WO2022137674A1 - ミラーデバイスの製造方法 - Google Patents
ミラーデバイスの製造方法 Download PDFInfo
- Publication number
- WO2022137674A1 WO2022137674A1 PCT/JP2021/033949 JP2021033949W WO2022137674A1 WO 2022137674 A1 WO2022137674 A1 WO 2022137674A1 JP 2021033949 W JP2021033949 W JP 2021033949W WO 2022137674 A1 WO2022137674 A1 WO 2022137674A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- layer
- mirror
- movable portion
- heating
- mirror layer
- Prior art date
Links
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 59
- 238000000034 method Methods 0.000 title claims abstract description 39
- 238000010438 heat treatment Methods 0.000 claims abstract description 151
- 238000005520 cutting process Methods 0.000 claims abstract description 32
- 235000012431 wafers Nutrition 0.000 claims description 104
- 238000009792 diffusion process Methods 0.000 claims description 42
- 230000002265 prevention Effects 0.000 claims description 35
- 238000004544 sputter deposition Methods 0.000 claims description 15
- 230000008878 coupling Effects 0.000 abstract 1
- 238000010168 coupling process Methods 0.000 abstract 1
- 238000005859 coupling reaction Methods 0.000 abstract 1
- 230000008859 change Effects 0.000 description 39
- 230000003287 optical effect Effects 0.000 description 17
- 239000000463 material Substances 0.000 description 11
- 238000005259 measurement Methods 0.000 description 10
- 229910052751 metal Inorganic materials 0.000 description 9
- 239000002184 metal Substances 0.000 description 9
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical group [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 7
- 230000015572 biosynthetic process Effects 0.000 description 7
- 238000004140 cleaning Methods 0.000 description 7
- 238000010586 diagram Methods 0.000 description 6
- 239000010408 film Substances 0.000 description 6
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 6
- 229910052786 argon Inorganic materials 0.000 description 5
- 230000007423 decrease Effects 0.000 description 5
- 239000012634 fragment Substances 0.000 description 5
- 239000007769 metal material Substances 0.000 description 5
- 238000000427 thin-film deposition Methods 0.000 description 5
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 4
- 229910052737 gold Inorganic materials 0.000 description 4
- 239000010931 gold Substances 0.000 description 4
- 238000012986 modification Methods 0.000 description 4
- 230000004048 modification Effects 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- 239000004065 semiconductor Substances 0.000 description 4
- 229910052710 silicon Inorganic materials 0.000 description 4
- 239000010703 silicon Substances 0.000 description 4
- 239000000758 substrate Substances 0.000 description 4
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 4
- 239000010937 tungsten Substances 0.000 description 4
- 229910052721 tungsten Inorganic materials 0.000 description 4
- 229910052782 aluminium Inorganic materials 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 230000007613 environmental effect Effects 0.000 description 3
- 229910052697 platinum Inorganic materials 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 229910052581 Si3N4 Inorganic materials 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 238000013459 approach Methods 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000001678 irradiating effect Effects 0.000 description 2
- 238000010584 magnetic trap Methods 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 2
- 239000010936 titanium Substances 0.000 description 2
- 229910052719 titanium Inorganic materials 0.000 description 2
- 229910000838 Al alloy Inorganic materials 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- -1 argon cations Chemical class 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 238000000059 patterning Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 230000002040 relaxant effect Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 229910052814 silicon oxide Inorganic materials 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
- B81C1/00—Manufacture or treatment of devices or systems in or on a substrate
- B81C1/00642—Manufacture or treatment of devices or systems in or on a substrate for improving the physical properties of a device
- B81C1/0065—Mechanical properties
- B81C1/00666—Treatments for controlling internal stress or strain in MEMS structures
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
- B81C1/00—Manufacture or treatment of devices or systems in or on a substrate
- B81C1/00865—Multistep processes for the separation of wafers into individual elements
- B81C1/00888—Multistep processes involving only mechanical separation, e.g. grooving followed by cleaving
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
- B81C99/00—Subject matter not provided for in other groups of this subclass
- B81C99/0035—Testing
- B81C99/004—Testing during manufacturing
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
- G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
- G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
- G02B26/0816—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements
- G02B26/0833—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
- G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
- G02B26/10—Scanning systems
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
- B81B2201/00—Specific applications of microelectromechanical systems
- B81B2201/04—Optical MEMS
- B81B2201/042—Micromirrors, not used as optical switches
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
- B81C2201/00—Manufacture or treatment of microstructural devices or systems
- B81C2201/01—Manufacture or treatment of microstructural devices or systems in or on a substrate
- B81C2201/0161—Controlling physical properties of the material
- B81C2201/0163—Controlling internal stress of deposited layers
- B81C2201/0167—Controlling internal stress of deposited layers by adding further layers of materials having complementary strains, i.e. compressive or tensile strain
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
- B81C2201/00—Manufacture or treatment of microstructural devices or systems
- B81C2201/01—Manufacture or treatment of microstructural devices or systems in or on a substrate
- B81C2201/0161—Controlling physical properties of the material
- B81C2201/0163—Controlling internal stress of deposited layers
- B81C2201/0169—Controlling internal stress of deposited layers by post-annealing
Definitions
- One aspect of the present disclosure relates to a method of manufacturing a mirror device having a movable part.
- Patent Document 1 describes a method for manufacturing a mirror device having a movable portion.
- a plurality of micromechanical structures having a movable structure are formed on a semiconductor substrate, and then dicing is performed to separate the plurality of micromechanical structures from each other.
- the movable structure is curved.
- the entire micromechanical structure is heated. This heat treatment flattens the movable structure.
- one aspect of the present disclosure is to provide a method for manufacturing a mirror device capable of satisfactorily manufacturing a mirror device having a movable portion.
- the method for manufacturing a mirror device includes a support portion, a movable portion, and a structure having a connecting portion for connecting the movable portion to the support portion so that the movable portion can swing or move, and a movable portion.
- a method for manufacturing a mirror device including a mirror layer provided on a portion, the first forming step of forming a plurality of portions corresponding to a structure on a wafer, and a movable portion in each of the plurality of portions.
- a cutting step of cutting the wafer so that the plurality of portions are separated from each other.
- Residual stress may be generated in the mirror layer when the mirror layer is formed, and the residual stress may cause warpage in the mirror layer. If the mirror device is shipped in that state, there is a concern that the amount of warpage of the mirror layer will change due to the relaxation of residual stress due to the environmental temperature and self-heating during use.
- a plurality of parts each corresponding to a structure are formed on a wafer, and a mirror layer is formed on a part corresponding to a movable part in each of the plurality of parts. Later, the portion corresponding to the moving part in each of the plurality of portions is heated.
- the residual stress existing in the mirror layer can be relaxed, and it is possible to suppress the change in the amount of warpage of the mirror layer when the mirror device is used.
- the wafer is cut after the heating.
- the temperature of the mirror layer at the time of heating can be made uniform among the plurality of portions as compared with the case where the heat treatment is performed after cutting the wafer.
- by heating in a wafer state many mirror devices can be arranged in a constant temperature bath used for heating, for example. As a result, the manufacturing efficiency of the mirror device can be improved.
