Optical scanning device

Abstract

To provide an optical scanner which can suppress the occurrence of damage and the residue of foreign matter in a mirror device.SOLUTION: A mirror device (optical scanner) 1C comprises: a base unit; a movable unit 22 that is supported in the base unit; a connection unit that is connected to be movable unit 22 so that the movable unit 22 is movable with respect to the base unit; and a mirror layer 3 that is provided in the movable unit 22. A first penetration region 22d exhibiting an annular shape and extending along an outer edge of the movable unit 22, a plurality of second penetration regions 22e located outside of the first penetration region 22d, and a connection part 26 crossing a section of the first penetration region 22d that overlaps with the second penetration regions 22e are formed in the movable unit 22. A width D3 of a section of the movable unit 22 on the outside of the second penetration regions 22e is larger than a width D4 of a section of the movable unit 22 between the first penetration region 22d and the second penetration regions 22e.SELECTED DRAWING: Figure 17

Description

Technical Field

[0001] The present invention relates to an optical scanning device.

Background Art

[0002] As a MEMS (Micro Electro Mechanical Systems) device composed of an SOI (Silicon On Insulator) substrate, a structure including a base portion and a movable portion supported by the base portion, and a mirror layer provided on the movable portion is known. As a manufacturing method of such a mirror device, after releasing the movable portion so that the movable portion can move with respect to the base portion, the wafer may be washed with a cleaning liquid (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the manufacturing method of the mirror device as described above, since the wafer with the released movable portion is washed with a cleaning liquid, there is a risk of damage to a plurality of movable portions due to the load of the cleaning liquid. In order to suppress the occurrence of such damage, it is conceivable to weaken the strength of cleaning with the cleaning liquid, but in that case, there is a risk of foreign matter remaining on the wafer.

[0005] An object of the present invention is to provide a manufacturing method of a mirror device capable of suppressing the occurrence of damage and the remaining of foreign matter in the mirror device.

Means for Solving the Problems

[0006] The manufacturing method of the mirror device of the present invention is a manufacturing method of a mirror device including a base portion and a structure including a movable portion supported by the base portion, and a mirror layer provided on the movable portion, comprising: a first step of preparing a wafer having a support layer and a device layer; after the first step, by removing a part of each of the support layer and the device layer from the wafer by etching, a slit is formed in the wafer so that the movable portion can move with respect to the base portion, and a second step of forming a plurality of portions each corresponding to the structure in the wafer; after the second step, a third step of performing wet cleaning of washing the wafer with a cleaning liquid; after the third step, a fourth step of cutting out each of the plurality of portions from the wafer, and in the second step, by etching, a through hole penetrating the wafer is formed in a portion of the wafer other than the slit.

[0007] In this manufacturing method of the mirror device, in the third step, the wafer in a state where the movable portion can move with respect to the base portion (hereinafter referred to as "the movable portion is released") is washed with a cleaning liquid. Thereby, foreign matters can be removed from the wafer in which a plurality of movable portions are released. Here, in the second step, by etching, a through hole penetrating the wafer is formed in a portion of the wafer other than the slit. Therefore, in the wet cleaning in the third step, the wafer in which a plurality of movable portions are released can be washed while allowing the cleaning liquid to flow through the through holes. Therefore, the load applied to the plurality of movable portions by the cleaning liquid can be reduced, and damage to the plurality of movable portions can be suppressed. Thus, according to this manufacturing method of the mirror device, the occurrence of damage and the remaining of foreign matters in the mirror device can be suppressed.

[0008] In the manufacturing method of the mirror device of the present invention, in the second step, a mirror layer may be formed on a portion of the wafer corresponding to the movable portion. Thereby, foreign matters attached to the mirror layer can be removed by the wet cleaning in the third step.

[0009] In the method for manufacturing the mirror device of the present invention, between the third step and the fourth step, a fifth step of forming a correction layer on the first surface of the wafer where the mirror layer is formed and / or the second surface opposite to the first surface may be further provided. Thereby, it is possible to suppress foreign matter from being covered by the correction layer.

[0010] In the method for manufacturing the mirror device of the present invention, in the second step, after removing a part of the support layer from the wafer, a protective film removal for removing the protective film may be performed, and after the protective film removal, a plurality of parts may be completed. Thereby, foreign matter attached to the wafer when removing a part of the support layer from the wafer can be removed by the protective film removal in the second step. Further, when removing the protective film, foreign matter and the like remaining on the wafer can be removed by the wet cleaning in the third step.

[0011] In the method for manufacturing the mirror device of the present invention, in the protective film removal, the protective film may be removed by a wet process. When the protective film is removed by a wet process, for example, stains or the like may occur due to the unevenness of the device layer. In this case, such stains or the like can be removed by the wet cleaning in the third step.

[0012] In the method for manufacturing the mirror device of the present invention, in the second step, a patterning member removal for removing the patterning member may be performed, and after the patterning member removal, a plurality of parts may be completed. Thereby, since the patterning member is removed before the plurality of movable parts are released, the occurrence of damage in the mirror device due to the patterning member removal can be suppressed.

[0013] In the method for manufacturing the mirror device of the present invention, in the patterning member removal, the patterning member may be removed by a wet process. Thereby, since the patterning member is removed before the plurality of movable parts are released, even if the patterning member is removed by a wet process, the occurrence of damage in the mirror device can be suppressed.

[0014] In the method for manufacturing a mirror device of the present invention, in the second step, a plurality of flow holes may be formed in a portion corresponding to the movable part. Thereby, in the wet cleaning in the third step, turbulent flow of the cleaning liquid is likely to occur near the movable part, so that foreign matters can be reliably removed from the portion corresponding to the movable part.

[0015] In the method for manufacturing a mirror device of the present invention, a flow hole may be formed in a portion corresponding to the base part. Thereby, in the wet cleaning in the third step, the cleaning liquid can be circulated through the flow hole formed in the portion corresponding to the base part. Therefore, the load applied to the wafer by the cleaning liquid can be reduced, and the occurrence of damage in the mirror device can be suppressed.

[0016] In the method for manufacturing a mirror device of the present invention, in the second step, a slit may be formed so that the movable part is supported by the base part by a connecting part, and a flow hole may be formed in a portion corresponding to the connecting part. Thereby, while maintaining the strength of the connecting part, in the wet cleaning in the third step, turbulent flow of the cleaning liquid is likely to occur near the connecting part, so that foreign matters can be reliably removed from the portion corresponding to the connecting part.

[0017] In the method for manufacturing a mirror device of the present invention, in the second step, the flow hole may be formed so that at least a part thereof includes a curved part. Thereby, in the wet cleaning in the third step, the load applied to the curved part of the flow hole by the cleaning liquid is reduced, so that the occurrence of damage in the wafer can be suppressed.

[0018] In the method for manufacturing a mirror device of the present invention, in the second step, the flow hole may be formed so that the width of the flow hole in a direction perpendicular to the thickness direction changes when viewed from the thickness direction of the wafer. Thereby, in the wet cleaning in the third step, turbulent flow of the cleaning liquid is likely to occur, so that foreign matters can be reliably removed from the wafer.

[0019] In the method for manufacturing the mirror device of the present invention, in the second step, the flow-through holes may be formed such that, when viewed in the thickness direction of the wafer, the edge on one side of the flow-through hole and the edge on the other side opposite to the one side exhibit different shapes. Thereby, by forming larger flow-through holes, a larger amount of cleaning liquid can be circulated through the flow-through holes in the wet cleaning in the third step. Therefore, foreign matter can be reliably removed from the wafer.

[0020] In the method for manufacturing the mirror device of the present invention, in the second step, the flow-through holes may be formed such that a connecting portion straddling the flow-through holes is formed. Thereby, in the wet cleaning in the third step, since the wafer is reinforced by the connecting portion, the occurrence of damage to the wafer can be suppressed.

[0021] In the method for manufacturing the mirror device of the present invention, in the second step, the flow-through holes may be formed such that the flow-through holes communicate with the slits. Thereby, in the wet cleaning in the third step, a larger amount of cleaning liquid can be circulated through the flow-through holes.

[0022] In the method for manufacturing the mirror device of the present invention, in the second step, when viewed in the thickness direction of the wafer, the flow-through holes may be formed in a portion corresponding to the movable part so as to include a first flow region and a second flow region adjacent to each other in a direction perpendicular to the thickness direction. Thereby, in the wet cleaning in the third step, since turbulent flow of the cleaning liquid is likely to occur at a location where the first flow region and the second flow region are adjacent, foreign matter can be reliably removed from the wafer.

[0023] In the method for manufacturing a mirror device of the present invention, in the second step, a flow hole may be formed such that a connecting portion straddling the first flow region is formed in the direction in which the first flow region and the second flow region are arranged when viewed from the thickness direction. Thereby, in the wet cleaning in the third step, since the wafer is reinforced by the connecting portion, the occurrence of damage to the wafer can be suppressed. Further, in the wet cleaning in the third step, since the cleaning liquid can be circulated through the second flow region, the load applied to the connecting portion by the cleaning liquid can be reduced, and damage to the connecting portion can be suppressed.

[0024] In the method for manufacturing a mirror device of the present invention, in the second step, a flow hole may be formed such that the second flow region includes a portion where the width of the second flow region in the direction perpendicular to the thickness direction is smaller than the width of the first flow region in the direction perpendicular to the thickness direction when viewed from the thickness direction. Thereby, since the width of the first flow region and the width of the second flow region are different, turbulent flow of the cleaning liquid is likely to occur in the wet cleaning in the third step. Therefore, foreign matter can be reliably removed from the wafer.

[0025] In the method for manufacturing a mirror device of the present invention, in the second step, a slit is formed so that the movable portion is supported by the base portion by the connecting portion, and the second flow region is formed such that the second flow region is adjacent to the connecting portion in the direction in which the first flow region and the second flow region are arranged when viewed from the thickness direction. Thereby, in the wet cleaning in the third step, since the cleaning liquid can be circulated through the second flow region, the load applied to the connecting portion by the cleaning liquid can be reduced, and damage to the connecting portion can be suppressed.

Effect of the Invention

[0026] According to the present invention, it is possible to provide a method for manufacturing a mirror device that can suppress the occurrence of damage and the remaining of foreign matter in the mirror device.

Brief Description of the Drawings

[0027]

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Mode for Carrying Out the Invention

[0028] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In each figure, the same or corresponding parts are denoted by the same reference numerals, and overlapping parts are omitted.

[0029] [First Embodiment] As shown in FIGS. 1 and 2, the mirror device 1A of the first embodiment includes a structure 2A, a mirror layer 3, and a correction layer 4. The mirror device 1A has a shape that is line-symmetric with respect to each of a first axis X1 along the X-axis direction and a second axis X2 along the Y-axis direction, for example. The mirror device 1A may have a shape that is point-symmetric with respect to the intersection of the first axis X1 and the second axis X2. The mirror device 1A may have an asymmetric shape. The mirror device 1A is a MEMS device and is used, for example, in an optical switch for optical communication, an optical scanner, or the like.

[0030] The structure 2A is constituted by, for example, an SOI substrate. The structure 2A has a support layer 11, a device layer 12, and an intermediate layer 13. The support layer 11 is a first silicon layer. The device layer 12 is a second silicon layer. The intermediate layer 13 is an insulating layer disposed between the support layer 11 and the device layer 12. As an example, the thickness of the support layer 11 is about 100 μm to 700 μm, the thickness of the device layer 12 is about 20 μm to 200 μm, and the thickness of the intermediate layer 13 is about 50 nm to 3000 nm.

[0031] The structure 2A has, for example, a rectangular plate shape. The structure 2A has a first surface 2a and a second surface 2b. The first surface 2a is the surface on the side opposite to the intermediate layer 13 in the device layer 12. The second surface 2b is the surface on the side opposite to the first surface 2a in the structure 2A. The second surface 2b includes the surface on the side opposite to the intermediate layer 13 in the support layer 11 and the surface on the side opposite to the first surface 2a in the device layer 12.

