Abstract
The effect of various top electrodes (Au, Ag, Cu and Al) on the hysteresis loop behavior of 1-μm thick PZT has been investigated. The PZT films and PT bottom electrode were prepared by MOCVD, and various top electrodes were deposited by evaporation. Using an Ag and Cu top electrode, an improvement in the polarization hysteresis loops of PZT films was observed compared to the other electrodes (Au and Al). A well-saturated P-V hysteresis loop was obtained when Ag and Cu top electrodes were applied. By applying an Au electrode, a decrease in polarization was observed, and the Al top electrode produced P-V hysteresis loops with para-electric behavior. The improvement in the polarization hysteresis loops was affected by the electrical conductivity of the top metal electrode. Namely, a faster supply of compensation charges, which are required to bind polarization charges located near the interface in PZT films, was obtained as the conductivity of the top electrode increased. The electrical conductivity of the metals displayed the following trend: (Ag>Cu>Au>Al).
Highlights
Top and bottom electrodes have a strong effect on the ferroelectric properties of a material
We developed various top metal electrodes including Au, Ag, Cu and Al on PZT thin films with a Pt bottom electrode for ferroelectric capacitors using vacuum evaporation
The effect of various top electrodes (Au, Ag, Cu and Al) deposited by evaporation on the hysteresis loops of 1-μm thick PZT films prepared by metal organic chemical vapor deposition (MOCVD) was investigated
Summary
Top and bottom electrodes have a strong effect on the ferroelectric properties of a material. The bottom electrode plays a critical role in determining the texture and quality of ferroelectric films, which are closely related to the remnant polarization (Pr). For electrode materials based on PZT thin films in ferroelectric random access memory (FeRAMs), various materials such as platinum (Pt) [1], strontium oxide (SrO) [2], ruthenium [Ru] [3, 4], ruthenium oxide (RuO2) [5], Iridium (Ir) [6], and Iridium oxide (IrO2) [7] have been studied. Pt thin films are widely used as bottom electrodes for PZT capacitors due to the low electrical resistivity, large work function, high melting point, high stability in high temperature oxidizing atmospheres and high catalytic activity of Pt [1]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
