OPTICAL SCANNING DEVICE AND METHOD FOR MAKING THE SAME

Abstract

Optical scanning device comprising the following: a scanning structure (3) with a reflective surface (5) for reflecting light; a support body (21) as an anchor; and one or more drive units (7, 7a, 7b) connected between the scanning structure (3) and the carrier body (21) to drive the scanning structure (3), where which one or more drive units (7, 7a, 7b) have the following features: a first drive beam (9, 9a) with a first fixed end connected to the support body (21) and a first drive end connected to the scanning structure (3), a first electrode connection (13, 13a) formed on the first drive beam (9, 9a), a pair of first supports (17, 17a) each connected to the support body (21) and also arranged such that they sandwich-like enclose the first drive beam (9, 9a), a first layer magnet (15, 15a, 15b) arranged on each of the pair of first supports (17, 17a), a second drive beam (9, 9b) with a second fixed end connected to the carrier body (21) and a second drive end connected to the scanning structure (3) and the first drive end, a second electrode connection (13, 13b) formed on the second drive beam (9, 9b) and electrically connected to the first electrode connection (13, 13a), pairs of second supports (17, 17b) arranged to sandwich the second drive beams (9, 9b), and a second layer magnet (15, 15c, 15d) arranged on each of the pair of second supports (17, 17b), wherein the first layer magnet (15, 15a, 15b) is arranged such that magnetic force lines are generated in a first direction which intersects the direction in which the first electrode connection (13, 13a) runs, wherein the second layer magnet (15, 15c, 15d) is arranged such that magnetic force lines are generated in a second direction which intersects the direction in which the second electrode connection (13, 13b) extends, where the first direction and the second direction are opposite to each other, wherein the direction of a current flowing through the first electrode connection (13, 13a) and the direction of a current flowing through the second electrode connection (13, 13b) are opposite to each other.

Description

TECHNICAL FIELD

[0001] The present invention relates to an optical scanning device and a method for manufacturing the optical scanning device. STATE OF THE ART

[0002] In an optical scanning device, such as a laser distance sensor or an optical scanner, MEMS (Micro Electro Mechanical System) technology is used to incorporate a MEMS mirror. To drive the MEMS mirror, there is a MEMS mirror that utilizes an electromagnetic force, an electrostatic force, or a piezoelectric effect. Light scanning is achieved by rotating and oscillating the MEMS mirror around a support (or axis).

[0003] For example, Patent Document 1 describes an optical scanning device comprising a silicon substrate configured to form a support beam and a movable plate. A drive coil is formed by forming a connection on the movable plate. A current is passed through the drive coil. A Lorentz force is generated between the current flowing through the drive coil and a magnetic field of a permanent magnet arranged outside the MEMS mirror. Using the Lorentz force as the driving force, the movable plate is rotated around the support beam, thereby scanning light.

[0004] Patent Document 2 describes an actuator comprising a drive unit and a base unit connected to a mounting unit and connected by a first link unit such that their respective rotation centers are arranged on a first axis. Within the base unit, a driven part is connected by a second link unit extending in a second axis direction perpendicular to the first axis. The actuator is provided with an asymmetric structure with respect to the first axis. STATE OF THE ART Patent document 1: WO 2013 / 124 913 A1 Patent document 2: JP 2019 - 041 513 A SUMMARY OF THE INVENTION Problems to be solved by the invention

[0005] As described above, the conventional optical pickup device requires a permanent magnet to rotate a MEMS mirror. This is one of the factors hindering the miniaturization of the optical pickup device.

[0006] The present invention is intended to address this problem and has the object of providing an optical pickup device that can be miniaturized, and another object is to provide a method of manufacturing such an optical pickup device. Means to solve the problems

[0007] According to the present invention, an optical scanning device comprises: a scanning structure having a reflective surface for reflecting light; a support body as an armature; and one or more drive units connected between the scanning structure and the support body to drive the scanning structure, wherein the one or more drive units comprise: a first drive beam having a first fixed end connected to the support body and a first drive end connected to the scanning structure; a first electrode connection formed on the first drive beam; a pair of first supports, each connected to the support body and also arranged to sandwich the first drive beam; a first layer magnet arranged on each of the pair of first supports; a second drive beam having a second fixed end;which is connected to the support body, and a second drive end connected to the sensing structure and the first drive end, a second electrode connection formed on the second drive beam and electrically connected to the first electrode connection, pairs of second supports arranged to sandwich the second drive beams, and a second layer magnet arranged on each of the pair of second supports, wherein the first layer magnet is arranged to generate magnetic lines of force in a first direction that intersects the direction in which the first electrode connection extends, wherein the second layer magnet is arranged to generate magnetic lines of force in a second direction that intersects the direction in which the second electrode connection extends, wherein the first direction and the second direction are opposite to each other,wherein the direction of a current flowing through the first electrode connection and the direction of a current flowing through the second electrode connection are opposite to each other.,

[0008] According to the present invention, a method for manufacturing an optical scanning device includes the following steps: preparing a substrate (51) consisting of a semiconductor substrate and a semiconductor layer formed on a surface of a body of the semiconductor substrate, with a first insulating layer disposed therebetween; forming a first electrode connection and a second electrode connection electrically connected to the first electrode connection, and a reflection mirror on the semiconductor layer with a second insulating layer disposed therebetween; forming a first layer magnet and a second layer magnet on the second insulating layer; and processing the second insulating layer, the semiconductor layer, the first insulating layer, and the body of the semiconductor substrate into a support body as an armature, a scanning structure with the reflection mirror disposed thereon,a first drive beam having the first electrode connection arranged thereon, one end being connected to the support body as a first fixed end and the other end being connected to the sensing structure as a first drive end; a second drive beam having the second electrode connection arranged thereon, one end being connected to the support body as a second fixed end and the other end being connected to the sensing structure and the first drive end as a second drive end; a pair of first supports each having the first layer magnet arranged thereon and connected to the support body to sandwich the first drive beam; and a pair of second supports each having the second layer magnet arranged thereon and connected to the support body to sandwich the second drive beam; wherein in the step of forming the first layer magnet,the first layer magnet is formed such that magnetic lines of force are generated in a direction that intersects the direction in which the first electrode connection extends, wherein in the step of forming the second layer magnet, the second layer magnet is formed such that magnetic lines of force are generated in a second direction that intersects the direction in which the second electrode connection extends, wherein the direction of a current flowing through the first electrode connection and the direction of a current flowing through the second electrode connection are opposite to each other.

