ZrAlxOy high-k dielectrics for MIM decoupling capacitors in the BEOL

A material, electrical and reliability study of MIM decoupling capacitors placed in the BEOL of 300mm wafers using Al2O3-doped ZrO2 dielectric thin films is reported. By using two aluminum contents (7.8% and 13.1%) within thin (< 10nm) ZrO2 dielectric films, the capacitance density of up to 25.7 fF/mu m(2) with field linearity of 592 ppm/(MV/cm)(2) at 10kHz was achieved. J- E curves and dielectric breakdown characteristics at temperatures from 25 degrees C to 150 degrees C were investigated. Low leakage current (<0.1 mu A/cm(2)) was achieved up to 200 degrees C for both Al contents. Further, reliability measurements were carried out over temperature (25-175 degrees C). Capacitors reached more than 300 years of extrapolated lifetime for the 13.1% Al content within ZrO2 at 150 degrees C and up to more than 400 years of lifetime for both Al contents at 25 degrees C.