• RAJESH KUMAR JHA

Articles written in Bulletin of Materials Science

• On the structural and electrical properties of metal–ferroelectric–high k dielectric–silicon structure for non-volatile memory applications

In this article, we report the structural and electrical properties of metal–ferroelectric–high k dielectric–silicon (MFeIS) gate stack for non-volatile memory applications. Thin film of sputtered SrBi$_2$Nb$_2$O$_9$ (SBN) was used as ferroelectric material on 5–15 nm thick high-k dielectric (Al$_2$O$_3$) buffer layer deposited using plasma-enhanced atomic layer deposition (PEALD). The effect of annealing on structural and electrical properties of SBN and Al$_2$O$_3$ films was investigated in the temperature range of 350–1000$^{\circ}$C. X-ray diffraction results of the SBN and Al$_2$O$_3$ show multiple phase changes with an increase in the annealing temperature. Multiple angle ellipsometry data show the change in the refractive index ($n$) of SBNfilm from 2.0941 to 2.1804 for non-annealed to samples annealed at 600$^{\circ}C. For Al$_2$O$_3$film,$n$< 1.7 in the case of PEALDand$n$> 1.7 for sputtered film was observed. The leakage current density in MFeIS structure was observed to two orders of magnitude lower than metal/ferroelectric/silicon (MFeS) structures. Capacitance–voltage (C–V) characteristics for the voltage sweep of$−$10 to 10 V in dual mode show the maximum memory window of 1.977 V in MFeS structure, 2.88 Vwith sputtered Al$_2$O$_3$and 2.957 V with PEALD Al$_2$O$_3$in the MFeIS structures at the annealing temperature of 500$^{\circ}\$C.

• # Bulletin of Materials Science

Volume 43, 2020
All articles
Continuous Article Publishing mode

• # Editorial Note on Continuous Article Publication

Posted on July 25, 2019