JP5527152B2 - Optical deflection device - Google Patents

Description

  The present application relates to an optical deflection apparatus that deflects a light beam (refers to changing the reflection direction of the light beam) and uses an MEMS (Micro Electro Mechanical Systems) technology.

  Patent Document 1 discloses an electrostatic drive type optical deflection apparatus 1000 that deflects a light beam. 86 and 87, a plurality (two in this example) of electrodes 1103, a fulcrum member 1106, a regulating member 1108, and a landing member 1109 are formed on a substrate 1101 with an insulating film 1102 interposed therebetween. 87, reference numeral 1107 denotes a plate member as a mirror member (FIG. 86 shows a state in which the plate member 1107 is removed). The plate-like member 1107 has a light reflection region on the upper surface thereof, and at least the back surface thereof is a conductor layer. The fulcrum member 1106 also serves as an electrode for applying a potential to the plate-like member 1107, and the conductor is exposed at least at the top, and is in electrical contact with the plate-like member 1107. The plate-like member 1107 can be inclined in the direction shown in FIG. 87 with the top of the fulcrum member 1106 as a fulcrum, or in the opposite direction. Specifically, when a driving voltage is applied between the plate-like member 1107 and one of the pair of electrodes 1103, an electrostatic attractive force acts between the electrode 1103 to which the driving voltage is applied and the plate-like member 1107, The plate-like member 1107 is inclined so that the two approach each other. The movement range of the plate-like member 1107 in the substrate surface direction is limited by the regulating member 1108. Further, an umbrella-shaped stopper portion 1108 a is provided on the top of the regulating member 1108 in order to prevent the plate-like member 1107 from jumping out. The restricting member 1108 and the stopper portion 1108a prevent the plate-like member 1107 from being lost.

  The optical deflecting device 1000 of Patent Document 1 does not have a fixing portion such as a support beam for supporting the plate-like member 1107. Therefore, since the resistance force (such as the torsional resistance of the support beam) when the plate-like member 1107 is inclined can be reduced, the plate-like member 1107 can be driven at a low voltage.

JP 2008-225363 A

  In the optical deflecting device 1000 of Patent Document 1, the movement of the corner of the plate-like member 1107 is restricted by the restricting member 1108 and the stopper portion 1108a. Since the corner portion of the plate-like member 1107 is the part farthest from the fulcrum member 1106, the moving distance when the plate-like member 1107 is tilted becomes the longest. Then, since it is necessary to create the regulating member 1108 and the stopper portion 1108a according to the moving distance of the corner portion, the regulating member 1108 and the stopper portion 1108a are increased in size. As a result, when the optical deflecting device 1000 is viewed in plan, the ratio (opening ratio) of the area of the plate-like member 1107 to the area occupied by the optical deflecting device 1000 is reduced.

  The optical deflecting device of the present application has a substrate, a flat plate-shaped movable portion, a first protrusion connected to the first end of the movable portion, and the same central axis as the first protrusion. And a second protrusion connected to the second end of the movable part, and a second protrusion disposed on the substrate, the first protrusion being rotatable around the central axis of the first protrusion. A first restricting portion that surrounds, a second restricting portion that is installed on the substrate and surrounds the central axis of the second projecting portion so that the second projecting portion can rotate, and a movable portion And an actuator for swinging. The first restricting portion supports the first projecting portion, and the second restricting portion supports the second projecting portion, so that the movable portion is separated from the upper side of the substrate at the center. The shaft is swingably supported.

  The actuator is a mechanism that swings the movable part by applying a driving torque to the movable part. Examples of the actuator drive system include an electrostatic drive system, an electromagnetic drive system, and a thermal drive system.

  As a comparison object, a case will be described in which a part away from the central axis is restricted when the movement range of the movable part is restricted. In this case, the movement distance of the restriction part when the movable part swings increases as the restriction part moves away from the central axis. And since it is necessary to create a control part according to the movement distance of a control part, a control part will become large, so that movement distance becomes large. In the optical deflecting device of the present application, the central axis is formed by the first protrusion and the second protrusion. And while surrounding the 1st protrusion part with the 1st control part and surrounding the 2nd protrusion part with the 2nd control part, the movement range of the center axis in the direction perpendicular to the center axis Can be regulated. When the movable part swings, it swings around the central axis, so the position of the central axis does not move even when the movable part swings. Therefore, the restriction portion can be made smaller as compared with the case where the portion away from the central axis is restricted. Thereby, when the optical deflecting device is viewed in plan, the ratio (aperture ratio) occupied by the area of the movable portion to the area occupied by the optical deflecting device can be increased.

  In the optical deflecting device of the present application, the distance by which the first protrusion protrudes from the first end along the central axis, and the second protrusion from the second end along the central axis. Each of the protruding distances includes a first separation distance along the central axis between the first end of the movable part and the first restricting part, a second end of the movable part, and a second The distance may be larger than the total distance of the second separation distances along the central axis between the restriction portions. When the movable portion moves along the central axis until the first end portion and the first restricting portion come into contact with each other, the distance between the second end portion and the second restricting portion becomes the maximum distance. This maximum distance is the sum of the first separation distance and the second separation distance. In the optical deflecting device of the present application, the distance at which the second protrusion protrudes is greater than the total distance (maximum distance) of the first separation distance and the second separation distance. It can prevent that a protrusion part remove | deviates from a 2nd control part. Similarly, even when the movable portion moves along the central axis until the second end portion and the second restricting portion come into contact with each other, the distance at which the first protruding portion protrudes is the first separation. Since the distance is greater than the total distance (maximum distance) of the second separation distance, it is possible to prevent the first projecting portion from being detached from the first restricting portion.

  Further, in the optical deflecting device of the present application, the shape of the lower surface of the first projecting portion in the cross section perpendicular to the central axis is a shape having a curved surface and projecting to the substrate side, and the cross section perpendicular to the central axis. The shape of the lower surface of the second protrusion may be a shape having a curved surface and protruding toward the substrate. A case where the movable part swings in a state where the lower surface of the first projecting part is supported by the first restricting part will be described. When the lower surface of the first projecting portion and the support surface of the first restricting portion supporting the first restricting portion are both flat, the flat surface and the flat surface are in contact with each other. That is, they are in line contact with each other in a cross section perpendicular to the central axis. Then, if the movable part is swung around the central axis, the moving part cannot be smoothly swung because the contact between the first projecting part and the first restricting part is caught. On the other hand, in the optical deflecting device of the present application, the shape of the lower surface of the first protrusion is a shape that has a curved surface and protrudes toward the substrate in a cross section perpendicular to the central axis. Then, when the lower surface of the first projecting portion and the support surface of the first restricting portion come into contact with each other, the curved surface comes into contact with a flat surface. In other words, they are always in point contact with each other in a cross section perpendicular to the central axis. Therefore, when the movable part swings, the movable part can swing smoothly because no catch occurs. Similarly, in the second projecting portion and the second restricting portion, the movable portion can be smoothly swung because the catch does not occur.

  Further, in the optical deflecting device of the present application, in the cross section perpendicular to the central axis of the first restricting portion, the surface facing the lower surface of the first projecting portion has a curved surface and is recessed. In the cross section perpendicular to the central axis of the second restricting portion, the surface facing the lower surface of the second projecting portion has a curved shape and is recessed, and the curvature of the lower surface of the first projecting portion is The curvature of the surface facing the lower surface of the first projecting portion of the first restricting portion is equal to or greater than the curvature of the second projecting portion, and the curvature of the lower surface of the second projecting portion is the lower surface of the second projecting portion of the second restricting portion. The curvature may be equal to or greater than the curvature of the opposing surface. Thereby, the lower surface of the first projecting portion and the surface of the first restricting portion that faces the lower surface of the first projecting portion mesh with each other. Therefore, the first protrusion can be restricted from moving in a direction parallel to the substrate and perpendicular to the central axis. That is, the first protrusion can be positioned on the first restricting portion. Moreover, both the lower surface of the 1st protrusion part and the surface facing the lower surface of the 1st protrusion part of the 1st control part are formed in the curved surface. Therefore, even when the movable portion is swung around the central axis in a state where both surfaces are meshed with each other, the movable portion can be smoothly swung because no catch occurs at the meshing portion. Similarly, in the second projecting portion and the second restricting portion, the movable portion can be smoothly swung because the catch does not occur.

