The invention discloses a coating solution for use in forming Bi-based ferroelectric thin films containing Bi, metallic element A (at least one selected from the group consisting of Bi. Pb, Ba, Sr, Ca, Na, K and rare earth elements) and metallic element B (at least one selected from the group consisting of Ti, Nb, Ta, W, Mo, Fe, Co and Cr), wherein it contains metal alkoxides of Bi, metallic element A and metallic element B respectively, and contains composite metal alkoxides formed by any two or more of said metal alkoxides; and a ferroelectric thin film, a ferroelectric capacitor and a ferroelectric memory formed by the use of such coating solution, and a method for producing the same.
A non-volatile memory cell wherein the capacitor comprises a Bi-based metal oxide having a crystallographic texture to produce high switchable polarization.
The invention provides a method for forming a ferroelectric thin film that is uniform and good in crystallinity. The method includes applying a liquid to a surface of a substrate. The liquid includes ultra-fine particle powder comprising at least one element constituting the ferroelectric thin film to a surface of a substrate. The liquid applied to the surface of substrate is then baked.
The invention provides a method for forming a ferroelectric thin film that is uniform and good in crystallinity. The method includes applying a liquid to a surface of a substrate. The liquid includes ultra-fine particle powder comprising at least one element constituting the ferroelectric thin film to a surface of a substrate. The liquid applied to the surface of substrate is then baked.
The invention discloses a coating solution for use in forming Bi-based ferroelectric thin films containing Bi, metallic element A (at least one selected from the group consisting of Bi, Pb, Ba, Sr, Ca, Na, K and rare earth elements) and metallic element B (at least one selected from the group consisting of Ti, Nb, Ta, W, Mo, Fe, Co and Cr), wherein it contains metal alkoxides of Bi, metallic element A and metallic element B respectively, and an organometallic compound obtainable by hydrolyzing composite metal alkoxides, formed by any two or more of said metal alkoxides, with water alone or in combination with a catalyst, and contains Bi in a molar amount 1-1.1 times as great as the stoichiometric amount; a ferroelectric thin film (5), a ferroelectric capacitor (10) and a ferroelectric memory with the use of such a coating solution; and a method for producing the same.
The method of this invention provides a method for manufacturing a capacitor element composed of films. The films have a precise etched shape without a residue that may be generated as a reaction product in a dry-etching process. In this invention, washing in a non-oxidizing atmosphere, inclining a side of a mask for etching or heating a substrate prevents the reaction product from remaining on the film as a residue. The reaction product can be washed away with water, acid or organic solvent in inert gas. The reaction product can be removed from the side of the mask by sputter-etching with ions for dry-etching. The reaction product can be exhausted without adhering to the mask by heating the substrate at a temperature between 100.degree. C. and 400.degree. C.