- the amount of warpage of the mirror layer after heating when measuring the amount of warpage of the mirror layer after heating, the amount of warpage can be measured in the wafer state. In this case, since it is easy to accurately grasp the position of the mirror layer, it is possible to improve the efficiency of measurement. Further, for example, when the mirror layer is washed after heating, it can be washed in a wafer state, and the workability of washing can be improved. Further, when the heat treatment is performed after cutting the wafer, the wafer fragments generated during cutting may adhere to the mirror layer. In this case, the fragments are heated during the heat treatment, so that the semiconductor material constituting the fragments is released. There is a concern that it will diffuse into the mirror layer and the reflectance of the mirror layer will decrease.
- the method for manufacturing a mirror device may further include a measurement step for measuring the amount of warpage of the mirror layer between the heating step and the cutting step.
- the amount of warpage of the mirror layer can be measured in the wafer state, and the measurement efficiency can be improved.
- the wafer may be cut by forming a modified region inside the wafer by irradiation with laser light and extending cracks from the modified region in the thickness direction of the wafer.
- the stress acting on the wafer at the time of cutting can be reduced, and the deformation of the mirror layer and the movable portion due to the stress can be suppressed. Further, it is possible to suppress the change in the amount of warpage of the mirror layer at the time of cutting.
- the second forming step may be carried out after the first forming step. In this case, it is possible to prevent the quality of the mirror layer from being deteriorated due to the heat generated when the plurality of portions are formed.
- the amount of warpage of the mirror layer may be reduced by heating the portion corresponding to the movable portion in each of the plurality of portions.
- the amount of warpage of the mirror layer may be increased by heating the portion corresponding to the movable portion in each of the plurality of portions. In either case, the residual stress existing in the mirror layer can be relaxed, and it is possible to suppress the change in the amount of warpage of the mirror layer when the mirror device is used.
- the mirror layer may be formed by sputtering. In this case, the mirror layer can be formed satisfactorily.
- the mirror device may further include a coil or a piezoelectric element for applying a driving force to the moving portion.
- heat is likely to be generated when the mirror device is used, but according to the method for manufacturing the mirror device, it is possible to suppress the change in the amount of warpage of the mirror layer when the mirror device is used even in such a case. can.
- the portion corresponding to the movable portion in each of the plurality of portions may be heated to 60 ° C. or higher and 300 ° C. or lower. In this case, the residual stress existing in the mirror layer can be effectively relaxed.
- the maximum width of the mirror layer may be 0.5 mm or more and 30 mm or less.
- the amount of warpage of the mirror layer tends to change when the mirror device is used, but according to the manufacturing method of this mirror device, the amount of warpage of the mirror layer changes when the mirror device is used even in such a case. It can be suppressed.
- the mirror layer may include an adhesion layer, a diffusion prevention layer and a reflection layer formed in this order on the movable portion.
- the mirror layer can be stably formed on the movable portion.
- the diffusion prevention layer it is possible to suppress the generation of metal diffusion between the reflective layer and the adhesion layer during heating.
- the mirror layer includes a plurality of layers including a reflective layer, and the plurality of layers include a layer in which compressive stress remains at the completion of the second forming step and a layer in which tensile stress remains at the completion of the second forming step. , May be included.
- the amount of warpage of the mirror layer before the heating step can be reduced.
- the change in the amount of warpage of the mirror layer in the heating step can be reduced, and as a result, the heating time can be shortened and the amount of warpage of the mirror layer can be easily controlled.
- the entire wafer may be heated.
- the temperature of the mirror layer during heating can be made uniform among the plurality of portions.
- the portion corresponding to the movable portion in each of the plurality of portions may be heated without heating the entire wafer. Even in this case, even if the position and output of the heat source used in the heating step vary, the temperature of the mirror layer can be made uniform among a plurality of parts by conducting the heat in the wafer. ..
- a method for manufacturing a mirror device capable of satisfactorily manufacturing a mirror device having a movable portion.
- FIG. 1 It is a top view of a mirror device. It is a schematic cross-sectional view along II-II of FIG. (A) and (b) are diagrams for explaining a method of manufacturing a mirror device.
- (A) and (b) are diagrams for explaining a method of manufacturing a mirror device.
- (A) and (b) are diagrams for explaining a process of forming a mirror layer. It is a graph which shows the example of the change of the warp amount of a mirror layer in a heating process. It is a figure for demonstrating the cutting process. It is sectional drawing of the mirror device housed in a package.
- (A) and (b) are diagrams for explaining a method of manufacturing a mirror device according to a modified example. It is a graph which shows the example of the change of the warp amount of the mirror layer in the heating process of a modification. It is a graph which shows the example of the change of the warp amount of a mirror layer in a reliability test.
- the mirror device 1 has a support portion 2 and a movable mirror portion 10.
- the movable mirror portion 10 has a first movable portion 3, a second movable portion 4, a pair of first connecting portions 5, a pair of second connecting portions 6, and a mirror layer 7.
- the support portion 2, the first movable portion 3, the second movable portion 4, the pair of first connecting portions 5, and the pair of second connecting portions 6 constitute the structure 50.
- the mirror device 1 includes a structure 50 and a mirror layer 7.
- the structure 50 is integrally formed of, for example, an SOI (Silicon on Insulator) substrate 8. That is, the mirror device 1 is configured as a MEMS (Micro Electro Mechanical Systems) device.
- the SOI substrate 8 has a support layer 81, a device layer 82, and an intermediate layer 83.
- the support layer 81 and the device layer 82 are semiconductor layers made of, for example, silicon.
- the intermediate layer 83 is an insulating layer made of, for example, silicon oxide, and is arranged between the support layer 81 and the device layer 82.
- the first movable portion 3 is formed, for example, in the shape of a rectangular plate.
- the second movable portion 4 is formed in a rectangular ring shape, for example, and surrounds the first movable portion 3 when viewed from the optical axis direction A.
- the support portion 2 is formed in a rectangular frame shape, for example, and surrounds the second movable portion 4 when viewed from the optical axis direction A. That is, the support portion 2 surrounds the first movable portion 3 and the second movable portion 4 when viewed from the optical axis direction A.
- the optical axis direction A is a direction perpendicular to the plane on which the support portion 2, the first movable portion 3, the second movable portion 4, the pair of first connecting portions 5 and the pair of second connecting portions 6 are arranged, and is a mirror. It is a direction that intersects with the layer 7.
- the first movable portion 3 has a first portion 31 and a second portion 32.
- the first portion 31 is formed, for example, in a circular shape when viewed from the optical axis direction A.
- the second portion 32 is formed, for example, in a rectangular ring shape when viewed from the optical axis direction A.
- the second portion 32 surrounds the first portion 31 when viewed from the optical axis direction A, and is connected to the first portion 31 via a pair of connecting portions 33.
- the pair of connecting portions 33 are arranged on the second axis X2, which will be described later, so as to sandwich the first portion 31.
- the second portion 32, the connecting portion 33, and the like are not shown.
- the first movable portion 3 does not have to have the second portion 32 and the connecting portion 33.
- the pair of first connecting portions 5 are arranged on the first axis X1 so as to sandwich the first movable portion 3 in the gap between the second portion 32 of the first movable portion 3 and the second movable portion 4. There is.
- Each first connecting portion 5 functions as a torsion bar.
- Each first connecting portion 5 connects the first movable portion 3 to the second movable portion 4 so that the first movable portion 3 can swing around the first axis X1.
- Each first connecting portion 5 supports the first movable portion 3 via the second movable portion 4 and the second connecting portion 6 so that the first movable portion 3 can swing around the first axis X1. It can also be considered to be connected to 2.
