Realization of a composite ferroelectric characterization test system using a modified constant current method and a modified virtual ground method.

Abstract

A composite ferroelectric characterization test system constructed using a modified constant current method (CCM) and a modified virtual ground method (VGM) has been successfully designed and implemented. By sending instructions to the microcontroller through software, the system's test mode can be easily changed by arranging the switching status of six switching elements. When validating the system, a dual-channel precision source/measure unit B2912B was used to verify this design. There is also parasitic capacitance that cannot be ignored in this commercial machine. This parasitic capacitance affects the appearance of the entire hysteresis curve. However, the parasitic capacitance values also differ in various test current ranges. In addition, to confirm the data credibility of this composite ferroelectric test system, Keysight B1530A and Radiant Premier II were used to conduct cross-verification between different systems. The results obtained between different systems show good consistency. Furthermore, reproducible and recoverable imprint phenomena were found in this composite system during interactive validation using VGM and CCM methods. After designing different voltage profiles for verification, it was found that the root cause of this imprint phenomenon was the difference between the final polarization state of the previous test and the pre-initialized polarization state. This imprint phenomenon exists in traditional Pb(Zr, Ti)O3(PZT) ferroelectric capacitors and Hf0.5Zr0.5O2-based ferroelectric capacitors. Fortunately, this imprint phenomenon is reversible. Moreover, this imprint phenomenon disappears through the design of the time-varying voltage profile on the ferroelectric capacitor of the CCM method.