BEOL-Compatible Ferroelectric Capacitor with Excellent Endurance and Retention by Improving Interface Quality

In this paper, we have successfully fabricated a metal-ferroelectricity-metal (MFM) capacitor of an ultrathin 6.5 nm HZO utilizing Molybdenum (Mo) as the electrodes. We propose a novel atomic layer deposition (ALD) scheme to overcome the challenge of oxidation of the bottom Mo electrode. The fabricated sample annealed at 400 °C demonstrated a 2Pr value of 54.3 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">μ C/cm²</tex> at an operating voltage of 2V, which meets the stringent requirements of Back-End-of-Line (BEOL) integration. Furthermore, in endurance testing, the sample maintained a 2Pr value of 52.2 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">μ C/cm²</tex> even after 10 10 cycles ( <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2Pr/2Prₚᵣᵢₛₜₘₑ≈ 4%</tex> from pristine to 10 10 cycles).