[0009] According to the present invention, another method for manufacturing an optical pickup device includes the steps of: preparing a substrate comprising a semiconductor substrate and a semiconductor layer formed on a surface of a body of the semiconductor substrate with a first insulating layer interposed therebetween; forming a first electrode interconnection and a second electrode interconnection electrically connected to the first electrode interconnection on the semiconductor layer with a second insulating layer interposed therebetween; forming a first layer magnet and a second layer magnet on the second insulating layer; processing the second insulating layer, the semiconductor layer, the first insulating layer, and the body of the semiconductor substrate to form: a support body as an armature, a first drive beam,on which the first electrode connection is arranged and one end of which is connected to the support body as a first fixed end and the other end of which is a first drive end, a second drive beam on which the second electrode connection is arranged and one end of which is connected to the support body as a second fixed end and the other end of which is connected to the first drive end as a second drive end, a pair of first beams, each of which has the first layer magnet arranged thereon and is connected to the support body so as to sandwich the first drive beam, and a pair of second beams, each of which has the second layer magnet arranged thereon and is connected to the support body,to sandwich the second drive beam; forming a scanning structure having a reflection mirror arranged thereon; and connecting the scanning structure to the first drive end of the first drive beam and the second drive end of the second drive beam, which are connected to each other, wherein in the step of forming the first layer magnet, the first layer magnet is formed such that magnetic lines of force are generated in a direction intersecting the direction in which the first electrode connection extends, wherein in the step of forming the second layer magnet, the second layer magnet is formed such that magnetic lines of force are generated in a second direction intersecting the direction in which the second electrode connection extends, wherein the direction of a current flowing through the first electrode connection and the direction of a current flowing through the second electrode connection,are opposite to each other., Advantageous effects of the invention

[0010] According to the present invention, an optical scanning device is configured such that a first layer magnet is arranged such that magnetic lines of force are generated in a first direction intersecting the direction in which a first electrode connection extends, and the optical scanning device can thus be miniaturized.

[0011] According to the present invention, a method for manufacturing an optical pickup device is such that a first layer magnet configured to generate magnetic lines of force in a direction intersecting the direction in which a first electrode connection extends is formed as a layer, and the method makes it possible to manufacture an optical pickup device that can contribute to miniaturization.

[0012] According to the present invention, another method for manufacturing an optical pickup device is provided such that a first layer magnet configured to generate magnetic lines of force in a direction intersecting the direction in which a first electrode connection extends is layered, and a pickup structure is formed separately from a first drive beam, etc., and finally bonded to the first drive beam, the method enabling the manufacture of an optical pickup device capable of contributing to miniaturization. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a plan view of an optical pickup device according to a first embodiment; Fig. 2 is a partial cross-section along a Fig. 1 indicated line II-II according to the embodiment; Fig. 3A is a cross-section along a line corresponding to a Fig. 1, and shows a step of a method for manufacturing the optical pickup device according to the embodiment; Fig. Figure 3B is a cross-section showing a step taken after the Fig. 3A is performed according to the embodiment; Fig. Figure 3C is a cross-section showing a step taken after the Fig. 3B is carried out according to the embodiment; Fig. 3D is a cross-section showing a step that follows the one in Fig. 3C is carried out according to the embodiment; Fig. Figure 4A is a partial cross-section showing a step taken after the Fig. 3D is carried out according to the embodiment; Fig. Figure 4B is a partial cross-section showing a step taken after the Fig. 4A is carried out according to the embodiment; Fig. 5 is a partial cross-section showing a modified example of the Fig. 4A and Fig. 4B shows steps according to the embodiment; Fig. Figure 6A is a cross-section showing a step taken after the Fig. 4B is carried out according to the embodiment; Fig. Figure 6B is a cross-section showing a step taken after the Fig. 6A is carried out according to the embodiment; Fig. 7A is a partial cross-section along a Fig. 1 indicated line VIIA-VIIA for illustrating an operation of the optical pickup device according to the embodiment; Fig. 7B is a partial cross-section along a Fig. 1 indicated line VIIB-VIIB for illustrating an operation of the optical pickup device according to the embodiment; Fig. 8 is a plan view of an optical pickup device according to a second embodiment; Fig. 9 is a partial cross-section along a Fig. 8 indicated line IX-IX according to the embodiment; Fig. 10 is a partial plan view of an optical pickup device according to a third embodiment; Fig. 11 is a plan view of an optical pickup device according to a fourth embodiment; Fig. 12 is a cross section along a Fig. 11 indicated line XII-XII according to the embodiment; Fig. 13 is a partial plan view showing an exemplary variation of an electrode connection according to the respective embodiment; Fig. 14 is a partial cross-section along a Fig. 13 indicated line XIV-XIV according to each embodiment; Fig. 15 is a partial plan view showing another exemplary variation of the electrode connection according to each embodiment; Fig. 16 is a partial cross-section along a Fig. 15 indicated line XVI-XVI according to each embodiment, and Fig. 17 is a partial cross-sectional view showing an exemplary variation of a thin film magnet according to each embodiment. DESCRIPTION OF THE EMBODIMENTS Embodiment 1

[0013] An optical scanning device according to a first embodiment will now be described. As shown in Fig. 1 and Fig. As shown in Figure 2, an optical scanning device 1 includes a scanning structure 3, an armature 21, and a drive unit 7. The drive unit 7 is connected between the scanning structure 3 and the armature 21 to drive the scanning structure 3. The drive unit 7 includes a drive beam 9, a connecting beam 11, an electrode connection 13, a support 17, and a thin-film magnet 15. The drive unit 7 includes a first drive unit 7a and a second drive unit 7b. In the present description, an X-axis, a Y-axis, and a Z-axis are used as needed. The surface on which the optical scanning device 1 is arranged is defined as an XY plane. The Z-axis is orthogonal to the XY plane.

