Tdk Corporation

Mitsubishi Electric Corporation

Hitoshi Sakuma

Kazuhiko Maejima

Yasuhiro Aida

Katsuyuki Kurachi

Kazushige Kawasaki

Katsuomi Shiozawa

Kyozo Kanamoto

Yoshitomo Tanaka

Toshihiko Shiga

Ryu Ohta

Yuji Abe

Shinji Abe

Toshiyuki Oishi

Kenta Ishii

Mayumi Nakajima

Yasuo Nakajima

Takao Noguchi

Hiroshi Kurokawa

Junichi Horie

Kyosuke Kuramoto

Kyung-Ku Choi

Yasunori Tokuda

Tsutomu Yamaguchi

Yoshiyuki Suehiro

Taku Masai

Masaru Nanao

Tomohisa Azuma

Yuiko Hirose

Masatsugu Kusunoki

Toshiyasu Fujiwara

Hiroshi Chihara

Takafumi Oka

Kazuyuki Onoe

Matobu Kikuchi

Kazumasa Kishimoto

Yoshiyuki Nakashima

The present invention is characterized by comprising: forming a stacked structure in which a lower cladding layer, an active layer and an upper cladding layer are stacked on an InP substrate in a shape having a mesa stripe structure; forming a first insulation film on the stacked structure by a sputtering method; forming a second insulation film thinner than the first insulation film, on the first insulation film by a plasma CVD method at a film forming temperature higher than that when the first insulation film has been formed; and forming a first electrode on the upper cladding layer, and forming a second electrode on a back surface of the InP substrate.

Semiconductor laser device manufacturing method and semiconductor laser device

A semiconductor optical element includes a first cladding layer; a second cladding layer formed in a ridge shape; and optical confinement layer interposed between the first cladding layer and the second cladding layer to propagate light, wherein the second cladding layer is configured with a ridge bottom layer; a ridge intermediate layer; and a ridge top layer in this order from the optical confinement layer, and the ridge intermediate layer is formed wider in cross section perpendicular to the optical axis&#x2014;the light propagating direction in optical confinement layer&#x2014;than the ridge bottom layer and the ridge top layer.

Semiconductor optical element, semiconductor optical integrated element, and method for manufacturing semiconductor optical element

A thin film laminate comprises a metal layer consisting of a metal, and a thin film laminated on the surface of the metal layer, wherein a first direction is defined as one direction parallel to the surface of the metal layer, and a second direction is defined as one direction parallel to the surface of the metal layer and crossing the first direction; and the metal layer contains a plurality of first metal grains consisting of the metal and extending in the first direction on the surface of the metal layer, and a plurality of second metal grains consisting of the metal and extending in the second direction on the surface of the metal layer.

Thin film laminate, thin film device and multilayer substrate

A method for manufacturing an optical semiconductor device having a ridge stripe configuration containing an active layer and current blocking layers which embed both sides of the ridge stripe configuration, comprises steps of forming a mask of an insulating film on a surface of a semiconductor layer containing an active layer, forming a ridge stripe configuration by etching a semiconductor layer using gas containing SiCl, removing an oxide layer with regard to a Si based residue which is attached on a surface which is etched of the ridge stripe configuration which is formed and removing a Si based residue whose oxide layer is removed.

Method for manufacturing optical semiconductor device

A method of manufacturing a dielectric device includes epitaxially growing a metal film on a substrate, forming a dielectric film on the metal film such that the dielectric film has a preferentially oriented structure, forming a first electrode film having a non-oriented or amorphous structure on the dielectric film, removing the substrate and the metal film from the dielectric film or removing the substrate from the metal film, and forming a second electrode film having a non-oriented or amorphous structure on the dielectric film or the metal film.

Method of manufacturing a dielectric device

A piezoelectric thin film-stacked body is provided. A piezoelectric thin film-stacked body has a first electrode layer, a first oxide layer stacked on the first electrode layer, a second oxide layer stacked on the first oxide layer, and a piezoelectric thin film stacked on the second oxide layer, the electrical resistivity of the first oxide layer is higher than the electrical resistivity of the second oxide layer, the first oxide layer includes K, Na, and Nb, and the piezoelectric thin film includes (K,Na)NbO.

Piezoelectric thin film-stacked body, piezoelectric thin film substrate, piezoelectric thin film device, piezoelectric actuator, piezoelectric sensor, head assembly, head stack assembly, hard disk drive, printer head, and ink-jet printer device

A method of manufacturing a semiconductor device, includes a step of forming, on a semiconductor substrate, a mesa stripe including an active layer, and a semiconductor layer covering the mesa stripe, a masking step of forming, on the semiconductor layer, a mask pattern through which the semiconductor layer is exposed on opposite sides of the mesa stripe, an isotropic etching step of performing isotropic etching on the semiconductor layer exposed through the mask pattern so that concaves having a circular-arc sectional shape are formed in the semiconductor layer, and an anisotropic etching step of performing anisotropic etching on the semiconductor layer through the mask pattern after the isotropic etching step so that etching progresses to the semiconductor substrate.