  Further, in the optical deflecting device of the present application, the shape of the cross section perpendicular to the central axis of the first protrusion is circular, and the shape of the cross section perpendicular to the central axis of the second protrusion is circular. It may be. When various forces such as electrostatic attraction act on the movable part, the movable part is shaken in a state where the outer peripheral surface of the first protruding part is in contact with the side surface part or the upper surface part of the inner wall of the first restricting part. May move. In the optical deflecting device of the present application, since the shape of the cross section perpendicular to the central axis of the first protrusion is circular, the outer peripheral surface of the first protrusion is all curved. Accordingly, even in such a case, the movable portion can be smoothly swung because the catch does not occur at the contact portion between the outer peripheral surface of the first protrusion and the inner wall of the first restricting portion. . Similarly, in the second projecting portion and the second restricting portion, the movable portion can be smoothly swung because the catch does not occur.

  Further, in the optical deflecting device of the present application, a terminal portion that is installed on the substrate and is electrically connected to the outside, and has a width smaller than a width in the direction along the substrate of the first protruding portion, and a conductive material And a conducting portion in which one end is electrically connected to the terminal portion and the other end is electrically connected to the end portion of the first projecting portion. In addition, the actuator may include a pair of lower electrodes at positions symmetrical with respect to a plane passing through the central axis and perpendicular to the substrate on the substrate. Moreover, the movable part and the first projecting part may be made of a conductive material, and the first projecting part and the movable part may be electrically connected. The conducting portion, the first projecting portion, and the movable portion are made of a conductive material. An example of the conductive material is polysilicon. The conductive part, the first projecting part, and the movable part may have a conductive material exposed on the surface, or the surface may be covered with an insulating material such as a silicon oxide film.

  The terminal portion, the conduction portion, the first protrusion, and the movable portion are electrically connected to each other. And an electrostatic attraction can be made to act between a movable part and one lower electrode by applying a drive voltage between a terminal part and one lower electrode. As a result, the movable portion in a range facing one of the lower electrodes can be attracted toward the substrate, so that the movable portion can be swung with respect to the substrate.

  In addition, the optical deflection apparatus of the present application may further include a terminal portion that is installed on the substrate and electrically connected to the outside. In addition, the actuator may include a pair of lower electrodes at positions symmetrical with respect to a plane passing through the central axis and perpendicular to the substrate. The first restricting portion may be formed of a conductive material and electrically connected to the terminal portion. Moreover, the movable part and the first projecting part may be formed of a conductive material. Further, the first projecting portion and the movable portion are electrically connected, and the inner wall surface of the portion surrounding the first projecting portion and the first projecting portion of the first restricting portion is electrically connected. The conductive material may be exposed.

The conductive material is exposed on the surface of the first protrusion and the inner wall surface of the portion surrounding the first protrusion of the first restricting portion. Therefore, when the first projecting portion is supported by the first restricting portion, electrical conduction can be obtained by bringing the conductive materials into contact with each other. Then, the terminal portion, the first restricting portion, the first projecting portion, and the movable portion are electrically connected to each other.
And an electrostatic attraction can be made to act between a movable part and one lower electrode by applying a drive voltage between a terminal part and one lower electrode. As a result, the movable portion in a range facing one of the lower electrodes can be attracted toward the substrate, so that the movable portion can be swung with respect to the substrate.

  According to the present invention, it is possible to provide an optical deflecting device capable of swinging a mirror with a low driving force.

1 is a plan view of an optical deflecting device according to Embodiment 1. FIG. It is sectional drawing in the II-II line of the optical deflection apparatus shown in FIG. It is sectional drawing in the III-III line of the optical deflection | deviation apparatus shown in FIG. It is sectional drawing in the IV-IV line of the optical deflection apparatus shown in FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is sectional drawing in the XXIX-XXIX line | wire of the optical deflection apparatus shown in FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 1. FIG. 6 is a plan view of an optical deflecting device of Embodiment 2. FIG. It is sectional drawing in the LIV-LIV line | wire of the optical deflection apparatus shown in FIG. It is sectional drawing in the LV-LV line of the optical deflection apparatus shown in FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 2. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 2. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 2. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 2. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 2. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 2. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 2. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 2. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 2. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 2. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 2. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 2. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 2. FIG. It is sectional drawing in the LXIX-LXIX line | wire of the optical deflection apparatus shown in FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 2. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 2. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 2. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 2. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 2. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 2. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 2. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 2. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 2. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 2. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 2. FIG. It is a figure explaining the manufacturing process of the optical deflection | deviation apparatus of Example 2. FIG. It is a figure which shows the modification of a protrusion part and a control part. It is a figure which shows the modification of a protrusion part and a control part. It is a figure which shows the modification of an optical deflection apparatus. It is a figure which shows the modification of a protrusion part and a control part. It is a figure which shows the optical apparatus of a prior art example. It is a figure which shows the optical apparatus of a prior art example.

The main features of the embodiments described below are listed below.
(Feature 1) The conducting portion has a folded shape. Thereby, the twisting resistance force of the conduction part is made smaller than the twisting resistance force of the protruding part. Therefore, it is possible to reduce the influence of the twisting resistance force of the conducting portion on the swinging motion of the movable portion.
(Feature 2) A first columnar portion and a second columnar portion are formed in the lower layer of the substrate. First and second protrusions protrude from one end of the outer periphery of the first and second columnar parts. The 1st and 2nd control part is formed in the edge part of a movable part. The 1st control part has surrounded the circumference of the central axis of the 1st projection part. The second restricting portion surrounds the center axis of the second protrusion.

  The optical deflecting device 20 according to the first embodiment will be described. FIG. 1 is a plan view of the light deflecting device 20. 2 is a cross-sectional view taken along line II-II in FIG. 3 is a cross-sectional view taken along line III-III in FIG. FIG. 4 is an enlarged view of a section taken along line IV-IV in FIG. FIG. 4 corresponds to a cross-sectional view of a cross section perpendicular to the central axis 240 of the restricting portion 250a. 29 is an enlarged view of a cross section taken along line XXIX-XXIX in FIG.

  The movable part 220 includes a conductive layer 225 and insulating layers 223 and 224 formed around the conductive layer 225. A conductive layer 225 is formed on the upper surface of the insulating layer 223, and an insulating layer 224 is formed on the upper surface and side surfaces of the conductive layer 225. In addition, a reflective layer (not shown) is formed on the upper part of the movable part 220, so that the movable part 220 functions as a mirror. A protruding portion 241 a is formed at the end 242 a of the movable portion 220. Further, a protruding portion 241 b is formed at the end 242 b of the movable portion 220. The protrusions 241a and 241b have the same central axis 240. As shown in FIG. 3, the pair of protruding portions 241 a and 241 b includes insulating layers 223 and 224 and a conductive layer 225. As shown in FIGS. 1 and 3, the projecting portions 241a and 241b are elongated. The longitudinal axis of the protrusions 241 a and 241 b is the central axis 240 of the movable part 220.

  As shown in FIGS. 1 and 3, restricting portions 250 a and 250 b are installed on the substrate lower layer 200. The restricting portion 250a surrounds the periphery of the central axis 240 of the protruding portion 241a with an appropriate gap that allows the protruding portion 241a to rotate. Similarly, the restricting portion 250b surrounds the central axis 240 of the protruding portion 241b so that the protruding portion 241b can rotate. Accordingly, the protruding portion 241a is supported by the restricting portion 250a, and the protruding portion 241b is supported by the restricting portion 250b. The movable portion 220 is supported so as to be swingable around the central axis 240 at a position separated above the substrate lower layer 200.

  As shown in FIG. 1, the protruding portion 241a protrudes from the end portion 242a along the central axis 240 by a distance La. Similarly, the protruding portion 241b protrudes from the end portion 242b along the central axis 240 by a distance Lb. The distance between the end on the movable portion 220 side of the restricting portion 250a and the end 242a of the movable portion 220 is defined as a distance Da. Similarly, the distance between the end on the movable portion 220 side of the restricting portion 250b and the end 242b of the movable portion 220 is defined as a distance Db. Here, each of the distance La and the distance Lb is made larger than the total distance of the distance Da and the distance Db.