[0014] The scanning structure 3 is essentially rectangular in plan view. A reflection mirror 5 is formed on the scanning structure 3. The armature 21 is formed in the shape of a rectangular frame in plan view. The armature 21 is shaped to surround the scanning structure 3, the drive beam 9, and the support 17. The optical scanning device 1 has a size of, for example, several hundred micrometers to several tens of millimeters.

[0015] The drive beam 9 includes a first drive beam 9a and a second drive beam 9b. The drive beam 9 is, for example, approximately 10 to 3000 µm wide. The drive beam 9 has, for example, a length of approximately 100 to 20,000 µm.

[0016] The first drive beam 9a has a first fixed end and a first drive end, the first fixed end being connected to the armature 21, and the first drive end being connected via the connecting beam 11 to the sensing structure 3 on a negative side along the Y-axis. The second drive beam 9b has a second fixed end and a second drive end, the second fixed end being connected to the armature 21, the second drive end being connected to the first drive end, and is also connected via the connecting beam 11 to the sensing structure 3 on the negative side along the Y-axis.

[0017] The electrode connection 13 includes an electrode connection 13a as the first electrode connection and an electrode connection 13b as the second electrode connection. The electrode connection 13 is formed on the drive beam 9 with a silicon oxide layer 59 interposed therebetween. The electrode connection 13 is, for example, approximately 0.1 to 10 µm thick. The silicon oxide layer 59 has, for example, a thickness of approximately 0.01 to 1 µm.

[0018] Electrode connection 13a has one end side electrically connected to an electrode 19a. Electrode connection 13b has one end side electrically connected to an electrode 19b. Electrode connections 13a and 13b have their respective other end sides electrically connected to each other.

[0019] The support 17 includes a support 17a as a pair of first supports and a support 17b as a pair of second supports. The supports 17a and 17b are connected to the armature 21.

[0020] The thin-film magnet 15 includes the thin-film magnets 15a and 15b as the first layer magnet and the thin-film magnets 15c and 15d as the second layer magnet. The thin-film magnets 15a and 15b generate magnetic lines of force in a first direction that intersects the direction along the Y-axis in which the electrode connection 13a extends, and it is a positive direction along the X-axis.

[0021] The thin-film magnets 15c and 15d generate magnetic lines of force in a second direction, which intersects the direction along the Y-axis in which the electrode connection 13b extends and is a negative direction along the X-axis. The first direction and the second direction are opposite directions to each other. In the present specification, the thin-film magnet 15 is a magnet formed from a film formed by a semiconductor process such as sputtering, CVD (Chemical Vapor Deposition), or the like, and refers to a film-shaped magnet with a thickness of about 100 μm or less.

[0022] Silicon is designated as the main material for the sensing structure 3, the drive beam 9, the connecting beam 11, the carrier 17, and the armature 21. The silicon used can be, for example, the silicon of an SOI (Silicon On Insulator) substrate. By using the SOI substrate, the thickness of the sensing structure 3, the drive beam 9, and the connecting beam 11 can be varied.

[0023] The thickness of the sensing structure 3 can be made larger to suppress deformation of the sensing structure 3. Conversely, the thickness of the drive beam 9 can be made smaller to reduce the rigidity of the drive beam 9 and to allow for a greater displacement of the drive beam 9. In addition to single-crystal silicon, polysilicon, for example, can also be used as the silicon.

[0024] A reflection mirror 5 with a silicon oxide layer 59 interposed therebetween is arranged on the scanning structure 3. The reflection mirror 5 is formed from a metal layer having a relatively high reflectance. A gold (Au) layer, for example, is suitable as a metal layer with a high reflectance. If the gold layer is formed directly on a silicon surface or a silicon oxide layer, the gold layer may be peeled off from the surface of the underlying silicon or the like due to poor adhesion between the gold layer and the underlying silicon or the like. To suppress this, it is desirable to interpose an adhesion layer between the gold layer and the surface of the underlying silicon or the like.

[0025] The adhesion layer is preferably a chromium (Cr) layer, a stack of a chromium (Cr) layer and a nickel (Ni) layer, a titanium (Ti) layer, a stack of a titanium (Ti) layer and a platinum (Pt) layer, or the like. The reflection mirror 5 has a diameter of, for example, approximately 100 to 10,000 µm.

[0026] The metal layer forming the reflection mirror 5 is not limited to a gold layer and may be, for example, a platinum (Pt) layer, a silver (Ag) layer, or the like. It is desirable to use a metal layer that has a higher reflectance depending on the wavelength of the light to be used. Furthermore, the scanning structure 3 including the reflection mirror 5 can be packaged by vacuum sealing, hermetically sealing, or the like. In such a case, the reflection mirror 5 can be formed of an aluminum (Al) layer or a similar oxidizable metal layer.

[0027] The metal layer is preferably produced by sputtering. A sputtered metal layer is considered to be of satisfactory quality. Instead of sputtering, evaporation deposition, for example, can be used.

[0028] Aluminum (Al) is suitable as a material for the electrode connection 13. Any material capable of conducting electrical current is sufficient for the electrode connection 13; in addition to aluminum, aluminum-silicon (Al-Si), gold (Au), or the like can be used.

[0029] Gold (Au) is suitable as the material for the electrode 19. The electrode 19 is preferably formed by the same method as that used to manufacture the reflection mirror 5. The electrode 19 can be formed by the same method as that used to form the electrode connection 13.

[0030] NdFeB (neodymium) is a suitable material for the thin-film magnet 15. A material capable of generating a magnetic field is sufficient for the thin-film magnet 15. In addition to NdFeB (neodymium), SmCo (samarium cobalt), CoPtCr (cobalt platinum chromium), or the like can be used.

[0031] An example of a method for manufacturing the optical scanning device 1 as described above is described below using a section along the line shown in Fig. 1 indicated line III-III.