[0032] The structure 2A is integrally composed of a base portion 21, a first movable portion 22, a second movable portion 23, a pair of first connecting portions 24, and a pair of second connecting portions 25. The base portion 21 is composed of a part of the support layer 11, a part of the device layer 12, and a part of the intermediate layer 13. The base portion 21 has, for example, a rectangular ring shape when viewed from the Z-axis direction (the thickness direction of the structure 2A). The base portion 21 has a size of, for example, about 10 mm × 15 mm when viewed from the Z-axis direction.

[0033] The first movable portion 22, the second movable portion 23, the first connecting portion 24, and the second connecting portion 25 are composed of a part of the device layer 12. The first movable portion 22 and the second movable portion 23 are supported by the base portion 21 by the first connecting portion 24 and the second connecting portion 25, respectively. Specifically, the first movable portion 22 and the second movable portion 23 are disposed inside the base portion 21 when viewed from the Z-axis direction. More specifically, the second movable portion 23 is disposed inside the base portion 21 through a second slit 23a that penetrates the structure 2A when viewed from the Z-axis direction. The second movable portion 23 has, for example, a rectangular ring shape when viewed from the Z-axis direction. The second slit 23a extends along the outer edge of the second movable portion 23 when viewed from the Z-axis direction. In the second slit 23a, the end face 11a of the support layer 11 in the base portion 21, the end face 12a of the device layer 12 in the base portion 21, and the end face 13a of the intermediate layer 13 in the base portion 21 are respectively exposed. The second slit 23a is formed to make the second movable portion 23 movable with respect to the base portion 21. In the present embodiment, the second slit 23a has the minimum width necessary to make the second movable portion 23 movable with respect to the base portion 21.

[0034] When viewed from the Z-axis direction, each second connecting portion 25 is disposed on both sides of the second movable portion 23 in the Y-axis direction. Each second connecting portion 25 extends linearly along the Y-axis direction, for example. Each second connecting portion 25 is connected to the base portion 21 and the second movable portion 23 so that the second movable portion 23 can move with respect to the base portion 21. Specifically, each second connecting portion 25 connects the second movable portion 23 and the base portion 21 to each other on the second axis X2 so that the second movable portion 23 can swing around the second axis X2. Note that the second slit 23a includes portions that extend along the Y-axis direction on both sides of each second connecting portion 25 in the X-axis direction. That is, each second connecting portion 25 is disposed inside the base portion 21 via the second slit 23a.

[0035] When viewed from the Z-axis direction, the first movable portion 22 is disposed inside the second movable portion 23 via a first slit 22a that penetrates the structure 2A. When viewed from the Z-axis direction, the first movable portion 22 has, for example, a rectangular shape. The first slit 22a extends along the outer edge of the first movable portion 22 when viewed from the Z-axis direction. The first slit 22a is formed to enable the first movable portion 22 to move with respect to the base portion 21. In the present embodiment, the first slit 22a has the minimum width necessary for enabling the first movable portion 22 to move with respect to the base portion 21.

[0036] When viewed from the Z-axis direction, each first connecting portion 24 is disposed on both sides of the first movable portion 22 in the X-axis direction. Each first connecting portion 24 extends linearly along the X-axis direction, for example. Each first connecting portion 24 is connected to the second movable portion 23 and the first movable portion 22 so that the first movable portion 22 can move with respect to the base portion 21. Specifically, each first connecting portion 24 connects the first movable portion 22 and the second movable portion 23 to each other on the first axis X1 so that the first movable portion 22 can swing around the first axis X1 along the X-axis direction.

[0037] The structure 2A is formed with a plurality of flow holes 21b, 22b, 23b that penetrate the structure 2A. The plurality of flow holes 21b, 22b, 23b are formed in portions of the structure 2A other than the first slit 22a and the second slit 23a. Specifically, for example, four flow holes 21b are formed in the base portion 21. Each flow hole 21b is respectively located at each corner of the base portion 21 when viewed in the Z-axis direction. The four flow holes 21b are line-symmetric to each other with respect to the first axis X1 and the second axis X2. Each flow hole 21b, when viewed in the Z-axis direction, exhibits a rectangular shape, for example. Each flow hole 21b penetrates the base portion 21. In each flow hole 21b, the end face 11b of the support layer 11, the end face 12b of the device layer 12, and the end face 13b of the intermediate layer 13 are respectively exposed. The flow hole 21b is larger than each of the flow hole 22b and the flow hole 23b.

[0038] The first movable portion 22 is formed with a pair of flow holes 22b. That is, a plurality of flow holes 22b are formed for one first movable portion 22. The pair of flow holes 22b are line-symmetric to each other with respect to the second axis X2. Each flow hole 22b, when viewed in the Z-axis direction, exhibits a semi-annular shape, for example. Each flow hole 22b penetrates the first movable portion 22.

[0039] The second movable portion 23 is formed with a pair of flow holes 23b. That is, a plurality of flow holes 23b are formed for one second movable portion 23. The pair of flow holes 23b are line-symmetric to each other with respect to the second axis X2. Each flow hole 23b, when viewed in the Z-axis direction, exhibits a semi-rectangular annular shape, for example. Each flow hole 23b extends along the outer edge of the second movable portion 23 when viewed in the Z-axis direction. Each flow hole 23b penetrates the second movable portion 23.

[0040] As shown in FIG. 2, the end face 13a of the intermediate layer 13 is formed so as not to be recessed with respect to both the end face 11a of the support layer 11 and the end face 12a of the device layer 12. The end face 13a of the intermediate layer 13, the end face 11a of the support layer 11, and the end face 12a of the device layer 12 are flush with each other. Similarly, the end face 13b of the intermediate layer 13 is formed so as not to be recessed with respect to both the end face 11b of the support layer 11 and the end face 12b of the device layer 12. The end face 13b of the intermediate layer 13, the end face 11b of the support layer 11, and the end face 12b of the device layer 12 are flush with each other.

[0041] The phrase "the end face of the intermediate layer is not recessed with respect to both the end face of the support layer and the end face of the device layer" means a state excluding the case where "when the end face of the intermediate layer is recessed with respect to both the end face of the support layer and the end face of the device layer, the end face of the intermediate layer is recessed by more than three times the thickness of the intermediate layer from either the end face of the support layer or the end face of the device layer". Therefore, not only the state where "the end face of the intermediate layer, the end face of the support layer, and the end face of the device layer are flush with each other", but also the state where "even when the end face of the intermediate layer is recessed with respect to both the end face of the support layer and the end face of the device layer, the end face of the intermediate layer is recessed by only 0.5 times the thickness of the intermediate layer from either the end face of the support layer or the end face of the device layer" can be said that the end face of the intermediate layer is not recessed with respect to both the end face of the support layer and the end face of the device layer.

[0042] The end face 13a of the intermediate layer 13 is recessed with respect to both the end face 11a of the support layer 11 and the end face 12a of the device layer 12, preferably by 3 times or less, more preferably 2 times or less, still more preferably 1 time or less, and most preferably 0.5 times or less the thickness of the intermediate layer 13. In other words, the end face 13a of the intermediate layer 13 is not recessed by more than 3 times, more preferably more than 2 times, still more preferably more than 1 time, and most preferably more than 0.5 times the thickness of the intermediate layer 13 with respect to both the end face 11a of the support layer 11 and the end face 12a of the device layer 12. Similarly, the end face 13b of the intermediate layer 13 is recessed with respect to both the end face 11b of the support layer 11 and the end face 12b of the device layer 12, preferably by 3 times or less, more preferably 2 times or less, still more preferably 1 time or less, and most preferably 0.5 times or less the thickness of the intermediate layer 13. In other words, the end face 13b of the intermediate layer 13 is not recessed by more than 3 times, more preferably more than 2 times, still more preferably more than 1 time, and most preferably more than 0.5 times the thickness of the intermediate layer 13 with respect to both the end face 11b of the support layer 11 and the end face 12b of the device layer 12.

[0043] The mirror layer 3 is provided on the first movable part 22. Specifically, the mirror layer 3 is provided in a region corresponding to the first movable part 22 on the first surface 2a of the structure 2A. The mirror layer 3 is disposed inside the pair of flow holes 22b when viewed in the Z-axis direction. The mirror layer 3 has, for example, a circular shape when viewed in the Z-axis direction. The mirror layer 3 is disposed with the intersection of the first axis X1 and the second axis X2 as the center position (center of gravity position). The mirror layer 3 is constituted by, for example, a reflective film made of aluminum, an aluminum-based alloy, silver, a silver-based alloy, gold, a dielectric multilayer film, or the like.

[0044] The correction layer 4 is formed over the entire second surface 2b. Specifically, in the base portion 21, the correction layer 4 is formed on the surface of the support layer 11 opposite to the intermediate layer 13. In the first movable portion 22, the second movable portion 23, each first connecting portion 24, and each second connecting portion 25, the correction layer 4 is formed on the surface of the device layer 12 opposite to the mirror layer 3. The correction layer 4 corrects warping and the like of the first movable portion 22, the second movable portion 23, each first connecting portion 24, and each second connecting portion 25. The correction layer 4 is made of a material such as silicon oxide or silicon nitride, for example. The correction layer 4 may be a metal thin film such as aluminum, for example. The thickness of the correction layer 4 is about 10 nm to 1000 nm, for example.

[0045] The mirror device 1A further includes a first coil 221 and a second coil 231. The first coil 221 is embedded in the first movable portion 22, for example, and extends in a spiral shape outside the pair of flow holes 22b (the outer edge portion of the first movable portion 22) when viewed from the Z-axis direction. The second coil 231 is embedded in the second movable portion 23, for example, and extends in a spiral shape outside the pair of flow holes 23b (the outer edge portion of the second movable portion 23) when viewed from the Z-axis direction. The first coil 221 and the second coil 231 are made of a metal material such as copper, for example. In FIG. 2, illustration of the first coil 221 and the second coil 231 is omitted.

[0046] In the mirror device 1A configured as described above, the first movable portion 22 provided with the mirror layer 3 is swung around the first axis X1 and the second axis X2 that are orthogonal to each other. Specifically, when a drive signal for linear motion is input to the second coil 231 via an electrode pad (not shown) and wiring (not shown) provided in the structure 2A, a Lorentz force acts on the second coil 231 due to the interaction with a magnetic field generated by a magnetic field generation unit (not shown). By utilizing the balance between the Lorentz force and the elastic force of each second connecting portion 25, the mirror layer 3 (the first movable portion 22) can be linearly moved together with the second movable portion 23 around the second axis X2.

[0047] When a driving signal for resonance operation is input to the first coil 221 via an electrode pad and a wiring, a Lorentz force acts on the first coil 221 due to the interaction with the magnetic field generated by the magnetic field generation unit. In addition to the Lorentz force, by utilizing the resonance of the first movable part 22 at the resonance frequency, the mirror layer 3 (the first movable part 22) can be resonantly operated around the first axis X1.

[0048] Next, a method for manufacturing the mirror device 1A will be described. First, as shown in FIGS. 3 and 4(a), a wafer 10W having a support layer 11, a device layer 12, and an intermediate layer 13 is prepared (step S1, the first step). The wafer 10W has a front surface (the first surface) 10a and a back surface (the second surface) 10b opposite to the front surface 10a. The front surface 10a is the surface that becomes the first surface 2a of the structure 2A. The wafer 10W includes a plurality of portions 11W each of which becomes the structure 2A. The portion 11W is a part of the wafer 10W before the structure 2A is formed. Each step of the method for manufacturing the mirror device 1A is carried out at the wafer level. Note that in FIGS. 4, 5, 7, and 9, one portion 11W of the wafer 10W is shown. Hereinafter, the description will focus on one portion 11W of the wafer 10W.