  As shown in FIG. 2, the substrate lower layer 200 includes a wafer layer 201, insulating layers 202 and 203, and fixed electrodes 204a and 204b. The wafer layer 201, the insulating layer 202 formed on the entire upper surface of the wafer layer 201, and the fixed electrodes 204a and 204b are planar. The fixed electrodes 204 a and 204 b are formed symmetrically with respect to a plane that includes the central axis 240 of the movable portion 220 and is perpendicular to the movable portion 220. The fixed electrodes 204a and 204b are insulated from each other. Each of the external terminals 231a and 231b passes through the insulating layers 203, 223, and 224. The fixed electrode 204a is electrically connected to the external terminal 231a, and the fixed electrode 204b is electrically connected to the external terminal 231b. An insulating layer 203 is formed on the upper surfaces of the fixed electrodes 204 a and 204 b and the insulating layer 202. The entire substrate lower layer 200 is planar.

  As shown in FIGS. 1 and 3, a columnar section 210 is formed on the substrate lower layer 200. A conducting portion 270 extends from one end of the outer periphery of the columnar portion 210 and is electrically connected to the end portion 244 of the protruding portion 241a. The conducting portion 270 has a width that is smaller than the width Wa of the protruding portion 241a. The conduction part 270 has a folded shape. Thereby, the twisting resistance force of the conduction | electrical_connection part 270 is made smaller than the twisting resistance force of the protrusion part 241a. Therefore, the influence of the twisting resistance force of the conducting portion 270 on the driving force required when the movable portion 220 is swung can be reduced. Further, by reducing the influence of the torsional resistance force of the conducting portion 270, the respective inclination angles when the movable portion 220 is inclined so as to approach the fixed electrode 204a and when the movable portion 220 is inclined so as to approach the fixed electrode 204b are made uniform. Can do.

  As shown in FIG. 3, the columnar part 210 includes insulating layers 223 and 224 and a conductive layer 225 formed between the insulating layer 223 and the insulating layer 224. The conductive layer extracted from the external terminal 232 penetrates the insulating layer 224 and is electrically connected to the conductive layer 225. The insulating layer 223 of the columnar part 210 and the insulating layer 223 of the movable part 220 are continuous by the conductive part 270 and the insulating layer 223 of the protruding part 241a. Further, the insulating layer 224 of the columnar part 210 and the insulating layer 224 of the movable part 220 are continuous by the conductive part 270 and the insulating layer 224 of the protruding part 241a. Further, the conductive layer 225 of the columnar part 210 and the conductive layer 225 of the movable part 220 are continuous by the conductive part 270 and the conductive layer 225 of the protruding part 241a. Thereby, the external terminal 232, the conduction | electrical_connection part 270, the protrusion part 241a, and the movable part 220 are mutually electrically connected.

  In FIG. 4, the cross section perpendicular to the central axis 240 of the protrusion 241a is circular, and its diameter is R1. Further, the cross section perpendicular to the central axis 240 of the restricting portion 250a has a shape surrounding the protrusion 241a in a circular shape. The inner wall diameter of the restricting portion 250a is R2. The diameter R1 of the protruding portion 241a is smaller than the diameter R2 of the inner wall of the restricting portion 250a. The cross section of the projecting portion 241 a is circular over the entire length along the central axis 240. Similarly, the protrusion 241 b has a circular cross section over the entire length along the central axis 240. The restricting portion 250 a is formed above the conductive layer 204 installed on the insulating layer 202 of the substrate lower layer 200. The restricting portion 250a includes a conductive layer 254 and a conductive layer 295 existing therein, an insulating layer 253 and an insulating layer 296 covering the outer periphery of the conductive layer, and an insulating layer 255 and an insulating layer 294 covering the inner periphery of the conductive layer. ing. The distance between the lowest point of the inner wall of the restricting portion 250a (the point closest to the substrate lower layer 200) and the insulating layer 203 is a distance H. The distance H is the minimum value of the distance at which the movable part 220 is separated from the surface of the insulating layer 203. In addition, the protruding portion 241a includes a conductive layer 225 present at the center, an insulating layer 223 that covers the outer periphery of the conductive layer, and an insulating layer 224. In addition, since the structure of the control part 250b and the protrusion part 241b is the same as that of each of the control part 250a and the protrusion part 241a, detailed description is abbreviate | omitted here.

  The operation of the optical deflection apparatus 20 will be described. The light deflection apparatus 20 is an electrostatic drive type apparatus. In the optical deflecting device 20, the movable part 220 is swung around the central axis 240 by controlling the drive voltage applied to the fixed electrode 204a and the drive voltage applied to the fixed electrode 204b. For example, the case where the external terminal 232 is grounded and the external terminals 231a and 231b are connected to a drive signal generator (not shown) will be described. Since the external terminal 232, the conducting portion 270, the protruding portion 241a, and the movable portion 220 are electrically connected to each other, the potential of the movable portion 220 is set to the ground potential.

  When a drive voltage is applied to the fixed electrode 204a using the drive signal generator, an electrostatic attractive force is generated between the conductive layer 225 of the movable part 220 and the fixed electrode 204a. Therefore, the movable part 220 at a position facing the fixed electrode 204 a is attracted to the substrate lower layer 200. Accordingly, in FIG. 2, the movable portion 220 is tilted so that the lower end of the first end portion 227a of the movable portion 220 approaches the fixed electrode 204a and the second end portion 227b moves away from the fixed electrode 204b.

  Next, when a driving voltage is applied to the fixed electrode 204b, an electrostatic attractive force is generated between the conductive layer 225 and the fixed electrode 204b. Therefore, the movable portion 220 is tilted so that the lower end of the second end portion 227b of the movable portion 220 approaches the fixed electrode 204b and the first end portion 227a is separated from the fixed electrode 204a.

  The effect of the optical deflection apparatus 20 according to the first embodiment will be described. In the optical deflecting device 20 of the present application, a central axis 240 is formed by the protruding portion 241a and the protruding portion 241b. And while surrounding the protrusion part 241a with the restriction part 250a and surrounding the protrusion part 241b with the restriction part 250b, the movement range of the central axis 240 in the direction perpendicular to the central axis 240 can be restricted. . When the movable part 220 swings, it swings around the central axis 240. Therefore, even when the movable part 220 swings, the position of the central axis 240 does not move. Therefore, as in the case of the optical deflecting device 1000 of Patent Document 1 shown in FIGS. 86 and 87, the restricting portion can be made smaller as compared with the case where the portion away from the central axis is restricted. Thereby, when the optical deflecting device 20 is viewed in plan, the ratio (opening ratio) occupied by the area of the movable portion 220 to the area occupied by the optical deflecting device 20 can be increased.

  Further, in the optical deflecting device 20 of the present application, each of the distance La and the distance Lb is set larger than the total distance of the distance Da and the distance Db. When the movable part 220 moves to the left side of FIG. 1 along the central axis 240 until the end part 242a and the restricting part 250a come into contact with each other, the separation distance between the end part 242b and the restricting part 250b is maximized. The maximum value of the separation distance is the sum of the distance Da and the distance Db. In the optical deflecting device 20 of the present application, the distance Lb from which the protruding portion 241b protrudes is larger than the sum of the distance Da and the distance Db, so that the protruding portion 241b is disengaged from the restricting portion 250b. Can be prevented. Similarly, even when the movable portion 220 moves to the right side in FIG. 1 along the central axis 240 until the end portion 242b and the restricting portion 250b come into contact with each other, the distance La that the protruding portion 241a protrudes is the distance Da. Since the distance Db is larger than the total distance, the protruding portion 241a can be prevented from coming off the restricting portion 250a.

  A case will be described in which the movable portion 220 swings in a state where the protruding portions 241a and 241b are supported by the restricting portions 250a and 250b. In the optical deflecting device 20 of the present application, the cross section of the projecting portion 241a is circular in the cross section perpendicular to the central axis 240. Therefore, the shape of the lower surface of the protruding portion 241a has a curved surface and protrudes toward the substrate lower layer 200 side. Then, when the lower surface of the protruding portion 241a and the inner wall of the restricting portion 250a come into contact with each other, they come into contact with a curved surface. That is, when viewed in a cross section perpendicular to the central axis 240 (FIG. 4), both are always in point contact. Therefore, when the movable part 220 swings, no catch is generated, so that the movable part 220 can swing smoothly. Similarly, the protrusion 241b and the restricting portion 250b are not caught in the same manner, so that the movable portion 220 can be smoothly swung.

