Japan Aviation Electronics Industry, Limited

Nec Corporation

Kenji Kondou

Keiichi Mori

Yoshichika Kato

Osamu Imaki

Yoshihiko Hamada

Satoshi Yoshida

Manabu Ando

A microminiature moving device has disposed on a single-crystal silicon substrate movable elements such as a movable rod and a movable comb electrode that are displaceable in parallel to the substrate surface and stationary parts that are fixedly secured to the single-crystal silicon substrate with an insulating layer sandwiched between. Depressions are formed in the surface regions of the single-crystal silicon substrate where no stationary parts are present and the movable parts are positioned above the depressions. The depressions form gaps large enough to prevent foreign bodies from causing shorts and malfunctioning of the movable parts.

Method of making microminiature moving device

A microminiature moving device has disposed on a single-crystal silicon substrate movable elements such as a movable rod and a movable comb electrode that are displaceable in parallel to the substrate surface and stationary parts that are fixedly secured to the single -crystal silicon substrate with an insulating layer sandwiched between. Depressions are formed in the surface regions of the single-crystal silicon substrate where no stationary parts are present and the movable parts are positioned above the depressions. The depressions form gaps large enough to prevent foreign bodies from causing shorts and malfunctioning of the movable parts.

Microminiature moving device

Marker grooves of an optical fiber are formed by a marker groove forming device including at least, on a substrate, a fiber guide and optical fiber pressing springs formed on a side wall surface in the fiber guide. The optical fiber pressing springs include edges contacted and pressed to the side of an optical fiber stored in the fiber guide, and plate springs for pressing the edges to the side of the optical fiber with fulcra on the side wall surface in the fiber guide. The optical fiber is pressed to a side wall surface in the fiber guide, and the edges are formed at a predetermined distance from each other.

Marker groove forming device

A micro-optic device including a complicate structure and a movable mirror is made to be manufactured in a reduced length of time. A silicon substrate and a single crystal silicon device layer with an intermediate layer of silicon dioxide interposed therebetween defines a substrate on which a layer of mask material is formed and is patterned to form a mask having the same pattern as the configuration of the intended optical device as viewed in plan view. A surface which is to be constricted as a mirror surface is chosen to be in a plane of the silicon crystal. Using the mask, the device layer is vertically etched by a reactive ion dry etching until the intermediate layer is exposed. Subsequently, using KOH solution, a wet etching which is anisotropic to the crystallographic orientation is performed with an etching rate which is on the order of 0.1 &#x3bc;m/min for a time interval on the order of ten minutes is performed to convert the sidewall surface of the mirror into a smooth crystallographic surface. Subsequently, the intermediate layer is selectively subject to a wet etching to remove the intermediate layer only in an area located below the movable part of the optical device.

Method of manufacturing micro-optic device

Method of forming an optical fiber

A micro-optic device including a complicate structure and a movable mirror is made to be manufactured in a reduced length of time. A silicon substrate and a single crystal silicon device layer with an intermediate layer of silicon dioxide interposed therebetween defines a substrate on which a layer of mask material is formed and is patterned to form a mask having the same pattern as the configuration of the intended optical device as viewed in plan view. A surface which is to be constructed as a mirror surface is chosen to be in a plane of the silicon crystal. Using the mask, the device layer is vertically etched by a reactive ion dry etching until the intermediate layer is exposed. Subsequently, using KOH solution, a wet etching which is anisotropic to the crystallographic orientation is performed with an etching rate which is on the order of 0.1 &#x3bc;m/min for a time interval on the order of ten minutes is performed to convert the sidewall surface of the mirror into a smooth crystallographic surface. Subsequently, the intermediate layer is selectively subject to a wet etching to remove the intermediate layer only in an area located below the movable part of the optical device.

Micro-optic device and method of manufacturing same

An optical fiber device comprising a positioning/fixing substrate has a fiber guide and an optical fiber pressing spring formed in the fiber guide, and an optical fiber stored in the fiber guide. The optical fiber includes an end part having at least one marker groove. The fiber guide is a groove having two side wall surfaces. The optical fiber pressing spring includes a plate spring formed on one of the side wall surfaces in the fiber guide and an edge formed on the plate spring. The plate spring presses the edge to the side of the optical fiber with a fulcrum on one of the side wall surfaces, and the end part of the optical fiber is positioned by aligning the marker groove of the optical fiber with the edge of the optical fiber pressing spring.

Optical fiber device

In a microminiature moving device that has disposed, on a single-crystal silicon substrate, movable elements (a movable rod, a movable comb electrode, etc.) displaceable in parallel to the substrate surface and stationary parts (a stationary part, etc.), the stationary parts are fixedly secured to the single-crystal silicon substratewith an insulating layersandwiched therebetween, and depressionsare formed in those surface regions of the single-crystal silicon substratewhere no stationary parts are present, and the movable parts are positioned above the depressions. The depressionsform gapslarge enough to prevent foreign bodies from causing troubles such as malfunction of the movable parts and shoring.