[0032] First, as in Fig. 3A, an SOI substrate 51 is manufactured. For the SOI substrate 51, a silicon substrate 53 as the body of a semiconductor substrate has a main surface with a silicon layer 57 formed thereon, between which a silicon oxide layer 55 is arranged. Furthermore, a silicon oxide layer 59 is formed on one surface of the silicon layer 57. A silicon oxide layer 61 is formed on the other main surface of the silicon substrate 53. The silicon substrate 53 is, for example, approximately 100 to 1000 µm thick. The silicon layer 57 has, for example, a thickness of approximately 2 to 200 µm.

[0033] If the silicon oxide layers 59 and 61 are not formed on the SOI substrate 51, then the silicon oxide layer 59 is formed on one surface of the silicon layer 57, and the silicon oxide layer 61 is formed on the other major surface of the silicon substrate 53 in advance. The silicon oxide layers 59 and 61 are preferably formed by thermal oxidation. By thermal oxidation, silicon oxide layers 59 and 61 of good quality can be formed as a layer. In contrast to the SOI substrate 51, for example, a single-crystal silicon substrate can be used. In this case, when etching the backside of a single-crystal silicon substrate, as described below, it is necessary to control the etching timing.

[0034] Subsequently, a layer (not shown) intended to be an electrode connection is formed, e.g., by sputtering, so that it covers the silicon oxide layer 59. The layer intended to be the electrode connection is then photolithographically processed and etched. The layer is suitably etched, e.g., by reactive ion etching. A chlorine (Cl2) / argon (Ar)-based gas is suitably used for reactive ion etching. In photolithography, a photoresist pattern is formed as a mask (a protective layer) for the etching.

[0035] So, as in Fig. 3B, the electrode connection 13 is formed. When the electrode connection 13 is formed, a portion of the electrode 19 is also formed. In addition to reactive ion etching, wet etching with an etching solution, for example, can also be performed. During etching, it is necessary to set an etching condition under which the underlying silicon oxide layer 59 is not easily etched. After the electrode connection 13 and the like are formed, the photoresist pattern is removed. O2 ashing is suitable for removing the photoresist pattern. Alternatively, the photoresist pattern can also be removed with a stripping solution.

[0036] Subsequently, a layer (not shown) is formed as a reflection mirror and an electrode is formed to cover the silicon oxide layer 59. Photolithography and etching are then carried out. Thus, as shown in Fig. 3C, the reflection mirror 5 and a remaining portion of the electrode 19 are formed. Suitable layers for the reflection mirror and the electrode include, for example, a chromium (Cr) layer / nickel (Ni) layer / gold (Au) layer, a titanium (Ti) layer / platinum (Pt) layer / gold (Au) layer, or a similar layer. Such a layer has high adhesion to an underlying material and also exhibits a high degree of reflection. The layer is expediently formed by sputtering.

[0037] When forming a gold (Au) layer, wet etching with an etchant is preferred. Alternatively, the layer that will serve as the reflection mirror and electrode can be formed by lift-off or ion beam etching (IBE). After the reflection mirror 5 and the electrode 19 are formed, the photoresist pattern is removed.

[0038] To prevent the electrode connection 13 from being etched during the etching process for structuring the reflection mirror 5 and the electrode 19, it is advantageous to form a protective layer (not shown) covering the electrode connection 13 before forming the layer intended to be the reflection mirror and the electrode. An insulating layer made of silicon oxide is expediently used as the protective layer. To establish the electrical connection between the electrode 19 and the electrode connection 13, it is necessary to remove a portion of the protective layer located beneath the electrode 19.

[0039] Furthermore, the electrode connection 13 and the reflection mirror 5 can be formed simultaneously. In this case, it is preferable to form a layer suitable for both the electrode connection 13 and the reflection mirror 5. It is preferable to form the electrode connection 13 according to the conditions (layer type, pattern, etc.) used in forming the reflection mirror 5.

[0040] Subsequently, a layer (not shown) for forming the thin-film magnet is formed to cover the silicon oxide layer 59. The layer intended for the thin-film magnet is suitably formed by sputtering, whereby the layer has a good quality as a layer. Subsequently, as shown in Fig. 3D, the thin-film magnet layer 14 is patterned to form a pattern of the thin-film magnet layer 14. The thin-film magnet layer 14 is suitably patterned by ion beam etching (IBE).

[0041] In contrast to ion beam etching, reactive ion etching can also be used. In this case, it is necessary to set an etching condition under which the underlying silicon oxide layer 59 is not so easily etched. When reactive ion etching is used, it is suitable to use chlorine (Cl2) / argon (Ar)-based gas.

[0042] Note that when reactive ion etching is used to form the thin-film magnet 15, in order to suppress etching of the electrode interconnection 13, the reflection mirror 5, and the electrode 19, it is advantageous to form a protective layer (not shown) covering the electrode interconnection 13, the reflection mirror 5, and the electrode 19 before forming the thin-film magnet layer. A silicon oxide insulating layer is suitably used as the protective layer. After the pattern of the thin-film magnet layer 14 is formed, the protective layer covering a surface of the reflection mirror 5 is removed by reactive ion etching to reflect light through the reflection mirror 5.

[0043] The pattern of the thin-film magnet layer 14 is then magnetized to determine a magnetic pole. The pattern is magnetized, for example, using a magnetizing yoke. As shown in Fig. 4A and Fig. 4B, a magnetizing yoke 81 is used to provide the magnetization for each pattern pair of the thin film magnet layer 14.

[0044] It should be noted that in this case, the thin film magnet 15, which is magnetized for the first time, forms a magnetic field, and it is expected that the magnetic field may prevent accurate magnetization of the pattern of the thin film magnet layer 14 for the second time. Accordingly, as shown in Fig. 5, it is desirable to perform the magnetization using the magnetizing yoke 81 with a Halbach array. The magnetizing yoke in the Halbach arrangement may have a magnetic pole that is rearranged in the direction to concentrate a magnetic field on one side of a magnet, in this case on a side on which the pattern of the layer 14 intended to be the thin-film magnet is arranged, and the magnetizing yoke can thus provide magnetization of the thin-film magnet 15c to generate a magnetic field in the opposite direction to that of the thin-film magnet 15b. The magnetization may be in the Fig. 6B shown step.