[0049] Subsequently, by removing a part of each of the support layer 11, the device layer 12, and the intermediate layer 13 from the wafer 10W, first slits 22a and second slits 23a are formed in the wafer 10W so that the first movable part 22 and the second movable part 23 can move with respect to the base part 21, and a plurality of portions 12WA (see FIG. 7(b)), each corresponding to the structure 2A, are formed in the wafer 10W (second step). The portion 12WA is a part of the wafer 10W on which the structure 2A is formed. First, a part of the device layer 12 is removed from the wafer 10W by etching (step S2). Specifically, portions of the device layer 12 corresponding to the first slit 22a, the second slit 23a, and the flow holes 21b, 22b, 23b are removed. As a result, end faces 12a and 12b of the device layer 12 are formed. In step S2, the first coil 221, the second coil 231, and electrode pads and wirings for inputting drive signals to the first coil 221 and the second coil 231 are provided in the device layer 12. In step S2, a mirror layer 3 is formed on a portion of the surface 10a of the wafer 10W corresponding to the first movable part 22. The mirror layer 3 is formed, for example, by vapor deposition of a metal. In step S2, the patterning member used for removing the device layer 12 is removed from the wafer 10W by patterning member removal (details will be described later) for removing the patterning member.

[0050] Subsequently, as shown in FIG. 4(b), the back surface 10b of the wafer 10W is polished (step S3). The wafer 10W is thinned by polishing the back surface 10b. The polished back surface 10b of the wafer 10W is a surface that becomes a part of the second surface 2b of the structure 2A.

[0051] Subsequently, as shown in Fig. 5(a), the patterning member 19 is patterned on the back surface 10b of the wafer 10W (step S4). Specifically, the patterning member 19 is provided in a region of the back surface 10b corresponding to the base portion 21, excluding the region corresponding to the flow hole 21b. The patterning member 19 is, for example, a resist or the like. Subsequently, as shown in Fig. 5(b), a part of the support layer 11 is removed from the wafer 10W by etching through the patterning member 19 (step S5). Specifically, a part of the support layer 11 that is inside the portion corresponding to the base portion 21 and the portion corresponding to the flow hole 21b is removed. As a result, the end faces 11a and 11b of the support layer 11 are formed. In step S5, a part of the support layer 11 is removed from the wafer 10W so that the end faces 11a and 11b of the support layer 11 are flush with the end faces 12a and 12b of the device layer 12, respectively. A part of the support layer 11 is removed from the wafer 10W, for example, by reactive ion etching (DRIE) using a Bosch process. In step S5, when removing a part of the support layer 11 from the wafer 10W, a polymer or the like is used as a protective film.

[0052] Subsequently, as shown in Fig. 6, patterning member removal and protective film removal are performed (step S6). First, patterning member removal is performed. Patterning member removal is a step for removing (peeling off) the patterning member 19 from the back surface 10b of the wafer 10W. In patterning member removal, after removing a part of the support layer 11 from the wafer 10W, the patterning member 19 is removed by a wet process. Specifically, first, a plurality of wafers 10W are set in a carrier 50 having a box shape.

[0053] On the inner wall surface of the carrier 50, a plurality of grooves (not shown) are formed at predetermined intervals along the Z-axis direction. The grooves extend along the XY plane. In removing the patterning member, the plurality of wafers 10W are arranged along the Z-axis direction (the thickness direction of the wafer 10W) by fitting each wafer 10W into each groove. That is, on each of one side and the other side of the wafer 10W in the Z-axis direction, another wafer 10W having the same structure as the wafer 10W is arranged. A second region R2 is formed between the wafer 10W adjacent to each other and the other wafer 10W. Subsequently, the patterning member 19 is removed with the patterning member removing liquid present in the second region R2. Specifically, as described above, with the plurality of wafers 10W and the other wafers 10W set in the carrier 50, the plurality of wafers 10W and the other wafers 10W are immersed in the patterning member removing liquid. The patterning member removing liquid is stored in a pool, for example. The plurality of wafers 10W and the other wafers 10W are immersed in the patterning member removing liquid such that the orientation of the opening of the carrier 50 is the same as the orientation of the liquid surface of the patterning member removing liquid. The patterning member removing liquid is a chemical solution or the like for removing the patterning member 19 from the wafer 10W.

[0054] Subsequently, with the plurality of wafers 10W immersed in the patterning member removing liquid, the plurality of wafers 10W are reciprocated (oscillated) along the X-axis direction (the thickness direction of the wafer 10W and the direction intersecting the liquid surface of the patterning member removing liquid). The reciprocation of the plurality of wafers 10W is carried out by reciprocating the carrier 50. In patterning member removal, the plurality of wafers 10W are reciprocated at a second speed for a second time. The "reciprocation speed" refers to the number of reciprocations per unit time. The second speed is, for example, about 70 times / minute. The second time is, for example, about 40 minutes. The second time is the cumulative time for reciprocating the plurality of wafers 10W at the second speed. In patterning member removal, for example, the type of the patterning member removing liquid can be changed, or the reciprocation of the plurality of wafers 10W can be temporarily stopped. In patterning member removal, after removing the patterning member 19 by a wet process, the plurality of wafers 10W are immersed in, for example, water for a predetermined time.

[0055] In patterning member removal, after removing the patterning member 19, that is, after immersing the wafer 10W in water for a predetermined time, second spin drying for drying the wafer 10W is carried out. In the second spin drying, the wafer 10W is dried by rotating the wafer 10W at a second rotation speed for a fourth time. When patterning member removal is carried out, as shown in FIG. 7(a), the patterning member 19 is removed from the wafer 10W.

[0056] Subsequently, protective film removal is carried out. The protective film removal is a step for removing a polymer or the like used as the protective film from the wafer 10W in step S5. In the protective film removal, after removing a part of the support layer 11 from the wafer 10W, the protective film is removed by a wet process using a protective film removing liquid. The protective film removing liquid is a chemical solution or the like for removing a polymer or the like from the wafer 10W.

[0057] Subsequently, as shown in FIG. 7(b), a part of the intermediate layer 13 is removed from the wafer 10W by etching (step S7). Specifically, the part of the intermediate layer 13 inside the part corresponding to the base portion 21 and the part corresponding to the flow hole 21b are removed. As a result, the first slit 22a and the second slit 23a are formed. At this time, the end face 13a of the intermediate layer 13 is formed. In step S7, the first slit 22a and the second slit 23a are formed in the wafer 10W so that the first movable portion 22 and the second movable portion 23 are movable with respect to the base portion 21, thereby forming a plurality of portions 12WA corresponding to the structure 2A in the wafer 10W and completing the plurality of portions 12WA. That is, the plurality of first movable portions 22 and the plurality of second movable portions 23 are released. "Release" means changing the first movable portion or the second movable portion from a fixed state to a movable state with respect to the base portion.

[0058] In step S7, the first slit 22a and the second slit 23a are formed so that the first movable portion 22 and the second movable portion 23 are supported by the respective first connecting portions 24 and the respective second connecting portions 25 in the base portion 21.

[0059] Also, in step S7, as described above, by removing a part of the intermediate layer 13 from the wafer 10W, a plurality of flow holes 21b, 22b, 23b penetrating the wafer 10W are formed in the part of the wafer 10W other than the first slit 22a and the second slit 23a. Specifically, in step S7, a flow hole 21b penetrating the wafer 10W is formed in the part of the wafer 10W corresponding to the base portion 21, a flow hole 22b penetrating the wafer 10W is formed in the part corresponding to the first movable portion 22, and a flow hole 23b penetrating the wafer 10W is formed in the part corresponding to the second movable portion 23. At this time, the end face 13b of the intermediate layer 13 is formed.

[0060] In step S7, etching is performed so that the end face 13a of the intermediate layer 13 does not recess with respect to both the end face 11a of the support layer 11 and the end face 12a of the device layer 12. In step S7, etching is performed so that the end face 13a of the intermediate layer 13 is flush with the end face 11a of the support layer 11 and the end face 12a of the device layer 12. Similarly, in step S7, etching is performed so that the end face 13b of the intermediate layer 13 does not recess with respect to both the end face 11b of the support layer 11 and the end face 12b of the device layer 12. In step S7, etching is performed so that the end face 13b of the intermediate layer 13 is flush with the end face 11b of the support layer 11 and the end face 12b of the device layer 12. In step S7, a part of the intermediate layer 13 is removed from the wafer 10W by anisotropic etching. In step S7, a part of the intermediate layer 13 is removed from the wafer 10W by dry etching.

[0061] Subsequently, as shown in FIG. 8, wet cleaning is performed (step S8, third step). The wet cleaning is a cleaning for removing foreign substances and the like attached to the wafer 10W. In the wet cleaning, the wafer 10W is cleaned with a cleaning liquid (not shown). Specifically, first, a plurality of wafers 10W and a plurality of dummy wafers (monitor wafers) 20W are set in a carrier 60 having a box shape. The thickness of the dummy wafer 20W is, for example, about 625 μm.

[0062] A plurality of grooves (not shown) are formed on the inner wall surface of the carrier 60 at predetermined intervals along the Z-axis direction. The grooves extend along the XY plane. In the wet cleaning, each wafer 10W and each dummy wafer 20W are fitted into their respective grooves, whereby the plurality of wafers 10W and the plurality of dummy wafers 20W are alternately arranged along the Z-axis direction (the thickness direction of the wafers 10W and the dummy wafers 20W). That is, dummy wafers 20W are arranged on each of one side and the other side of the wafer 10W in the Z-axis direction. A first region R1 is formed between the wafer 10W and the dummy wafer 20W adjacent to each other. The width of the first region R1 in the Z-axis direction is larger than the width of the second region R2 in the Z-axis direction.

[0063] Subsequently, with the cleaning liquid present in the first region R1, the wafer 10W is cleaned. Specifically, as described above, with the plurality of wafers 10W and the plurality of dummy wafers 20W set in the carrier 60, the plurality of wafers 10W and the plurality of dummy wafers 20W are immersed in the cleaning liquid. The cleaning liquid is stored in a pool, for example. The plurality of wafers 10W and the plurality of dummy wafers 20W are immersed in the cleaning liquid such that the direction of the opening of the carrier 60 is the same as the direction of the liquid surface of the cleaning liquid. The cleaning liquid is a chemical solution or the like for removing foreign substances and the like from the wafer 10W. Subsequently, with the plurality of wafers 10W and the plurality of dummy wafers 20W immersed in the cleaning liquid, the plurality of wafers 10W and the plurality of dummy wafers 20W are reciprocated (oscillated) along the X-axis direction (the thickness direction of the wafer 10W and the direction intersecting the liquid surface of the cleaning liquid). The reciprocation of the plurality of wafers 10W and the plurality of dummy wafers 20W is performed by reciprocating the carrier 60.

[0064] In wet cleaning, the plurality of wafers 10W and the plurality of dummy wafers 20W are reciprocated at a first speed for a first time. The load applied to the wafer 10W in the wet cleaning in step S8 is smaller than the load applied to the wafer 10W in the removal of the patterning member in step S6. That is, the intensity of the wet cleaning in step S8 is smaller than the intensity of the removal of the patterning member in step S6. Similarly, the load applied to the wafer 10W in the wet cleaning in step S8 is smaller than the load applied to the wafer 10W in the removal of the protective film in step S6. That is, the intensity of the wet cleaning in step S8 is smaller than the intensity of the removal of the protective film in step S6. "The load applied to the wafer" refers to the magnitude of the mechanical work (energy) applied to the wafer. For example, in the wet cleaning in step S8, the greater the speed at which the wafer 10W is reciprocated, the greater the load applied to the wafer 10W. Also, for example, in the wet cleaning in step S8, the longer the time for which the wafer 10W is reciprocated, the greater the load applied to the wafer 10W.