In a microminiature moving device that has disposed, on a single-crystal silicon substrate, movable elements (a movable roda movable comb electrodeetc.) displaceable in parallel to the substrate surface and stationary parts (a stationary partetc.), the stationary parts are fixedly secured to the single-crystal silicon substratewith an insulating layersandwiched therebetween, and depressionsare formed in those surface regions of the single-crystal silicon substratewhere no stationary parts are present, and the movable parts are positioned above the depressionsThe depressionsform gapslarge enough to prevent foreign bodies from causing troubles such as malfunction of the movable parts and shoring.

Microminiature moving device and method of making the same

An optical switch, wherein the first and second output ports (optical fibers) are disposed on the opposite sides of the input port (optical fiber) so as to form acute angles with respect to the input port, the input port and the first output port are optically coupled to each other through a first mirror surface, and the input port and the second output port are optically coupled to each other through a second mirror surface. The incident angles of an incident light beam with respect to the mirror surfaces are equalized, and optical path lengths between the input port and the first and second output ports are equalized. The actuator inserts and withdraws the second mirror surface on a position at the front of the first mirror surface.

Optical switch

The end parts of three optical waveguide parts are supported, mutually in parallel, on a substrate, the end part of the center optical waveguide part being one input port and the end parts of other two optical waveguide parts being a first and a second output port, the emitted light from the input port is switched, by means of a first moving mirror and a second moving mirror which are switchingly inserted into positions having the same distance from the end face of the input port, to either the first output port side or the second output port side, the light from the first moving mirror and the light from the second moving mirror being reflected respectively in a first fixed mirror or a second fixed mirror, the light being respectively coupled to the first or the second output port.

Optical switch with three optical ports on one side

A miniature movable device comprises a movable part (a mirror, a movable rod, support arms, and a movable comb tooth electrode) formed on a substrate and adapted to be displaced in a direction parallel to the sheet surface of the substrate, a fixing part formed and fixedly mounted on the substrate, and hinges, each having its opposite ends connected to the movable part and the fixing part and assuming two flexural conditions which are reversed in flexural, the hinges being effective to maintain the movable part at two positions by a self-holding action when it assumes either flexural condition. The substrate is formed with wall surfaces which are disposed oppositely to the opposite surfaces of the hinges over a movable range of the hinges. Spacings between the hinges and the wall surfaces disposed on the opposite sides thereof are equal to each other at every point along the lengthwise direction of the hinges when the hinges assume one of the two flexural conditions (an initial condition assumed upon manufacture). This eliminates an inconvenience that during a drying step which follows a wet etching operation during the manufacture, a liquid may remain on only one side of the hinges to cause the hinges to be held attracted to the wall surfaces.

Miniature movable device

An optical device formed on a substrate comprises: plural fiber channels formed in the top surface of the substrate; a mirror to be pushed into and pulled out of an optical path between optical fibers disposed in the fiber channels; a movable rod carrying at one end the mirror; a comb-type electrostatic actuator disposed in association with the intermediate portion of the movable rod, for moving the movable rod lengthwise thereof; and plural support beams disposed near the one and the other end of the movable rod on both sides of the point of application of driving force by the comb-type electrostatic actuator, for movably supporting the movable rod. The support beams support the movable rod at positions having line symmetry with respect to a center line parallel to the lengthwise direction of the movable rod, and points of supporting the movable rod by the plural support beams are symmetrical with respect to the point of application of the driving force by the comb-type electrostatic actuator. Even if the driving force by the comb-type electrostatic actuator contains a vector component of a direction different from the desired one in which to drive the movable rod, it is possible to suppress movement of the movable rod in other directions than the desired one to drive the movable rod.

Optical device

A movable part formed on a substrate and adapted to be displaced in a direction parallel to the sheet surface of the substrate, a fixing part formed and fixedly mounted on the substrate, and springy hinges extending parallel to the sheet surface of the substrate and having their opposite ends connected to the movable part and the fixing part for supporting the movable part in a displaceable manner are provided. As viewed in cross section in a plane perpendicular to the lengthwise direction of the hinges, the hinge has a width which is diminishing as the top surface of the substrate is approached, thus having a trapezoidal or triangular cross section. A width as measured on the top surface of the hinge which is required to provide an equivalent spring constant can be chosen to be greater than the width of a hinge having a rectangular cross section (constant width), and this facilitates the implementation of the photolithography during the manufacture.

A load element, which is controlled by a control signal acquired by a logical operation of a write/read enable signal and a row address signal, is provided at a pair of digit lines. This structure provides a semiconductor memory device that suppresses a change in the potential difference between the digit line pair, which is caused by a parasitic resistor, to ensure an uniform read delay time and improve the reading speed.

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Tokyo, Japan

Kenji Kondou