Mitsubishi Denki Kabushiki Kaisha

Other

Mitsubishi Electric Corporation

Teruya Fukaura

Yasuo Yamaguchi

Kunihiro Nakamura

Shinichiro Katsuki

Seishi Shibata

Yutaka Katahara

Shiro Yamasaki

Kenji Oota

Nobuhisa Nakashima

A capacitive acceleration sensor that prevents sticking of a mass body, made of silicon, to a first sealing substrate or a second sealing substrate, made of glass. The capacitive acceleration sensor includes a first sealing substrate and a second sealing substrate each made of glass. The mass body is suspended between the first and second sealing substrates by a beam attached to a substrate, and one or both of the sealing substrates is processed such that the mass body only contacts with a subsection of the substrate surface.

Capacitive acceleration sensor

An acceleration sensor in accordance with an aspect of the present invention comprises a first substrate, a multilayer second substrate and a sensor portion. The multilayer second substrate is opposed to the first substrate. The multilayer second substrate is provided with an electrode drawing opening. Further, the multilayer second substrate consists of a plurality of layers. The sensor portion (a movable mass body and a fixed electrode) is provided in a sealed cavity portion which is formed between the first substrate and the multilayer second substrate which are opposed to each other.

Acceleration sensor having single and multi-layer substrates

Acceleration sensor

Each of outermost segments (OMSG) and innermost segments (IMSG) is utilized as a dummy segment. A top surface of a protruding portion (OMPP, IMPP) of each of the outermost segments (OMSG) and the innermost segments (IMSG) is covered with an insulating layer (S+P), and a clearance (CL) is provided between a top surface of the insulating layer (S+P) and a bottom surface (BS) of a cathode strain relief plate. Each of all the other segments (SG) than the outermost and innermost segments has a protruding portion PP on which a cathode electrode (K-AL) is formed. A thickness (T) of the cathode electrode (K-AL) is determined so as to allow a top surface of the cathode electrode (K-AL) to be in contact with the bottom surface (BS) of the cathode strain relief plate.

Pressure contact type semiconductor device having dummy segment

Provided is a method of manufacturing an acceleration sensor capable of preventing bonding of a movable electrode and a fixed electrode. A stain filmfor reducing bonding adsorption force is formed on side surfaces of a movable electrode, fixed electrodesandand a frame portionIn the case in which the movable electrodeand the fixed electrodesandare to be formed of a silicon substrate, it is preferable that an insulating film having irregular bonding of silicon atoms and oxygen atoms and irregular bonding of silicon atoms and nitrogen atoms should be employed for the stain filmfor example. The formation of the stain filmcan suppress the bonding between the movable electrodeand the fixed electrodesandeven if Coulomb force is generated between both electrodes when the silicon substrate and a back side substrateare joined by using an anode junction method.

Method of manufacturing acceleration sensor

Provided is a method of manufacturing an acceleration sensor capable of preventing bonding of a movable electrode and a fixed electrode. A stain film for reducing bonding adsorption force is formed on side surfaces of a movable electrode , fixed electrodes and and a frame portion . In the case in which the movable electrode and the fixed electrodes and are to be formed of a silicon substrate, it is preferable that an insulating film having irregular bonding of silicon atoms and oxygen atoms and irregular bonding of silicon atoms and nitrogen atoms should be employed for the stain film , for example. The formation of the stain film can suppress the bonding between the movable electrode and the fixed electrodes and even if Coulomb force is generated between both electrodes when the silicon substrate and a back side substrate are joined by using an anode junction method.

Providing an acceleration sensor in which a base portion and a cap portion are bonded to each other and a sensor portion is sealed off between these two, and which has an improved bonding strength between the base portion and the cap portion. A sensor portion and a frame portion surrounding a periphery of the sensor portion are disposed on a semiconductor substrate. A base portion is comprised, where a diffusion preventing layer and a non-doped polycrystalline silicon layer are stacked one atop the other on the frame portion. A cap portion is comprised, where a nickel layer is formed on a base unit. The non-doped polycrystalline silicon layer of the base portion and the nickel layer of the cap portion are bonded to each other by eutectic bonding.

Growing community of inventors

Fukuoka, Japan

Teruya Fukaura