Interfacial and electrical properties of SrBi{sub 2}Ta{sub 2}O{sub 9}/ZrO{sub 2}/Si heterostructures for ferroelectric memory devices

Journal Article · Mon Sep 15 04:00:00 EDT 2008 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2978233· OSTI ID:21182639

Roy, A; Dhar, A; Ray, S K ^[1]

---

1. Department of Physics and Meteorology, IIT Kharagpur, Kharagpur 721302 (India)

We have investigated the interfacial and frequency dependent electrical properties of metal-ferroelectric-insulator-semiconductor capacitors with SrBi{sub 2}Ta{sub 2}O{sub 9} (SBT) ferroelectric films grown on ZrO{sub 2} buffer layer coated Si. Heterostructure SBT and ZrO{sub 2} thin films were deposited using rf magnetron sputtering. Interfacial and surface roughness parameters of heterostructures were extracted from the simulation of specular x-ray reflectivity data. The structure exhibited clockwise capacitance-voltage hysteresis with a maximum memory window of 2.0 V at a bias voltage of {+-}7 V. Frequency dependent (5 kHz-1 MHz) measurements at room temperature indicated that the clockwise hysteresis originates from the ferroelectric domain reversal. A minimum leakage current density of 4x10{sup -8} A/cm{sup 2} of fabricated capacitors at an applied voltage of {+-}5 V revealed that the ZrO{sub 2} buffer layer prevents the interfacial diffusion between SBT thin film and the substrate, resulting in an improvement of interface quality. The charge retention time of the ferroelectric capacitor was studied as a function of buffer layer thickness.

• OSTI ID: 21182639
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 6 Vol. 104; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BISMUTH COMPOUNDS
CAPACITANCE
CURRENT DENSITY
FERROELECTRIC MATERIALS
FREQUENCY DEPENDENCE
HYSTERESIS
LAYERS
LEAKAGE CURRENT
MEMORY DEVICES
REFLECTIVITY
ROUGHNESS
SEMICONDUCTOR MATERIALS
SILICON
SPUTTERING
STRONTIUM COMPOUNDS
SURFACE COATING
TANTALATES
TEMPERATURE RANGE 0273-0400 K
THIN FILMS
ZIRCONIUM OXIDES