- the pair of second connecting portions 6 are arranged on the second axis X2 so as to sandwich the second movable portion 4 in the gap between the support portion 2 of the second movable portion 4.
- Each second connecting portion 6 functions as a torsion bar.
- Each second connecting portion 6 connects the second movable portion 4 to the support portion 2 so that the second movable portion 4 can swing around the second axis X2.
- the first movable portion 3 also swings around the second axis X2 together with the second movable portion 4. In this way, the first movable portion 3 can swing around each of the first axis line X1 and the second axis line X2.
- the first axis X1 and the second axis X2 are perpendicular to the optical axis direction A and intersect each other (in this example, they are orthogonal to each other).
- the support portion 2, the first movable portion 3, and the second movable portion 4 are composed of a support layer 81, a device layer 82, and an intermediate layer 83.
- the first connecting portion 5 and the second connecting portion 6 are composed of a device layer 82.
- the thickness of the support layer 81 (thickness along the optical axis direction A) constituting the first movable portion 3 and the second movable portion 4 is thinner than the thickness of the support layer 81 constituting the support portion 2.
- the support layer 81 constituting the first movable portion 3 functions as a beam portion for suppressing the warp of the first movable portion 3 and the mirror layer 7.
- the first movable portion 3 and the second movable portion 4 may be composed of only the device layer 82.
- the mirror layer 7 is formed in a circular shape on the surface 31a of the first portion 31 of the first movable portion 3.
- the surface 31a is composed of a surface of the device layer 82 opposite to the intermediate layer 83, and extends so as to intersect the optical axis direction A.
- the mirror layer 7 is formed in a region including an intersection of the first axis line X1 and the second axis line X2.
- the center (geometric center) of the mirror layer 7 when viewed from the optical axis direction A coincides with the intersection of the first axis line X1 and the second axis line X2.
- the outer edge of the mirror layer 7 extends at a certain interval from the outer edge of the first portion 31.
- the diameter of the mirror layer 7 (maximum width when viewed from the optical axis direction A) is 0.5 mm or more and 30 mm or less. In this example, the diameter of the mirror layer 7 is about 2 mm.
- the mirror layer 7 may be formed in any shape such as an ellipse, a rectangle, or a polygon.
- the first portion 31 may be formed in any shape such as an ellipse, a rectangle, or a polygon.
- the second portion 32 and the second movable portion 4 of the first movable portion 3 may be formed in any shape such as an annular shape, an elliptical annular shape, or a polygonal annular shape.
- the mirror layer 7 includes an adhesion layer 71, a diffusion prevention layer (intermediate layer) 72, and a reflection layer 73.
- the adhesion layer 71, the diffusion prevention layer 72, and the reflection layer 73 are laminated in this order on the surface 31a of the first portion 31.
- the adhesion layer 71 has higher adhesion to the first portion 31 (silicon) than the diffusion prevention layer 72 and the reflection layer 73.
- the diffusion prevention layer 72 suppresses the generation of metal diffusion between the adhesion layer 71 and the reflection layer 73 during heating.
- the surface of the reflective layer 73 opposite to the first portion 31 constitutes a mirror surface 73a extending so as to intersect the optical axis direction A.
- Each of the adhesion layer 71, the diffusion prevention layer 72, and the reflection layer 73 is made of a metal material.
- the adhesion layer 71 is made of titanium
- the diffusion prevention layer 72 is made of platinum
- the reflective layer 73 is made of gold.
- the thickness of each of the adhesion layer 71 and the diffusion prevention layer 72 is, for example, about 50 nm to 300 nm, preferably about 100 nm.
- the thickness of the reflective layer 73 is, for example, about 50 nm to 300 nm, preferably about 200 nm.
- the adhesion function of the adhesion layer 71 or the diffusion prevention function of the diffusion prevention layer 72 can be effectively exerted.
- the thickness of the reflective layer 73 is 50 nm or more, the reflectance of the reflective layer 73 can be increased.
- the thickness of the adhesion layer 71, the diffusion prevention layer 72 or the reflection layer 73 is 300 nm or less, the stress generated in the adhesion layer 71, the diffusion prevention layer 72 or the reflection layer 73 can be reduced, and before the heating step described later.
- the amount of warpage of the mirror layer 7 can be reduced, and the change in the amount of warpage of the mirror layer 7 in the heating step can be reduced.
- the diffusion prevention layer 72 may be formed of tungsten.
- the reflective layer 73 may be made of aluminum. When the reflective layer 73 is made of gold, the reflectance for light in the near infrared region can be increased as compared with the case where the reflective layer 73 is made of aluminum.
- compressive stress force in the direction of convex warp
- tensile stress concave warp
- force in the direction of stress is generated.
- the type (compression or tension) and magnitude of stress are determined by manufacturing conditions such as the material, thickness, area, and film formation temperature of each layer. By adjusting the material, thickness, area, film formation temperature, etc., it is possible to adjust the type and magnitude of stress in the state before the heating step, which will be described later, and the amount of change in warpage during the heating step.
- the adhesion layer 71 and the diffusion prevention layer 72 are formed so that compressive stress remains in the state before the heating step (at the time of completion of the second forming step described later), and is a reflective layer.
- 73 is formed so that tensile stress remains in the state before the heating step (at the time of completion of the second forming step).
- the mirror device 1 includes a first drive coil 11, a second drive coil 12, wirings 15a and 15b, wirings 16a and 16b, electrode pads 21a and 21b, and electrode pads 22a and 22b.
- first drive coil 11 and the second drive coil 12 are shown by alternate long and short dash lines, and the wirings 15a and 15b and the wirings 16a and 16b are shown by solid lines.
- the first drive coil 11, the second drive coil 12, and the like are actually covered with an insulating layer 42, which will be described later.
- the first drive coil 11 is provided in the second portion 32 of the first movable portion 3.
- the first drive coil 11 is wound in a spiral shape (spiral shape) a plurality of times.
- a magnetic field generated by a magnetic field generating unit acts on the first driving coil 11.
- the magnetic field generator is configured to include, for example, a permanent magnet in a Halbach array.
- the first drive coil 11 is arranged in a groove formed on the surface of the second portion 32. That is, the first drive coil 11 is embedded in the first movable portion 3.
- the first drive coil 11 is arranged in the groove via the insulating layer 41.
- the insulating layer 41 is, for example, a silicon nitride film.
- the insulating layer 41 is formed over the surfaces of the support portion 2, the first movable portion 3, the second movable portion 4, the pair of first connecting portions 5, and the pair of second connecting portions 6, but the first movable portion is formed. It is not formed in the first portion 31 of 3.
- An insulating layer 42 made of, for example, silicon nitride is formed on the insulating layer 41.
- the wiring 15a extends from the first movable portion 3 to the support portion 2 via one first connecting portion 5, a second movable portion 4, and one second connecting portion 6.
- the wiring 15a and the electrode pad 21a are integrally formed of a metal material such as tungsten, aluminum, gold, silver, copper or an aluminum alloy.
- the wiring 15a is provided as surface wiring on the surfaces of one first connecting portion 5, the second movable portion 4, and one second connecting portion 6.
- the wirings 15b, 16a, 16b described later are provided as surface wirings like the wirings 15a.
- the other end of the first drive coil 11 is connected to the electrode pad 21b via the wiring 15b.
