Mitsubishi Electric Corporation

Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Cornoration

Eiji Yoshikawa

Masahiro Tsugai

Nobuaki Konno

Yukihisa Yoshida

Shinichi Izuo

Jyunichi Ichikawa

Hiroyuki Fujita

Masaaki Taruya

Toru Araki

Yoshiaki Hirata

The present application provides a semiconductor pressure sensor having high manufacturing stability and high accuracy. A second silicon substrate is bonded across an oxide film to one main face of a first silicon substrate, in which a recessed portion that becomes a reference pressure chamber and an alignment mark are formed, whereby the first silicon substrate and the second silicon substrate are joined in a state wherein the recessed portion and the alignment mark are covered by the second silicon substrate. The alignment mark is detected using an infrared sensor, positioning is carried out using the alignment mark, and a gauge resistor, which is a pressure-sensitive element portion, is formed in a diaphragm formed in the second silicon substrate positioned above the recessed portion.

Manufacturing method of a semiconductor pressure sensor having first silicon and second silicon substrates including an oxide film

In a semiconductor pressure sensor element, a first hydrogen permeation protection film is provided on a principal surface side of a first silicon substrate, and a second hydrogen permeation protection film is provided on a principal surface side of a second silicon substrate. The permeation paths of the hydrogen fluxes shown by the arrows A and B in FIG.are blocked by the films. Also, a trench surrounding a reference pressure chamber is provided, and the first hydrogen permeation protection film and a third hydrogen permeation protection film are joined at the bottom portion of the trench, thereby blocking the permeation path of the hydrogen flux shown by the arrow C in FIG.. Furthermore, by providing a hydrogen storage chamber, hydrogen is trapped before the hydrogen reaches the reference pressure chamber.

Semiconductor pressure sensor

A semiconductor pressure sensor includes: a first semiconductor substrate having a plurality of recesses formed thereon; an intermediate semiconductor substrate joined to the first semiconductor substrate with a first oxide film interposed therebetween; a second semiconductor substrate joined to the intermediate semiconductor substrate with a second oxide film interposed therebetween; a first reference pressure chamber formed as a space surrounded by a first recess of the first semiconductor substrate and the intermediate semiconductor substrate; a second reference pressure chamber formed as a space surrounded by a second recess formed on the first semiconductor substrate, the intermediate semiconductor substrate, and the second semiconductor substrate, the intermediate semiconductor substrate having a through hole communicating with the second recess of the first semiconductor substrate; and piezoresistors formed on a surface of the second semiconductor substrate that receives pressure, along outer peripheries of the first and second reference pressure chambers.

Provided is a semiconductor pressure sensor that can maintain high reliability and measure pressure with high accuracy without increasing the size thereof and that has hydrogen permeation prevention performance. The semiconductor pressure sensor includes: a first semiconductor substrate having a recess formed thereon; a second semiconductor substrate joined to the first semiconductor substrate with an oxide film interposed therebetween; a reference pressure chamber formed as a space surrounded by the recess of the first semiconductor substrate and the second semiconductor substrate; a piezoresistor formed on a surface of the second semiconductor substrate that receives pressure, along an outer periphery of the reference pressure chamber; and a protective film formed on the surface of the second semiconductor substrate that receives pressure, and side surfaces of the second semiconductor substrate and the oxide film.

A semiconductor differential pressure sensor element is such that as strain sensitive elements are disposed only inside a diaphragm, and strain relaxation grooves are provided along the diaphragm, it is difficult for thermal stress caused by expansion or contraction of a case to propagate to the strain sensitive elements, thus suppressing characteristic fluctuations resulting from a change in external temperature. Also, as a configuration is such that a sacrificial column is provided inside a depressed portion, and that the diaphragm is held by the sacrificial column in a diaphragm formation step which thins a second semiconductor substrate and a functional element formation step which repeatedly implements a cleaning step, breakage of the diaphragm can be prevented, thus achieving a significant improvement in yield.

Semiconductor differential pressure sensor and manufacturing method of the same

In order to obtain a SOI wafer having an excellent ability of gettering metal impurities, an efficient method of manufacturing a SOI wafer, and a highly reliable MEMS device using such a SOI wafer, provided is a SOI wafer including: a support wafer () and an active layer wafer () which are bonded together with an oxide film () therebetween, each of the support wafer () and the active layer wafer () being a silicon wafer; a cavity () formed in a bonding surface of at least one of the silicon wafers; and a gettering material () formed on a surface on a side opposite to the bonding surface.

