Fabrication and Study on One-Transistor-Capacitor Structure of Nonvolatile Random Access Memory TFT Devices Using Ferroelectric Gated Oxide Film

Abstract

Recently, non-volatile and volatile memory devices such as static random access memory (SRAM), dynamic random access memory (DRAM), Flash memory, EPROM and E2PROM were very important for applications in conventional personal computer and microprocessor, and performance efficiency of hardware improved by their low voltage, high operation speed, and large storage capacity. The non-volatile memory devices were widely investigated and discussed among these memory devices. Many kind of the non-volatile memory device were ferroelectric random access memory (FeRAM), magnetron random access memory (MRAM), and resist random access memory (RRAM) devices. Up to now, the non-volatile ferroelectric random access memory (FeRAM) devices were attractive because of their low coercive filed, large remnant polarization, and high operation speed among various non-volatile access random memory devices [1]. The non-volatile FeRAM devices were limited by their relative larger one-transistor-onecapacitor (1T-1C) size. Thus, one-transistor-capacitor (1TC) structure ferroelectric memory was desirable because of the better sensitivity and small size than 1T-1C structure ferroelectric memory [2-4]. The operation characteristics and reliability of ferroelectric capacitor structure of 1T-1C memory cell were spending lots cost during the fabrication process. In addition, electronic devices and system-on-panel (SOP) technology were widely discussed and researched. For SOP concept, the switch characteristics of various thin-film transistor (TFT) structures were widely investigated for applications in amorphous silicon (α-Si) and polycrystal silicon (poly-Si) active matrix liquid-crystal-display (AM-LCD) displays [5-7]. Integrated electron devices such as memory devices, control devices, and central processing units (CPU) on transparent conductive thin films will be important in the future. The excellent electrical, physical, and reliability characteristics of metal-ferroelectricmetal (MFM) capacitor structures for 1T1C memory cells were enhanced using transparent conductive thin films on glass substrates.