- the wiring 15b extends from the first movable portion 3 to the support portion 2 via the other first connecting portion 5, the second movable portion 4, and the other second connecting portion 6.
- the wiring 15b and the electrode pad 21b are integrally formed of the same metal material as the wiring 15a.
- the second drive coil 12 is provided in the second movable portion 4.
- the second drive coil 12 is spirally wound a plurality of times in the second movable portion 4.
- a magnetic field generated by the magnetic field generating portion acts on the second drive coil 12.
- the second drive coil 12 is arranged in the groove 4b formed on the surface 4a of the second movable portion 4. That is, the second drive coil 12 is embedded in the second movable portion 4.
- the second drive coil 12 is arranged in the groove via the insulating layer 41.
- the wiring 16a extends from the second movable portion 4 to the support portion 2 via one of the second connecting portions 6.
- the wiring 16a and the electrode pad 22a are integrally formed of the same metal material as the wiring 15a.
- the other end of the second drive coil 12 is connected to the electrode pad 22b via the wiring 16b.
- the wiring 16b extends from the second movable portion 4 to the support portion 2 via the other second connecting portion 6.
- the wiring 16b and the electrode pad 22b are integrally formed of the same metal material as the wiring 15a.
- first to fifth examples will be described as examples of the operation of the movable mirror unit 10 in the mirror device 1.
- a high frequency drive current is applied to the first drive coil 11.
- Lorentz force is generated in the first drive coil 11.
- the first movable portion 3 is swung around the first axis X1 at the resonance frequency level, for example.
- a drive current having a certain magnitude is applied to the second drive coil 12.
- Lorentz force is generated in the second drive coil 12.
- the second movable portion 4 is rotated around the second axis X2 according to, for example, the magnitude of the driving current, and is stopped in that state.
- the mirror device 1 the light from the light source incident along the optical axis direction A can be reflected by the mirror surface 73a and scanned.
- the first movable portion 3 is fluctuated at the resonance frequency and the second movable portion 4 is statically used.
- the first movable portion 3 swings according to the resonance frequency by applying a high frequency drive current to the first drive coil 11.
- a high frequency drive current is applied to the second drive coil 12, so that the second movable portion 4 is oscillated according to the resonance frequency.
- both the first movable portion 3 and the second movable portion 4 are fluctuated at the resonance frequency.
- the first movable portion 3 is driven by applying a drive current of a certain magnitude to the first drive coil 11.
- the second movable portion 4 is rotated around the first axis X1 according to the magnitude of the current to be stopped, and a constant magnitude of drive current is applied to the second drive coil 12. Is rotated around the second axis X2 and stopped according to the magnitude of the drive current.
- both the first movable portion 3 and the second movable portion 4 are used statically.
- the first movable portion 3 is driven.
- the first movable portion 3 is oscillated according to the resonance frequency by applying a high frequency drive current to the first drive coil 11.
- the first movable portion 3 is rotated around the first axis X1 according to the magnitude of the drive current. It is stopped.
- the fourth example and the fifth example can be used, for example, when the second movable portion 4 is not provided.
- the manufacturing method of the mirror device 1 will be described with reference to FIGS. 3 to 8.
- the SOI wafer 80 before processing is prepared (preparation step, FIG. 3A).
- the SOI wafer 80 has a support layer 81, a device layer 82, and an intermediate layer 83.
- the SOI wafer 80 has a plurality of regions R. Each of the plurality of regions R becomes the SOI substrate 8 of the mirror device 1 after the cutting step described later.
- the plurality of regions R are set so as to be arranged in a grid pattern, for example, and a dicing line L is set at the boundary between adjacent regions R.
- the SOI wafer 80 is cut along the dicing line L in the cutting step.
- a plurality of portions S each corresponding to the structure 50 are formed on the SOI wafer 80 (first forming step, FIG. 3 (b)).
- the "part corresponding to the structure 50" means a part that becomes the structure 50 after the cutting step.
- the structure 50 is formed in each of the plurality of regions R.
- the structure 50 is composed of a support portion 2, a first movable portion 3, a second movable portion 4, a pair of first connecting portions 5, and a pair of second connecting portions 6.
- the structure 50 (part S) is formed using MEMS techniques (patterning, etching, etc.).
- the first driving coil 11, the second driving coil 12, and the like are formed in each of the plurality of regions R.
- the first movable portion 3 can swing around the first axis X1 with respect to the second movable portion 4, and swings around the first axis X1 and the second axis X2 with respect to the support portion 2. It becomes movable, and the second movable portion 4 can swing around the second axis X2 with respect to the support portion 2.
- the first driving coil 11, the second driving coil 12, the wirings 15a, 15b, 16a, 16b, and the electrode pads 21a, 21b, 22a, 22b are formed in each region R (1). Wiring formation process). Subsequently, a support portion 2, a first movable portion 3, a second movable portion 4, a pair of first connecting portions 5 and a pair of second connecting portions 6 are formed in each region R (structure forming step). The structure forming step may be carried out before the wiring forming step.
- the mirror layer 7 is formed on the portion corresponding to the first movable portion 3 in each of the plurality of portions S (second forming step, FIG. 4A). More specifically, a mirror layer 7 composed of an adhesion layer 71, a diffusion prevention layer 72 and a reflection layer 73 is formed on the surface 31a of the first portion 31 of the first movable portion 3.
- the mirror layer 7 is formed by sputtering (sputtering method), but the mirror layer 7 may be formed by thin-film deposition (deposited method).
- FIG. 5A and 5 (b) are diagrams for explaining the second forming step.
- a shadow mask 91 made of silicon is arranged on a plurality of portions S.
- the shadow mask 91 is formed with an opening 91a that exposes a region to be formed of the mirror layer 7.
- the mirror layer 7 is formed by sputtering.
- the shadow mask 91 is removed after the formation of the mirror layer 7.
- the central portion is thicker than the edge portion.
- the opening 91a of the shadow mask 91 may be larger than the mirror layer 7. In this case, the mirror layer 7 having a uniform thickness can be formed.
- the temperature of the SOI wafer 80 rises to, for example, close to 100 ° C. during processing.
- the temperature of the SOI wafer 80 drops from this state, residual stress may be generated in the mirror layer 7 due to the difference in the coefficient of thermal expansion between the mirror layer 7 and the SOI wafer 80. In this case, the residual stress may cause the mirror layer 7 and the first movable portion 3 to warp.
- the temperature of the SOI wafer 80 may be raised during the formation of the mirror layer 7.
- the mirror layer 7 and the SOI wafer 80 shrink.
- the degree of shrinkage depends on the coefficient of thermal expansion.
- the coefficient of thermal expansion of the mirror layer 7 is smaller than the coefficient of thermal expansion of the SOI wafer 80, compressive stress is generated in the mirror layer 7 so that the mirror layer 7 warps in a convex shape.
- the coefficient of thermal expansion of the mirror layer 7 is larger than the coefficient of thermal expansion of the SOI wafer 80, tensile stress is generated in the mirror layer 7 so that the mirror layer 7 warps in a concave shape.
- the lattice constant of the mirror layer 7 is different from the lattice constant of the SOI wafer 80.
- the lattice constant of the mirror layer 7 tends to approach the lattice constant of the SOI wafer 80.
- the lattice constant of the mirror layer 7 approaches the value peculiar to the substance. Therefore, the mirror layer 7 is distorted in the vicinity of the boundary surface, and stress is generated accordingly.