[0065] The first speed is smaller than the second speed. The first speed is, for example, about 40 revolutions per minute. The first time is shorter than the second time. The first time is, for example, about 20 minutes. The first time is the cumulative time for reciprocating the plurality of wafers 10W and the plurality of dummy wafers 20W at the first speed. In wet cleaning, for example, the type of cleaning liquid can be changed, or the reciprocating movement of the plurality of wafers 10W and the plurality of dummy wafers 20W can be temporarily stopped. In wet cleaning, after cleaning the wafer 10W with the cleaning liquid, the plurality of wafers 10W and the plurality of dummy wafers 20W are immersed in water for a predetermined time, for example.

[0066] In wet cleaning, after cleaning the wafer 10W, that is, after immersing the wafer 10W in water for a predetermined time, first spin drying for drying the wafer 10W is performed. In the first spin drying, the wafer 10W is rotated at the first rotation speed for the third time. The load applied to the wafer 10W in the first spin drying in step S8 is smaller than the load applied to the wafer 10W in the second spin drying in step S6. That is, the strength of the first spin drying in step S8 is smaller than the strength of the second spin drying in step S6. For example, in the first spin drying in step S8, the greater the rotation speed at which the wafer 10W is rotated, the greater the load applied to the wafer 10W. Also, for example, in the first spin drying in step S8, the longer the time for which the wafer 10W is rotated, the greater the load applied to the wafer 10W. The first rotation speed is smaller than the second rotation speed. The first rotation speed is, for example, about 200 rpm. The third time is, for example, about 5 minutes.

[0067] Subsequently, as shown in FIG. 9(a), a correction layer 4 is formed on the back surface 10b of the wafer 10W opposite to the surface 10a on which the mirror layer 3 is formed (step S9, fifth step). The correction layer 4 is formed on the surface of each of the support layer 11 and the device layer 12 opposite to the mirror layer 3. Subsequently, as shown in FIG. 9(b), each of the plurality of portions 12WA is cut out from the wafer 10W (step 10, fourth step). Thereby, a plurality of mirror devices 1A are manufactured.

[0068] As described above, in the method for manufacturing the mirror device 1A, in step S8 (the third step), the wafer 10W in which the plurality of first movable parts 22 and second movable parts 23 are released is cleaned with a cleaning liquid. Thereby, foreign matters can be removed from the wafer 10W in which the plurality of first movable parts 22 and second movable parts 23 are released. When the wafer 10W in which the plurality of first movable parts 22 and second movable parts 23 are released is cleaned by the wet cleaning in step S8, the plurality of first movable parts 22 and second movable parts 23 are likely to be damaged. Here, in step S7 (the second step), through etching, flow-through holes 21b, 22b, 23b that penetrate the wafer 10W are formed in portions of the wafer 10W other than the first slit 22a and the second slit 23a. Therefore, in the wet cleaning in step S8, the wafer 10W in which the plurality of first movable parts 22 and second movable parts 23 are released can be cleaned while flowing the cleaning liquid through the flow-through holes 21b, 22b, 23b. Therefore, the load applied to the plurality of first movable parts 22 and second movable parts 23 by the cleaning liquid can be reduced, and damage to the plurality of first movable parts 22 and second movable parts 23 can be suppressed. Thus, according to the method for manufacturing the mirror device 1A, the occurrence of damage and the remaining of foreign matters in the mirror device 1A can be suppressed. Also, it becomes easier for the cleaning liquid to flow between one side and the other side of the wafer 10W in the Z-axis direction through the flow-through holes 21b, 22b, 23b. Therefore, the cleaning efficiency by wet cleaning is improved.

[0069] Also, in the method for manufacturing the mirror device 1A, in step S2, the mirror layer 3 is formed on the portion of the wafer 10W corresponding to the first movable part 22. Thereby, foreign matters attached to the mirror layer 3 can be removed by the wet cleaning in step S8.

[0070] Also, the method for manufacturing the mirror device 1A includes a step S9 of forming a correction layer 4 on the back surface 10b of the wafer 10W between step S8 and step S10. Thereby, it is possible to suppress foreign matters from being covered by the correction layer 4.

[0071] Also, in the manufacturing method of the mirror device 1A, in step S6, after removing a part of the support layer 11 from the wafer 10W, a protective film removal for removing the protective film is performed. After the protective film removal, a plurality of portions 12WA are completed. Also, in the manufacturing method of the mirror device 1A, in the protective film removal in step S6, the protective film is removed by a wet process. When removing a part of the support layer 11 from the wafer 10W, as described above, a polymer or the like is used as the protective film. The polymer may remain on the wafer 10W after a part of the support layer 11 is removed from the wafer 10W. Further, due to the fact that the wafer 10W has an uneven shape by removing a part of the device layer 12 from the wafer 10W and that a part of the intermediate layer 13 has not yet been removed from the wafer 10W, etc., in the protective film removal, the protective film removal liquid may remain on the surface of the mirror layer 3 formed on the wafer 10W. When the remaining protective film removal liquid dries, there is a risk of stain formation. If the polymer and stains or the like remain on the wafer 10W, the presence of the polymer or stains or the like may cause a defective appearance of the mirror device 1A and there is a risk of a decrease in yield. According to the manufacturing method of the mirror device 1A, the polymer (foreign matter) or the like remaining on the wafer 10W when removing a part of the support layer 11 from the wafer 10W can be removed by the protective film removal. Further, when removing the protective film, the stains (foreign matter) or the like remaining on the wafer 10W can be removed by the wet cleaning in step S8. Thereby, it is possible to suppress a decrease in yield due to a defective appearance of the mirror device 1A.

[0072] Also, in the manufacturing method of the mirror device 1A, in step S6, a patterning member removal for removing the patterning member 19 is performed. After the patterning member removal, a plurality of portions 12WA are completed. Thereby, since the patterning member 19 is removed before the plurality of first movable portions 22 and second movable portions 23 are released, it is possible to suppress the occurrence of damage in the mirror device 1A due to the patterning member removal.

[0073] In the method for manufacturing the mirror device 1A, in the removal of the patterning member in step S6, the patterning member 19 is removed by a wet process. As a result, since the patterning member 19 is removed before the plurality of first movable portions 22 and second movable portions 23 are released, even if the patterning member 19 is removed by a wet process, the occurrence of damage in the mirror device 1A can be suppressed.

[0074] In the method for manufacturing the mirror device 1A, in step S7, a plurality of flow holes 22b and a plurality of flow holes 23b are formed in portions corresponding to the first movable portion 22 and the second movable portion 23, respectively. As a result, in the wet cleaning in step S8, turbulent flow of the cleaning liquid is likely to occur in the vicinity of the first movable portion 22 and the second movable portion 23, so that foreign matter can be surely removed from the portions corresponding to the first movable portion 22 and the second movable portion 23. Further, foreign matter can be surely removed from the mirror layer 3.

[0075] In the method for manufacturing the mirror device 1A, in step S7, a flow hole 21b is formed in a portion corresponding to the base portion 21. As a result, in the wet cleaning in step S8, in addition to the flow holes 22b and 23b, a larger amount of cleaning liquid can be circulated through the flow hole 21b. Therefore, the load applied to the wafer 10W by the cleaning liquid can be made more surely smaller, and the occurrence of damage in the wafer 10W can be more surely suppressed. Further, the cleaning efficiency by wet cleaning is surely improved.

[0076] [Second Embodiment] As shown in FIG. 10, the mirror device 1B of the second embodiment is mainly different from the mirror device 1A of the first embodiment in that it includes a beam portion 5 instead of the correction layer 4. Since the rest of the mirror device 1B is the same as that of the mirror device 1A, detailed description thereof will be omitted.

[0077] The structure 2B of the mirror device 1B includes a plurality of beam portions 5. The beam portions 5 are constituted by a part of the support layer 11 and the intermediate layer 13. The beam portions 5 are provided on the first movable portion 22. The beam portions 5 are provided on the surface of the device layer 12 opposite to the mirror layer 3. The beam portions 5 extend linearly, for example, along the Y-axis direction. The plurality of beam portions 5 are arranged at predetermined intervals along the X-axis direction. The plurality of beam portions 5 may be arranged, for example, in a radial shape when viewed from the Z-axis direction. The structure 2B may include one beam portion 5. In this case, the beam portion 5 may have, for example, an annular shape when viewed from the Z-axis direction. That is, the beam portion 5 may have a cylindrical shape. The beam portions 5 may have various shapes. The beam portions 5 are provided to reinforce the structure 2B. In the beam portion 5, the end face 11c of the support layer 11 is formed so as not to be recessed with respect to the end face 13c of the intermediate layer 13. The end face 11c of the support layer 11 and the end face 13c of the intermediate layer 13 are flush with each other. When viewed from the Z-axis direction, the end face 11c of the support layer 11 and the end face 13c of the intermediate layer 13 are located inside the end face 22c of the first movable portion 22 (the end face forming the flow hole 22b).

[0078] Next, a manufacturing method of the mirror device 1B will be described. The manufacturing method of the mirror device 1B is mainly different from the manufacturing method of the mirror device 1A of the first embodiment in that the beam portions 5 are formed instead of the correction layer 4. Since the other aspects of the manufacturing method of the mirror device 1B are the same as those of the manufacturing method of the mirror device 1A of the first embodiment, detailed description thereof will be omitted.

[0079] First, as shown in FIG. 11, prepare a wafer 10W in the same manner as step S1 (refer to FIG. 4(a)) of the first embodiment (step S21, first step). Subsequently, in the same manner as the first embodiment, by removing a part of each of the support layer 11, the device layer 12, and the intermediate layer 13 from the wafer 10W by etching, first slits 22a and second slits 23a are formed in the wafer 10W so that the first movable part 22 and the second movable part 23 can move with respect to the base part 21, and a plurality of portions 12WB (refer to FIG. 15(a)) each corresponding to the structure 2B are formed in the wafer 10W (second step). First, in the same manner as step S2 of the first embodiment, a part of the device layer 12 is removed from the wafer 10W by etching, and a first coil 221, a second coil 231, an electrode pad, wiring, etc. are provided in the device layer 12, and the mirror layer 3 is formed on the surface 10a of the wafer 10W (step S22). Subsequently, in the same manner as step S3 (refer to FIG. 4(b)) of the first embodiment, the back surface 10b of the wafer 10W is polished (step S23).

[0080] Subsequently, as shown in FIG. 12(a), pattern the patterning member 29 on the back surface 10b of the wafer 10W in the same manner as step S4 of the first embodiment (step S24). Subsequently, as shown in FIG. 12(b), remove a part of the support layer 11 from the wafer 10W by etching through the patterning member 29 (step S25). In step S25, only a part of the support layer 11 in the thickness direction is removed. Other aspects of step S25 are the same as step S5 of the first embodiment. Subsequently, perform patterning member removal and protective film removal in the same manner as step S6 (refer to FIG. 6) of the first embodiment (step S26). When the patterning member removal is performed, as shown in FIG. 13(a), the patterning member 29 is removed from the wafer 10W.

[0081] Subsequently, as shown in FIG. 13(b), the patterning member 39 is patterned on the back surface 10b of the wafer 10W (step S27). Specifically, the patterning member 39 is provided in a region of the back surface 10b corresponding to the base portion 21, excluding the region corresponding to the circulation hole 21b, and in a region of the back surface 10b corresponding to the beam portion 5. Subsequently, as shown in FIG. 14(a), a part of the support layer 11 is removed from the wafer 10W by etching through the patterning member 39 (step S28). Specifically, a part of the support layer 11 that is inside the part corresponding to the base portion 21, excluding the part corresponding to the beam portion 5, and the part corresponding to the circulation hole 21b are removed. As a result, the end face 11c of the support layer 11 is formed.

