AVS 63rd International Symposium & Exhibition
    MEMS and NEMS Friday Sessions
       Session MN+MS-FrM

Invited Paper MN+MS-FrM2
Effect of Top Electrode Material on Radiation-Induced Degradation of Ferroelectric Thin Films

Friday, November 11, 2016, 8:40 am, Room 102B

Session: Radiation Effect in Emerging Micro/Nano Structures, Devices, and Systems
Presenter: Nazanin Bassiri-Gharb, Georgia Institute of Technology
Authors: N. Bassiri-Gharb, Georgia Institute of Technology
S.J. Brewer, Georgia Institute of Technology
C.Z. Deng, Georgia Institute of Technology
C.P. Callaway, Georgia Institute of Technology
M.K. Paul, Woodward Academy
K.J. Fisher, Riverwood International Charter School
J.E. Guerrier, North Carolina State University
J.L. Jones, North Carolina State University
R.Q. Rudy, Army Research Laboratory
R.G. Polcawich, Army Research Laboratory
E.R. Glaser, Naval Research Laboratory
C.D. Cress, Naval Research Laboratory
Correspondent: Click to Email
The effects of gamma irradiation on the dielectric and piezoelectric responses of Pb[Zr0.52Ti0.48]O3 (PZT) thin films were investigated for structures with conductive oxide (IrO2) and metallic (Pt) top electrodes. All samples showed a general degradation of various key dielectric, ferroelectric, and electromechanical responses when exposed to 2.5 Mrad(Si) 60Co gamma radiation. However, the low-field, relative dielectric permittivity, εr, remained largely unaffected by irradiation in samples with both types of electrodes. Samples with Pt top electrodes showed substantial degradation of the remanent polarization and overall piezoelectric response, as well as pinching of the polarization hysteresis curves and creation of multiple peaks in the permittivity-electric field curves post irradiation. The samples with oxide electrodes, however, were largely impervious to the same radiation dose, with less than 5% change in any of the functional characteristics. The results suggest a radiation-induced change in the defect population or defect energy in PZT with metallic top electrodes, which substantially affects motion of internal interfaces such as domain walls. Additionally, the differences observed for devices with different electrode materials implicates the ferroelectric-electrode interface as either the predominant source of radiation-induced effects (Pt electrodes) or the site of healing for radiation-induced defects (IrO2 electrodes).