  In the optical deflecting device 20 of the present application, the protrusions 241a and 241b have a circular cross section perpendicular to the central axis 240. When various forces such as electrostatic attraction act on the movable part 220, the movable part 220 is in a state where the outer peripheral surface of the projecting part 241a is in contact with various parts such as the side surface part and the upper surface part of the inner wall of the restricting part 250a. May swing. In the optical deflecting device 20 of the present application, since the shape of the cross section perpendicular to the central axis 240 of the protruding portion 241a is circular, the outer peripheral surface of the protruding portion 241a is all curved. Therefore, even when the outer peripheral surface of the projecting portion 241a contacts any position on the inner wall of the restricting portion 250a, the movable portion 220 can be smoothly swung because the contact portion between the both does not occur. Can do. Similarly, the protrusion 241b and the restricting portion 250b are not caught in the same manner, so that the movable portion 220 can be smoothly swung.

  As a comparative example, an optical deflecting device in which the movable part is supported by a support beam and has a fixed end will be described. In the optical deflecting device, in order to make it difficult for the support beam to bend in the vertical vertical direction of the lower layer of the substrate, it is necessary to increase the thickness in the direction perpendicular to the movable portion of the cross section of the support beam. However, as the thickness of the cross section of the support beam in the direction perpendicular to the movable portion increases, the torsional resistance force of the support beam increases, so that the driving force required to swing the movable portion increases. Therefore, since it is necessary to balance the flexibility of the support beam and the driving force, there is a problem that it becomes difficult to design the optical deflecting device. On the other hand, in the optical deflecting device 20 of the present application, the protrusions 241a and 241b are surrounded by the restricting parts 250a and 250b, so that the ends of the protrusions 241a and 241b supporting the movable part 220 are provided. It is not fixed. Therefore, since there is no twisting resistance of the support beam, in order to make the protrusions 241a and 241b difficult to bend in the vertical vertical direction of the substrate lower layer 200, the thickness in the direction perpendicular to the movable part 220 of the cross section of the protrusions 241a and 241b is set. Even when the thickness is increased, the driving force required to swing the movable portion does not increase. Therefore, it is possible to achieve both a reduction in the amount of movement of the movable portion 220 in the vertical vertical direction of the substrate lower layer 200 and a large swing angle with a small driving force. Thus, even when a large acceleration having a direction perpendicular to the wafer surface is applied to the movable part 220, such as when the optical deflection apparatus 20 is assembled or when the optical deflection apparatus 20 is dropped, the movable part 220 is moved to the lower substrate layer 200. The amount of sinking in the direction can be reduced. Therefore, it is possible to prevent the occurrence of so-called sticking in which the lower surface of the movable portion 220 sticks to the upper surface of the substrate lower layer 200.

  Next, a method for manufacturing the optical deflection apparatus 20 including the restricting portions 250a and 250b will be described with reference to FIGS. 5 to 28 show the state of the material wafer in each step of the manufacturing process of the optical deflecting device 20 or a laminated body in which an insulating layer or the like is laminated on the upper surface of the material wafer, in the same cross section as FIG. 30 to 51 show the state of the laminated body in the same cross section as FIG. In addition, about the other structure of the optical deflection | deviation apparatus 20, the manufacturing method of the optical deflection | deviation apparatus using the general MEMS technique used conventionally can be applied.

  First, each layer constituting the substrate lower layer 200 is formed. First, a material wafer 201 as shown in FIG. 5 is prepared. As a material of the material wafer 201, for example, a single crystal silicon substrate can be used. Next, thermal oxidation or the like is performed to form an insulating layer 202 made of an oxide film on the upper surface of the material wafer 201. Next, a conductive layer 204 made of polysilicon or the like is formed on the upper surface of the insulating layer 202, and is patterned by photo-etching to form a base portion of the restricting portion 250a. In addition, the fixed electrodes 204a and 204b (see FIGS. 1 and 2) are also formed simultaneously by this photoetching. Here, the photoetching means a series of processes from photolithography to etching. Further, the insulating layer 203 is formed over the insulating layer 202, the conductive layer 204, and the fixed electrodes 204a and 204b. Thereby, the substrate lower layer 200 shown in FIG. 6 can be formed.

  A first sacrificial layer 251 made of polysilicon or the like is formed on the stacked body shown in FIG. Next, thermal oxidation or the like is performed to form an etching mask 261 made of an oxide film on the upper surface of the first sacrificial layer 251. An etching hole 262 is formed by patterning the etching mask 261 by photoetching. As a result, an etching mask 261 having an etching hole 262 is formed as shown in FIGS. In FIG. 7, the center position of the etching hole 262 coincides with the center position of the restricting portion 250a. Further, the opening width W5 of the etching hole 262 is smaller than the width W1 of the restricting portion 250a (see FIG. 4). This is because etching in the lateral direction of the etching hole 262 occurs by isotropic etching, as will be described later.

Next, an isotropic etching process is performed on the first sacrificial layer 251 through the etching hole 262. As an example of isotropic etching, dry etching using XeF ₂ (xenon difluoride) gas or the like can be given. Moreover, wet etching using TMAH (Tetra methyl ammonium hydroxide) containing a surfactant or the like can be given. By the isotropic etching process, a recess 263 is formed around the opening of the etching hole 262 as shown in FIGS. In isotropic etching, since etching is performed simultaneously in the vertical and horizontal directions, an undercut (etching in the horizontal direction of the etching hole 262) occurs. Therefore, as shown in FIG. 8, the cross-sectional shape of the recess 263 formed in the first sacrificial layer 251 by etching can be made semicircular. Further, the value of the radius of the semicircular shape of the recess 263 can be adjusted by the processing time of the isotropic etching process. In addition, as shown in the plan view of FIG. 52, the recessed portion 263 is formed so as to dig up the entire region including the movable portion 220, the protruding portions 241a and 241b, the regulating portions 250a and 250b, and the conducting portion 270. Thereafter, the etching mask 261 is removed to obtain a shape in which the recess 263 is formed in the first sacrificial layer 251 as shown in FIGS.

  Next, a resist layer (not shown) is applied on the first sacrificial layer 251. Then, the resist layer is patterned by photoetching so that an opening is formed at the bottom of the recess 263. The first sacrificial layer 251 and the insulating layer 203 are anisotropically etched through the patterned resist layer. An example of anisotropic etching is RIE (Reactive Ion Etching). Thereafter, the resist layer is removed. Thereby, as shown in FIGS. 10 and 33, the first sacrificial layer 251 and the insulating layer 203 on the bottom surface of the recess 263 are removed, and a hole 264 is formed.

  The stacked body shown in FIGS. 10 and 33 is subjected to thermal oxidation treatment, and an insulating layer 253 made of an oxide film is formed on the surfaces of the first sacrificial layer 251 and the conductive layer 204. Thereby, the laminated body shown in FIG. 11 and FIG. 34 is obtained.

  The stacked body shown in FIGS. 11 and 34 is planarized by CMP (Chemical Mechanical Polishing). As a result, the insulating layer 253 formed on the upper surface of the first sacrificial layer 251 is removed, so that the insulating layer 253 remains only on the surfaces of the recess 263 and the hole 264. Further, a resist layer (not shown) in which only the bottom surface of the hole 264 is exposed is formed, and after performing an anisotropic etching process, the resist layer is removed. Thereby, the insulating layer 253 on the bottom surface of the hole 264 is removed, and the conductive layer 204 is exposed. Therefore, the laminate shown in FIGS. 12 and 35 is obtained.

  A polysilicon conductive layer 254 is formed on the stacked body shown in FIGS. Then, only the conductive layer 254 formed on the upper surface of the first sacrificial layer 251 is removed by planarization by CMP. Then, a resist layer 265 that matches the shapes of the movable portion 220 and the restricting portions 250a and 250b is formed. Then, the conductive layer 254 is patterned by a photoetching process. Thereby, the laminated body shown in FIG. 13 and FIG. 36 is obtained. Also, as shown in FIG. 36, the conductive layer 254 in the region of the movable portion 220 and the conductive layer 254 in the region of the protruding portion 241b are separated.

  The resist layer 265 is removed from the stacked body shown in FIGS. Then, an insulating layer 255 made of a thermal oxide film is formed on the upper surface of the conductive layer 254. Further, only the insulating layer 255 formed on the upper surface of the first sacrificial layer 251 is removed by planarization by CMP. Thereby, the laminated body shown in FIG. 14 and FIG. 37 is obtained.

