Mitsubishi Materials Corporation

Toshihiro Doi

Nobuyuki Soyama

Hideaki Sakurai

Toshiaki Watanabe

Takashi Noguchi

Kenzo Nakamura

Kazunori Igarashi

A piezoelectric PTZT film is formed of a metal oxide having a perovskite structure including Pb, Ta, Zr, and Ti, in which the metal oxide further includes carbon, and a content of the carbon is 80 to 800 ppm by mass. In a process for producing a liquid composition for forming a piezoelectric film, a Ta alkoxide, a Zr alkoxide, &#x3b2;-diketones, and a diol are refluxed, a Ti alkoxide is added into a first synthesis solution obtained by the refluxing, and then refluxing is performed again, a Pb compound is added into a second synthesis solution obtained by performing the additional refluxing, and then refluxing is performed again, a solvent is removed from a third synthesis solution obtained by performing the additional refluxing, and then, dilution with alcohol is performed, to produce the liquid composition for forming a piezoelectric PTZT film.

Piezoelectric PTZT film, and process for producing liquid composition for forming said piezoelectric film

A composition for forming a Ce-doped PZT-based piezoelectric film contains: PZT-based precursors containing metal atoms configuring the composite metal oxides; a diol; and polyvinylpyrrolidone. The PZT-based precursors are contained so that a metal atom ratio (Pb:Ce:Zr:Ti) in the composition satisfies (1.00 to 1.28):(0.005 to 0.05):(0.40 to 0.55):(0.60 to 0.45) and the total of Zr and Ti in a metal atom ratio is 1. A concentration of the PZT-based precursor in 100 mass % of the composition is from 17 mass % to 35 mass % in terms of an oxide concentration, a rate of diol in 100 mass % of the composition is from 16 mass % to 56 mass %, and a molar ratio of polyvinylpyrrolidone to 1 mole of the PZT-based precursor is 0.01 moles to 0.25 moles in terms of monomers.

Composition for forming Ce-doped PZT-based piezoelectric film

A composition for forming a PZT-based piezoelectric film formed of Mn-doped composite metal oxides is provided, the composition including: PZT-based precursors containing metal atoms configuring the composite metal oxides; a diol; and polyvinylpyrrolidone, in which when a metal atom ratio in the composition is shown as Pb:Mn:Zr:Ti, the PZT-based precursors are contained so that a metal atom ratio of Pb is satisfied to be from 1.00 to 1.20, a metal atom ratio of Mn is satisfied to be equal to or greater than 0.002 and less than 0.05, a metal atom ratio of Zr is satisfied to be from 0.40 to 0.55, a metal atom ratio of Ti is satisfied to be from 0.45 to 0.60, and the total of Zr and Ti in a metal atom ratio is 1.

Composition for forming Mn-doped PZT-based piezoelectric film and Mn-doped PZT-based piezoelectric film

A composition used for forming a PZT-based piezoelectric film formed of Mn and Nb co-doped composite metal oxides is provided, in which the composition includes PZT-based precursors so that a metal atom ratio (Pb:Mn:Nb:Zr:Ti) in the composition satisfies (1.00 to 1.25):(0.002 to 0.056):(0.002 to 0.056):(0.40 to 0.60):(0.40 to 0.60), a rate of Mn is from 0.20 to 0.80 when the total of metal atom rates of Mn and Nb is 1, a rate of Zr is from 0.40 to 0.60 when the total of metal atom rates of Zr and Ti is 1, and the total rate of Zr and Ti is from 0.9300 to 0.9902 when the total of metal atom rates of Mn, Nb, Zr, and Ti is 1.

Composition for forming Mn and Nb co-doped PZT-based piezoelectric film

A method includes: coating a composition for forming a PZT ferroelectric film not containing Nb on a lower electrodeformed on a substrate, prebaking the composition, and baking the composition to be crystallized and to thereby form a crystallization promoting layerhaving a thickness 45 to 90 nm thereon; coating a composition for forming a PNbZT-based ferroelectric film, containing 4 to 10 at % of Nb in 100 at % of all the perovskite B site atoms (Zr, Ti) contained in the composition, on the formed crystallization promoting layerto form a coating filmof PNbZT thereon; and pre-baking the coating filmand then baking the coating filmto be crystallized and to thereby form a PNbZT ferroelectric thin film on the lower electrode

Method of forming PNbZT ferroelectric thin film

A composition containing a precursor of a ferroelectric thin film, a solvent, and a reaction control substance, can form a ferroelectric thin film by temporary firing and permanent firing of a coating film. The composition contains the reaction control substance in such an amount that a Young's modulus of a film formed in a step of temporary firing at a temperature of 200&#xb0; C. to 300&#xb0; C. becomes equal to or less than 42 GPa, and a Young's modulus of a film formed in a step of permanent firing at a temperature of 400&#xb0; C. to 500&#xb0; C. becomes equal to or greater than 55 GPa. Thus a thin film having high crystallinity can be formed which substantially does not crack at the time of permanent firing even if the thickness of the coating film formed per single coating operation is increased.

Composition for forming ferroelectric thin film, and method for manufacturing same

A residual stress in a PZT type ferroelectric filmformed on a substrate bodyby a sol-gel process is &#x2212;14 MPa to &#x2212;31 MPa, and the ferroelectric filmis crystal oriented in a (100) plane.

