Denso Corporation

Yutaka Hayakawa

Hisanori Yokura

Minekazu Sakai

Masaaki Tanaka

Tomoya Jomori

Kazuaki Mawatari

Takahiro Higuchi

Yuji Koyama

A piezoelectric element includes a plurality of vibration regions that are separated from each other by a slit, and the slit is formed to have a tapered portion that is tapered from a first surface of the vibration regions on an opposite side to a support to a second surface opposite to the first surface. An electrode film is positioned inside than the slit when being viewed from a normal direction orthogonal to the first surface, and an angle formed by a side surface of the tapered portion in the vibration region and a surface parallel to the first surface is in a range of 39 to 81 degrees.

Piezoelectric element, piezoelectric device, and method of manufacturing piezoelectric element

In a physical quantity sensor, a first substrate has a recess depressed from a second surface to provide a thin film section adjacent to a first surface, and a second substrate has a first surface bonded to the first surface of the first substrate, and has a hollow depressed from the first surface and facing the recess. The recess and the hollow have such sizes that a projected line defined by projecting an end of a bottom surface in the recess to the first surface of the first substrate surrounds an open end of the hollow. When the thin film section is displaced toward the hollow, a maximum tensile stress is generated at a position on a rear surface of the thin film section intersecting an extended line along a normal direction to the first surface of the first substrate and passing through the open end of the hollow.

Physical quantity sensor

A manufacturing method of a semiconductor device, in which a vacuum-pressure airtight chamber is defined by a space between a first substrate and a recessed portion of a second substrate, includes preparing the first substrate and the second substrate both of which contain silicon, joining the two substrates together, performing a heat treatment to emit hydrogen gas from the airtight chamber, and generating OH groups on the substrates before the joining. In the joining of the substrates together, the OH groups are bonded together to generate covalent bonds, and in the heat treatment, a part on which the OH groups are generated is heated at a temperature rise rate of 1&#xb0; C./sec or smaller until a temperature of the substrate increases to 700&#xb0; C. or higher, and a heating temperature and heating time are adjusted to emit hydrogen gas from the airtight chamber.

Manufacturing method of semiconductor device

Growing community of inventors

Kariya, Japan

Yutaka Hayakawa