  A resist layer 266 that matches the shapes of the movable portion 220 and the restricting portions 250a and 250b is formed on the top surface of the laminate shown in FIGS. Then, the insulating layer 255 and the insulating layer 253 are patterned by a photoetching process. Thereby, the laminated body shown in FIG. 15 and FIG. 38 is obtained. As shown in FIG. 38, the insulating layers 253 and 255 in the region of the movable portion 220 are separated from the insulating layers 253 and 255 in the region of the restricting portion 250b.

  A second sacrificial layer 256 is formed on the upper surface of the stacked body shown in FIGS. 15 and 38 using polysilicon. Then, by flattening by the CMP process, only the second sacrificial layer 256 in the recess 257 (FIG. 16) and the recess 263 (FIG. 39) is left. Thereby, the laminated body shown in FIG. 16 and FIG. 39 is obtained.

  Next, thermal oxidation or the like is performed to form an etching mask 280 made of an oxide film on the upper surface of the stacked body shown in FIGS. An etching hole 282 is formed by patterning the etching mask 280 by photoetching. The shape of the etching hole 262 is a shape corresponding to the movable portion 220 and the protruding portions 241a and 241b, as shown in the hatched portion in the top view of FIG. The center position of the etching hole 282 corresponding to the protrusion 241a coincides with the center position of the protrusion 241a. Next, an isotropic etching process is performed on the second sacrificial layer 256 through the etching hole 282. As shown in FIGS. 17 and 40, a recess 283 is formed around the opening of the etching hole 282 by the isotropic etching process. In the isotropic etching, the etching is simultaneously performed in the vertical and horizontal directions. Therefore, in the region corresponding to the protruding portion 241a, the cross-sectional shape of the recessed portion 283 can be a semicircular shape as shown in FIG. Moreover, the radius in the semicircle shape of the hollow part 283 can be adjusted with the processing time of an isotropic etching process. The radius of the recess 283 in FIG. 17 may be determined so as to coincide with the radius of the circle in the cross section of the protrusion 241a.

  After removing the etching mask 280 from the stacked body shown in FIGS. 17 and 40, a resist layer 267 having an etching hole 268 is formed. The etching hole 268 is formed so as to be located in a region where the movable portion 220 is formed when the stacked body shown in FIGS. 17 and 40 is observed from the upper surface. Then, the second sacrificial layer 256 is patterned by a photoetching process. Thereby, the trench part 269 is formed. In addition, the insulating layer 255 is exposed on the bottom surface of the trench portion 269. And the laminated body shown in FIG. 18 and FIG. 41 is obtained.

  After removing the resist layer 267 from the stacked body shown in FIGS. 18 and 41, an insulating layer 223 made of an oxide film is formed. At this time, the inside of the trench portion 269 is filled with the insulating layer 223. Then, the insulating layer 223 filled in the trench portion 269 is connected to the insulating layer 255 exposed on the lower surface of the trench portion 269. Thereafter, planarization is performed by a CMP process, so that only the insulating layer 223 in the recess 283 is left. Thereby, the laminated body shown in FIG. 19 and FIG. 42 is obtained.

  A polysilicon conductive layer 225 is formed on the stacked body shown in FIGS. Then, planarization is performed by CMP. Thereby, the laminated body shown in FIG. 20 and FIG. 43 is obtained.

  A resist layer 258 is applied to the stacked body of FIGS. Next, the resist layer 258 is exposed using a special mask called a gray scale mask to perform a patterning process. The patterning is performed according to the size and shape of the conductive layer of the protruding portion 241a. The gray scale mask is a mask that has light and shade in the mask portion and can control the amount of light transmitted during exposure by the light and shade. In the exposure process of the resist layer 258, the deeper part of the resist is exposed as the light transmission amount of the mask increases. Then, in the case of using a positive type resist (a resist whose solubility in a developer increases when exposed to light and the exposed part is removed), the resist layer that remains after development as the light transmission amount increases. The height of 258 is lowered. Thereby, the laminated body shown in FIG. 21 and FIG. 44 is obtained.

  The gray scale mask used in Example 1 has a small amount of light transmission at the central portion (FIG. 21, point P1) of the upper surface of the conductive layer of the protrusion 241a, and both ends of the conductive layer of the protrusion 241a (FIG. 21). , The light transmission amount increases as the point P2) is reached. Then, by developing the resist layer 258 after the exposure, as shown in FIG. 21, a three-dimensional resist layer 258 having a curved surface is formed on the upper surface of the region where the protruding portion 241a is formed. can do.

  Note that it is also possible to use a negative resist (a resist whose solubility in a developing solution is reduced when exposed and in which an exposed portion remains after development). In this case, the amount of light transmitted through the central portion (FIG. 21, point P1) of the upper surface of the projecting portion 241a is large, and the amount of transmitted light decreases toward the end portion (FIG. 21, point P2) of the projecting portion 241a. Such a gray scale mask may be used.

  Next, the conductive layer 225 is anisotropically etched through the resist layer 258 patterned into a three-dimensional shape. At this time, the three-dimensional shape of the resist layer 258 is transferred to the lower conductive layer 225. Thereby, the laminated body shown in FIG. 22 and FIG. 45 is obtained. Therefore, as shown in FIG. 22, a conductive layer 225 having a circular cross section in a cross section perpendicular to the central axis 240 is formed.

  Note that the conductive layer 225 is simultaneously formed in the region where the movable portion 220 is formed. Then, the conductive layer 225 in the region for forming the movable part 220 is patterned into the shape of the movable part 220 by another photoetching process before and after the etching process using the gray scale mask of FIG. Thereby, the conductive layer 225 (FIG. 2, FIG. 3) inside the movable part 220 is formed.

  An insulating layer 224 made of an oxide film is formed by performing thermal oxidation treatment on the stacked body shown in FIGS. Thereby, the laminated body shown in FIG. 23 and FIG. 46 is obtained.

  A resist layer 292 is formed on the stacked body shown in FIGS. Then, the insulating layer 224 and the insulating layer 223 are patterned by photoetching that matches the shapes of the protruding portions 241a and 241b and the movable portion 220. Thus, only the insulating layer 224 covering the conductive layer 225 is left, so that the stacked body shown in FIGS. 24 and 47 is formed. Note that the insulating layer 224 in the region for forming the movable portion 220 is also simultaneously photo-etched to be patterned into the shape of the movable portion 220. Thereby, the insulating layer 224 (FIGS. 2 and 3) on the upper surface of the movable portion 220 is formed.

  24 and 47, the resist layer 292 is removed, and a third sacrificial layer 293 made of polysilicon is formed. Then, the third sacrificial layer 293 is patterned by photoetching that matches the shape of the second sacrificial layer 256. Thereby, only the third sacrificial layer 293 covering the insulating layer 224 is left, so that the stacked body shown in FIGS. 25 and 48 is formed.

  An insulating layer 294 made of an oxide film is formed by performing thermal oxidation treatment on the stacked body in FIGS. Then, the insulating layer 294 is patterned by photoetching that matches the shapes of the restricting portions 250a and 250b. Thereby, the laminated body shown in FIGS. 26 and 49 is formed. Then, as shown in FIG. 26, only the insulating layer 294 covering the third sacrificial layer 293 is left.

  In the same manner, a conductive layer 295 made of polysilicon is formed on the stack of FIGS. 26 and 49, and photoetching is performed in accordance with the shapes of the restricting portions 250a and 250b. Is formed. In addition, an insulating layer 296 made of an oxide film is formed on the stacked body shown in FIGS. Thereafter, the insulating layer 296 and the insulating layer 294 other than the restricting portions 250a and 250b are removed by photoetching. Thereby, the laminated body shown in FIGS. 28 and 51 is formed.

When the stacked body shown in FIGS. 28 and 51 is subjected to isotropic etching or the like with XeF ₂ gas, the first sacrificial layer 251, the second sacrificial layer 256, and the third sacrificial layer 293 are removed. The isotropic etching process performed in the steps of FIGS. 28 and 51 is performed until all of the first sacrificial layer 251 to the third sacrificial layer 293 are completely removed. As a result, as shown in FIGS. 4 and 29, the protruding portion 241a can be separated from the inner wall of the restricting portion 250a, and the protruding portion 241b can be separated from the inner wall of the restricting portion 250b. Thereby, the optical deflection apparatus 20 shown in FIGS. 1 to 3 is completed.