[0082] Subsequently, patterning member removal is performed again (step S29). When patterning member removal is performed again, the patterning member 39 is removed from the wafer 10W as shown in FIG. 14(b). Subsequently, as shown in FIG. 15(a), a part of the intermediate layer 13 is removed from the wafer 10W by etching (step S30). Specifically, a part of the intermediate layer 13 that is inside the part corresponding to the base portion 21, excluding the part corresponding to the beam portion 5, and the part corresponding to the circulation hole 21b are removed. As a result, the end face 13c of the intermediate layer 13 is formed. In step S30, etching is performed so that the end face 13c of the intermediate layer 13 does not recess with respect to the end face 11c of the support layer 11. In step S30, etching is performed so that the end face 13c of the intermediate layer 13 is flush with the end face 11c of the support layer 11. Subsequently, wet cleaning is performed in the same manner as step S8 (see FIG. 8) of the first embodiment (step S31, third step). Subsequently, as shown in FIG. 15(b), each of the plurality of portions 12WB is cut out from the wafer 10W (step 32, fourth step). Thereby, a plurality of mirror devices 1B are manufactured.

[0083] As described above, according to the manufacturing method of the mirror device 1B, similar to the manufacturing method of the mirror device 1A of the first embodiment described above, the occurrence of damage and the remaining of foreign matter in the mirror device 1B can be suppressed.

[0084] Further, in the manufacturing method of the mirror device 1B, in step S30 (second step), etching is performed so that the end face 13c of the intermediate layer 13 does not dent with respect to the end face 11c of the support layer 11. Therefore, it becomes difficult for the beam portion 5 to be peeled off from the first movable portion 22. If the end face 13c of the intermediate layer 13 is dented with respect to the end face 11c of the support layer 11, the beam portion 5 may be peeled off from the first movable portion 22, and as a result, the structure 2B may be damaged. Here, since it becomes difficult for the beam portion 5 to be peeled off from the first movable portion 22, the breakage of the structure 2B is suppressed. Since wet cleaning is performed in step S31 after step S30, it is particularly important that it becomes difficult for the beam portion 5 to be peeled off from the first movable portion 22.

[0085] [Third Embodiment] As shown in FIG. 16, the mirror device 1C of the third embodiment is mainly different from the mirror device 1A of the first embodiment in that the flow hole 22b includes the first flow region 22d and the second flow region 22e, the flow hole 23b communicates with the first slit 22a, and the flow hole 25b is formed in the second connecting portion 25. The detailed description of the portions similar to those in the mirror device 1A in the mirror device 1C will be omitted.

[0086] The first movable portion 22 of the structure 2C has, for example, an N-sided shape (N is a natural number of 4 or more) when viewed from the Z-axis direction. N is preferably a natural number of 5 or more. The first movable portion 22 has, for example, an octagonal shape when viewed from the Z-axis direction. The first movable portion 22 may have, for example, a circular shape when viewed from the Z-axis direction. The second connecting portion 25 is disposed on both sides of the second movable portion 23 in the X-axis direction.

[0087] The flow hole 22b formed in the first movable part 22 includes a first flow region 22d and a plurality of second flow regions 22e. The first flow region 22d extends along the outer edge of the first movable part 22 when viewed in the Z-axis direction. The first flow region 22d has, for example, an annular shape when viewed in the Z-axis direction. A plurality of connecting parts 26 straddling the first flow region 22d are formed in the first movable part 22. As a result, the first flow region 22d is divided into a plurality of regions arranged along the outer edge of the first movable part 22. Each connecting part 26 is arranged in the circumferential direction of the first flow region 22d when viewed in the Z-axis direction.

[0088] The plurality of second flow regions 22e are located outside the first flow region 22d when viewed in the Z-axis direction. The plurality of second flow regions 22e are arranged along the outer edge of the first movable part 22 when viewed in the Z-axis direction. Each second flow region 22e extends along the outer edge (each side of the octagon) of the first movable part 22 when viewed in the Z-axis direction. Thus, the first flow region 22d and the second flow regions 22e are adjacent to each other in a direction perpendicular to the Z-axis direction.

[0089] The direction perpendicular to the Z-axis direction means the direction along the direction from the inside of the first flow region to the outside of the first flow region when viewed in the Z-axis direction. The direction perpendicular to the Z-axis direction is the direction perpendicular to the outer edge of the first movable part 22 when viewed in the Z-axis direction. The direction perpendicular to the Z-axis direction is the radial direction of the first movable part 22 when viewed in the Z-axis direction. Hereinafter, the direction perpendicular to the Z-axis direction is referred to as the "radial direction".

[0090] When viewed in the Z-axis direction, the width of the second flow region 22e in the radial direction is smaller than the width of the first flow region 22d in the radial direction. The second flow region 22e may include a portion whose width in the radial direction is smaller than the width of the first flow region 22d in the radial direction. In other words, the second flow region 22e may include a portion whose width in the radial direction is equal to or greater than the width of the first flow region 22d in the radial direction.

[0091] The flow hole (flow auxiliary region) 23b formed in the second movable part 23 communicates with the first slit 22a. Specifically, the flow hole 23b is formed by a part of the first slit 22a spreading in the direction opposite to the first movable part 22 in the X-axis direction. The region constituted by the first slit 22a and the flow hole 23b has, for example, a rectangular outer shape when viewed from the Z-axis direction. In FIG. 16, the boundary line between the flow hole 23b and the first slit 22a is shown by a dotted line. A pair of flow holes 25b are formed in each of the second connecting parts 25. In each of the second connecting parts 25, the pair of flow holes 25b are arranged in the Y-axis direction. Each flow hole 25b penetrates the second connecting part 25.

[0092] As shown in FIGS. 16 and 17, the inner part of the first flow region 22d of the first movable part 22 constitutes the main body part 30. The outer part of the first flow region 22d of the first movable part 22 constitutes the annular part 40. The main body part 30 has a circular shape in plan view, but may be formed in any shape such as an elliptical shape, a rectangular shape, a rhombic shape, etc. The center of the main body part 30 in plan view coincides with the intersection of the first axis X1 and the second axis X2. The annular part 40 is formed in an annular shape so as to surround the main body part 30 via the first flow region 22d in plan view. The annular part 40 has, for example, an outer edge and an inner edge that are octagonal in plan view. The plurality of connecting parts 26 connect the main body part 30 and the annular part 40 to each other.

[0093] The annular portion 40 has a pair of first portions 41, a pair of second portions 42, and two pairs of third portions (inclined portions) 43. The pair of first portions 41 are located on both sides of the main body portion 30 in the X-axis direction. Each first portion 41 extends along the Y-axis direction. The pair of second portions 42 are located on both sides of the main body portion 30 in the Y-axis direction. Each second portion 42 extends along the X-axis direction. The two pairs of third portions 43 are respectively located between the first portion 41 and the second portion 42 and are connected to the first portion 41 and the second portion 42. Each third portion 43 extends along a direction intersecting the X-axis direction and the Y-axis direction. Each third portion 43 obliquely intersects the center line (first axis X1) of the first connecting portion 24 and the second connecting portion 25.

[0094] According to the configuration in which each third portion 43 extends along a direction intersecting the X-axis direction and the Y-axis direction, each third portion 43 can be brought closer to the first axis X1 compared to the case where the annular portion 40 has, for example, a rectangular annular shape. Therefore, by concentrating the mass of the first movable portion 22 in a region close to the first axis X1, the moment of inertia of the first movable portion 22 around the first axis X1 can be reduced. In other words, when the first movable portion 22 has an N-sided shape when viewed from the Z-axis direction, the larger N is, the more the mass of the first movable portion 22 can be concentrated in a region close to the first axis X1, thereby reducing the moment of inertia of the first movable portion 22 around the first axis X1. As a result, the driving power for driving the first movable portion 22 can be reduced.

[0095] In each first part 41, a second flow region 22e is formed. Each first part 41 has a first frame part 41a on the side opposite to the main body part 30 with respect to the second flow region 22e, and a second frame part 41b on the side opposite to the first frame part 41a with respect to the second flow region 22e. The first frame part 41a is a part outside the second flow region 22e in the first movable part 22. The second frame part 41b is a part between the first flow region 22d and the second flow region 22e in the first movable part 22. The first frame part 41a and the second frame part 41b extend along the second flow region 22e. The width D1 of the first frame part 41a in the radial direction is substantially the same as the width D2 of the second frame part 41b in the radial direction.

[0096] In each first part 41, the second flow region 22e is arranged to be line-symmetrical with respect to the first axis X1. That is, in each first part 41, the second flow region 22e is formed at a position adjacent to the first connecting part 24 on the center line of the first connecting part 24 and the second connecting part 25. Thereby, for example, when stress is generated at the first connecting part 24 or the second connecting part 25 and the stress is transmitted to the first movable part 22, as a result of a part in the vicinity of the second flow region 22e in the first part 41 being locally distorted, the transmission of the stress to the main body part 30 of the first movable part 22 is suppressed. Thereby, distortion of the mirror layer 3 and the like can be suppressed.

[0097] Each second part 42 is formed with a second flow region 22e respectively. Each second part 42 has a first frame part 42a on the side opposite to the main body part 30 with respect to the second flow region 22e, and a second frame part 42b on the side opposite to the first frame part 42a with respect to the second flow region 22e. The first frame part 42a is a part outside the second flow region 22e in the first movable part 22. The second frame part 42b is a part between the first flow region 22d and the second flow region 22e in the first movable part 22. The first frame part 42a and the second frame part 42b extend along the second flow region 22e. The width D3 of the first frame part 42a in the radial direction is larger than the width D4 of the second frame part 42b in the radial direction. In each second part 42, the second flow region 22e is formed at a position away from the center lines of the first connecting part 24 and the second connecting part 25.

[0098] Each second frame part 42b functions as a stress relaxation region. Specifically, for example, when the first movable part 22 receives stress from the outside, as a result of local distortion of the second frame part 42b, transmission of the stress to the main body part 30 of the first movable part 22 is suppressed. Thereby, distortion of the mirror layer 3 and the like can be suppressed.

[0099] Each second part 42 is connected to the main body part 30 by a connecting part 26. Specifically, the connecting part 26 connects the second frame part 42b and the main body part 30. In each second part 42, the connecting part 26 straddles the first flow region 22d in the radial direction (the direction in which the first flow region 22d and the second flow region 22e are arranged side by side). In each second part 42, the connecting part 26 straddles the overlapping part of the first flow region 22d and the second flow region 22e in the radial direction. The connecting part 26 connecting the second part 42 and the main body part 30 is formed in the first flow region 22d on the side opposite to the first connecting part 24 with respect to the third part 43.

[0100] In each second part 42, the connection part 26 is adjacent to the second flow region 22e in the radial direction. That is, the connection part 26 is formed corresponding to the second flow region 22e. In each second part 42, the connection part 26 is connected to the second frame part 42b at a position substantially in the center of the second flow region 22e in the X-axis direction. Thereby, the second frame parts 42b can be evenly arranged on both sides of the connection part 26 in the X-axis direction. Therefore, it is possible to efficiently suppress the stress from being transmitted to the main body part 30 of the first movable part 22.

[0101] In each third part 43, a second flow region 22e is formed respectively. Each third part 43 has a first frame part 43a on the side opposite to the main body part 30 with respect to the second flow region 22e, and a second frame part 43b on the side opposite to the first frame part 43a with respect to the second flow region 22e. The first frame part 43a is a part outside the second flow region 22e in the first movable part 22. The second frame part 43b is a part between the first flow region 22d and the second flow region 22e in the first movable part 22. The first frame part 43a and the second frame part 43b extend along the second flow region 22e. The width D5 of the first frame part 43a in the radial direction is larger than the width D6 of the second frame part 43b in the radial direction.

[0102] Each second frame part 43b functions as a stress relaxation region. Specifically, for example, when the first movable part 22 receives stress from the outside, as a result of the local distortion of the second frame part 43b, the transmission of the stress to the main body part 30 of the first movable part 22 is suppressed. Thereby, the distortion of the mirror layer 3 and the like can be suppressed.

