Yamaha Corporation

Tamito Suzuki

Yukitoshi Suzuki

Masayoshi Omura

Toshiyuki Oohashi

Seiji Hirade

Kazushi Sakurauchi

Yuusaku Ebihara

A plurality of structures of condenser microphones is fabricated in a single condenser microphone array chip. The condenser microphone array chip includes a substrate having a plurality of openings serving as air cavities, a first insulating layer formed in the outer periphery of the openings, a first electrode layer stretched over each of the openings, a second insulating layer formed above the first electrode layer in the outer periphery of the openings, a second electrode layer formed above the second insulating layer relative to the first electrode layer via an air gap therebetween. The structures are connected via a plurality of bridges and separated via a plurality of channels therebetween. The channels circumvent the bridges so that at least the second insulating layer is partially removed from the channels. The bridges are formed using the second electrode layer serving as wiring for electrically connecting the structures of condenser microphones.

Condenser microphone array chip

The present invention provides a condenser microphone, in which, with a simple manufacturing process, vibration characteristics of a diaphragm are improved, and a parasitic capacitance occurring between the diaphragm and a back plate is reduced, thus improving sensitivity. Specifically, the diaphragm having a gear-like shape including a center portion and a plurality of arms and the back plate having a gear-like shape including a center portion and a plurality of arms are positioned opposite to each other above a substrate, wherein the arms of the diaphragm and the arms of the back plate are not positioned opposite to each other. Alternatively, it is possible to independently support the diaphragm and the back plate above the substrate. Furthermore, it is possible to support the back plate above the substrate by means of a plurality of supports inserted into a plurality of holes formed in the center portion of the diaphragm.

Condenser microphone

A capacitor microphone is constituted by a plate having a fixed electrode, a diaphragm including a center portion and at least one near-end portion that is fixed to the outer periphery, in which the center portion having a vibrating electrode, which is positioned relative to the fixed electrode and which vibrates in response to sound waves, is increased in rigidity in comparison with the near-end portion; and a spacer that is fixed to the plate and the near-end portion of the diaphragm and that has an air gap formed between the plate and the diaphragm. Alternatively, a diaphragm electrode is horizontally supported by extension arms extended from a circular plate thereof and is vertically held in a hanging state being apart from a fixed electrode with a controlled distance therebetween.

Capacitor microphone

An MEMS transducer is constituted of a diaphragm, a plate, a support structure for supporting the diaphragm and the plate with a gap layer surrounded by an interior wall, an electrode film (e.g. a pad conductive film) for covering a contact hole formed in the support structure, and a protective film (e.g. a pad protective film) which is formed on the support structure externally of the interior wall so as to cover the side surface of the electrode film having low chemical stability. The protective film is formed in the limited area including a part of the surface of the electrode film except for its center portion and the surrounding area of the electrode film. This allows the protective film to use materials having high membrane stress such as silicon nitride or silicon nitride oxide.

MEMS transducer

A method for manufacturing a capacitance sensor comprises the steps of (a) depositing a film to be a diaphragm forming a moving electrode, (b) heating the film to be the diaphragm to a first temperature, and (c) depositing a film to be a plate forming a fixed electrode opposing to the moving electrode. Stresses of the diaphragm and the plate of the capacitance sensor are optimized.

Method of making capacitance sensor

Gate insulating filmsA andB of different thickness are formed in element openingsandin the isolation filmof a wafer. The gate insulating filmB is the thinnest gate insulating film. A dummy insulating film having the same thickness as the thinnest gate insulating filmB is formed in wafer periphery area WP. Gate electrodesA andB are formed on the gate insulating filmsA andB, and thereafter an insulating film is deposited on the wafer surface. The deposited insulating film is dry-etched to form side wall spacerstoon side walls of the gate electrodesA andB. During dry etching, the time when the semiconductor surfaces are exposed in the element openingand area WP is detected as an etching end point by a change in the emission spectrum intensity of etching byproducts.

Method of manufacturing semiconductor device having side wall spacers

A moving member having a plurality of moving electrodes is supported by support members at both ends thereof on a substrate surface in such a way that it can be subjected to displacement in a two-dimensional plane. A plurality of fixed electrodes are arranged to face the plurality of moving electrodes respectively, thus forming different facing areas therebetween when an input acceleration is zero. The facing areas formed between pairs of the electrodes facing each other are varied in response to the displacement of the moving member, whereby a capacitance caused by one pair of the electrodes whose facing area is relatively small is used to detect a relatively small input acceleration, and a capacitance caused by the other pair of the electrodes whose facing area is relatively large is used to detect a relatively large input acceleration.

Electrostatic-capacity-type acceleration sensor and acceleration measuring device therewith

A micro structure has: a semiconductor substrate; an insulating film having a via hole and formed on the semiconductor substrate; an interlock structure formed on a side wall of the via hole and having a retracted portion and a protruded portion above the retracted portion; a conductive member having at one end a connection portion formed burying the via hole and an extension portion continuous with the connection portion and extending along a direction parallel to a surface of the semiconductor substrate.

Micro structure with interlock configuration

A sensor includes a first X-axis GMR element to a fourth X-axis GMR element fixed on a substrate, and a movable coil movably supported on the substrate. When electric current flows through the movable coil, a magnetic field is generated around the movable coil. The generated magnetic field is applied to the first to fourth X-axis GMR elements. The movable coil moves in accordance with acceleration generated in the sensor. The movement of the movable coil causes variation in the magnetic field applied to the first to fourth X-axis GMR element. While no electric current flows to the movable coil, the sensor measures an external magnetic field on the basis of resistances of the first to fourth X-axis GMR elements. While constant electric current flows through the movable coil, the sensor measures acceleration or the like on the basis of resistances of the first to fourth X-axis GMR elements.

Sensor, and method for measuring physical quantity by use of the sensor

An acceleration measurement method adapted to an electostatic-capacity-type acceleration sensor comprising a first capacitance detector and a second capacitance detector both of which have moving electrodes and fixed electrodes arranged on a substrate surface so that facing areas therebetween are varied in response to input acceleration, wherein said second capacitance detector sets the facing areas between the moving electrodes and the fixed electrodes to be larger than those of the first capacitance detector when the input acceleration is zero. If first acceleration information representing capacitance variations detected between the moving electrodes and fixed electrodes in the first capacitance detector exceed an upper limit value that is set in advance with respect to the first capacitance detector, it outputs second acceleration information representing capacitance variations detected between the moving electrodes and the fixed electrodes in the second capacitance detector. If not, it outputs the first acceleration information.

Acceleration measurement method using electrostatic-capacity-type acceleration sensor

A polysilicon etching method capable of completely removing polysilicon residues left on the side walls of a protrusion covered with a polysilicon layer after the polysilicon layer is patterned while form anisotropy of the polysilicon layer is retained and the underlying insulating film is left unetched. After a polysilicon layer is deposited over one principal surface of a substrate, covering a protrusion, a resist layer is formed on the polysilicon layer over the protrusion. By using the resist layer as a mask, a plasma etching process is performed to pattern the polysilicon layer and form a gate electrode polysilicon layer. At a first step, the polysilicon layer is etched by using HBr and Cluntil polysilicon spacer residues appear on the side walls of the protrusion, and at a second step the polysilicon residues are removed by using HBr at a pressure of 5 to 10 mTorr.

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Fukuroi, Japan

Tamito Suzuki