2005 年 26 巻 4 号 p. 220-225
Ferroelectrics has generated considerable interest as promising storage media. In this paper, an investigation of ultrahigh-density ferroelectric data storage based on scanning nonlinear dielectric microscopy (SNDM) was carried out. For the purpose of obtaining fundamental knowledge of high-density ferroelectric data storage, several experiments on nanodomain formation in lithium tantalate (LiTaO3) single crystal were conducted. As a result, a very small inverted domain with a radius of 6 nm was successfully formed in stoichiometric LiTaO3 (SLT), and in addition, a domain dot array with an areal density of 1.5 Tbit/inch2 was formed on congruent LiTaO3 (CLT). Moreover, it was found that fast nanosecond domain switching could be achieved by reducing the sample thickness of CLT plate. Additionally, the first prototype high-density ferroelectric data storage system was developed. Using this system, writing data transfer rates were evaluated and 256×256 bit data were recorded with the areal densities of 258 Gbit/inch2 and 717 Gbit/inch2.