[0103] Each third part 43 is connected to the main body part 30 by the connecting part 26. Specifically, the connecting part 26 connects the second frame part 43b and the main body part 30. In each third part 43, the connecting part 26 straddles the first flow region 22d in the radial direction (the direction in which the first flow region 22d and the second flow region 22e are arranged side by side). In each third part 43, the connecting part 26 straddles the portion of the first flow region 22d that overlaps with the second flow region 22e in the radial direction. The connecting part 26 that connects the third part 43 and the main body part 30 is formed in the first flow region 22d between the connecting part 26 that connects the second part 42 and the main body part 30 and the first connecting part 24. The connecting part 26 that connects the third part 43 and the main body part 30 is formed in the portion of the first flow region 22d that overlaps with the third part 43.

[0104] In each third part 43, the connecting part 26 is adjacent to the second flow region 22e in the radial direction. That is, the connecting part 26 is formed corresponding to the second flow region 22e. In each third part 43, the connecting part 26 is connected to the second frame part 43b at a position on the opposite side of the first connecting part 24 with respect to the center line X3 of the second flow region 22e. In each third part 43, the connecting part 26 is formed in the portion on the opposite side of the first connecting part 24 among the portions of the first flow region 22d that overlap with the second flow region 22e in the radial direction. That is, in each third part 43, the connecting part 26 is connected to the second frame part 43b at a position away from the first connecting part 24. Thereby, in each third part 43, the distance from the end of the second frame part 43b on the first connecting part 24 side (the end close to the first connecting part 24) to the connecting part 26 becomes long. That is, the region in which the stress transmitted from the first connecting part 24 is relaxed in the second frame part 43b becomes long. Therefore, for example, the transmission of the stress transmitted from the first connecting part 24 to the main body part 30 of the first movable part 22 through the connecting part 26 is effectively suppressed. Thereby, the distortion of the mirror layer 3 and the like can be effectively suppressed. Note that the center line X3 is a line that passes through the center in the extending direction of the second flow region 22e in the third part 43 and extends along the radial direction.

[0105] In a portion overlapping with the third portion 43 of the first flow area 22d, the connecting portion 26 may not be formed. The connecting portion 26 may be formed in a portion closer to the first connecting portion 24 than the third portion 43 of the first flow area 22d.

[0106] When the first movable portion 22 has an N-sided shape when viewed from the Z-axis direction, the larger N is (for example, when N = 8), compared to the case where the first movable portion 22 has a rectangular shape, for example, the distance between the pair of connecting portions 26 connecting each second portion 42 to the main body portion 30 and the first connecting portion 24 (the distance along the outer edge of the first movable portion 22) becomes smaller. As a result, there is a possibility that the stress transmitted from the first connecting portion 24 to the main body portion 30 via the pair of connecting portions 26 increases. Therefore, not only the pair of connecting portions 26 but also, as described above, it is preferable to provide a connecting portion 26 between the connecting portion 26 and the first connecting portion 24 to suppress the transmission of stress to the main body portion 30. Further, it is particularly preferable to provide a connecting portion 26 between the third portion 43, which is different from the second portion 42, and the main body portion 30. By connecting each connecting portion 26 to the main body portion 30 for each of the second portion 42 and the third portion 43, the stress transmitted from the first connecting portion 24 to the main body portion 30 can be further reduced. In the present embodiment, as described above, the pair of second portions 42 and the two pairs of third portions 43 are connected to the main body portion 30 by three pairs of connecting portions 26.

[0107] When viewed from the Z-axis direction, the first coil 221 of the mirror device 1C extends in a spiral shape outside the first flow region 22d (at the outer edge of the first movable part 22). Specifically, in each first part 41, the first coil 221 is disposed between the first flow region 22d and the second flow region 22e (between the first flow region 22d and the second flow region 22e existing on the first axis X1), and in each second part 42 and each third part 43, it is disposed outside the second flow region 22e (between the second flow region 22e provided corresponding to the connecting part 26 and the outer edge of the first movable part 22). That is, in each first part 41, the first coil 221 is provided on the second frame part 41b, and in each second part 42 and each third part 43, it is provided on the first frame part 42a and the first frame part 43a. The first coil 221 is, for example, a drive coil and / or a sensing coil.

[0108] When the first coil 221 is disposed on the second frame part 41b in each first part 41, since the first frame part 41a exists between the first connecting part 24 and the first coil 221, for example, the stress generated at the first connecting part 24 or the second connecting part 25 is suppressed from being transmitted to the first coil 221. Thereby, damage to the first coil 221 can be prevented. Further, when the first coil 221 is disposed on the first frame part 42a and the first frame part 43a in each second part 42 and each third part 43, the second frame part 42b and the second frame part 43b, which function as relatively easily distorted stress relaxation regions, can be avoided, and damage to the first coil 221 can be prevented. Further, when the first coil 221 is disposed on the first frame part 42a and the first frame part 43a in each second part 42 and each third part 43, the width D4 of the second frame part 42b in the radial direction and the width D6 of the second frame part 43b in the radial direction can be made sufficiently small, and the function of the second frame part 42b and the second frame part 43b as stress relaxation regions can be sufficiently exerted.

[0109] Next, a method for manufacturing the mirror device 1C will be described. The method for manufacturing the mirror device 1C mainly differs from the method for manufacturing the mirror device 1A of the first embodiment in that a flow hole 22b including a first flow region 22d and a second flow region 22e is formed, a flow hole 23b communicating with the first slit 22a is formed, and a flow hole 25b is formed in the second connecting portion 25. A detailed description of the parts that are the same as those in the method for manufacturing the mirror device 1A in the method for manufacturing the mirror device 1C will be omitted.

[0110] In the method for manufacturing the mirror device 1C, in the second step, portions corresponding to the first slit 22a, the second slit 23a, the region of the first flow region 22d excluding the connecting portion 26, the second flow region 22e, the flow hole 23b, and the flow hole 25b in the device layer are removed. Also, in the method for manufacturing the mirror device 1C, in the second step, a portion inside the portion corresponding to the base portion 21 in the intermediate layer is removed. As a result, the first slit 22a and the second slit 23a are formed, and a plurality of first movable portions 22 and a plurality of second movable portions 23 are released.

[0111] Also, in the method for manufacturing the mirror device 1C, in the second step, as described above, by removing a part of the intermediate layer 13 from the wafer, a plurality of flow holes 22b, 23b, 25b penetrating the wafer are formed in the portion of the wafer other than the first slit 22a and the second slit 23a. Specifically, in the method for manufacturing the mirror device 1C, in the second step, a flow hole 22b penetrating the wafer is formed in the portion of the wafer corresponding to the first movable portion 22, a flow hole 23b penetrating the wafer is formed in the portion corresponding to the second movable portion 23, and a flow hole 25b penetrating the wafer is formed in the portion corresponding to the second connecting portion 25.

[0112] Specifically, in the manufacturing method of the mirror device 1C, in the second step, the flow hole 23b is formed so as to communicate with the first slit 22a. Further, in the manufacturing method of the mirror device 1C, in the second step, when viewed from the Z-axis direction, the flow hole 22b is formed in a portion corresponding to the first movable portion 22 so as to include the first flow region 22d and the second flow region 22e that are adjacent to each other in the radial direction. Further, in the manufacturing method of the mirror device 1C, in the second step, when viewed from the Z-axis direction, the flow hole 22b is formed so that the connecting portion 26 straddling the first flow region 22d is formed in the radial direction. Further, in the manufacturing method of the mirror device 1C, in the second step, when viewed from the Z-axis direction, the flow hole 22b is formed so as to include a portion where the width of the second flow region 22e in the radial direction is smaller than the width of the first flow region 22d in the radial direction.

[0113] Further, in the manufacturing method of the mirror device 1C, in the second step, the first slit 22a is formed so that the first movable portion 22 is supported by the first connecting portion 24 on the base portion 21. Further, in the manufacturing method of the mirror device 1C, in the second step, when viewed from the Z-axis direction, the second flow region 22e is formed so that the second flow region 22e is adjacent to the first connecting portion 24 in the radial direction. Further, in the manufacturing method of the mirror device 1C, in the second step, the second slit 23a is formed so that the second movable portion 23 is supported by the second connecting portion 25 on the base portion 21. Further, in the manufacturing method of the mirror device 1C, in the second step, the flow hole 25b is formed in a portion corresponding to the second connecting portion 25.

[0114] As described above, according to the manufacturing method of the mirror device 1C, similar to the manufacturing method of the mirror device 1A of the first embodiment described above, the occurrence of damage and the remaining of foreign matter in the mirror device 1C can be suppressed.

[0115] In the manufacturing method of the mirror device 1C, in step S7, the first slit 22a and the second slit 23a are formed such that the first movable part 22 and the second movable part 23 are supported by the first connecting part 24 and the second connecting part 25 on the base part 21, respectively, and a flow hole 25b is formed in a part corresponding to the second connecting part 25. Thereby, while maintaining the strength of the second connecting part 25, in the wet cleaning in step S7, turbulent flow of the cleaning liquid is likely to occur in the vicinity of the second connecting part 25, so that foreign matter can be surely removed from the part corresponding to the second connecting part 25.

[0116] In the manufacturing method of the mirror device 1C, in step S7, the flow hole 23b is formed such that the flow hole 23b communicates with the first slit 22a. Thereby, in the wet cleaning in step S7, a larger amount of cleaning liquid can be made to flow through the flow hole 23b.

[0117] In the manufacturing method of the mirror device 1C, in step S7, the flow hole 22b is formed in the part corresponding to the first movable part 22 such that, when viewed from the Z-axis direction, the flow hole 22b includes a first flow region 22d and a second flow region 22e that are adjacent to each other in the radial direction. Thereby, in the wet cleaning in step S8, turbulent flow of the cleaning liquid is likely to occur at a location where the first flow region 22d and the second flow region 22e are adjacent, so that foreign matter can be surely removed from the wafer 10W.

[0118] In the manufacturing method of the mirror device 1C, in step S7, the flow hole 22b is formed such that, when viewed from the Z-axis direction, a connecting part 26 that straddles the first flow region 22d is formed in the radial direction. Thereby, in the wet cleaning in step S8, since the wafer 10W is reinforced by the connecting part 26, the occurrence of damage in the wafer 10W can be suppressed. Also, in the wet cleaning in step S8, since the cleaning liquid can be made to flow through the second flow region 22e, the load applied to the connecting part 26 by the cleaning liquid can be reduced, and the occurrence of damage to the connecting part 26 can be suppressed.

[0119] Also, in the method for manufacturing the mirror device 1C, in step S7, when viewed from the Z-axis direction, the flow hole 22b is formed such that the second flow region 22e includes a portion where the width of the second flow region 22e in the radial direction is smaller than the width of the first flow region 22d in the radial direction. Thereby, since the width of the first flow region 22d and the width of the second flow region 22e are different, turbulent flow of the cleaning liquid is likely to occur in the wet cleaning in step S8. Therefore, foreign matter can be reliably removed from the wafer 10W.

[0120] Also, in the method for manufacturing the mirror device 1C, in step S7, the first slit 22a and the second slit 23a are formed such that the first movable portion 22 and the second movable portion 23 are supported by the first connecting portion 24 and the second connecting portion 25, respectively, on the base portion 21, and when viewed from the Z-axis direction, the second flow region 22e is formed adjacent to the first connecting portion 24 in the direction in which the first flow region 22d and the second flow region 22e are aligned. Thereby, in the wet cleaning in step S8, since the cleaning liquid can be circulated through the second flow region 22e, the load received by the first connecting portion 24 by the cleaning liquid can be reduced, and damage to the first connecting portion 24 can be suppressed.

[0121] [Fourth Embodiment] As shown in FIG. 18, the mirror device 1D of the fourth embodiment is mainly different from the mirror device 1A of the first embodiment in that a flow hole 22f is formed in the first movable portion 22 and the flow hole 23b communicates with the first slit 22a. A detailed description of the portions of the mirror device 1D that are the same as those of the mirror device 1A will be omitted.