- the direction and size of the warp generated in the mirror layer 7 and the first movable portion 3 vary depending on the material, thickness, area, forming method, etc. of the mirror layer 7.
- the mirror layer 7 is curved in a convex shape as shown in FIG. 4 (a), but the mirror layer 7 may be curved in a concave shape as shown in FIG. 9 (a) described later. be.
- compressive stress remains in the adhesion layer 71 and the diffusion prevention layer 72, and tensile stress remains in the reflective layer 73. These stresses may remain even after the heating step. That is, at least at the time of completion of the second forming step, the compressive stress may remain in the adhesion layer 71 and the diffusion prevention layer 72, and the tensile stress may remain in the reflective layer 73.
- the SOI wafer 80 is heated (heating step, FIG. 4 (b)).
- the entire SOI wafer 80 is heated.
- the residual stress existing in the mirror layer 7 is relaxed (annealing treatment).
- the amount of warpage of the mirror layer 7 is reduced by relaxing the residual stress, and the mirror layer 7 is flattened.
- a cleaning step of cleaning the SOI wafer 80 is performed. The cleaning step may be carried out when foreign matter adheres to the mirror layer 7 in the heating step, may be carried out without fail, or may be omitted.
- the residual stress is relaxed for the following reasons.
- a stress relaxation layer (alloy layer) between the mirror layer 7 and the SOI wafer 80 can be mentioned.
- some of the atoms constituting the mirror layer 7 are diffused.
- the diffusion of the atoms reduces the difference in lattice constant between the mirror layer 7 and the SOI wafer 80, or between the adhesion layer 71, the diffusion prevention layer 72, and the reflection layer 73 constituting the mirror layer 7.
- a stress relaxation layer is formed, and as a result, residual stress is relaxed.
- the argon atom trapped between the crystal lattices in the mirror layer 7 is released into the atmosphere as described in (3) above, and as a result, the residual stress is relaxed. Conceivable.
- FIG. 6 is a graph showing an example of a change in the amount of warpage of the mirror layer 7 in the heating process.
- the horizontal axis represents the elapsed time (unit: time) from the start of heating, and the vertical axis represents the amount of warpage (unit: nm) of the mirror layer 7.
- the SOI wafer 80 was heated at 150 ° C. for 30 hours.
- the amount of warpage at the start of heating was about 300 nm, but it can be seen that the mirror layer 7 became substantially flat due to the heating step, and the change in the amount of warpage became smaller with the passage of time. ..
- the amount of warpage of the mirror layer 7 is a value measured by the same method as the measurement step described later.
- the heating temperature for heating the SOI wafer 80 in the heating step is set to, for example, 60 ° C. or higher and 300 ° C. or lower. The higher the heating temperature, the shorter the heating time can be, but if the heating temperature is too high, problems such as cracks and metal diffusion may occur.
- the heating temperature of 150 ° C. in the embodiment is a value obtained by adding 70 ° C., which is assumed to be the self-heating temperature, and 10 ° C., which is a margin temperature, to 70 ° C., which is assumed to be the maximum environmental temperature of the mirror device 1.
- the heating time is set to be equal to or longer than the time until the change in the warp amount is saturated and becomes smaller, based on the relationship between the time acquired in advance and the warp amount.
- the heating time may be 5 hours or more.
- the heating temperature is preferably set higher than at least the self-heating temperature of the mirror device 1 (the temperature of the mirror device 1 at the time of driving) in order to surely suppress the change in the amount of warpage at the customer's site.
- the SOI wafer 80 is arranged in a constant temperature bath (oven). As a result, the entire SOI wafer 80 is heated, and by extension, the portions corresponding to the first movable portions 3 in each of the plurality of portions S are simultaneously heated.
- One SOI wafer 80 may be arranged in the constant temperature bath, but a plurality of (for example, 2, 6 or 12) SOI wafers 80 may be arranged.
- the SOI wafer 80 may be arranged horizontally or vertically (along the vertical direction) in the constant temperature bath.
- the oven is preferably a clean oven from the viewpoint of preventing foreign matter from adhering to the mirror layer 7.
- the following effects can be achieved. That is, by heating a plurality of SOI wafers 80 at the same time, the manufacturing efficiency can be improved.
- the temperature variation in the constant temperature bath may become large due to the influence of air convection and the like.
- the temperature of the mirror layer 7 is adjusted. It can be made uniform among a plurality of portions S.
- the plurality of SOI wafers 80 are vertically arranged, even if minute particles are present in the constant temperature bath, the particles are less likely to be deposited on the mirror layer 7 in the heating process, and foreign matter adheres to them. It is possible to suppress the decrease in yield due to the above. In the mirror device 1, even if it is a minute particle, when it adheres to the mirror layer 7, it has a great influence on the scanning light. Further, as the heating time in the heating step becomes longer, the possibility that particles are deposited on the mirror layer 7 increases. Therefore, the above-mentioned manufacturing method capable of suppressing the accumulation of foreign matter in the heating step is effective.
- the amount of warpage of the mirror layer 7 may be reduced by the heating step as in the present embodiment, or may be increased by the heating step. Whether the amount of warpage increases or decreases depends on the material, thickness, area, forming method, and the like of the mirror layer 7.
- the mirror layer 7 is curved convexly before heating, and the amount of warpage of the mirror layer 7 is reduced by the heating step, but the mirror layer 7 is curved convexly before heating, and the heating step. In some cases, the amount of warpage of the mirror layer 7 may increase. Further, as in the modification described later, the mirror layer 7 may be curved in a concave shape before heating, and the amount of warpage of the mirror layer 7 may increase due to the heating step.
- the mirror layer 7 may be concavely curved before heating, and the amount of warpage of the mirror layer 7 may be reduced by the heating step. Further, the mirror layer 7 that has been curved convexly before heating may be curved concavely due to the heating process, and the mirror layer 7 that has been curved concavely before heating may be curved convexly due to the heating process. In some cases.
- the increase in the amount of warpage means that the absolute value of the amount of warpage increases. For example, the amount of warpage changes from 200 nm to 300 nm, or from ⁇ 200 nm to ⁇ 300 nm. Decreasing the amount of warpage means that the absolute value of the amount of warpage decreases.
- the amount of warpage changes from 200 nm to 100 nm, or from ⁇ 200 nm to ⁇ 100 nm.
- a positive value of the warp amount means that the height of the central portion of the mirror layer 7 is higher (convex) than that of the peripheral portion, and a negative value of the warp amount means that the mirror layer has a negative value. It means that the height of the central portion of 7 is lower (concave) than the peripheral portion.
- the amount of warpage of the mirror layer 7 is measured for each of the plurality of portions S (measurement step).
- the PV value and shape data (3D data) of the mirror layer 7 are measured using a laser interferometer.
- the diameter of the mirror layer 7 of the present embodiment is 2 mm.
- PV values and shape data in a region having a diameter of 1.9 mm concentric with the mirror layer 7 are measured.
- the PV value represents the difference in height between the point where the height of the mirror layer 7 (mirror surface 73a) is the highest and the point where the height is the lowest in the measurement range.
- the shape data is also used to determine whether the mirror layer 7 is convex or concave (whether the amount of warpage is a positive value or a negative value). Be measured.
- a predetermined mark is attached to the structure 50 in which the amount of warpage of the mirror layer 7 is larger than the predetermined value (marking).
- the marked structure 50 (mirror device 1) is removed, for example, after a cutting step.
