Patent ID: 6597492
Filing Date: 2003-07-22
Classification: C30B,G02F

Abstract:
A method of fabricating an invertedly poled domain structure having alternating sections of opposite electric polarities, from a ferroelectric crystal wafer having two opposite polar surfaces, the method comprising:(a) patterning at least one of said two polar surfaces of the wafer to comprise a plurality of alternating discrete regions, of which first regions are adapted for, and second regions are protected from, the direct application thereto of an electric contact; (b) applying to both polar surfaces of the wafer electrically conducting electrodes so that the first regions are in direct contact with the electrodes and the second regions are protected from such a contact; (c) applying to the electrodes a switching electrical field of the intensity E which satisfies the condition Ebr>E&gE;Ec, Ec being the coercive field of the ferroelectric crystal and Ebr being the breakdown field of the ferroelectric crystal; wherein said switching electrical field is applied to the wafer at a working temperature Tw which satisfies the condition Tminwx, where the temperature Tmin is the minimal temperature at which the intensity E of the switching electric field still satisfies the condition Ebr>E&gE;Ec and where Tx is the temperature at which a dielectric response time &tgr;res equals a switching time &tgr;sw of the ferroelectric crystal at the chosen intensity E of the electric field; and wherein a time interval &tgr;dur during which the switching electric field is applied to the ferroelectric crystal wafer, meets the condition (1:3)&tgr;sw&lE;&tgr;dur&lE;(0.1:3)&tgr;res.