Semiconductor device manufacturing method and semiconductor device

A piezoelectric element exhibiting a small leakage current density and high reliability as compared with a KNN thin film piezoelectric element in the related art is provided. The piezoelectric element is characterized by including a lower electrode, a piezoelectric layer primarily made from potassium-sodium niobate, which is a perovskite type compound represented by a general formula ABO, and an upper electrode, wherein the piezoelectric layer is present between the lower electrode and the upper electrode, and the piezoelectric layer has the value determined by dividing the maximum value of intensity of a diffraction peak, where the angle of 2&#x3b8; is within the range of 21.1&#xb0;&#x2266;2&#x3b8;&#x2266;23.4&#xb0; in the X-ray diffraction pattern (2&#x3b8;/&#x3b8;), by the intensity of a diffraction peak, where 2&#x3b8; is within the range of 30.1&#xb0;&#x2266;2&#x3b8;&#x2266;33.3&#xb0;, of 0.04 or less.

Piezoelectric device, piezoelectric actuator, piezoelectric sensor, hard disk drive, and inkjet printer apparatus

The present invention provides a piezoelectric thin film element having a pair of electrode layers and a piezoelectric thin film sandwiched between the pair of electrode layers, wherein the pair of electrode layers are composed of platinum (Pt), oxide particles are contained in at least one of the electrode layers, and the oxide particles are oxide particles of at least one element constituting the piezoelectric thin film or oxide particles of Pt.

Piezoelectric thin film element, piezoelectric actuator, piezoelectric sensor, hard-disk drive and ink jet printer device

A thin film piezoelectric element according to the present invention includes a potassium sodium niobate thin film having a structure in which a plurality of crystal grains are present in a film thickness direction; and a pair of electrode films sandwiching the potassium sodium niobate thin film. When the potassium sodium niobate thin film is divided into three regions of the same thickness in the film thickness direction and average crystal grain sizes A, A, and Aof the respective regions are determined, a ratio m/M of the smallest average crystal grain size m among A, A, and Ato the largest average crystal grain size M among A, A, and Ais 10% to 80%. The region having the smallest average crystal grain size m lies next to one of the pair of electrode films.

Thin film piezoelectric element, thin film piezoelectric actuator, thin film piezoelectric sensor, hard drive disk, and inkjet printer device

There are provided a thin-film piezoelectric element including a piezoelectric thin film which has an alkali niobate-based perovskite structure represented by the composition formula (KNaSr)(NbZr)Oand which is preferentially oriented to (001), and a pair of electrode films that sandwich the piezoelectric thin film, a thin-film piezoelectric actuator, and a thin-film piezoelectric sensor each including the thin-film piezoelectric element.

Thin-film piezoelectric element, thin-film piezoelectric actuator, thin-film piezoelectric sensor, hard disk drive, and inkjet printer apparatus

An object is to reduce the leakage current of a piezoelectric element including a potassium-sodium niobate thin film, enhance the reliability of the piezoelectric element and, in addition, enhance the withstand voltage by including a pair of electrodes and a piezoelectric layer sandwiched between the above-described pair of electrode layers, wherein the above-described piezoelectric layer is provided with at least one layer each of first piezoelectric layer which is a potassium-sodium niobate thin film substantially not containing Mn (manganese) and second piezoelectric layer which is a potassium-sodium niobate thin film containing Mn.

Piezoelectric element, piezoelectric actuator, piezoelectric sensor, hard disk drive, and inkjet printer device

An object is to increase the amount of displacement of a thin-film piezoelectric element including a piezoelectric thin film having an uneven-shaped contact surface with the planar shape and the layer structure of the thin-film piezoelectric element kept unchanged. The thin-film piezoelectric element includes a pair of electrode layers and a piezoelectric thin film sandwiched between the pair of electrode layers, in which a surface roughness P-V of an interface between the piezoelectric thin film and at least one of the pair of electrode layers is 220 nm or more and 500 nm or less.

Thin film piezoelectric element, thin film piezoelectric actuator, and thin film piezoelectric sensor; and hard disk drive, and inkjet printer

A piezoelectric device according to the present invention is provided with a pair of electrode films, a piezoelectric film sandwiched in between the pair of electrode films, and a stress control film which is in direct contact with a surface of at least one of the pair of electrode films, on the side where the electrode film is not in contact with the piezoelectric film, and which has a linear expansion coefficient larger than those of the relevant electrode film and the piezoelectric film.

Piezoelectric device

A piezoelectric element includes, as a piezoelectric layer, a thin film of potassium sodium niobate that is a perovskite compound represented by a general expression ABO, in which Sr (strontium) is substituted on both of an A site and a B site and Mn (manganese) is substituted only on the A site. Accordingly, the piezoelectric element is provided to decrease a leak current of the piezoelectric element using the thin film of potassium sodium niobate, to increase a withstand voltage thereof and to improve piezoelectric characteristics thereof.

Growing community of inventors

Tokyo, Japan

Hitoshi Sakuma