[0122] A flow hole 22f is formed in the first movable part 22 of the 2D structure. When viewed from the Z-axis direction, the flow hole 22f extends along the outer edge of the first movable part 22. The flow hole 22f has, for example, an annular shape when viewed from the Z-axis direction. A plurality of connecting parts 26 straddling the flow hole 22f are formed in the first movable part 22. For example, four connecting parts 26 are formed in the first movable part 22. Each connecting part 26 is formed at both ends of the first movable part 22 in the Y-axis direction when viewed from the Z-axis direction. As a result, the flow hole 22b is divided into a plurality of regions.

[0123] The portion inside the flow hole 22f of the first movable part 22 constitutes the main body part 30. The portion outside the flow hole 22f of the first movable part 22 constitutes the annular part 40. The main body part 30 has a circular shape in plan view, but may be formed in any shape such as an elliptical shape, a rectangular shape, or a rhombic shape. The center of the main body part 30 in plan view coincides with the intersection of the first axis X1 and the second axis X2. The annular part 40 is formed in an annular shape so as to surround the main body part 30 through the flow hole 22f in plan view. The annular part 40 has an outer shape of a hexagonal shape in plan view, but may have any outer shape such as a circular shape, an elliptical shape, a rectangular shape, or a rhombic shape. The main body part 30 and the annular part 40 are connected to each other by a plurality of connecting parts 26.

[0124] The second movable part 23 of the mirror device 1D is formed in a frame shape and is disposed inside the base part 21 so as to surround the first movable part 22. The second movable part 23 has a pair of first connecting parts 41A, 41B, a pair of second connecting parts 42A, 42B, a pair of first linear parts 43A, 43B, a pair of second linear parts 44A, 44B, a pair of third linear parts 45A, 45B, and a pair of fourth linear parts 46A, 46B. The second movable part 23 has a shape that is symmetric with respect to each of the first axis X1 and the second axis X2 in plan view. In the following description, being symmetric with respect to the first axis X1 or the second axis X2 means being symmetric in plan view.

[0125] The first connection parts 41A and 41B are located on both sides of the first movable part 22 in the X-axis direction. That is, each of the first connection parts 41A and 41B has a portion facing the first movable part 22 in the X-axis direction in a plan view. Each of the first connection parts 41A and 41B extends along the Y-axis direction.

[0126] The second connection parts 42A and 42B are located on both sides of the first movable part 22 in the Y-axis direction. That is, each of the second connection parts 42A and 42B has a portion facing the first movable part 22 in the Y-axis direction in a plan view. Each of the second connection parts 42A and 42B extends along the X-axis direction.

[0127] The first linear parts 43A and 43B are located on both sides of the second connection part 42A in the X-axis direction and are connected to the second connection part 42A. Each of the first linear parts 43A and 43B extends along the X-axis direction. The first linear parts 43A and 43B are arranged symmetrically with respect to the Y-axis. The second linear parts 44A and 44B are located on both sides of the second connection part 42B in the X-axis direction and are connected to the second connection part 42B. Each of the second linear parts 44A and 44B extends along the X-axis direction. The second linear parts 44A and 44B are arranged symmetrically with respect to the Y-axis.

[0128] The third linear parts 45A and 45B are located on the side opposite to the second connection part 42A with respect to each of the first linear parts 43A and 43B and are connected to the first linear parts 43A and 43B and the first connection parts 41A and 41B. The third linear part 45A extends along a direction inclined by 45 degrees with respect to each of the X-axis and the Y-axis in a plan view. The third linear part 45B extends symmetrically with respect to the Y-axis with respect to the third linear part 45A.

[0129] The fourth linear portions 46A and 46B are located on the side opposite to the second connecting portion 42B with respect to each of the second linear portions 44A and 44B, and are connected to the second linear portions 44A and 44B and the first connecting portions 41A and 41B. The fourth linear portion 46A extends symmetrically with respect to the X-axis with respect to the third linear portion 45A. The fourth linear portion 46B extends symmetrically with respect to the Y-axis with respect to the fourth linear portion 46A and extends symmetrically with respect to the X-axis with respect to the third linear portion 45B.

[0130] Each first connecting portion 24 is connected to the second movable portion 23 at the first connecting portions 41A and 41B. In the present embodiment, for relaxation of the stress acting on the first connecting portion 24, the width (width in the Y-axis direction) of the end portion on the first movable portion 22 side in each first connecting portion 24 increases as it approaches the first movable portion 22, and the width (width in the Y-axis direction) of the end portion on the second movable portion 23 side increases as it approaches the second movable portion 23.

[0131] Each second connecting portion 25 is connected to the second movable portion 23 at the second connecting portions 42A and 42B. Each second connecting portion 25 extends in a meandering shape in a plan view. Each second connecting portion 25 has a plurality of linear portions and a plurality of folding portions. The linear portions extend in the Y-axis direction and are arranged side by side in the X-axis direction. The folding portions alternately connect both ends of adjacent linear portions.

[0132] The flow hole (flow assisting region) 23b formed in the second movable part 23 communicates with the first slit 22a. The flow hole 23b includes four first parts 23c and two second parts 23d. When viewed from the Z-axis direction, the first parts 23c are arranged symmetrically with each other about the first axis X1 and the second axis X2 on the outside of the first movable part 22. Each first part 23c is formed by a part of the first slit 22a expanding toward the opposite side to the first movable part 22 in the X-axis direction. Each second part 23d is located between a pair of first parts 23c on both sides of the first movable part 22 in the Y-axis direction. Each second part 23d is formed by a part of the first slit 22a expanding toward the opposite side to the first movable part 22 in the Y-axis direction. Each second part 23d communicates with each first slit 22a. In FIG. 18, the boundary between the through holes 23b and the first slits 22a is indicated by a dotted line.

[0133] The mirror device 1D further includes a pair of coils 14, 15. Each of the coils 14, 15 is provided on the second movable part 23 so as to surround the first movable part 22, and has a spiral shape in a plan view (when viewed from a direction perpendicular to the plane on which the coils 14, 15 are arranged). Each of the coils 14, 15 is arranged along a plane including the X-axis and the Y-axis. Each of the coils 14, 15 is wound multiple times around the first movable part 22. The pair of coils 14, 15 are arranged so as to be alternately arranged in the width direction of the second movable part 23 in a plan view. No coil is provided on the first movable part 22.

[0134] Next, a manufacturing method for mirror device 1D will be described. The manufacturing method for mirror device 1D differs from that for mirror device 1A of the first embodiment mainly in that through holes 22f are formed in first movable part 22 and through holes 23b communicating with first slits 22a are formed. A detailed description of the parts of the manufacturing method for mirror device 1D that are similar to the manufacturing method for mirror device 1A will be omitted.

[0135] In the manufacturing method of the mirror device 1D, in the second step, the portions of the device layer corresponding to the first slit 22a, the second slit 23a, the flow holes 22f, and the flow holes 23b are removed. Also, in the manufacturing method of the mirror device 1D, in the second step, the portion of the intermediate layer that is inside the portion corresponding to the base portion 21 is removed. As a result, the first slit 22a and the second slit 23a are formed, and the plurality of first movable portions 22 and the plurality of second movable portions 23 are released.

[0136] Also, in the manufacturing method of the mirror device 1D, in the second step, as described above, by removing a part of the intermediate layer 13 from the wafer, a plurality of flow holes 22f, 23b that penetrate the wafer are formed in the portion of the wafer other than the first slit 22a and the second slit 23a. Specifically, in the manufacturing method of the mirror device 1D, in the second step, a flow hole 22f that penetrates the wafer is formed in the portion of the wafer corresponding to the first movable portion 22, and a flow hole 23b that penetrates the wafer is formed in the portion corresponding to the second movable portion 23.

[0137] As described above, according to the manufacturing method of the mirror device 1D, similar to the manufacturing method of the mirror device 1A of the first embodiment described above, the occurrence of damage and the remaining of foreign matter in the mirror device 1D can be suppressed.

[0138] [Modification Example] As described above, although one embodiment of the present invention has been described, the present invention is not limited to the above-described embodiment.

[0139] In each embodiment, an example was shown in which a part of the device layer 12, a part of the support layer 11, and a part of the intermediate layer 13 are removed from the wafer 10W in this order, but the present invention is not limited to this. A part of the support layer 11, a part of the device layer 12, and a part of the intermediate layer 13 may be removed from the wafer 10W in this order. In this case, before removing a part of the intermediate layer 13 from the wafer 10W, patterning member removal and protective film removal are performed. Further, a part of the support layer 11, a part of the intermediate layer 13, and a part of the device layer 12 may be removed from the wafer 10W in this order. In this case, before removing a part of the device layer 12 from the wafer 10W, patterning member removal and protective film removal are performed. That is, in these cases, after the patterning member removal and the protective film removal, the first movable part 22 and the second movable part 23 may be released.

[0140] Also, in each embodiment, in the patterning member removal, an example was shown in which the patterning members 19, 29, 39 are removed by a wet process, but in the patterning member removal, the patterning members 19, 29, 39 may be removed from the wafer 10W by a dry process. Similarly, in each embodiment, in the protective film removal, an example was shown in which the protective film is removed by a wet process, but in the protective film removal, the protective film may be removed from the wafer 10W by a dry process. In these cases, a part of the device layer 12, a part of the intermediate layer 13, and a part of the support layer 11 may be removed from the wafer 10W in this order. That is, in these cases, after releasing the first movable part 22 and the second movable part 23, patterning member removal and protective film removal may be performed. Also, in each embodiment, an example was shown in which the protective film removal is performed after the patterning member removal, but the patterning member removal may be performed after the protective film removal.

[0141] Also, in the first embodiment, an example of forming the first slit 22a, the second slit 23a, and the flow holes 21b, 22b, 23b by removing the portion of the intermediate layer 13 that is inside the portion corresponding to the base portion 21 and the portion corresponding to the flow hole 21b was shown, but it is not limited thereto. The order in which the first slit 22a, the second slit 23a, and the flow holes 21b, 22b, 23b are formed may be arbitrary. For example, after forming the first slit 22a and the second slit 23a, that is, after releasing the first movable portion 22 and the second movable portion 23, the flow holes 21b, 22b, 23b may be formed. In this case, first, the portion of the wafer 10W corresponding to the first slit 22a and the second slit 23a may be removed, and then the portion corresponding to the flow holes 21b, 22b, 23b may be removed. Also, after forming the flow holes 21b, 22b, 23b, the first slit 22a and the second slit 23a may be formed. In this case, first, the portion of the wafer 10W corresponding to the flow holes 21b, 22b, 23b may be removed, and then the portion corresponding to the first slit 22a and the second slit 23a may be removed.

[0142] Also, in the first embodiment, an example in which the correction layer 4 is formed on the back surface 10b of the wafer 10W was shown, but the correction layer 4 may be formed on the front surface 10a of the wafer 10W. Specifically, the correction layer 4 may be formed on the surface opposite to the intermediate layer 13 in the device layer 12 in the base portion 21, the second movable portion 23, each first connecting portion 24, and each second connecting portion 25. The correction layer 4 may be formed on the surface opposite to the intermediate layer 13 in the device layer 12 and on the surface opposite to the device layer 12 in the mirror layer 3 in the first movable portion 22. Also, the correction layer 4 may be formed on the front surface 10a and on the back surface 10b. That is, the correction layer 4 is formed on the front surface 10a and / or the back surface 10b.

[0143] Also, as shown in FIG. 19(a), each flow hole 22b may have a varying width in the X-axis direction (a direction perpendicular to the thickness direction of the wafer 10W) when viewed from the Z-axis direction. That is, when viewed from the Z-axis direction, the widths of the respective flow holes 22b in the X-axis direction may be different from each other at different positions in the Y-axis direction. Specifically, each flow hole 22b may have a width at the central portion in the Y-axis direction that is larger than the widths at both end portions in the Y-axis direction. Each flow hole 22b may include a curved portion at least in part when viewed from the Z-axis direction. Each flow hole 22b may have different shapes for one edge and the other edge in the X-axis direction when viewed from the Z-axis direction. Each flow hole 22b may have a crescent shape surrounding the mirror layer 3 when viewed from the Z-axis direction. In these cases, in the wet cleaning in the third step, complex water flows are likely to occur in the vicinity of each flow hole 22b, so the cleaning efficiency by wet cleaning is improved.

