40results about How to "Good ferroelectric properties" patented technology

There is provided a semiconductor device having a ferroelectric capacitor formed on a semiconductor substrate covered with an insulator film, wherein the ferroelectric capacitor comprises: a bottom electrode formed on the insulator film; a ferroelectric film formed on the bottom electrode; and a top electrode formed on the ferroelectric film. The ferroelectric film has a stacked structure of either of two-layer-ferroelectric film or three-layer-ferroelectric film. The upper ferroelectric film is metallized and prevents hydrogen from diffusing in lower ferroelectric layer. Crystal grains of the stacked ferroelectric films are preferably different.

A method is disclosed for fabricating a semiconductor device having a memory employing a ferroelectric capacitor in which the orientation of the ferroelectric film is controlled. The method for fabricating the semiconductor device includes a first film deposition process for forming a first ferroelectric layer, and a second film deposition process for forming a second ferroelectric layer on the first ferroelectric layer. The film deposition temperature of the first film deposition process is set to at least 600° C.

A method for fabricating a ferroelectric capacitive element of this invention includes the steps of forming a lower electrode made of a first conductive film on a substrate; forming a first ferroelectric film including bismuth in a first concentration on the lower electrode; forming a second ferroelectric film including bismuth in a second concentration on the first ferroelectric film; performing annealing after forming the first ferroelectric film and the second ferroelectric film; and forming an upper electrode made of a second conductive film on the second ferroelectric film after the annealing. The first conductive film is a metal film more easily etched than a platinum film, and the second ferroelectric film is formed in such a manner that the second concentration is lower than the first concentration before the annealing.

A method for manufacturing a ferroelectric capacitor, includes the steps of: forming a ferroelectric capacitor layer having a lower electrode layer, a ferroelectric layer and an upper electrode layer on a base substrate; forming a titanium oxide layer on the ferroelectric capacitor layer; patterning the titanium oxide layer by high-temperature etching between 200° C. and 500° C. to thereby form a mask pattern; and etching the ferroelectric capacitor layer by using the mask pattern as a mask, to thereby form a ferroelectric capacitor having a lower electrode, a ferroelectric film and an upper electrode.

The invention discloses an anhydrous zinc tartrate ferroelectric function material, the molecular formula of which is Zn(C4H4O6), and the ferroelectric function material can pass through white powder with purity of no less than 99 percent of 100 meshes, the heat quantitative temperature of the white powder is 350 DEG C, parameters of the ferroelectric properties of the ferroelectric function material is respectively as follows: Ps=0.43 mu C.cm<-2>, 2Pr=0.73 mu C.cm<-2>, 2Ec=0.47 kV.cm<-1>; thereby, the anhydrous zinc tartrate ferroelectric function material has better ferroelectric properties and thermal stability; the invention also discloses a preparation method of the ferroelectric function material, which can realize the nucleus formation and growth processes of the prophase product of the anhydrous zinc tartrate through controlling the concentration and proportion of the materials, the adding speed of the reactants, the stirring time, the temperature of the reaction system, pH control of the solution and the like, in addition, dehydration treatment is then carried out, and anhydrous zinc tartrate ferroelectric power with higher purity and good performance can be obtained.

The invention provides a method for manufacturing a PNbZT ferroelectric thin film and a composite electronic component. In this method, a composition for forming a Nb-free PZT ferroelectric thin film is coated on a lower electrode (11) formed on a substrate (10), pre-sintered, and fired to crystallize it, thereby A crystallization promoting layer (12) with a thickness of 45 to 90 nm is formed, and a composition for forming a PNbZT ferroelectric thin film is coated on the crystallization promoting layer (12) formed above to form a coating film (13a) of PNbZT. After the coating film (13a) is pre-sintered, it is fired to crystallize it, thereby forming a PNbZT ferroelectric thin film on the above-mentioned lower electrode (11), wherein, in the PNbZT ferroelectric thin film, the 4-10 atomic % of Nb is contained in the total 100 atomic % of Zr and Ti contained perovskite B-site atoms.

The invention discloses a hydrated L-tartaric acid neodymium sulfate ferroelectric functional material and a preparation method thereof. The ferroelectric functional material has a molecular formula of {Nd2(H2O)2(L-C4H4O6)2(SO4)}.4H2O. The ferroelectric functional material has the following ferroelectric characteristic parameters: the remanent polarization 2Pr is 0.390 mu C / cm<2>; the coercive electric field 2Ec is 74.7 kv / cm; and the saturation polarization Ps is 0.307 mu C / cm<2>. The saturation polarization of the ferroelectric functional material is 1.23 times that of seignette salt, so that the ferroelectric functional material disclosed by the invention is a novel ferroelectric body with excellent ferroelectric performance. The preparation method comprises the following steps: carrying out a solvothermal reaction between neodymium oxide and L-tartaric acid by using an ethanol solvent; and adding a sulfuric acid solution into the mixture and nucleating in a reaction kettle so as to grow into the hydrated L-tartaric acid neodymium sulfate. The preparation method has the advantages of short flow, simple process, low equipment requirement, no pollution and low cost and can be easily industrialized.

The invention discloses an o-phenanthroline m-hydroxybenzoic acid copper ferroelectric function material and a preparation method thereof. The molecular formula of the o-phenanthroline m-hydroxybenzoic acid copper ferroelectric function material is Cu2(C12H8N2)2Cl2(C7H5O3)2. The ferroelectric function material is dark blue powder with the purity being not less than 99% and has a C2v point group structure. The ferroelectric characteristic parameters are respectively as follows: the remanent polarization 2Pr equals to 0.08muC*cm<-2>, the coercive electric field 2Ec equals to 5.03kv*cm<-1>; and the saturated polarization Ps equals to 0.195muC*cm<-2>. The ferroelectric function material has good ferroelectric characteristics. According to the ferroelectric function material, m-hydroxybenzoic acid solution and copper chloride solution are stirred for reacting, and then o-phenanthroline solution is added to realize nucleation and growth of o-phenanthroline m-hydroxybenzoic acid copper. The o-phenanthroline m-hydroxybenzoic acid copper ferroelectric function material is simple and practicable in process, low in facility request, low in raw material cost, high in productivity, less in pollution and the like.

The invention discloses a hydrate D-cerous tartrate ferroelectric functional material and a preparation method thereof. The ferroelectric functional material has a molecular formula of [Ce2(H2O)]3(D-C4HO6)3].3H2O, is triclinic white powder with the purity of not lower than 99% and is a C1 polar point group structure; the ferroelectric characteristic parameters are as follows: the remanent polarization 2Pr=0.019 micro C.cm<-2>, the coercive electric field 2Ec=1.139kv.cm<-2>, and the saturated polarization intensity Ps=0.233 micro C.cm<-2>; the powder lattice parameters are shown in the specification; the polarizability value of the ferroelectric functional material is similar to that of a common ferroelectric rochelle salt; and the ferroelectric functional material has excellent ferroelectric characteristics. The preparation method has the advantages of less flow, simplicity in process, low requirement on equipment, no pollution, low cost and easiness for industrialization.