[0045] Furthermore, a finer magnetization can be achieved if the layer 14 intended to become the thin-film magnet is locally subjected to heat treatment by local laser annealing or the like. Alternatively, the thin-film magnet 15 can be manufactured separately and bonded to the silicon oxide layer 59. When bonding the thin-film magnet 15, it is preferable that, after etching the silicon layer 57, the silicon with the resulting thin-film magnet 15 is bonded to the silicon substrate 53 by room-temperature bonding.

[0046] Furthermore, a protective layer may be formed in a region other than the region where the reflection mirror 5 and the electrode 19 are formed. The protective layer is preferably a silicon oxide layer, an organic layer, or the like that is resistant to moisture or the like.

[0047] Subsequently, a process for forming a structure as an optical scanning device is carried out. First, the silicon oxide layer 59 is structured by photolithography and etching (see Fig. 10). The silicon oxide layer 59 is suitably patterned by reactive ion etching. Subsequently, the silicon layer 57 is etched, with the patterned silicon oxide layer 59 or the like serving as an etching mask. The layer is expediently etched using inductive coupling plasma (ICP) RIE. The layer is etched until the silicon oxide layer 55 has an exposed surface (see Fig. 10).

[0048] Subsequently, the exposed silicon oxide layer 55 is etched. The layer is expediently etched continuously using ICP-RIE with a varied etching condition. Thus, as in Fig. 6A, a surface of the silicon substrate 53 is exposed. This etching can be performed with another reactive ion etching device.

[0049] Subsequently, the back surface of the SOI substrate 51 is processed. First, photolithography and etching are performed to pattern the silicon oxide layer 61 (see Fig. 11). Then, as in Fig. 6B, the silicon substrate 53 is etched, with the pattern of the silicon oxide layer 61 or the like serving as an etching mask. This forms the carrier 17, the drive beam 9, the scanning structure 3, and the like. Thereafter, the SOI substrate 51 is cut to form the Fig. 1 and the like.

[0050] When a wafer-level package or the like is considered as a package form, before dicing the SOI substrate 51, a glass substrate or a silicon substrate may be bonded to the front surface side of the SOI substrate 51 and the back surface side of the SOI substrate 51 to provide a sealed optical pickup device 1 structure. The SOI substrate 51 and the glass substrate are preferably bonded together by anodic bonding. The SOI substrate 51 and the silicon substrate are preferably adhered together at room temperature.

[0051] An example of the operation of the optical pickup device 1 is described below. When a current flows through the electrode connection 13, a Lorentz force is generated in a direction substantially orthogonal to the direction in which the current flows and the direction of the magnetic lines of force formed by the thin-film magnet 15.

[0052] As in Fig. As shown in Figure 1, the thin-film magnets 15a and 15b in the first drive unit 7a generate magnetic lines of force in one direction (a positive direction) along the X-axis. The thin-film magnets 15c and 15d generate magnetic lines of force in one direction (a negative direction) along the X-axis (see empty arrows). The thin-film magnets 15d and 15c in the second drive unit 7b generate magnetic lines of force in the direction (the positive direction) along the X-axis. The thin-film magnets 15b and 15a generate magnetic lines of force in one direction (the negative direction) along the X-axis (see empty arrows).

[0053] In this state, for example, when a current is conducted in the first drive unit 7a from the electrode 19a to the electrode 19b (see arrows), the electrode connection 13a conducts the current in one direction (the negative direction) along the Y-axis. The electrode connection 13b conducts the current in the direction (a positive direction) along the Y-axis. When a current is conducted in the second drive unit 7b from the electrode 19a to the electrode 19b (see arrows), the electrode connection 13a conducts the current in the direction (the positive direction) along the Y-axis. The electrode connection 13b conducts the current in the direction (the negative direction) along the Y-axis.

[0054] Then in this case, as in Fig. 7A, in the first drive unit 7a, a Lorentz force is generated in one direction (the positive direction) along the Z-axis on the first drive beam 9a with the electrode connection 13a arranged thereon and the second drive beam 9b with the electrode connection 13b arranged thereon (see arrows). In contrast, as shown in Fig. 7B, in the second drive unit 7b, a Lorentz force is generated in one direction (a negative direction) along the Z-axis (see arrows) on the second drive beam 9b with the electrode connection 13b arranged thereon and the first drive beam 9a with the electrode connection 13a arranged thereon.

[0055] In the first drive unit 7a, the drive end of the drive beam 9 is displaced in the positive direction along the Z-axis, and one end of the scanning structure 3 on the negative direction side along the Y-axis is raised. In contrast, in the second drive unit 7b, the drive end of the drive beam 9 is displaced in the negative direction along the Z-axis, and one end of the scanning structure 3 on the positive direction side along the Y-axis is lowered. This tilts the scanning structure 3 with respect to the XY plane.

[0056] Thus, the reflection mirror 5 formed on the scanning structure 3 can be tilted in a desired direction by controlling the direction and intensity of the current flowing through the electrode connections 13a and 13b in the first drive unit 7a and the direction and intensity of the current flowing through the electrode connections 13a and 13b in the second drive unit 7b.

[0057] In the optical scanning device 1 described above, the thin-film magnet 15 generates magnetic lines of force, which exert a Lorentz force on the drive beam 9. Compared to an optical scanning device with an externally arranged permanent magnet, the former can contribute to the miniaturization of the optical scanning device 1.

[0058] Furthermore, the scanning structure 3 can be moved differently by adjusting the frequency and phase of the current flowing through the electrode connections 13a and 13b in the first drive unit 7a and those of the current flowing through the electrode connections 13a and 13b in the second drive unit 7b. Furthermore, by adjusting the length of the connecting beams 11, the drive beam 9 can be separated from the reflection mirror 5, and stray light caused by light loss can be reduced. Embodiment 2

[0059] An optical pickup device according to a second embodiment will now be described. As shown in the Fig. 8 and Fig. As shown in Figure 9, the optical scanning device 1 includes the scanning structure 3, the armature 21, and the drive unit 7. The scanning structure 3 and the reflection mirror 5 are substantially circular. The drive unit 7 is connected between the scanning structure and the armature 21 to drive the scanning structure 3. The drive unit 7 is formed in an arc along the circumference of the circular scanning structure 3. The drive unit 7 includes a first drive unit 7a, a second drive unit 7b, a third drive unit 7c, and a fourth drive unit 7d.

