Sharp Kabushiki Kaisha Corporation

Hironori Matsunaga

Takeshi Kijima

Masayoshi Koba

Sakiko Satoh

Maho Ushikubo

Hirotaka Ohno

Yasunari Okamoto

Kenji Nakanishi

Noboru Ohtani

Yasuyuki Ito

Yoshiyuki Masuda

Seiichi Yokoyama

Yoshiharu Nakajima

Akira Okutoh

A ferroelectric thin film coated substrate is obtained by a producing method of forming a metal oxide buffer layer on a substrate, forming a first crystalline ferroelectric thin film thereon by means of a MOCVD method and forming a second ferroelectric thin film with a film thickness thicker than that of the first ferroelectric thin film thereon by means of the MOCVD method at a temperature lower than that of the first ferroelectric thin film. This producing method makes it possible to produce a ferroelectric thin film, where its surface is dense and even, a leakage current properties are excellent and sufficiently large remanent spontaneous polarization is shown, at a lower temperature.

Ferroelectric thin film coated substrate, producing method thereof and capacitor structure element using thereof

A bismuth silicate film (insulating film),of Bi,SiO,oriented predominantly in the direction of (,) is formed on a Si substrate,and a ferroelectric thin film,is formed on the bismuth silicate film,to create an MFIS structure having a c-axis-oriented ferroelectric thin film,formed with good reproducibility. A highly reliable thin film device is produced by applying the MFIS structure to a FET.

Insulating material, substrate covered with an insulating film, method of producing the same, and thin-film device

A ferroelectric thin film coated substrate is obtained by a producing method of forming a crystalline thin film on a substrate by means of a MOCVD method at a substrate temperature at which crystal grows and of forming a ferroelectric thin film on the crystalline thin film by means of the MOCVD method at a film forming temperature, which is lower than the film forming temperature of the crystalline thin film. This producing method makes it possible to produce a ferroelectric thin film, where a surface of the thin film is dense and even, leakage current properties are excellent and sufficiently large remanent spontaneous polarization is shown, at a lower temperature.

Method of producing a ferroelectric thin film coated substrate

A ferroelectric thin film includes: a bismuth oxide polycrystal thin film constituting a buffer layer, and a bismuth-based layered compound thin film represented by the formula: Bi,A,BmO,wherein A is an atom selected from the group consisting of Na, K, Pb, Ca, Sr, Ba and Bi; B is an atom selected from the group consisting of Fe, Ti, Nb, Ta, W and Mo; and m is an integer of 1 or more. The bismuth oxide polycrystal thin film and the bismuth-based layered compound thin film are formed into a single-phase.

Ferroelectric thin film, manufacturing method thereof and device incorporating the same

A ferroelectric thin film includes a ferroelectric crystal containing Bi, Ti and O as constituent elements, wherein the composition ratio of Bi/Ti in the ferroelectric thin film is shifted from a stoichiometric composition. Also, a substrate provided with a ferroelectric thin film, a device having a capacitor structure used for a ferroelectric memory device, a pyroelectric sensor device, a piezoelectric device or the like, and a method for manufacturing a ferroelectric thin film are disclosed.

Ferroelectric thin film, substrate provided with ferroelectric thin

A method for manufacturing a ferroelectric thin film having a layered perovskite crystal structure of the general formula: Bi.sub.2 A.sub.m-1 B.sub.m O.sub.3m+3, wherein A is selected from the group consisting of Na.sup.1+, K.sup.1+, Pb.sup.2+, Ca.sup.2+, Sr.sup.2+, Ba.sup.2+ and Bi.sup.3+, B is selected from the group consisting of Fe.sup.3+, Ti.sup.4+, Nb.sup.5+, Ta.sup.5+, W.sup.6+ and Mo.sup.6+, and m represents an integer of 1 or larger, which comprises introducing into a film formation chamber where a substrate is set, gaseous starting materials inclusive of oxygen gas for forming the ferroelectric thin film in which the flow rate of oxygen gas as one component of the gaseous starting materials is controlled to an arbitrary value necessary for the formation of the ferroelectric thin film having a desired orientation while the pressure inside the film formation chamber and the total flow rate of the gaseous starting materials and an optionally introduced carrier gas are maintained constant.

