Retention and Read Endurance Characteristics of a Ferroelectric Gate Field Effect Transistor Memory with an Intermediate Electrode

Abstract

Fundamental characteristics such as retention and read endurance of a ferroelectric gate field effect transistor (F-FET) memory with an intermediate electrode were investigated and reported. It was verified that the retention time of the new F-FET was longer than 98 h. By taking into account the leakage currents of both the ferroelectric capacitor C f and the MOSFET used for data writing (W-FET), we found that, for positive reading voltage, the leakage currents of the ferroelectric capacitor and the W-FET are unfavorable for the P r + state and the P r - state, respectively, in terms of read endurance. The overall read endurance is determined by a competition between the leakage currents of the C f and the W-FET. The drain-connected configuration (DCC) was effective to minimize the unexpected influence of the leakage current of the W-FET.

Disturb-Free Writing Operation for Ferroelectric-Gate Field-Effect Transistor Memories With Intermediate Electrodes

“…Although considerable researches on F-FET memories have been carried out [4]- [7], F-FET memories have not been commercialized because of problems such as short retention time [8], [9] and high writing voltage [10], [11]. To overcome these problems, we have proposed a new F-FET memory (denoted as IF-FET memory), in which an intermediate electrode (IE) for data writing is inserted between the ferroelectric capacitor C f and the buffer layer (the gate) of a reading MOSFET (R-MOSFET) [13]- [15]. For data writing, using the IE, a writing voltage Manuscript received January 27, 2009; revised September 4, 2009.…”

Operation of Ferroelectric Gate Field-Effect Transistor Memory with Intermediate Electrode using Polycrystalline Capacitor and Metal–Oxide–Semiconductor Field-Effect Transistor

“…Previously, we showed the basic memory operation, its analysis, and the effect of leakage current on the nondestructive reading, using an epitaxial PZT film grown on an epitaxial Ir/ epitaxial (Y 2 O 3 ) 1Àx ZrO 2 (YSZ)/Si substrate. [12][13][14] Although the epitaxial PZT film has excellent ferroelectric properties, it is unsuitable for commercial products, because the epitaxial growth technique is complicated and requires high cost for mass production. Therefore, we have fabricated IF- FET memories, using polycrystalline Pb(Zr 0:52 Ti 0:48 )O 3 (poly-PZT) films deposited on Pt/RuO 2 /SiO 2 /Si substrates.…”