A SrRuO/sub 3//IrO/sub 2/ top electrode FeRAM with Cu BEOL process for embedded memory of 130nm generation and beyond

摘要

An extremely damage-robust SrRuO/sub 3//IrO/sub 2/ top electrode FeRAM with Cu BEOL process is demonstrated for the first time as a promising device for 130nm CMOS embedded memory. The ferroelectric capacitor with SrRuO/sub 3//IrO/sub 2/ top electrode has no degradation during Cu metallization to suppress the oxygen and lead vacancies at the top electrode interface. Switching charge (Qsw) of 40uC/cm/sup 2/ is achieved for 0.45/spl times/0.45/spl mu/m/sup 2/ top electrode (TE) size capacitor. The opposite state polarization margin of 90% is retained against imprint at 70hrs, 150C bake. This high reliable capacitor with large Qsw and a small bit line capacitance of 'chain' structure (Ozaki, 2001) increase signal window drastically. A signal window of 730mV at 1.8V operation voltage after 3-level Cu metallization is achieved. This technology realizes future 130nm embedded FeRAM and beyond.