[0060] The drive unit 7 includes the drive beam 9, the electrode connection 13, the thin-film magnet 15, and the carrier 17. The drive end of the drive beam 9 or the connecting beam 11 in the first drive unit 7a is connected to a first position along the circumference of the scanning structure 3. The drive end of the drive beam 9 or the connecting beam 11 in the second drive unit 7b is connected to a second position along the circumference of the scanning structure 3, which is different from the first position.

[0061] The drive end of the drive beam 9 or the connecting beam 11 in the third drive unit 7c is connected to a third position along the circumference of the scanning structure 3, which differs from one of the first and second positions. The drive end of the drive beam 9 or the connecting beam 11 in the fourth drive unit 7d is connected to a fourth position along the circumference of the scanning structure 3, which differs from one of the first to third positions. Apart from this configuration, the optical scanning device of the present embodiment is configured similarly to that shown in Fig. 1 and the like, and each identical element is designated identically and will not be described repeatedly unless necessary.

[0062] A method for manufacturing the above-described optical scanning device 1 is described below. The above-described optical scanning device 1 has the same basic structure as the previously described optical scanning device 1, except that the scanning structure 3 and the drive unit 7 in the former are shaped differently than in the latter. Therefore, the above-described optical scanning device 1 can be manufactured using a process consisting essentially of the same manufacturing steps as the previously described method for manufacturing the optical scanning device 1, except for a modified masking pattern.

[0063] The operation of the above-described optical scanning device 1 will be described below. As described above, in the drive unit 7, the drive end of the drive beam 9 is displaced in a direction along the Z-axis by a Lorentz force generated in a direction substantially orthogonal to the direction of a current flowing through the electrode junction 13 and the direction of the magnetic lines of force generated by the thin-film magnet 15. The scanning structure 3 can be moved differently by adjusting the frequency and phase of the current flowing through each of the electrode junctions 13a and 13b in each of the first to fourth drive units 7a to 7d.

[0064] The optical scanning device 1 described above has a scanning structure 3 and a circular reflection mirror 5. The optical scanning device 1 is irradiated with a laser beam that essentially has the shape of a circular spot. By adjusting the scanning structure 3 and the reflection mirror 5 to a shape corresponding to the circular spot, the scanning structure 3 and the reflection mirror 5 can be minimized in terms of area if necessary. This can further contribute to the miniaturization of the optical scanning device 1.

[0065] Furthermore, the laser beam often falls obliquely at an angle of incidence onto the reflection mirror 5. Therefore, the spot of the laser beam is elliptical on the surface of the reflection mirror 5. Accordingly, the reflection mirror 5 is preferably elliptically shaped.

[0066] Furthermore, the optical scanning device 1 described above has a first to fourth drive unit 7a to 7d, each of which is connected at a different position along the circumference of the scanning structure 3, so that the scanning structure 3 can also be precessed and thus the optical scanning device 1 can be used in several applications.

[0067] While the above-described optical scanning device 1 having the first to fourth drive units 7a to 7d has been described as an example of the drive unit 7, the drive unit 7 of the scanning structure 3 enables a precessional movement if the drive unit 7 includes at least three drive units. Embodiment 3

[0068] An optical pickup device according to a third embodiment will now be described. As shown in Fig. As shown in Figure 10, the optical pickup device 1 includes a thin-film magnet 15 such that the thin-film magnets 15a, 15b, 15c, and 15d are arranged along an arc and spaced from each other. That is, the thin-film magnet 15 is divided into a plurality of pieces, and the multiple pieces of the divided thin-film magnet 15 are arranged along the electrode connection 13.

[0069] In Fig. 10 is a cross section along the line IX-IX in Fig. 8, the same as in Fig. 9. Apart from this configuration, the optical pickup device of the present embodiment is configured similarly to that shown in Fig. 8 and the like, and each identical element is designated identically and will not be described repeatedly unless necessary.

[0070] A method for manufacturing the above-described optical pickup device 1 will be described below. The above-described optical pickup device 1 has a basic structure identical to that of the first embodiment, except that the scanning structure 3 and the drive unit 7 including the thin-film magnet 15 are shaped differently in the former. Therefore, the above-described optical pickup device 1 can be manufactured using a process consisting of substantially the same manufacturing steps as the previously described method for manufacturing the optical pickup device 1, with only a different masking pattern.

[0071] The operation of the above-described optical scanning device 1 will now be described. As discussed in the first embodiment, the drive beam 9 in the drive unit 7 has a drive end that is displaced in a direction along the Z-axis by a Lorentz force generated in a direction substantially orthogonal to the direction of a current flowing through the electrode junction 13 and the direction of the magnetic lines of force generated by the thin-film magnet 15. The scanning structure 3 can be moved differently by adjusting the frequency and phase of the current flowing through each of the electrode junctions 13a and 13b in each first drive unit 7a, and the like.

[0072] In addition to the previously described effect of the optical scanning device 1, the above-described optical scanning device 1 has an effect as follows: Then, when, as shown in the Fig. 8 and Fig. 10, comparing the thin film magnet-destined layer 14 formed in an arc divided into a plurality of pieces with the undivided thin film magnet-destined layer 14, the former arc divided into individual thin film magnets can be reliably magnetized and, as a series of thin film magnets 15, can adjust a magnetic field in one direction as desired. Embodiment 4

[0073] An optical pickup device according to a fourth embodiment will now be described. As shown in the Fig. 11 and Fig. 12, the optical scanning device 1 is designed such that the scanning structure 3 with the reflection mirror 5 formed thereon is arranged to cover the drive unit 7. The drive unit 7 includes a first drive unit 7a and a second drive unit 7b. The first drive unit 7a and the second drive unit 7b each have more drive beams 9, more electrode connections 13 and more thin-film magnets 15 than the corresponding elements in the Fig. 1 shown optical scanning device 1 and the like.

