Thickness Scaling of Integrated Pt/(Al _0.9 Sc _0.1 )N/Pt Capacitor Stacks to 30 nm

Abstract The total thickness scaling of electrodes and the (Al 0.9 Sc 0.1 )N layer is evaluated for ferroelectric memory applications. The good crystal orientation and large remanent polarization ( P r ) above 100 µC cm −2 are obtained for 160‐nm‐thick (Al 0.9 Sc 0.1 )N films even when the Pt bottom electrode is reduced to a thickness of 5 nm. The (Al 0.9 Sc 0.1 )N film integrated on a 5‐nm‐thick Pt bottom electrode maintains a saturated P r value above 100 µC cm −2 at a thickness of 30 nm. Furthermore, the (Al 0.9 Sc 0.1 )N film exhibits improved crystal orientation by the post‐heat‐treatment of the Pt bottom electrode, and a saturated large P r value above 100 µC cm −2 is obtained at a thickness of 20 nm. Moreover, a P r value of 90 µC cm −2 is obtained at a (Al 0.9 Sc 0.1 )N thickness of 10 nm. No significant degradation in the P r characteristics is detected when the thickness of the Pt top electrode is reduced to 5 nm. Finally, the total thickness is successfully scaled down to 30 nm for a Pt (top electrode, 5 nm)/(Al 0.9 Sc 0.1 )N (20 nm)/Pt (bottom electrode, 5 nm) stack. This work presents guidelines for the thickness scaling of the (Al,Sc)N‐based stacks for ferroelectric memory applications, including ferroelectric thin films and electrodes.