Method for manufacturing ferroelectric thin film, substrate covered with

A method for producing a ferroelectric element having a lower electrode layer, a ferroelectric film and an upper electrode layer provided in sequence on the substrate is disclosed. The method comprising the step of applying a metal-contained precursor solution to the surface of the lower electrode layer formed on the substrate, the step of drying the applied precursor solution to remove the solution alone by heating it, a first heat treatment step for heating the dried precursor to form a ferroelectric film, and a second heat treatment step for heating the formed film element in a gas-pressurized atmosphere of lower than 1 atmosphere after forming an upper electrode layer on the ferroelectric film.

Method for producing ferroelectric film element, and ferroelectric film

A ferroelectrics thin-film coated substrate is manufactured in a low-temperature process by using a ferroelectrics having a dense and even surface and exhibiting a large residual spontaneous polarization. A ferroelectrics thin-film coated substrate has a structure with a buffer layer, a growth layer allowing a ferroelectrics thin-film to grow, and a ferroelectrics thin-film made of a ferroelectric material having a layered crystalline structure expressed in the chemical formula Bi.sub.2 A.sub.m-1 B.sub.m O.sub.3m+3 (A is selected from Na.sup.1+, K.sup.1+, Pb.sup.2+, Ca.sup.2+, Sr.sup.2+, Ba.sup.2+, Bi.sup.3+ and the like, B is selected from Fe.sup.3+, Ti.sup.4+, Nb.sup.5+, Ta.sup.5+, W.sup.6+ and Mo.sup.6+, and m is an integer not less than 1) formed in succession.

Ferroelectrics thin-film coated substrate and manufacture method thereof

A close a-axis orientating film having a smooth surface and excellent ferroelectric characteristics is manufactured at a low temperature with preferable reproducibility to apply ferroelectric Bi.sub.4 Ti.sub.3 O.sub.12 to development of various kinds of devices such as a ferroelectric non-volatile memory, a pyroelectric sensor, etc. A ferroelectric Bi.sub.4 Ti.sub.3 O.sub.12 thin film is formed on a substrate through a titanium oxide buffer layer so that closeness and surface smoothness of the Bi.sub.4 Ti.sub.3 O.sub.12 thin film manufactured on the titanium oxide buffer layer can be improved.

Ferroelectric thin film, ferroelectric thin film covering substrate and

Ferroelectric thin film coated substrate, producing method thereof and

The present invention provides a substrate providing a ferroelectric crystal thin film which includes an electrode formed on a semiconductor single crystal substrate and a ferroelectric crystal thin film of Bi.sub.4 Ti.sub.3 O.sub.12 formed on the electrode through the intermediary of a buffer layer.

Ferroelectric thin film with intermediate buffer layer

A method for evaluating a lithium niobate thin film includes measuring an absorption edge wavelength of a lithium niobate thin film and evaluating a lithium-to-niobium composition ratio of the thin film, and an apparatus for preparing a thin film including a thin film-forming body capable of controlling the lithium-to-niobium composition ratio of a lithium niobate thin film being formed and an evaluation device for evaluating the lithium-to-niobium composition ratio, the evaluation device being provided with a monitor substrate, an optical path for spectrometry, an ultraviolet ray source and a measurement part for measuring an absorption edge wavelength of the thin film.

Method for evaluating a lithium niobate thin film and apparatus for

A method of producing a ferroelectric thin film comprising the steps of evaporating metal Li or an oxide thereof as a Li source, metal Nb or an oxide thereof as a Nb source and metal Ta or an oxide thereof as a Ta source in a substantially oxygen gas plasma atmosphere while controlling the respective heating temperatures independently from each other and simultaneously depositing the Li, Nb and Ta on a substrate so as to obtain an LiNb.sub.1-x Ta.sub.x O.sub.3 (0&lt;x&lt;1) thin film which shows ferroelectricity.

Growing community of inventors

Noda, Japan

Hironori Matsunaga