Development of a High-Endurance Ferroelectric Capacitor for FeRAM in Automotive and Industrial Applications

A high-endurance ferroelectric capacitor (FC) incorporating a Pb(Zr, Ti)O3 (PZT) layer, fabricated via liquid delivery metal-organic chemical vapor deposition, and a sputter-deposited Bi-doped SrRuO3 (B-SRO) interlayer has been successfully developed. This FC exhibits excellent electrical properties, including a low coercive voltage, achieved by thinning the PZT layer, allowing it to function effectively across a wide temperature range of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$- 45~^{\circ }$ </tex-math></inline-formula>C to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$125~^{\circ }$ </tex-math></inline-formula>C, and at an operating voltage of 1.8 V. Typically, thinning the ferroelectric layer leads to increased leakage current and degradation in reliability, such as retention and endurance. However, our developed FC demonstrates robust retention after baking at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$150~^{\circ }$ </tex-math></inline-formula>C for 1000 h, low leakage current, and a predicted endurance of at least <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{{15}}$ </tex-math></inline-formula> cycles. Our developed FC has potential applications in ferroelectric random access memory (FeRAM) operating at 1.8 V with an endurance of at least over <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{{14}}$ </tex-math></inline-formula> cycles used for automotive and industrial devices within the specified temperature range.