This study is aimed at clarifying the mechanism of wear process for Ag plating. The samples of different hardness Ag plating on copper alloys were prepared as coupon and embossment specimens, which simulated terminal contacts. During the sliding test, the contact resistance and the friction coefficient versus sliding distance are measured. The surface observation and surface roughness of the Ag films after wear tests were investigated. As results, the hard Ag plating film (120 Hv) exhibited higher contact resistance comparing to the soft Ag plating film (80 Hv). The soft Ag film delivered wider wear trace on coupon specimens compared to the hard one. Moreover, the observation of tribofilms formed on the Ag films after wear tests suggested that a mixed-type of adhesive and abrasive wears occurred for both of soft and hard Ag films. Furthermore, the fretting corrosion resistance of Ag plating samples with different hardness was also investigated. As results, the wear resistance of hard Ag film was stronger than that of soft Ag film.

A 1T2C-type ferroelectric memory cell, in which two ferroelectric capacitors with the same area are connected to the gate of an usual MOSFET with a SiO2/Si interface, was fabricated and characterized. The relations between various device parameters and characteristics of memory cell were investigated by using SPICE simulation. It was found from the simulation results that the memory window significantly changed by the device parameters, which means that the operation voltage of the memory cell can be well controlled by these parameters. The fabricated cell is composed of a stacked gate structure of Pt/SBT/Pt/Ti/SiO2/Si with the area ratio of the MOS capacitor (SO) to the ferroelectric capacitor (SF) of 6 or 10. Nonvolatile memory operation was confirmed, and the obtained memory window coincided with the simulated results qualitatively. Furthermore, the current on/off ratio in the read-out operation was larger than 3-order-of magnitude and the data retention time was longer than 6 104 seconds. It was also predicted that low voltage operation was possible if the device parameters were optimized.