A novel method for characterizing the electrical properties of lead zirconate titanate (PZT) ferroelectric films and memory devices

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1993

OSTI ID:6933117

Pugh, R D

A novel technique for determining the electrical properties of lead zirconate titanate (PZT) ferroelectric-film memory devices is reported. This technique measures the electrical response of a ferroelectric material (device) to an electrical signal that is similar in amplitude and frequency to the signals used in digital computers. The technique also provides a method for consistently converting the measured electrical response into polarization values. The ability to consistently process the data allows researchers to accurately compare the results of different measurements. To implement the technique, two (or more) consecutive cycles of a triangular waveform are applied to the device under test, and the electrical response is measured using a Sawyer-Tower circuit. The first cycle of the waveform has the same amplitude as the signals typically found in the intended application. However, the last cycle of the waveform is of sufficient amplitude to saturate the ferroelectric polarization of the material. The saturation polarization has historically been taken to be constant from measurement to measurement and it is used as a consistent polarization reference for the approach developed in this research. The technique will allow other researchers to investigate the relationship between changes in the operating characteristics of a ferroelectric memory device and changes in the electrical properties of the ferroelectric material. Ferroelectric aging in a PZT film was investigated using this new technique. The results of this investigation indicated that ferroelectric aging in PZT films is similar to ferroelectric aging in many bulk ferroelectric materials. Specifically, [open quotes]effective[close quotes] internal electric fields increase linearly with the logarithm of the aging time. Additionally, the investigation revealed how earlier measurement techniques motivated investigators to believe that ferroelectric-film aging was different from bulk ferroelectric aging.

• Research Organization: Air Force Inst. of Tech., Wright-Patterson AFB, OH (United States)
• OSTI ID: 6933117
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ELECTRICAL PROPERTIES
FERROELECTRIC MATERIALS
LEAD COMPOUNDS
MEASURING METHODS
MEMORY DEVICES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PZT
TITANATES
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
ZIRCONATES
ZIRCONIUM COMPOUNDS