[0074] An end portion of the scanning structure 3 on the negative direction side along the Y-axis is connected via a support post 23 to connecting beams 11, which are connected to the drive end of the drive beam 9 in the first drive unit 7a. An end portion of the scanning structure 3 on the positive direction side along the Y-axis is connected via the support post 23 to the connecting beam 11, which is connected to the drive end of the drive beam 9 in the second drive unit 7b. Apart from this configuration, the optical scanning device of the present embodiment is constructed similarly to that shown in Fig. 1 and the like, and each identical element is designated identically and will not be described repeatedly unless necessary.

[0075] Next, a method for manufacturing the above-described optical pickup device 1 will be described. The above-described optical pickup device 1 is manufactured by a method similar to that described in the first embodiment, except that the pickup structure 3 is formed by a method different from that for forming the drive unit 7 and the like. That is, the drive unit 7 and the like, except for the pickup structure 3, are formed by a method similar to the method for the optical pickup device 1 described in the first embodiment.

[0076] The sensing structure 3, however, is formed separately, for example, by subjecting a silicon substrate or the like to a desired process. Furthermore, the support post 23 is formed from silicon or the like. Thereafter, the separately manufactured sensing structure 3 is connected via the support post 23 to the connecting beam 11 of the drive unit 7 or the like. The bonding / connection of the support post 23 and the sensing structure 3 is preferably carried out by room temperature bonding, just as the bonding of the support post 23 and the connecting beam 11 is. Alternatively, the bonding can also be carried out with an adhesive. Thus, the Fig. 11 and Fig. 12 shown optical scanning device 1 is completed.

[0077] The operation of the above-described optical scanning device 1 will now be described. As discussed in the first embodiment, the drive beam 9 in the drive unit 7 has a drive end that is displaced in a direction along the Z-axis by a Lorentz force generated in a direction substantially orthogonal to the direction of a current flowing through the electrode connection 13 and a direction of the magnetic lines of force generated by the thin-film magnet 15. The reflection mirror 5 formed on the scanning structure 3 can be tilted in a desired direction by adjusting the frequency and phase of a current flowing through each of the electrode connections 13a and 13b in each of the first drive unit 7a and the second drive unit 7b.

[0078] The optical scanning device 1 described above includes a drive unit 7 arranged to be covered by the scanning structure 3. This can further contribute to the miniaturization of the optical scanning device 1.

[0079] While the optical scanning device 1 according to each of the embodiments described above has been described with a single connection, exemplified as electrode connection 13, the electrode connection 13 may also be arranged in the form of a coil, as shown in the Fig. 13 and Fig. 14. Furthermore, the electrode connection 13, as shown in the Fig. 15 and Fig. 16, be formed as a stack of layers.

[0080] Furthermore, as a thin-film magnet 15, a thin-film magnet 15 is exemplified, which is formed from a layer 14 intended for the thin-film magnet, which is a single layer. As shown in Fig.As shown in Figure 17, the thin-film magnet 15 can, for example, be a layer stack consisting of one thin-film magnet 15 and another thin-film magnet 15, with an intermediate layer 16, e.g., made of tantalum (Ta), interposed between them. A thin-film magnet 15 in the form of such a layer stack enables increased magnetic force.

[0081] The optical scanning devices 1 according to the described embodiments can be combined differently as required.

[0082] The embodiments described herein are illustrative and not restrictive. The scope of the present invention is intended to encompass all modifications within the meaning thereof. The present invention is effectively applicable to optical scanning devices using MEMS technology. List of reference symbols 1 optical scanning device 3 Scanning structure 5 reflection mirrors 7 Drive unit 7a first drive unit 7b second drive unit 7c third drive unit 7d fourth drive unit 9, 9a, 9b, drive beam 11 connecting beams 13, 13a, 13b, 13c, 13d Electrode connection 14 layer intended for the thin-film magnet 15, 15a, 15b, 15c, 15d thin film magnet 16 Intermediate layer 17, 17a, 17b carrier 19, 19a, 19b Electrode 21 anchors 23 support posts 51 SOI substrate 53 Silicon substrate 55, 59, 61 Silicon oxide layer 57 silicon layer

