacitors focuses on capacitance density, leakage density, and voltage and temperature coefficients as well as device reliability. As compared to the reported MIM capacitors available in today's market, our fully integrated capacitors meet the wireless application requirements of the MIM capacitors with a low current leakage, a high capacitance density, low voltage and temperature coefficients. For large capacitors up to 160k mum(2) in size with 5fF/mum(2) capacitance dens we have achieved leakage current density of 4.9x10(-7) A/cm(2) at 27degrees C to 1.9x 10(-4) A/cm(2) at 125degrees C with a breakdown voltage of 20V. The fully integrated MIM capacitors surpass the lifetime reliability requirement under the accelerated conditions.