Improving Edge Dead Domain and Endurance in Scaled HfZrO_x FeRAM

Abstract

Scaling in area and voltage and its interplay with reliability of metal-ferroelectric-metal (MFM) capacitors are explored for scalable embedded FeRAM technology below 2× nm node. Size-dependent degradation in ferroelectricity due to the edge dead domains is identified both experimentally and theoretically. Optimization strategies including edge interface and work function tuning are detailed. The scaled MFM shows promising potential for achieving high maximum <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$P_{\mathrm{r}}$</tex> (36 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mu \mathrm{C}/\text{cm}^{2})$</tex> , small area <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$($0.16 $\mu \mathrm{m}^{2})$</tex> , excellent reliability <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(&gt; 10^{11})$</tex> cycles; retention <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$&gt; 10$</tex> years at 85°C), a low operating voltage of 1.7 V, and a high array yield (100 % in lkb test macro).