AVS 62nd International Symposium & Exhibition
    Electronic Materials and Processing Monday Sessions
       Session EM+AS+SS-MoA

Invited Paper EM+AS+SS-MoA5
World Record Tunable Microwave Dielectrics

Monday, October 19, 2015, 3:40 pm, Room 211A

Session: MIM Diodes, Functional Oxides, and TFTs
Presenter: Darrell Schlom, Cornell University
Authors: C.H. Lee, Cornell University
N.D. Orloff, National Institute of Standards and Technology (NIST)
T. Birol, Cornell University
Y. Zhu, Cornell University
Y. Nie, Cornell University
V. Goian, Institute of Physics ASCR
R. Haislmaier, Pennsylvania State University
J.A. Mundy, Cornell University
J. Junquera, Universidad de Cantabria
P. Ghosez, Université de Liège
R. Uecker, Leibniz Institute for Crystal Growth
V. Gopalan, Pennsylvania State University
S. Kamba, Institute of Physics ASCR
L.F. Kourkoutis, Cornell University
K.M. Shen, Cornell University
D.A. Muller, Cornell University
I. Takeuchi, University of Maryland, College Park
J.C. Booth, National Institute of Standards and Technology (NIST)
C.J. Fennie, Cornell University
D.G. Schlom, Cornell University
Correspondent: Click to Email
The miniaturization and integration of frequency-agile microwave circuits—relevant to electronically tunable filters, antennas, resonators, phase shifters and more—with microelectronics offers tantalizing device possibilities, yet requires thin films whose dielectric constant at GHz frequencies can be tuned by applying a quasi-static electric field. Appropriate systems, e.g., BaxSr1–xTiO3, have a paraelectric-to-ferroelectric transition just below ambient temperature, providing high tunability. Unfortunately such films suffer significant losses arising from defects. Recognizing that progress is stymied by dielectric loss, we start with a system with exceptionally low loss—Srn+1TinO3n+1 phases—where (SrO)2 crystallographic shear planes provide an alternative to point defect formation for accommodating non-stoichiometry. Guided by theoretical predictions, we biaxially strain a Srn+1TinO3n+1 phase with n = 6 to introduce a ferroelectric instability and create a new type of tunable microwave dielectric. This tunable dielectric exhibits a world record figure of merit at room temperature and frequencies up to 125 GHz. Our studies also reveal details about the microscopic growth mechanism of these phases, which are relevant to preparing atomically precise oxide interfaces to these and other Ruddlesden-Popper phases.