  In addition, since the conduction | electrical_connection part 270 is produced simultaneously with the protrusion part 241a similarly to the process of producing the protrusion part 241a, detailed description of the manufacturing process of the conduction | electrical_connection part 270 is abbreviate | omitted here.

  An optical deflecting device 30 according to the second embodiment will be described. FIG. 53 is a plan view of the light deflecting device 30. 54 is a cross-sectional view taken along line LIV-LIV in FIG. 55 is an enlarged view of a cross section taken along line LV-LV in FIG. 69 is an enlarged view of a cross section taken along line LXIX-LXIX of FIG. The movable part 320 is formed by a conductive layer 325. A projecting portion 341 a is formed at the end 342 a of the movable portion 320. In addition, a protruding portion 341 b is formed at the end 342 b of the movable portion 320. The protrusions 341a and 341b have the same central axis 340.

  As shown in FIGS. 53 and 54, restricting portions 350 a and 350 b are installed on the substrate lower layer 300. The protruding portion 341a is supported by the restricting portion 350a, and the protruding portion 341b is supported by the restricting portion 350b. The movable part 320 is supported so as to be swingable around the central axis 340 at a position separated above the substrate lower layer 300. An external terminal 332 is formed on the substrate lower layer 300. The conductive layer 304 that is the base of the restriction portion 350 a extends to the external terminal 332 side and is electrically connected to the external terminal 332.

  In FIG. 55, the cross section perpendicular to the central axis 340 of the protrusion 341a is circular. Further, the cross section of the restricting portion 350a perpendicular to the central axis 340 has a shape surrounding the protrusion 341a in a circular shape. The restriction portion 350 a is formed above the conductive layer 304 that is installed on the wafer layer 301 of the substrate lower layer 300. The restriction portion 350 a is formed by the conductive layer 354 and the conductive layer 395. Further, the protruding portion 341 a is formed by the conductive layer 325.

  In addition, since the structure of the control part 350b and the protrusion part 341b is the same as that of each of the control part 350a and the protrusion part 341a, detailed description is abbreviate | omitted here. Further, since the other structure of the optical deflecting device 30 is the same as that of the optical deflecting device 20 of the first embodiment, detailed description thereof is omitted.

  The conductive material is exposed on the surface of the protruding portion 341a and the inner wall surface of the portion surrounding the protruding portion 341a of the restricting portion 350a. Therefore, when the protruding portion 341a is supported by the restricting portion 350a, electrical conduction can be obtained by bringing the conductive materials into contact with each other. Then, the external terminal 332, the conductive layer 304, the restricting portion 350a, the protruding portion 341a, and the movable portion 320 are electrically connected to each other. Then, by applying a ground potential to the external terminal 332 and applying a drive voltage to one of the fixed electrodes 304a or 304b, an electrostatic attractive force can be applied between the movable portion 320 and the fixed electrode to which the drive voltage is applied. it can. Thereby, the movable part 320 can be swung with respect to the substrate lower layer 300.

  The effect of the light deflection apparatus 30 according to the second embodiment will be described. According to the optical deflecting device 30 of the second embodiment, the restricting portion 350a functions as a support portion that supports the protruding portion 341a, and also serves as a conduction portion for establishing conduction between the external terminal 332 and the movable portion 320. Can function. Thereby, since it is not necessary to form separately the conduction | electrical_connection part 270 with which the optical deflection | deviation apparatus 20 of Example 1 is provided, the structure of the optical deflection | deviation apparatus 30 can be simplified more.

  Next, a method for manufacturing the optical deflection apparatus 30 according to the second embodiment will be described with reference to FIGS. In the manufacturing method of the optical deflecting device 30, as compared with the manufacturing method of the optical deflecting device 20 according to the first embodiment (FIGS. 4 to 52), the restricting portion 350 a and the protruding portion 341 a are formed of only the conductive layer 325. The point is different. Another difference is that an oxide film is used as the sacrificial layer.

  As shown in FIG. 56, a conductive layer 304 made of polysilicon is formed on the upper surface of the material wafer 301, and is patterned by photoetching to form a base portion of the restricting portion 350a. In addition, the fixed electrodes 304a and 304b (see FIG. 53) are also formed simultaneously by this photoetching. After that, the insulating layer 302 and the conductive layer 303 are stacked in order. Thereby, the substrate lower layer 300 shown in FIG. 56 can be formed.

  A first sacrificial layer 351 made of an oxide film is formed on the stacked body shown in FIG. Next, an etching mask 361 made of a resist layer is formed on the upper surface of the first sacrificial layer 351. An etching hole 362 is formed by patterning the etching mask 361 by photoetching. An isotropic etching process is performed on the first sacrificial layer 351 through the etching hole 362. Examples of isotropic etching include dry etching using a fluorine-based gas or the like. As shown in FIGS. 57 and 70, a recess 363 is formed around the opening of the etching hole 362 by the isotropic etching process. The value of the radius in the semicircular shape of the recess 363 can be adjusted by the processing time of the isotropic etching process. Further, the recess 363 is formed so as to dig up the entire region including the movable portion 320, the protruding portions 341a and 341b, and the restricting portions 350a and 350b. Thereafter, the etching mask 361 is removed.

  A resist layer (not shown) is applied on the first sacrificial layer 351. Then, the resist layer is patterned by photoetching so that an opening is formed at the bottom of the recess 363. The conductive layer 303 and the insulating layer 302 are anisotropically etched through the patterned resist layer. Thereby, as shown in FIGS. 58 and 71, the first sacrificial layer 351, the conductive layer 303, and the insulating layer 302 on the bottom surface of the recess 363 are removed, and a hole 364 is formed.

  A polysilicon conductive layer 354 is formed on the stacked body shown in FIGS. Then, only the conductive layer 354 formed on the upper surface of the first sacrificial layer 351 is removed by planarization by CMP. Thereby, the laminated body shown in FIGS. 59 and 72 is obtained.

  An etching mask 380 made of a resist layer is formed on the top surface of the stacked body shown in FIGS. An etching hole 382 is formed by patterning the etching mask 380 by photoetching. Next, an isotropic etching process is performed on the conductive layer 354 through the etching hole 382. The laminated body shown in FIGS. 60 and 73 is obtained by the isotropic etching process. And in the area | region which produces the protrusion part 341b, as shown in FIG. 60, the hollow part 383 is formed centering on the opening part of the etching hole 382. As shown in FIG.

  After removing the etching mask 380 from the stacked body shown in FIGS. 60 and 73, a resist layer 366 is formed in accordance with the shapes of the movable portion 320 and the restricting portions 350a and 350b. Then, the conductive layer 354 is patterned by a photoetching process. Thereby, the laminated body shown in FIGS. 61 and 74 is obtained. As shown in FIG. 74, the conductive layer 354 in the region of the movable portion 320 and the conductive layer 354 in the region of the restricting portion 350b are separated.

  After removing the resist layer 366 from the stacked body shown in FIGS. 61 and 74, a second sacrificial layer 356 is formed using an oxide film. Then, by planarization by the CMP process, only the second sacrificial layer 356 in the recess 383 is left. Thereby, the laminated body shown in FIGS. 62 and 75 is obtained.

  A resist layer 367 having an etching hole 368 is formed in the stacked body shown in FIGS. The etching hole 368 is formed so as to be located in a region where the movable portion 320 is formed when the stacked body shown in FIGS. 62 and 75 is observed from the upper surface. Then, the second sacrificial layer 356 is patterned by a photoetching process. As a result, a trench portion 369 is formed. Further, the conductive layer 354 is exposed on the bottom surface of the trench portion 369. And the laminated body shown in FIG. 63 and FIG. 76 is obtained.

  After removing the resist layer 367 from the stacked body shown in FIGS. 63 and 76, a polysilicon conductive layer 325 is formed. At this time, the inside of the trench portion 369 is filled with the conductive layer 325. The conductive layer 325 filled in the trench portion 369 is connected to the conductive layer 354 exposed on the lower surface of the trench portion 369. Then, planarization is performed by CMP. Thereby, the laminated body shown in FIGS. 64 and 77 is obtained.

