FERROELECTRIC MEMORY DEVICE AND MANUFACTURING METHOD THEREOF

摘要

A memory device (700) for storing data includes at least one memory cell wherein the memory cell includes at least one ferroelectric element for storing data by means of one or more polarization directions of ferroelectric element. The ferroelectric element is fabricated from a ferroelectric material having a plurality of co-existing phases. The ferroelectric element may be fabricated from Lead Zirconate Titanate material and which corresponds to a morphotropic phase boundary composition. The Lead Zirconate Titanate material may also have a composition Pb(ZrxTi1-x)03, wherein the parameter x is in a range of 0.52 to 0.56. This range corresponds to a morphotropic phase boundary composition (MPB) which includes equal amounts of rhombohedral (space group R3c) and monoclinic (space group Cm_ phases. The monoclinic phase is a beneficially distorted version of the tetragonal phase, which can be considered as being metrically close to a tetragonal structure. The ferroelectric element or elements are provided with an electrode arrangement which enables the ferroelectric element to store a plurality of bits of data. A substrate 700 may be fabricated to include Gd3Ga5O12 (GDO) or SrZrO3.