- the amount of warpage of the mirror layer 7 may be measured by measuring the curvature of the mirror layer 7.
- the SOI wafer 80 is cut at the dicing line L so that the plurality of portions S are separated from each other (cutting step, FIG. 7). For example, by irradiating a laser beam, a modified region is formed inside the SOI wafer 80 along the dicing line L, and by tape expanding or the like, cracks are extended from the modified region in the thickness direction of the SOI wafer 80.
- the SOI wafer 80 is cut. In the cutting step, the SOI wafer 80 may be cut by another cutting method such as blade dicing.
- each mirror device 1 is housed in the package 60.
- the package 60 has a main body portion 61 for accommodating the mirror device 1 and a transparent window member 62 arranged so as to close the opening 61a of the main body portion 61.
- the light reflected by the mirror device 1 passes through the window member 62 and is incident on the mirror layer 7.
- a plurality of portions S each corresponding to the structure 50 are formed on the SOI wafer 80, and the first movable portion 3 in each of the plurality of portions S is formed.
- the SOI wafer 80 (the portion corresponding to the first movable portion 3 in each of the plurality of portions S) is heated.
- the residual stress existing in the mirror layer 7 can be relaxed (released), and it is possible to suppress the change in the amount of warpage of the mirror layer 7 when the mirror device 1 is used.
- the SOI wafer 80 is cut after the heating step.
- the temperature of the mirror layer 7 at the time of heating can be made uniform among the plurality of portions S as compared with the case where the heat treatment is performed after cutting the wafer. That is, as described above, the heat treatment is carried out in a constant temperature bath, for example, but the temperature may vary depending on the position in the constant temperature bath due to the influence of air convection, the heat source, the position of the object to be heated, and the like.
- the heat treatment is performed for each chip after cutting the wafer (after chipping), there is a concern that the chip will be heated at a temperature different from the set temperature depending on the place where the chip is placed.
- the heat treatment is performed in the state of the SOI wafer 80 having high thermal conductivity, and heat is easily conducted in the SOI wafer 80, so that the temperature of the mirror layer 7 is reached. Can be homogenized among the plurality of portions S. As a result, it is possible to suppress variations in the quality of the mirror device 1. Further, by heating in the wafer state, many mirror devices 1 can be arranged in the constant temperature bath. As a result, the manufacturing efficiency of the mirror device 1 can be improved. Further, in the measuring step, the amount of warpage of the mirror layer 7 can be measured in the wafer state.
- the position of the mirror layer 7 can be easily grasped accurately, so that the measurement efficiency can be improved. Further, when the cleaning step of cleaning the mirror layer 7 after heating is performed, the cleaning can be performed in a wafer state, and the cleaning workability can be improved. Further, in the method for manufacturing the mirror device 1 according to the embodiment, since the SOI wafer 80 is cut after the heating step, the fragments of the SOI wafer 80 generated at the time of cutting and adhering to the mirror layer 7 are heated to generate the fragments. It is possible to suppress the situation where the constituent semiconductor materials are diffused in the mirror layer 7, and it is possible to ensure the quality of the mirror device 1.
- the sealing resin or the like used in the package 60 may be deteriorated by heating, so that the upper limit of the heating temperature is limited. ..
- the heating temperature can be set regardless of the deterioration start temperature of the sealing resin, and the manufacturing efficiency can be improved. can.
- the mirror device 1 having a movable portion can be satisfactorily manufactured.
- a measurement step for measuring the amount of warpage of the mirror layer 7 is carried out between the heating step and the cutting step. As a result, the amount of warpage of the mirror layer 7 can be measured in the wafer state, and the measurement efficiency can be improved.
- the SOI wafer 80 is cut by forming a modified region inside the SOI wafer 80 by irradiation with laser light and extending cracks from the modified region in the thickness direction of the SOI wafer 80 (stealth). Dicing).
- the stress acting on the SOI wafer 80 at the time of cutting can be reduced, and the deformation of the mirror layer 7 and the first movable portion 3 due to the stress can be suppressed.
- the mirror layer 7 is heated before the cutting step, so that the first movable portion 3 is formed. It is particularly effective to use stealth dicing capable of suppressing the breakage of 3 and the change in the amount of warpage.
- the second forming step is carried out after the first forming step.
- the mirror layer 7 after forming the plurality of portions S as in the above embodiment, such a situation can be suppressed and the quality of the mirror layer 7 can be ensured.
- the diffusion prevention layer 72 is formed of tungsten, metal diffusion between the adhesion layer 71 and the reflection layer 73 can be effectively suppressed as compared with the case where the diffusion prevention layer 72 is formed of platinum. ..
- the diffusion prevention layer 72 is formed of platinum, the stress generated by the diffusion prevention layer 72 can be reduced as compared with the case where the diffusion prevention layer 72 is formed of tungsten, and handling can be facilitated. ..
- the amount of warpage of the mirror layer 7 is reduced.
- the residual stress existing in the mirror layer 7 can be relaxed, and it is possible to suppress the change in the amount of warpage of the mirror layer 7 when the mirror device 1 is used.
- the amount of warpage of the mirror layer 7 may be increased by heating the SOI wafer 80. Also in this case, the residual stress existing in the mirror layer 7 can be relaxed, and it is possible to suppress the change in the amount of warpage of the mirror layer 7 when the mirror device 1 is used.
- the mirror layer 7 is formed by sputtering.
- the mirror layer 7 can be formed satisfactorily. That is, when the mirror layer 7 is formed by sputtering, it is not necessary to rotate the wafer as in the case of thin film deposition, so that the structure 50 including the hollow structure is less likely to be damaged. Further, in sputtering, the directivity is high, and it is difficult for metal to adhere to a portion other than the mirror layer 7. In thin-film deposition with low directivity, metal may pass through the slit (gap) between the support portion 2 and the movable mirror portion 10 and wrap around to the back surface side of the movable mirror portion 10 or adhere to the support portion 2. be.
- the mirror layer 7 can be easily controlled.
- the amount of warpage of the mirror layer 7 tends to increase due to the argon atom trap during film formation, and the amount of warpage changes significantly because the argon trapped in the heating step is released into the atmosphere. .. According to the method for manufacturing the mirror device 1 according to the embodiment, even in such a case, it is possible to effectively suppress the change in the amount of warpage of the mirror layer 7 when the mirror device 1 is used.
- the mirror device 1 includes a first drive coil 11 and a second drive coil 12 for applying a driving force to the movable mirror portion 10.
- heat is likely to be generated when the mirror device 1 is used, but according to the manufacturing method of the mirror device 1 according to the embodiment, the amount of warpage of the mirror layer 7 changes when the mirror device 1 is used even in such a case. Can be suppressed.
- the SOI wafer 80 is heated to 60 ° C. or higher and 300 ° C. or lower. As a result, the residual stress existing in the mirror layer 7 can be effectively relaxed.
- the maximum width of the mirror layer 7 is 0.5 mm or more and 30 mm or less. In this case, the amount of warpage of the mirror layer 7 is likely to change when the mirror device 1 is used, but according to the manufacturing method of the mirror device 1 according to the embodiment, even in such a case, the mirror layer 7 is used when the mirror device 1 is used. It is possible to suppress the change in the amount of warpage.
