Study on Mechanism of Domain Inversion in LiNbO₃ and LiTaO₃ and Its Application of Memory -nm Size Domain Inversion by EB Irradiation-

Abstract

The ferroelectric large capacity memory that made direction of the spontaneous polarization of domain inversion correspond to binary values of a memory can be considered as one of the new devices adapting domain inversion technology. This paper describes the feature of LiNbO₃ (LN) and LiTaO₃ (LT) crystals investigated mainly for the purpose of memory application, the mechanism of domain inversion control, and its applicability in large capacity memory. LT crystal is considered to be a suitable material for nm-size polarization control memory, and this paper describes that the electron beam polarization controlling method is one of the methods effective for nm-size polarization control. Specifically, if thin LT crystal layer with a thickness of 1 μm can be formed, very small polarization structure with a diameter of less than 3 nm could be realizable. If polarization control of 1 dot is carried out into 10 nm × 10 nm region, a super-large capacity memory with a density of 1 T bit/cm² may be realized.