Sharp Kabushiki Kaisha Corporation

Sakiko Satoh

Masayoshi Koba

Hironori Matsunaga

Takeshi Kijima

Kenji Nakanishi

Noboru Ohtani

Yoshiyuki Masuda

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 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 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.

Growing community of inventors

Yachiyo, Japan

Sakiko Satoh