Silicon substrate having ferroelectric film attached thereto

This ferroelectric thin film-forming sol-gel solution contains: a PZT-based compound; a high-molecular compound used to adjust the viscosity containing polyvinyl pyrrolidone; and an organic dopant containing N-methyl pyrrolidone, in which the amount of the PZT-based compound is greater than or equal to 17 mass % in terms of oxides, the molar ratio (PZT-based compound:polyvinyl pyrrolidone) of the polyvinyl pyrrolidone to the PZT-based compound is 1:0.1 to 1:0.5 in terms of monomers, and the amount of the organic dopant containing N-methyl pyrrolidone in the sol-gel solution is 3 mass % to 13 mass %.

Ferroelectric thin film-forming sol-gel solution

A PZT-based ferroelectric thin film is formed by coating a PZT-based ferroelectric thin film-forming composition on a lower electrode of a substrate one or two or more times, pre-baking the composition, and baking the composition to be crystallized, and this thin film includes PZT-based particles having an average particle size in a range of 500 nm to 3000 nm when measured on a surface of the thin film, in which heterogeneous fine particles having an average particle size of 20 nm or less, which are different from the PZT-based particles, are precipitated on a part or all of the grain boundaries on the surface of the thin film.

PZT-based ferroelectric thin film and method of forming the same

To provide a ferrite thin film-forming composition material that is a composition material for forming a ferrite thin film by using the sol-gel method which can form a thin ferrite thin film having a uniform thickness and, furthermore, has excellent long-term storage stability, a method of forming a ferrite thin film using the above composition material, and a ferrite thin film formed by using the above method. A ferrite thin film-forming composition material is a composition material for forming a NiZn ferrite, CuZn ferrite, or NiCuZn ferrite thin film by using a sol-gel method, in which the composition material is formed by dissolving metallic raw materials in a solvent including acetonitrile, and the fraction of acetonitrile is 30 mass % to 60 mass % with respect to 100 mass % of the composition material.

Ferrite thin film-forming composition material, method of forming ferrite thin film, and ferrite thin film formed using the same

A method of preparing a ferroelectric thin film-forming composition, specifically, a method of preparing a PZT thin film-forming composition includes: a step of allowing composition precursor raw materials, which contain PZT precursor substances at a concentration of 23 to 38 mass % in terms of oxides in 100 mass % of the composition precursor raw materials, and a high-molecular compound to react with each other to obtain a PZT thin film-forming composition precursor; and a step of aging the PZT thin film-forming composition precursor at a temperature of 0 to 10&#xb0; C. for at least 30 days.

Method of producing ferroelectric thin film-forming composition and application of the same

When a ferroelectric thin film-forming sol-gel solution contains a PZT-based compound, a viscosity-adjusting macromolecular compound including polyvinylpyrrolidone, and an organic dopant including a formamide-based solvent, the PZT-based compound is included at 17 mass % or more in terms of an oxide, the molar ratio of the polyvinylpyrrolidone to the PZT-based compound is PZT-based compound:polyvinylpyrrolidone=1:0.1 to 0.5 in terms of a monomer, and the formamide-based solvent is included at 3 mass % to 13 mass % of the sol-gel solution, it is possible to form a thick layer by coating the sol-gel solution once, the production efficiency improves, and crack-free and dense film formation even after calcination and firing becomes possible.

A PZT-based ferroelectric thin film formed on a lower electrode of a substrate having the lower electrode in which the crystal plane is oriented in a (111) axis direction, having an orientation controlling layer which is formed on the lower electrode and has a layer thickness in which a crystal orientation is controlled in a (111) plane preferentially in a range of 45 nm to 270 nm, and a film thickness adjusting layer which is formed on the orientation controlling layer and has the same crystal orientation as the crystal orientation of the orientation controlling layer, in which an interface is formed between the orientation controlling layer and the film thickness adjusting layer.

PZT-based ferroelectric thin film and method of manufacturing the same

A method for producing a ferroelectric thin film comprising: coating a composition for forming a ferroelectric thin film on a base electrode of a substrate having a substrate body and the base electrode that has crystal faces oriented in the (111) direction, calcining the coated composition, and subsequently performing firing the coated composition to crystallize the coated composition, and thereby forming a ferroelectric thin film on the base electrode, wherein the method includes formation of an orientation controlling layer by coating the composition on the base electrode, calcining the coated composition, and firing the coated composition, where an amount of the composition coated on the base electrode is controlled such that a thickness of the orientation controlling layer after crystallization is in a range of 35 nm to 150 nm, and thereby controlling the preferential crystal orientation of the orientation controlling layer in the (100) plane.

Method for producing ferroelectric thin film

A method for producing a ferroelectric thin film comprising: coating a composition for forming a ferroelectric thin film on a base electrode of a substrate having a substrate body and the base electrode that has crystal daces oriented in the (111) direction, calcining the coated composition, and subsequently performing firing the coated composition to crystallize the coated composition, and thereby forming a ferroelectric thin film on the base electrode, wherein the method includes formation of an orientation controlling layer by coating the composition on the base electrode, calcining the coated composition, and firing the coated composition, where an amount of the composition coated on the base electrode is controlled such that a thickness of the orientation controlling layer after crystallization is in a range of 5 nm to 30 nm, and thereby controlling the preferential crystal orientation of the orientation controlling layer to be in the (110) plane.

Growing community of inventors

Naka-gun, Japan

Toshihiro Doi