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 Al 2 O 3 -doped ZrO 2 dielectric thin films is reported. By using two aluminum contents (7.8% and 13.1%) within thin (<10nm) ZrO 2 dielectric films, the capacitance density of up to $25.7\ \text{fF}/\mu\mathrm{m}^{2}$ with field linearity of 592 ppm/(MV/cm)2 at 10kHz was achieved. J-E curves and dielectric breakdown characteristics at temperatures from 25°C to 150°C were investigated. Low leakage current $(< 0.1\mu\mathrm{A}/\text{cm}^{2})$ was achieved up to 200°C for both Al contents. Further, reliability measurements were carried out over temperature (25-175°C). Capacitors reached more than 300 years of extrapolated lifetime for the 13.1% Al content within ZrO 2 at 150°C and up to more than 400 years of lifetime for both Al contents at 25°C.