Patent ID: 8669121

Claim:
A method for forming a ferroelectric spontaneous polarization reversal in a desired region of a ferroelectric substrate, comprising the steps of forming, for said desired region of a surface of the ferroelectric substrate, an electrode pattern or a mask pattern composed of aggregates of micropatterns having a width of less than 10 μm, generating many nucleuses corresponding to said micropatterns by applying a voltage using the electrode pattern or the mask pattern, forming another electrode pattern or another mask pattern composed of patterns having a width of more than 20 μm corresponding to said desired region, and then applying a homogeneous voltage all over said desired region to form ferroelectric spontaneous polarization reversal regions around the nucleuses, so that said ferroelectric spontaneous polarization reversal regions around said many nucleuses merge and become a homogeneous ferroelectric spontaneous polarization reversal region which corresponds to said another electrode pattern or said another mask pattern.