Claims

[1] Optical scanning device comprising: a scanning structure (3) having a reflective surface (5) for reflecting light; a carrier body (21) as an anchor; and one or more drive units (7, 7a, 7b) connected between the scanning structure (3) and the support body (21) to drive the scanning structure (3), where the one or more drive units (7, 7a, 7b) comprise: a first drive beam (9, 9a) having a first fixed end connected to the support body (21) and a first drive end connected to the scanning structure (3), a first electrode connection (13, 13a) formed on the first drive beam (9, 9a), a pair of first supports (17, 17a), each connected to the support body (21) and also arranged to sandwich the first drive beam (9, 9a), a first layer magnet (15, 15a, 15b) arranged on each of the pair of first supports (17, 17a), a second drive beam (9, 9b) having a second fixed end connected to the support body (21) and a second drive end connected to the scanning structure (3) and the first drive end, a second electrode connection (13, 13b) formed on the second drive beam (9, 9b) and electrically connected to the first electrode connection (13, 13a), pairs of second supports (17, 17b) arranged to sandwich the second drive beams (9, 9b), and a second layer magnet (15, 15c, 15d) arranged on each of the pair of second supports (17, 17b), wherein the first layer magnet (15, 15a, 15b) is arranged so that magnetic lines of force are generated in a first direction which intersect the direction in which the first electrode connection (13, 13a) runs, wherein the second layer magnet (15, 15c, 15d) is arranged such that magnetic lines of force are generated in a second direction which intersects the direction in which the second electrode connection (13, 13b) extends, where the first direction and the second direction are opposite to each other, wherein the direction of a current flowing through the first electrode connection (13, 13a) and the direction of a current flowing through the second electrode connection (13, 13b) are opposite to each other. [2] An optical scanning device according to claim 1, wherein the one or more drive units (7, 7a, 7b, 7c) a first drive unit (7, 7a), a second drive unit (7, 7b) and a third drive unit (7, 7c), the first drive unit (7, 7a) is connected between a first position along the circumference of the scanning structure (3) and the carrier body (21), the second drive unit (7, 7b) is connected between a second position along the circumference of the scanning structure (3) and the carrier body (21), the second position being different from the first position, and the third drive unit (7, 7c) is connected between a third position along the circumference of the scanning structure (3) and the carrier body (21), wherein the third position differs from the first and second positions. [3] An optical pickup device according to claim 1, wherein the first layer magnet (15, 15a, 15b) is divided into a plurality of pieces, and the first layer magnet (15, 15a, 15b) divided into the plurality of pieces is aligned in the direction in which the first electrode connection (13, 13a) extends. [4] An optical scanning device according to claim 1, wherein the scanning structure (3) is arranged to cover the one or more drive units (7). [5] An optical pickup device according to claim 1, wherein the first electrode interconnection (13, 13a) is a plurality of first electrode interconnections disposed between the first sheet magnet (15, 15a, 15b) disposed on one of the pair of first supports (17, 17a) and the one disposed on the other of the pair of first supports (17, 17a). [6] Optical scanning device according to claim 1, wherein the first layer magnet (15, 15a, 15b) is formed as a layer stack. [7] A method for manufacturing an optical scanning device, comprising the following steps: Producing a substrate (51) consisting of a semiconductor substrate and a semiconductor layer (57) formed on a surface of a body (53) of the semiconductor substrate, with a first insulation layer (55) arranged therebetween Forming a first electrode connection (13, 13a) and a second electrode connection (13, 13b) electrically connected to the first electrode connection (13, 13a), and a reflection mirror (5) on the semiconductor layer (57) with a second insulation layer (59) arranged therebetween; Forming a first layer magnet (15, 15a, 15b) and a second layer magnet (15, 15c, 15d) on the second insulation layer (59); and Processing the second insulation layer (59), the semiconductor layer (57), the first insulation layer (55) and the body (53) of the semiconductor substrate into a carrier body (21) as an anchor, a scanning structure (3) with the reflection mirror (5) arranged thereon, a first drive beam (9, 9a) with the first electrode connection (13, 13a) arranged thereon, one end being connected to the carrier body (21) as a first fixed end and the other end being connected to the scanning structure (3) as a first drive end, a second drive beam (9, 9b) on which the second electrode connection (13, 13b) is arranged and whose one end is connected to the carrier body (21) as a second fixed end and whose other end is connected as a second drive end to the scanning structure (3) and the first drive end, a pair of first supports (17, 17a) each having the first layer magnet (15, 15a, 15b) arranged thereon and connected to the support body (21) to sandwich the first drive beam (9, 9a), and a pair of second supports (17, 17b) each having the second layer magnet (15, 15c, 15d) arranged thereon and connected to the support body (21) to sandwich the second drive beam (9, 9b), wherein in the step of forming the first layer magnet (15, 15a, 15b), the first layer magnet (15, 15a, 15b) is formed so that magnetic lines of force are generated in a direction intersecting the direction in which the first electrode connection (13, 13a) extends, wherein in the step of forming the second layer magnet (15, 15c, 15d), the second layer magnet (15, 15c, 15d) is formed such that magnetic lines of force are generated in a second direction intersecting the direction in which the second electrode connection (13, 13b) extends, the direction of a current flowing through the first electrode connection (13, 13a) and the direction of a current flowing through the second electrode connection (13, 13b) being opposite to each other. [8] A method of manufacturing an optical pickup device according to claim 7, wherein the step of forming the first layer magnet (15, 15a, 15b) includes the following steps: Forming a layer intended for the magnet so that the first electrode connection (13, 13a) is located therebetween; and Magnetizing the layer intended to be the magnet by a magnetizing yoke to form the first layer magnet (15, 15a, 15b). [9] A method for manufacturing an optical scanning device, comprising the following steps: Producing a substrate (51) comprising a semiconductor substrate and a semiconductor layer (57) formed on a surface of a body (53) of the semiconductor substrate, with a first insulation layer (55) disposed therebetween; Forming a first electrode connection (13) and a second electrode connection (13) electrically connected to the first electrode connection (13) on the semiconductor layer (57), with a second insulation layer (59) arranged therebetween; Forming a first layer magnet (15) and a second layer magnet (15) on the second insulation layer (59); Processing the second insulating layer (59), the semiconductor layer (57), the first insulating layer (55) and the body (53) of the semiconductor substrate to form: a carrier body (21) as an anchor, a first drive beam (9) on which the first electrode connection (13) is arranged and one end of which is connected to the carrier body (21) as a first fixed end and the other end of which is a first drive end, a second drive beam (9) on which the second electrode connection (13) is arranged and whose one end is connected to the carrier body (21) as a second fixed end and whose other end is connected to the first drive end as a second drive end, a pair of first supports (17), each of which has the first layer magnet (15) arranged thereon and which are connected to the support body (21) so as to sandwich the first drive beam (9), and a pair of second supports (17) each having the second layer magnet (15) arranged thereon and connected to the support body (21) to sandwich the second drive beam (9); Forming a scanning structure (3) with a reflection mirror (5) arranged thereon; and Connecting the scanning structure (3) to the first drive end of the first drive beam (9) and the second drive end of the second drive beam (9), which are connected to each other, wherein in the step of forming the first layer magnet (15), the first layer magnet (15) is formed so that magnetic lines of force are generated in a direction intersecting the direction in which the first electrode connection (13) extends, wherein in the step of forming the second layer magnet (15), the second layer magnet (15) is formed such that magnetic lines of force are generated in a second direction which intersects the direction in which the second electrode connection (13) extends, wherein the direction of a current flowing through the first electrode connection (13) and the direction of a current flowing through the second electrode connection (13) are opposite to each other. [10] A method of manufacturing an optical pickup device according to claim 9, wherein the step of forming the first layer magnet (15) includes the steps of: Forming a layer intended for the magnet such that the first electrode connection (13) is sandwiched; and Magnetizing the layer intended to be the magnet by a magnetizing yoke to form the first layer magnet (15).

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