[0144] In the second step of each embodiment, each flow hole 22b may be formed such that the width in the X-axis direction changes when viewed from the Z-axis direction. Thereby, in the wet cleaning in the third step, turbulent flow of the cleaning liquid is likely to occur, so that foreign matters can be surely removed from the wafer 10W. In the second step of each embodiment, each flow hole 22b may be formed so as to include a curved portion at least partially. Thereby, in the wet cleaning in step S8, since the load on the curved portion of the flow hole 22b due to the cleaning liquid is reduced, the occurrence of damage in the mirror device 1A can be suppressed. In the second step of each embodiment, each flow hole 22b may be formed such that one edge and the other edge have different shapes when viewed from the Z-axis direction. Thereby, by forming a larger flow hole 22b, a larger amount of cleaning liquid can be circulated through the flow hole 22b in the wet cleaning in the third step. Therefore, foreign matters can be surely removed from the wafer 10W. Note that the structures 2A, 2B, 2C, and 2D may not have the second movable portion 23. In this case, the first movable portion 22 is disposed inside the base portion 21 through the first slit 22a when viewed from the Z-axis direction. Note that each first connecting portion 24 may be disposed on both sides of the first movable portion 22 in the Y-axis direction when viewed from the Z-axis direction.

[0145] Also, as shown in FIG. 19(b), the flow hole 22b may have an annular shape centered on the intersection of the first axis X1 and the second axis X2 when viewed from the Z-axis direction. In this case, a connecting portion 26 straddling the flow hole 22b is formed in the first movable portion 22. For example, four connecting portions 26 are formed in the first movable portion 22. When viewed from the Z-axis direction, the respective connecting portions 26 are arranged at equal intervals in the circumferential direction of the flow hole 22b. As a result, the flow hole 22b is divided into a plurality of regions. The first movable portion 22 is point-symmetrical with respect to the intersection of the first axis X1 and the second axis X2 when viewed from the Z-axis direction. In this case, while appropriately reinforcing the first movable portion 22 by each connecting portion 26, the area occupied by the flow hole 22b in the first movable portion 22 can be increased. Therefore, in the wet cleaning of the third step, a larger amount of cleaning liquid can flow through the flow hole 22b. Thereby, foreign matter can be reliably removed from the wafer 10W. Further, since the first movable portion 22 is point-symmetrical, the occurrence of damage in the first movable portion 22 can be suppressed in the wet cleaning of the third step.

[0146] Also, in the second step of each embodiment, the flow hole 22b may be formed such that the connecting portion 26 straddling the flow hole 22b is formed. In the second step of each embodiment, a flow hole other than the flow hole 22b (for example, the flow hole 23b) may be formed such that a connecting portion straddling the flow hole other than the flow hole 22b is formed. Thereby, in the wet cleaning of the third step, since the wafer 10W is reinforced by the connecting portion 26, the occurrence of damage in the mirror device 1A can be suppressed. Note that the first movable portion 22 may have a circular shape when viewed from the Z-axis direction.

[0147] Further, as shown in FIG. 19(c), the pair of flow holes 22b may be line-symmetric with respect to the first axis X1. Each flow hole 22b may have a crescent shape surrounding the mirror layer 3 when viewed from the Z-axis direction. In this case, in the wet cleaning in the third step, complex water flow is likely to occur in the vicinity of each flow hole 22b, so the cleaning efficiency by wet cleaning is improved. Note that the first movable part 22 may have an elliptical shape whose major axis extends along the Y-axis direction when viewed from the Z-axis direction.

[0148] Further, as shown in FIG. 20(a), the second movable part 23 may not have the flow hole 23b formed therein. Also, as shown in FIG. 20(b), the first movable part 22 may not have the flow hole 22b formed therein.

[0149] Further, as shown in FIG. 21, the flow holes 22b and 23b may not be formed. That is, only the base part 21 may have the flow hole 21b formed therein.

[0150] Further, as shown in FIG. 22, a pair of flow holes 24b may be formed on both sides of each first connecting part 24 in the X-axis direction. Each flow hole 24b penetrates the base part 21. Each flow hole 24b is located inside each first slit 22a in the X-axis direction. Also, the base part 21 may not have the flow hole 21b formed therein.

[0151] Also, the flow holes 21b, 22b, 23b, 24b, and 25b may not be formed for circulating the cleaning liquid. The flow holes 21b, 22b, 23b, 24b, and 25b may be merely through holes or through regions.

[0152] Note that the following inventions can be extracted from the above embodiments.

[0153] Invention 1: An optical scanning device comprising a base portion, a movable portion supported by the base portion, a connecting portion connected to the movable portion such that the movable portion is movable with respect to the base portion, and a mirror layer provided on the movable portion, wherein the movable portion has a first through region that is annular and extends along the outer edge of the movable portion, a plurality of second through regions located outside the first through region, and a connecting portion straddling a portion of the first through region that overlaps the second through region, and the width of the portion outside the second through region in the movable portion is larger than the width of the portion between the first through region and the second through region in the movable portion.

[0154] Invention 2: The optical scanning device according to Invention 1, wherein the second through region is formed at a position on the center line of the connecting portion.

[0155] Invention 3: The optical scanning device according to Invention 1 or 2, wherein the connecting portion is formed at a portion of the first through region that overlaps the second through region and is on the side opposite to the connecting portion.

[0156] Invention 4: The optical scanning device according to any one of Inventions 1 to 3, wherein the portion outside the first through region in the movable portion includes an inclined portion that intersects obliquely with the center line of the connecting portion.

[0157] Invention 5: The optical scanning device according to any one of Inventions 1 to 4, wherein the movable portion has an N-sided shape (N is a natural number of 5 or more).

[0158] Invention 6: The optical scanning device according to any one of Inventions 1 to 5, wherein the portion outside the first through region in the movable portion includes an inclined portion that intersects obliquely with the center line of the connecting portion, the connecting portion is formed in the first through region on the side opposite to the connecting portion with respect to the inclined portion, and the connecting portion is further formed in the first through region between the connecting portion formed on the side opposite to the connecting portion with respect to the inclined portion and the connecting portion.

[0159] Invention 7: The connecting portion formed in the first through region between the connecting portion and the connecting portion on the side opposite to the connecting portion with respect to the inclined portion is formed in a portion overlapping the inclined portion of the first through region or a portion on the connecting portion side of the inclined portion of the first through region. The optical scanning device according to Invention 6.

[0160] Invention 8: The optical scanning device further includes a coil extending at the outer edge of the movable portion. The second through region is formed at a position on the center line of the connecting portion and a position away from the center line of the connecting portion. The coil is disposed between the second through region formed at the position on the center line of the connecting portion and the first through region, and between the second through region formed at the position away from the center line of the connecting portion and the outer edge of the movable portion. The optical scanning device according to any one of Inventions 1 to 7.

Explanation of Reference Numerals

[0161] 1A, 1B, 1C, 1D... mirror devices, 2A, 2B, 2C, 2D... structures, 3... mirror layer, 4... correction layer, 10W... wafer, 10a... front surface, 10b... back surface, 11... support layer, 12... device layer, 13... intermediate layer, 11a, 11b, 11c, 12a, 12b, 13a, 13b, 13c... end faces, 19... patterning member, 21... base portion, 22... first movable portion, 22a... first slit, 23... second movable portion, 23a... second slit, 21b, 22b, 22f, 23b, 24b, 25b... flow holes, 22d... first flow region, 22e... second flow region, 24... first connecting portion, 25... second connecting portion, 26... connecting portion.

Claims

1. A base portion, a movable portion supported by the base portion, a connecting portion connected to the movable portion such that the movable portion is swingable about a predetermined axis with respect to the base portion, and a mirror layer provided on the movable portion, wherein the movable portion is formed with a first through region that is annular and extends along the outer edge of the movable portion, a plurality of second through regions located outside the first through region, and a connecting portion straddling the first through region, wherein the width of the portion outside the second through region in the movable portion is larger than the width of the portion between the first through region and the second through region in the movable portion, wherein the movable portion has a main body portion on which the mirror layer is formed, and an annular portion that surrounds the main body portion through the first through region in a plan view of the movable portion and is connected to the connecting portion, wherein the plurality of second through regions include at least one on-axis second through region formed at a position overlapping the axis in the annular portion in the plan view, and at least one off-axis second through region formed at a position not overlapping the axis in the annular portion in the plan view, wherein the connecting portion connects the main body portion and the annular portion to each other so as to straddle a portion of the first through region overlapping the at least one off-axis second through region in a direction from the main body portion toward the annular portion, wherein the main body portion and the annular portion are not connected to each other at a portion of the first through region overlapping the at least one on-axis second through region in a direction from the main body portion toward the annular portion, an optical scanning device.

2. The optical scanning device according to claim 1, wherein the connecting portion is formed at a portion on the opposite side of the at least one off-axis second through region in the first through region in a direction from the main body portion toward the annular portion.

3. The optical scanning device according to claim 1 or 2, wherein the portion outside the first through region in the movable portion includes an inclined portion that obliquely intersects the axis.

4. The optical scanning device according to any one of claims 1 to 3, wherein the movable portion has an N-sided shape (N is a natural number of 5 or more).

5. A portion of the movable part outside the first through region includes an inclined portion that intersects the axis obliquely. A connection portion is formed in the first through region on the side opposite to the connection portion with respect to the inclined portion. The connection portion is further formed in the first through region between the connection portion formed on the side opposite to the connection portion with respect to the inclined portion and the connection portion. The optical scanning device according to any one of claims 1 to 4.

6. The connection portion formed in the first through region between the connection portion formed on the side opposite to the connection portion with respect to the inclined portion and the connection portion is formed in a portion overlapping the inclined portion of the first through region or in a portion closer to the connection portion side than the inclined portion of the first through region. The optical scanning device according to claim 5.

7. The optical scanning device further includes a coil extending at an outer edge portion of the movable part. The coil is disposed between the at least one second through region on the axis and the first through region, and between the at least one second through region outside the axis and the outer edge of the movable part. The optical scanning device according to any one of claims 1 to 6.

8. A base portion, A movable part supported by the base portion, A connection portion connected to the movable part so that the movable part can swing around a predetermined axis with respect to the base portion, A mirror layer provided on the movable part, and includes: The movable part is formed with a first through region that is annular and extends along the outer edge of the movable part, a plurality of second through regions located outside the first through region, and a connection portion straddling the first through region. The width of a portion outside the second through region in the movable part is larger than the width of a portion between the first through region and the second through region in the movable part. The movable part has a main body portion on which the mirror layer is formed, and an annular portion that surrounds the main body portion through the first through region in a plan view of the movable part and is connected to the connection portion. The connection portion straddles a portion of the first through region that overlaps the second through region in a direction from the main body portion toward the annular portion. A portion of the movable part outside the first through region includes an inclined portion that intersects the axis obliquely. The optical scanning device.

9. A base portion, A movable part supported by the base portion, A connection portion connected to the movable part so that the movable part can move with respect to the base portion, comprising a mirror layer provided on the movable part; the movable part is formed with a first through region that is annular and extends along the outer edge of the movable part, a plurality of second through regions located outside the first through region, and a connecting part straddling the first through region; the width of the outer portion of the second through region in the movable part is larger than the width of the portion between the first through region and the second through region in the movable part; the movable part has a main body part on which the mirror layer is formed, and an annular part that surrounds the main body part through the first through region in a plan view of the movable part and is connected to the connecting part; the connecting part straddles a portion of the first through region that overlaps with the second through region in a direction from the main body part toward the annular part; the movable part is a polygon having N (N is a natural number of 5 or more) sides, and is an optical scanning device.

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