- the mirror layer 7 includes an adhesion layer 71, a diffusion prevention layer 72, and a reflection layer 73 formed in this order on the first movable portion 3. Thereby, by including the close contact layer 71, the mirror layer 7 can be stably formed on the first movable portion 3. Further, by including the diffusion prevention layer 72, it is possible to suppress the generation of metal diffusion between the reflection layer 73 and the adhesion layer 71 during heating.
- the mirror layer 7 includes an adhesion layer 71 and a diffusion prevention layer 72 in which compressive stress remains at the completion of the second forming step, and a reflective layer 73 in which tensile stress remains at the completion of the second forming step. ..
- the amount of warpage of the mirror layer 7 before the heating step can be reduced.
- the change in the amount of warpage of the mirror layer 7 in the heating step can be reduced, and as a result, the heating time can be shortened and the amount of warpage of the mirror layer 7 can be easily controlled.
- the entire SOI wafer 80 is heated. Thereby, the temperature of the mirror layer 7 at the time of heating can be made uniform among the plurality of portions S. [Modification example]
- FIG. 9 (a) and 9 (b) are diagrams for explaining the manufacturing method of the mirror device 1 according to the modified example.
- the mirror layer 7 is concavely curved before the heating step.
- heating the SOI wafer 80 in the heating step increases the amount of warpage of the mirror layer 7.
- FIG. 10 is a graph showing an example of a change in the amount of warpage of the mirror layer 7 in the heating process of the modified example.
- the SOI wafer 80 was heated at 150 ° C. for 30 hours.
- the change in the amount of warpage for the five samples is shown by different line types. As shown in FIG. 10, for each sample, the amount of warpage at the start of heating was about 100 nm, but the amount of warpage increased to about 250 to 350 nm by the heating step, and the amount of warpage increased with the passage of time. It can be seen that the change has become smaller.
- the heating time may be 2 hours or more. By setting the heating time to about the time until the change in the amount of warpage reaches saturation, the energy for heating can be reduced.
- FIG. 11 is a graph showing an example of a change in the amount of warpage of the mirror layer 7 in the reliability test.
- the mirror device 1 obtained by the manufacturing method of the mirror device 1 according to the modified example was operated, and the amount of warpage of the mirror layer 7 during the operation was measured.
- the amount of warpage of the mirror layer 7 in the initial state (0 hours) was set to 0 nm, and the change in the amount of warpage of the mirror layer 7 was measured every 250 hours for up to 1000 hours.
- the first movable portion 3 was continuously operated with an optical runout angle of 10 ° around the first axis X1 and an optical runout angle of 10 ° around the second axis line X2. As shown in FIG. 11, it can be seen that the change in the amount of warpage of the mirror layer 7 during operation was suppressed to ⁇ 50 nm or less.
- the mirror device 1 is configured to be electromagnetically driven, but the mirror device 1 may be configured to be piezoelectrically driven or electrostatically driven.
- the piezoelectric drive type or, for example, a piezoelectric film (piezoelectric element) may be provided in place of the first drive coil 11 and the second drive coil 12.
- the first drive coil 11 may be provided in the second movable portion 4. Even in this case, the first movable portion 3 can be swung around the first axis X1 at a resonance frequency. Specifically, when a drive current having a frequency equal to the resonance frequency of the first movable portion 3 around the first axis X1 is input to the first drive coil 11, the second movable portion 4 moves around the first axis X1. It vibrates slightly at that frequency. By transmitting this vibration to the first movable portion 3 via the first connecting portion 5, the first movable portion 3 can be oscillated around the first axis X1 at the frequency.
- the first drive coil 11 or the piezoelectric element When the first drive coil 11 or the piezoelectric element is provided in the first movable portion 3, heat is easily transferred to the mirror layer 7 because the heat generation source is close to the mirror layer 7.
- the method for manufacturing the mirror device 1 described above According to the above, even in such a case, it is possible to suppress the change in the amount of warpage of the mirror layer 7 when the mirror device 1 is used.
- the second forming step may be carried out before the first forming step.
- the mirror layer 7 may be formed on the portion of the SOI wafer 80 corresponding to the first movable portion 3, and then the structure forming step may be carried out.
- the measurement step may be omitted.
- the first connecting portion 5 may connect the first movable portion 3 to the support portion 2 so that the first movable portion 3 can move along a predetermined direction.
- the first movable portion 3 may be movable along the optical axis direction A (direction perpendicular to the mirror layer 7).
- the mirror layer 7 does not have to include the adhesion layer 71. For example, if the mirror device 1 does not reach a high temperature during operation, the adhesion layer 71 may be omitted.
- the mirror layer 7 does not have to include the diffusion prevention layer 72.
- the diffusion prevention layer 72 may be omitted when a high reflectance is not required for the mirror layer 7 or when the appearance of the mirror layer 7 is not questioned.
- the entire SOI wafer 80 is heated by using a constant temperature bath, but the portion corresponding to the first movable portion 3 in each of the plurality of portions S may be heated, and the heating means is not limited. ..
- the heating means is not limited. ..
- by irradiating a spot light such as a laser beam without heating the entire SOI wafer 80 only the portion corresponding to the first movable portion 3 in each of the plurality of portions S may be heated at the same time. Even in this case, by conducting heat in the SOI wafer 80, the portion corresponding to the first movable portion 3 in each of the plurality of portions S can be uniformly heated. Further, even if the output of the irradiated laser beam varies, uniform heating can be realized.
- heating is performed using a heat source located outside the mirror device 1 instead of self-heating generated by driving the mirror device 1.
