Tunability Investigation in the BaTiO3-CaTiO3-BaZrO3 Phase Diagram Using a Refined Combinatorial Thin Film Approach

Coatings

Sandrine Payan¹  Mario Maglione¹  Jerome Wolfman²  Quentin Simon²  Nazir Jaber²  Christophe Daumont²  Beatrice Negulescu²  Pascal Gardes³  Patrick Poveda³ 

[1] Physics Department, Université de Bordeaux, 33608 Pessac, France;Physics Department, Université de Tours, INSA CVL, Parc de Grandmont, 37200 Tours, France;STMicroelectronics, 10 Rue Thalès de Milet, 37071 Tours, France;

关键词: BCTZ;    thin films;    dielectric;    tunable capacitors;    PLD;    lead-free relaxor;   

DOI  :  10.3390/coatings11091082

来源: DOAJ

【 摘 要 】

Tunable ferroelectric capacitors, which exhibit a decrease in the dielectric permittivity under an electric field, are widely used in electronics for RF tunable applications. Current devices use barium strontium titanate (BST) as the tunable dielectric, but new applications call for tunable materials with specific performance improvements. It is then of crucial importance to dispose of a large panel of electrically characterized materials to identify the most suited compound for a given set of device specifications. Here, we report on the dielectric tuning properties of Ba_1−xCa_xTi_1−yZr_yO₃ (BCTZ) thin films libraries (0 ≤ x ≤ 30% and 0 ≤ y ≤ 28.5%) synthesized by combinatorial pulsed laser deposition (CPLD). An original CPLD approach allowing reliable and statistical ternary phase diagrams exploration is reported. The effects of Ca and Zr content on tunability, breakdown voltage and dielectric losses are explicated and shown to be beneficial up to a certain amount. Compounds close to (Ba_0.84Ca_0.16)(Ti_0.8Zr_0.2)O₃ exhibit the highest figures of merit, while a zone with compositions around (Ba_0.91Ca_0.09)(Ti_0.81Zr_0.19)O₃ show the best compromise between tuning ratio and figure of merit. These results highlight the potential of BCTZ thin films for electrically tunable applications.

【 授权许可】

Unknown