  A resist layer 359 is applied to the stacked body of FIGS. Next, the resist layer 359 is exposed using a gray scale mask to perform a patterning process. Patterning is performed in accordance with the size and shape of the protrusion 341a. By developing the resist layer 359 after exposure, the laminate shown in FIGS. 65 and 78 is obtained. At this time, as shown in FIG. 65, a three-dimensional resist layer 359 having a curved surface and protruding can be formed on the upper surface of the region where the protruding portion 341a is formed. Next, the conductive layer 325 is anisotropically etched through the resist layer 359 patterned into a three-dimensional shape. At this time, the three-dimensional shape of the resist layer 359 is transferred to the lower conductive layer 325. Therefore, the laminate shown in FIGS. 66 and 79 is obtained. At this time, as shown in FIG. 66, a conductive layer 325 having a circular cross section in a cross section perpendicular to the central axis 340 is formed.

  Note that the conductive layer 325 is simultaneously formed in a region where the movable portion 320 is formed. The conductive layer 325 in the region for forming the movable part 320 is patterned into the shape of the movable part 320 by another photoetching process before and after the etching process using the gray scale mask of FIGS. 66 and 79. Thereby, the movable part 320 (FIGS. 53 and 54) is formed by the conductive layer 325.

  A third sacrificial layer 393 made of an oxide film is formed on the stacked body of FIGS. 66 and 79. Next, an etching mask 398 made of a resist is formed. Then, the third sacrificial layer 393 is patterned by photoetching that matches the shapes of the protruding portions 341a and 341b and the movable portion 320. Thereby, the laminated body shown in FIGS. 67 and 80 is formed.

  The etching mask 398 is removed from the stacked body shown in FIGS. 67 and 80, and a conductive layer 395 made of polysilicon is formed. Next, an etching mask 399 is formed using a resist as a material. Then, the conductive layer 395 is patterned by photoetching that matches the shapes of the restricting portions 350a and 350b. Thereby, the laminated body shown in FIGS. 68 and 81 is formed.

  When the etching mask 399 is removed from the stacked body illustrated in FIGS. 68 and 81 and isotropic etching or the like is performed using a fluorine-based gas, the first sacrificial layer 351, the second sacrificial layer 356, and the third sacrificial layer 393 are performed. Is removed. The isotropic etching process performed in the process of FIG. 68 is performed until all of the first sacrificial layer 351 to the third sacrificial layer 393 are completely removed. Thereby, as shown in FIGS. 55 and 69, the protruding portion 341a can be separated from the inner wall of the restricting portion 350a. Thereby, the optical deflection apparatus 30 shown in FIGS. 53 and 54 is completed.

  The effect of the manufacturing method of the optical deflection apparatus 30 according to the second embodiment will be described. In the optical deflecting device 30 according to the second embodiment, the movable portion 320, the protruding portions 341a and 341b, and the restricting portions 350a and 350b can be formed of only a polysilicon conductive layer. Therefore, as compared with the optical deflecting device 20 according to the first embodiment, the process for covering the surface of the conductive layer with the insulating layer can be omitted, so that the optical deflecting device 30 can be formed with fewer steps. It becomes possible.

  As mentioned above, although the Example of this invention was described in detail, these are only illustrations and do not limit a claim. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

  In the first and second embodiments, the case where a gray scale mask is used has been described. However, the present invention is not limited to this form. Even when the gray scale mask is not used, it is possible to form the protruding portion and the restricting portion of the present application. In the process of FIG. 21 of the first embodiment, when a normal mask is used instead of the gray scale mask, the resist layer 258 is patterned into a two-dimensional shape having a certain thickness. In this case, the two-dimensional shape of the resist layer 258 is transferred to the lower conductive layer 225 during the anisotropic etching process. Thereafter, when the steps of FIGS. 22 to 28 are applied, a protruding portion 441a and a restricting portion 450a as shown in FIG. 82 are obtained. In the cross section perpendicular to the central axis of the protruding portion 441a, the lower surface has a semicircular shape and the upper surface has a rectangular shape. That is, the shape of the lower surface of the protruding portion 441a is a shape having a curved surface and protruding toward the substrate lower layer 400 side. Further, in the cross section perpendicular to the central axis of the restricting portion 450a, the lower surface of the inner wall surface is semicircular and the upper surface of the inner wall surface is rectangular. That is, of the inner wall of the restricting portion 450a, the portion facing the lower surface of the protruding portion 441a has a curved shape and is recessed.

  As a result, the lower surface of the protruding portion 441a and the upper surface (the recessed surface) of the inner wall of the restricting portion 450a mesh with each other. Therefore, it is possible to restrict the protrusion 441a from moving in a direction parallel to the substrate lower layer 400 and perpendicular to the central axis. That is, the protrusion 441a can be positioned on the restricting portion 450a. Moreover, both the lower surface of the protrusion part 441a and the upper surface of the inner wall of the control part 450a are formed in the curved surface. Therefore, even when the movable portion is swung around the central axis in a state where both surfaces are meshed with each other, the movable portion can be smoothly swung because no catch occurs at the meshing portion.

  Similarly, in the process of FIG. 65 of Embodiment 2, when a normal mask is used, the resist layer 359 is patterned into a two-dimensional shape having a constant thickness. In this case, the two-dimensional shape of the resist layer 359 is transferred to the lower conductive layer 325 during the anisotropic etching process. Thereafter, when the steps of FIGS. 66 to 68 are applied, a protruding portion 541a and a restricting portion 550a as shown in FIG. 83 are obtained. In the cross section perpendicular to the central axis of the protrusion 541a, the lower surface has a semicircular shape and the upper surface has a rectangular shape. In the cross section perpendicular to the central axis of the restricting portion 550a, the lower surface of the inner wall surface has a semicircular shape, and the upper surface of the inner wall surface has a rectangular shape. Therefore, also in the structure shown in FIG. 83, the movable part can be smoothly swung similarly to the structure shown in FIG.

  Moreover, although Example 1 and 2 demonstrated the case where a protrusion part was formed in a movable part and the control part surrounding the circumference | surroundings of a protrusion part was formed on a board | substrate lower layer, it is not restricted to this form. A configuration like the light deflection device 60 shown in the perspective view of FIG. 84 may be adopted. In the optical deflection device 60, columnar portions 610a and 610b are formed in the lower layer of the substrate. Protruding portions 641a and 641b protrude from one end of the outer periphery of the columnar portions 610a and 610b. In addition, restricting portions 650 a and 650 b are formed at the end of the movable portion 620. The restricting portion 650a surrounds the center axis 640 of the protruding portion 641a. Similarly, the restricting portion 650b surrounds the center axis 640 of the protruding portion 641b. Also in this form, the movable part 620 can be supported so as to be swingable around the central axis 640 at a position separated upward from the lower layer of the substrate.

  Moreover, various combinations are possible for the shapes of the protruding portion and the restricting portion. For example, a combination of the protruding portion 741a and the restricting portion 750a as shown in FIG. 85 may be used. In FIG. 85, in the cross section perpendicular to the central axis, the shape of the lower surface of the projecting portion 741a is a shape having a curved surface and projecting to the substrate lower layer 700. Then, when the lower surface of the projecting portion 741a and the upper surface of the inner wall of the restricting portion 750a (surface supporting the projecting portion 741a) come into contact, the curved surface and the flat surface are brought into contact. Therefore, when the movable part swings, the movable part can swing smoothly because no catch occurs.

  In the first and second embodiments, the case where the actuator that swings the movable portion is of the electrostatic drive type has been described. However, the present invention is not limited to this configuration. The technique of the present application is a technique related to the swinging of the movable part. Therefore, the technique of the present application can be applied to other driving systems such as an electromagnetic driving system and a thermal driving system.