SOI wafer, manufacturing method therefor, and MEMS device

A semiconductor pressure sensor that can improve diaphragm breakage pressure tolerance is provided. Included are: a first semiconductor substrate on which is formed a recess portion that has an opening on a first surface in a thickness direction; a second semiconductor substrate that is disposed so as to face the first surface of the first semiconductor substrate; and a first silicon oxide film that is interposed between the first semiconductor substrate and the second semiconductor substrate, and on which is formed a penetrating aperture that communicates between the recess portion and the second semiconductor substrate, and at least a portion of an edge portion of the penetrating aperture is positioned inside an opening edge portion of the recess portion when viewed from a side facing the penetrating aperture and the opening of the recess portion.

A semiconductor pressure sensor includes a first substrate having a concave portion and an alignment mark at a main surface thereof, and a second substrate formed on the main surface of the first substrate and having a diaphragm provided to cover a space inside the concave portion of the first substrate and a gauge resistor provided on the diaphragm. The alignment mark is provided to be exposed from the second substrate. Accordingly, it is possible to obtain a semiconductor pressure sensor and a method of manufacturing the same with reduced production costs and with improved pressure measuring accuracy.

Semiconductor pressure sensor and method of manufacturing semiconductor pressure sensor

An SOI substrate includes a thin diaphragm portion that is formed by removing a portion of the substrate from a rear surface side, and a thick outer frame portion that surrounds the diaphragm portion. A piezoresistive element that outputs an electrical signal in response to pressure is formed on the diaphragm portion, and an electrode that extracts the electrical signal from the piezoresistive element is formed on the outer frame portion. The electrode is disposed at a position on the outer frame portion that is separated by greater than or equal to 100 &#x3bc;m from a boundary line between the diaphragm portion and the outer frame portion.

Semiconductor strain sensor

An acceleration sensor includes first and second fixed electrodes on a substrate, and a movable electrode located above the first and second fixed electrodes, with respect to the substrate, and facing them. The movable electrode is elastically supported on the substrate by a first elastic supporting body and is movable. A mass, which is elastically supported on the substrate by a second elastic supporting body, moves in response to an acceleration in a direction perpendicular to the substrate. A linking portion links the movable electrode and the mass at a position spaced from an axis of movement of the movable electrode by a distance. Acceleration is measured based on changes in a first capacitance between the first fixed electrode and the movable electrode and a second capacitance between the second fixed electrode and the movable electrode. Thus, a highly impact resistant and highly reliable acceleration sensor is obtained.

Acceleration sensor

A sensitive angular velocity sensor is provided without increasing an inter-electrode gap for inducing a torsional vibration. An angular velocity sensor which employs an electrostatic drive system for inducing drive vibration by using inter-electrode electrostatic attraction includes a pair of inertial mass members which are connected to each other through a connection frame having a length such that the inertial mass members are point-symmetrical with respect to a central point of the connection frame and which are held along a plane direction of a substrate, a pair of elastic beams which are connected to each other at an interval in opposite directions along a longitudinal direction from the central point of the connection frame on opposite sides of the connection frame, a pair of drive plates which are connected to the ends of the elastic beams, which have an electrode constituting an electrostatic attraction generating structure together with a drive electrode on the substrate, and which are supported such that the drive plates can be moved in at least one direction along the plane direction of the substrate to torsionally vibrate the inertial mass members about the central point of the connection frame.

Angular velocity sensor

A pressure switch with improved sealing of an airtight chamber, and improved electrical characteristics reducing chattering, increasing response rate, and minimizing the pressure necessary for activation. The pressure switch includes an upper substrate with a diaphragm readily deformed by an applied stress, a lower substrate overlapped with the upper substrate to form the airtight chamber, a contact electrically switched in response to the deformation of the diaphragm, and a sealing member continuously surrounding the airtight chamber, disposed between the first and second substrate, and hermetically sealing the airtight chamber.

Pressure switch

A semiconductor accelerometer switch having a fixed portion including a first control electrode and a movable portion including a movable body. By applying a voltage between the first control electrode and an electrode on the movable body, electrostatic attraction holds the movable body in an initial position. The movable body is displaced when acceleration having a magnitude in a direction acts on the switch. The threshold of acceleration to be detected and general-purpose properties of the accelerometer switch are easily adjusted.

Growing community of inventors

Tokyo, Japan

Eiji Yoshikawa