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Manufacturing & Machinery (AREA)
- Microelectronics & Electronic Packaging (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Mechanical Engineering (AREA)
- Micromachines (AREA)
- Mechanical Optical Scanning Systems (AREA)
- Mechanical Light Control Or Optical Switches (AREA)
Abstract
Description
[ミラーデバイス]
[ミラーデバイスの製造方法]
(1)ミラー層7とSOIウェハ80との間の熱膨張率の違い
(2)ミラー層7とSOIウェハ80との間の格子定数の違い
(3)スパッタリングによるSOIウェハ80及びミラー層7でのアルゴン原子トラップ
[作用及び効果]
[変形例]
Claims (15)
- 支持部、可動部、及び前記可動部が揺動又は移動可能となるように前記可動部を前記支持部に連結する連結部を有する構造体と、前記可動部上に設けられたミラー層と、を備えるミラーデバイスの製造方法であって、
各々が前記構造体に対応する複数の部分をウェハに形成する第1形成工程と、
前記複数の部分の各々における前記可動部に対応する部分上に前記ミラー層を形成する第2形成工程と、
前記第1形成工程及び前記第2形成工程の後に、前記複数の部分の各々における前記可動部に対応する前記部分を加熱する加熱工程と、
前記加熱工程の後に、前記複数の部分が互いに分離されるように前記ウェハを切断する切断工程と、を含む、ミラーデバイスの製造方法。 - 前記加熱工程と前記切断工程との間に、前記ミラー層の反り量を測定する測定工程を更に含む、請求項1に記載のミラーデバイスの製造方法。
- 前記切断工程では、レーザ光の照射によって前記ウェハの内部に改質領域を形成し、前記改質領域から前記ウェハの厚さ方向に亀裂を伸展させることにより、前記ウェハを切断する、請求項1又は2に記載のミラーデバイスの製造方法。
- 前記第1形成工程の後に前記第2形成工程が実施される、請求項1~3のいずれか一項に記載のミラーデバイスの製造方法。
- 前記加熱工程では、前記複数の部分の各々における前記可動部に対応する前記部分を加熱することにより、前記ミラー層の反り量を減少させる、請求項1~4のいずれか一項に記載のミラーデバイスの製造方法。
- 前記加熱工程では、前記複数の部分の各々における前記可動部に対応する前記部分を加熱することにより、前記ミラー層の反り量を増加させる、請求項1~4のいずれか一項に記載のミラーデバイスの製造方法。
- 前記第2形成工程では、スパッタリングにより前記ミラー層を形成する、請求項1~6のいずれか一項に記載のミラーデバイスの製造方法。
- 前記ミラーデバイスは、前記可動部に駆動力を作用させるためのコイル又は圧電素子を更に備えている、請求項1~7のいずれか一項に記載のミラーデバイスの製造方法。
- 前記加熱工程では、前記複数の部分の各々における前記可動部に対応する前記部分を60℃以上300℃以下に加熱する、請求項1~8のいずれか一項に記載のミラーデバイスの製造方法。
- 前記ミラー層の最大幅は、0.5mm以上30mm以下である、請求項1~9のいずれか一項に記載のミラーデバイスの製造方法。
- 前記ミラー層は、前記可動部上にこの順に形成された密着層、拡散防止層及び反射層を含んでいる、請求項1~10のいずれか一項に記載のミラーデバイスの製造方法。
- 前記ミラー層は、反射層を含む複数の層を含み、
前記複数の層は、前記第2形成工程の完了時点において圧縮応力が残留する層と、前記第2形成工程の完了時点において引張応力が残留する層と、を含んでいる、請求項1~11のいずれか一項に記載のミラーデバイスの製造方法。 - 前記加熱工程では、前記ウェハの全体を加熱する、請求項1~12のいずれか一項に記載のミラーデバイスの製造方法。
- 前記加熱工程では、恒温槽内に複数の前記ウェハが鉛直方向に沿って配置される、請求項13に記載のミラーデバイスの製造方法。
- 前記加熱工程では、前記ウェハの全体を加熱することなく、前記複数の部分の各々における前記可動部に対応する前記部分を加熱する、請求項1~12のいずれか一項に記載のミラーデバイスの製造方法。
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202180086100.9A CN116635325A (zh) | 2020-12-21 | 2021-09-15 | 反射镜器件的制造方法 |
US18/037,142 US20240002219A1 (en) | 2020-12-21 | 2021-09-15 | Method for manufacturing mirror device |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2020-211201 | 2020-12-21 | ||
JP2020211201A JP2022097939A (ja) | 2020-12-21 | 2020-12-21 | ミラーデバイスの製造方法 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2022137674A1 true WO2022137674A1 (ja) | 2022-06-30 |
Family
ID=82157498
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2021/033949 WO2022137674A1 (ja) | 2020-12-21 | 2021-09-15 | ミラーデバイスの製造方法 |
Country Status (4)
Country | Link |
---|---|
US (1) | US20240002219A1 (ja) |
JP (1) | JP2022097939A (ja) |
CN (1) | CN116635325A (ja) |
WO (1) | WO2022137674A1 (ja) |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010044410A (ja) * | 2005-01-05 | 2010-02-25 | Nippon Telegr & Teleph Corp <Ntt> | ミラー装置 |
JP2011180249A (ja) * | 2010-02-26 | 2011-09-15 | Ricoh Co Ltd | 光偏向器、光偏向器の製造方法、光学装置及び表示装置 |
JP2018010038A (ja) * | 2016-07-11 | 2018-01-18 | 浜松ホトニクス株式会社 | ファブリペロー干渉フィルタ及び光検出装置 |
CN110927960A (zh) * | 2019-12-06 | 2020-03-27 | 北京理工大学 | 一种热驱动可变形微镜 |
-
2020
- 2020-12-21 JP JP2020211201A patent/JP2022097939A/ja active Pending
-
2021
- 2021-09-15 CN CN202180086100.9A patent/CN116635325A/zh active Pending
- 2021-09-15 US US18/037,142 patent/US20240002219A1/en active Pending
- 2021-09-15 WO PCT/JP2021/033949 patent/WO2022137674A1/ja active Application Filing
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010044410A (ja) * | 2005-01-05 | 2010-02-25 | Nippon Telegr & Teleph Corp <Ntt> | ミラー装置 |
JP2011180249A (ja) * | 2010-02-26 | 2011-09-15 | Ricoh Co Ltd | 光偏向器、光偏向器の製造方法、光学装置及び表示装置 |
JP2018010038A (ja) * | 2016-07-11 | 2018-01-18 | 浜松ホトニクス株式会社 | ファブリペロー干渉フィルタ及び光検出装置 |
CN110927960A (zh) * | 2019-12-06 | 2020-03-27 | 北京理工大学 | 一种热驱动可变形微镜 |
Also Published As
Publication number | Publication date |
---|---|
CN116635325A (zh) | 2023-08-22 |
JP2022097939A (ja) | 2022-07-01 |
US20240002219A1 (en) | 2024-01-04 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5775409B2 (ja) | 光スキャナの製造方法 | |
US10710874B2 (en) | Micromechanical structure and method for manufacturing the same | |
US20070111480A1 (en) | Wafer product and processing method therefor | |
JP7256204B2 (ja) | 圧電層を支持基板上に転写する方法 | |
US10862018B2 (en) | Method for manufacturing a piezoelectric device | |
JP5876329B2 (ja) | 光スキャナの製造方法 | |
JP2002346782A (ja) | レーザビームを利用した非メタル基板の切断方法及び装置 | |
JP2013042119A (ja) | 発光素子の製造方法 | |
WO2022137674A1 (ja) | ミラーデバイスの製造方法 | |
JP2004198648A (ja) | プレーナ型アクチュエータ | |
JP4458704B2 (ja) | プレーナー型ガルバノ装置及びその製造方法 | |
JP5934621B2 (ja) | 光偏向器の製造方法 | |
JP2011112806A (ja) | Mems光スキャナおよびその製造方法 | |
JP4578001B2 (ja) | ガルバノ装置の製造方法 | |
JP6220648B2 (ja) | 光偏向器及びその製造方法 | |
US10373855B2 (en) | Method for processing a wafer and method for processing a carrier | |
JP4376679B2 (ja) | プレーナ型アクチュエータの製造方法 | |
WO2020188732A1 (ja) | 光走査装置およびその製造方法 | |
US9359193B2 (en) | Method for manufacturing an integrated MEMS device | |
KR20220049010A (ko) | 액체 렌즈의 어레이를 제조하고 어레이를 개별 액체 렌즈로 분리하는 것과 같은, 접합부를 통해 기판들을 접합하고 접합된 기판의 일부를 분리하는 방법 | |
JP2010166371A (ja) | 圧電デバイスの製造方法 | |
KR100931324B1 (ko) | 레이저 디스플레이용 박막형 2축 구동거울 및 그 제조방법 | |
US20120132349A1 (en) | Method for producing tunable interference filter | |
US11939216B2 (en) | Method with stealth dicing process for fabricating MEMS semiconductor chips | |
JP6092590B2 (ja) | 光偏向器の製造方法 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 21909832 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 18037142 Country of ref document: US |
|
WWE | Wipo information: entry into national phase |
Ref document number: 202180086100.9 Country of ref document: CN |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 21909832 Country of ref document: EP Kind code of ref document: A1 |