  The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

20, 30, 60 Optical deflecting device 200, 300, 400 Substrate lower layer 220, 320, 620 Movable part 240, 340, 640 Center axis 241a, 241b, 341a, 341b, 441a, 441b, 641a, 641b, 741a, 741b Protruding part 250a, 250b, 350a, 350b, 650a, 650b, 750a, 750b, restriction part

Claims (8)

A substrate,
A plate-shaped movable part;
A first protrusion connected to the first end of the movable part;
A second protrusion connected to the second end of the movable part so as to have the same central axis as the first protrusion;
A first restricting portion disposed on the substrate and surrounding the periphery of the central axis of the first protruding portion so that the first protruding portion can rotate;
A second restricting portion disposed on the substrate and surrounding the central axis of the second protruding portion so that the second protruding portion can rotate;
An actuator for swinging the movable part;
With
The first protrusion is supported by the first restricting portion, and the second protrusion is supported by the second restricting portion, so that the movable portion is separated above the substrate. is swingably supported at a position around the central axis,
In a cross section perpendicular to the central axis of the first restricting portion, the surface facing the lower surface of the first projecting portion has a curved surface and is recessed.
In a cross section perpendicular to the central axis of the second restricting portion, the surface facing the lower surface of the second projecting portion has a curved surface and is recessed.
The shape of the lower surface of the first projecting portion in the cross section perpendicular to the central axis is a shape having a curved surface and projecting to the substrate side,
The curvature of the lower surface of the first projecting portion is equal to or greater than the curvature of the surface of the first restricting portion facing the lower surface of the first projecting portion;
The shape of the lower surface of the second projecting portion in the cross section perpendicular to the central axis is a shape having a curved surface and projecting toward the substrate side,
The light deflection apparatus , wherein a curvature of a lower surface of the second projecting portion is equal to or greater than a curvature of a surface of the second restricting portion facing the lower surface of the second projecting portion . A substrate,
A plate-shaped movable part;
A first protrusion connected to the first end of the movable part;
A second protrusion connected to the second end of the movable part so as to have the same central axis as the first protrusion;
A first restricting portion disposed on the substrate and surrounding the periphery of the central axis of the first protruding portion so that the first protruding portion can rotate;
A second restricting portion disposed on the substrate and surrounding the central axis of the second protruding portion so that the second protruding portion can rotate;
An actuator having a pair of lower electrodes at a position symmetrical to a plane perpendicular to the substrate passing through the central axis on the substrate, the actuator swinging the movable part;
A terminal portion installed on the substrate and electrically connected to the outside;
The first protrusion has a width smaller than the width in the direction along the substrate, is formed of a conductive material, one end is electrically connected to the terminal portion, and the other end is the first A conductive portion electrically connected to the end of the protruding portion;
With
The first protrusion is supported by the first restricting portion, and the second protrusion is supported by the second restricting portion, so that the movable portion is separated above the substrate. is swingably supported at a position around the central axis,
The movable portion and the first projecting portion are formed of the conductive material,
The optical deflecting device, wherein the first projecting portion and the movable portion are electrically connected. A substrate,
A plate-shaped movable part;
A first protrusion connected to the first end of the movable part;
A second protrusion connected to the second end of the movable part so as to have the same central axis as the first protrusion;
A first restricting portion disposed on the substrate and surrounding the periphery of the central axis of the first protruding portion so that the first protruding portion can rotate;
A second restricting portion disposed on the substrate and surrounding the central axis of the second protruding portion so that the second protruding portion can rotate;
An actuator having a pair of lower electrodes at a position symmetrical to a plane perpendicular to the substrate passing through the central axis on the substrate, the actuator swinging the movable part;
A terminal portion installed on the substrate and electrically connected to the outside;
With
The first protrusion is supported by the first restricting portion, and the second protrusion is supported by the second restricting portion, so that the movable portion is separated above the substrate. is swingably supported at a position around the central axis,
The first restricting portion is formed of a conductive material, and is electrically connected to the terminal portion,
The movable portion and the first projecting portion are formed of the conductive material,
The first protrusion and the movable part are electrically connected;
The light deflecting device, wherein the conductive material is exposed on a surface of the first projecting portion and an inner wall surface of the first restricting portion surrounding the first projecting portion. . The distance that the first protrusion protrudes from the first end along the central axis, and the second protrusion protrudes from the second end along the central axis. Each of the distances
A first separation distance along the central axis between the first end of the movable part and the first restricting part; and the second end of the movable part and the second restricting part. optical deflecting device according to any one of claims 1 to 3, wherein the greater than the distance which is the sum of a second separating distance along the central axis between the parts. The shape of the cross section perpendicular to the central axis of the first protrusion is a circular shape,
5. The optical deflection apparatus according to claim 1, wherein a shape of a cross section of the second projecting portion perpendicular to the central axis is a circular shape. 6. A substrate,
A plate-shaped movable part;
A first base portion that is installed at a position facing the first end of the movable portion on the substrate and extends above the substrate;
A second base portion that is installed at a position facing the second end of the movable portion on the substrate and extends above the substrate;
A first protrusion extending in parallel with the substrate from the first base portion toward the movable portion;
A second protrusion extending in parallel with the substrate from the second base portion toward the movable portion so as to have the same central axis as the first protrusion;
A first restricting portion connected to a first end of the movable portion, the first projecting portion rotatably surrounding the central axis of the first projecting portion;
A second restricting portion connected to the second end of the movable portion, the second projecting portion rotatably surrounding the central axis of the second projecting portion;
An actuator for swinging the movable part;
With
The first restricting part is supported by the first projecting part, and the second restricting part is supported by the second projecting part, so that the movable part is separated above the substrate. is swingably supported at a position around the central axis,
In a cross section perpendicular to the central axis of the first restricting portion, a surface facing the upper surface of the first projecting portion has a curved surface and is recessed.
In a cross section perpendicular to the central axis of the second restricting portion, the surface facing the upper surface of the second projecting portion has a curved surface and is recessed.
The shape of the upper surface of the first protrusion in the cross section perpendicular to the central axis is a shape having a curved surface and protruding upward of the substrate,
The curvature of the upper surface of the first projecting portion is equal to or greater than the curvature of the surface of the first restricting portion facing the upper surface of the first projecting portion;
The shape of the upper surface of the second projecting portion in the cross section perpendicular to the central axis is a shape having a curved surface and projecting upward of the substrate,
The optical deflection device , wherein the curvature of the upper surface of the second protrusion is equal to or greater than the curvature of the surface of the second restricting portion facing the upper surface of the second protrusion . A substrate,
A plate-shaped movable part;
A first base portion that is installed at a position facing the first end of the movable portion on the substrate and extends above the substrate;
A second base portion that is installed at a position facing the second end of the movable portion on the substrate and extends above the substrate;
A first protrusion extending in parallel with the substrate from the first base portion toward the movable portion;
A second protrusion extending in parallel with the substrate from the second base portion toward the movable portion so as to have the same central axis as the first protrusion;
A first restricting portion connected to a first end of the movable portion, the first projecting portion rotatably surrounding the central axis of the first projecting portion;
A second restricting portion connected to the second end of the movable portion, the second projecting portion rotatably surrounding the central axis of the second projecting portion;
An actuator having a pair of lower electrodes at a position symmetrical to a plane perpendicular to the substrate passing through the central axis on the substrate, the actuator swinging the movable part;
A terminal portion installed on the substrate and electrically connected to the outside;
The first protrusion has a width smaller than the width in the direction along the substrate, is formed of a conductive material, one end is electrically connected to the terminal portion, and the other end is the first A conduction part electrically connected to the end of the restriction part;
With
The first restricting portion supports the first restricting portion, and the second projecting portion supports the second restricting portion, so that the movable portion is separated above the substrate. is swingably supported at a position around the central axis,
The movable part and the first restricting part are formed of the conductive material,
The optical deflecting device, wherein the first restricting portion and the movable portion are electrically connected. A substrate,
A plate-shaped movable part;
A first base portion that is installed at a position facing the first end of the movable portion on the substrate and extends above the substrate;
A second base portion that is installed at a position facing the second end of the movable portion on the substrate and extends above the substrate;
A first protrusion extending in parallel with the substrate from the first base portion toward the movable portion;
A second protrusion extending in parallel with the substrate from the second base portion toward the movable portion so as to have the same central axis as the first protrusion;
A first restricting portion connected to a first end of the movable portion, the first projecting portion rotatably surrounding the central axis of the first projecting portion;
A second restricting portion connected to the second end of the movable portion, the second projecting portion rotatably surrounding the central axis of the second projecting portion;
An actuator having a pair of lower electrodes at a position symmetrical to a plane perpendicular to the substrate passing through the central axis on the substrate, the actuator swinging the movable part;
A terminal portion installed on the substrate and electrically connected to the outside;
With
The first restricting portion supports the first restricting portion, and the second projecting portion supports the second restricting portion, so that the movable portion is separated above the substrate. is swingably supported at a position around the central axis,
The first protrusion is formed of a conductive material, and is electrically connected to the terminal portion.
The movable part and the first restricting part are formed of the conductive material,
The first restricting portion and the movable portion are electrically connected;
The light deflecting device, wherein the conductive material is exposed on a surface of the first projecting portion and an inner wall surface of the first restricting portion surrounding the first projecting portion. .

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