Dielectric and Room Temperature Tunable Properties of Mg-Doped Ba 0.96 Ca 0.04 Ti 0.84 Zr 0.16 O 3 Thin Films on Pt/MgO
- PDF / 87,020 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 101 Downloads / 151 Views
DIELECTRIC AND ROOM TEMPERATURE TUNABLE PROPERTIES OF Mg-DOPED Ba 0.96 Ca 0.04 Ti 0.84Zr 0.16 O3 THIN FILMS on Pt/MgO T.S. Kalkur, Woo-Chul Yi, Elliott Philofsky* and Lee Kammerdiner* Microelectronics Research Laboratories, Department of Electrical and Computer Engineering, University of Colorado at Colorado Springs, Colorado Springs, CO 80933-7150. *Applied Ceramics Research Company, Colorado Springs, CO 80919.
ABSTRACT Mg- doped Ba0.96 Ca0.04 Ti0.84 Zr0.16 O3 (BCTZ) thin films were fabricated on Pt/MgO substrate by metallorganic decomposition method. The structures of the films were analyzed by x-ray diffraction. The electrical measurements were performed on metal-ferroelectric-metal capacitors with platinum as the top and bottom electrode. The dielectric properties were improved after the capacitors were post annealed at 700 oC in oxygen atmosphere for 30 min. A high dielectric constant of 504 and a dissipation factor of less than 4% was obtained at 1 MHz. The Pt/BCTZ/Pt/MgO capacitors exhibited high tunability of 55% at an applied field of 55 kV/cm.
INTRODUCTION Thin films of barium strontium titanates Ba1-xSrxTiO3 have become very attractive as dielectrics for storage capacitors for high density dynamic random access memories(DRAM), decoupling capacitors and electric field tunable elements for high frequency microwave circuits[1-5]. Barium Titanium Zirconate Ba(Ti,Zr)O3 which is a solid solution of barium titanate BaTiO3 and barium zirconate BaZrO3 shows a lot of analogies to BaSrTiO3 solution(6). In the related system, Ba1-xCaxTi1-yZriO3 (BCTZ) bulk ceramics used as dielectrics for chip capacitors, when prepared in oxidizing atmophere exhibit a broad dielectric constant-temperature (ε-T) curve near critical temperature Tc in which peak values of ε = 18000 with nickel electrodes(7). Since, the dielectric constant of BCTZ is significantly higher than that of bulk BST and therefore it is natural to explore the possibility of using BCTZ thin film as a replacement for BST. The fabrication of doped and undoped BCTZ films on Pt/Ti/SiO2/Si substrates by metalorganic decomposition (MOD) method and its dielectric properties have been reported by our group recently (8). The variation of dielectric constant with applied electric field (which is characterized as tunability) of high dielectric constant materials is important for the fabrication of jitter free high frequency voltage controlled oscillators, matching networks and phase delay elements. So far most of the tunability investigations are confined to BST and strontium titanate thin films. In this paper, we are reporting the results of electrical characteristics and tunability of magnesium(Mg) doped BCTZ films on Pt/MgO substrates.
B2.8.1 Downloaded from https://www.cambridge.org/core. Columbia University Libraries, on 30 Aug 2017 at 20:34:02, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1557/PROC-716-B2.8
SAMPLE PREPARATION Platinum film of thickness 200 nm was deposited on (100) MgO substrate
Data Loading...
