JP2000199870A - Optical scanning device - Google Patents

Abstract

(57) [Problem] To provide an optical scanning device having a compact configuration and easy optical adjustment. SOLUTION: An optical waveguide 1 is provided on a cantilever 105 having a thin film shape.
04 and the first conductive region 103a.
5 has an insulating layer 101a, and a second conductive region 102a is arranged with the insulating layer 101a interposed therebetween. Due to the electrostatic force generated between the first conductive region 103a and the second conductive region 102a in the cantilever 105 and the elastic force of the cantilever 105 restoring from the deformation, the second conductive region 102
a cantilever 105 in the form of a thin film along the shape of the structure including
Is moved from the light source disposed at the base of the cantilever 105 to the optical waveguide 10 disposed within the cantilever 105.
The light beam introduced into 4 is moved. On the opposite side of the optical waveguide 104 of the cantilever 105, the same configuration as described above is symmetrically arranged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical scanning device capable of oscillating a light beam using electrostatic force.

[0002]

2. Description of the Related Art Conventionally, optical deflectors and optical scanning devices which are mainly used include an acousto-optic type utilizing distortion of a crystal by ultrasonic waves and an electric type utilizing a refractive index change by an electric field of a crystal. Or a mechanical type using a vibrating plane mirror (so-called galvano mirror) or a rotating polyhedron (so-called polygon mirror). Above all, the mechanical optical deflector can perform equiangular deflection regardless of the wavelength of light, so it is very useful when a multi-wavelength light source is used as a light source or when there is a wavelength fluctuation. In order to obtain a stable rotational speed and a highly accurate deflection angle, these use a heavy rotating shaft or use a large electromagnet for the rotor.

On the other hand, using photolithography technology,
Fabrication of an extremely small actuator has been studied. As a typical micromachine, a micromotor (M.
Mehregany et al., "Operation of microfabricated har
monic and ordinary side-drive motors ", Proceedings
IEEE Micro Electro Mechanical Systems Workshop 199
0 p1-8) or a comb-shaped linear microactuator driven by electrostatic force on a flat plate (W. Tang et al., "Lat
erally driven polysilicon resonant microstructure
s ", Sensors and Actuators 20 (1989), p. 25-32. These micro-machines make it easy to form an array, reduce the cost, and achieve high precision.

Some mechanical optical elements have been proposed. Among them, as a light deflector, a spatial light deflector (Larry Jay Horn) for a double-supported beam in consideration of improvement of optical efficiency and deflection stability. Beck, JP-A-2-8812) is known.

FIG. 18 shows a part of one pixel of this spatial light deflector.
It is the perspective view which made the cross section. In FIG. 18, pixels are mono
Two flexible, based on lithic silicon
Have a reflecting surface by the beams of the above. That is,
The insulating spacer 9 is provided on the control board 91 with the insulating layer 93 interposed therebetween.
4. The metal hinge layer 95 and the metal beam layer 96 are laminated.
You. In other words, the flexible beam 97 on the same layer as the metal hinge layer 95
Flexure beam 97₁ A reflective surface 98 of the same layer as the metal beam layer 96;
Change the angle of the reflective surface 98 through the air gap under the reflective surface 98
Fixed electrode 99 for driving, fixed electrode 99₁ , Fixed electricity
Pole 99_Two Consists of For example, the fixed electrode 99₁ To voltage
Is applied, the reflection surface 98 and the fixed electrode 99 ₁ Electrostatic between
The elastic beams 97, 97₁ The deflection angle
The light generated and incident on the reflecting surface 98 depends on the amount of the deflection angle.
It is deflected by obtaining a reflection angle. Such an optical deflector deflects light to 1
And the silicon substrate 92
Based silicon process.
Therefore, it can be manufactured at relatively low cost,
By two-dimensionally arranging them on the
For printers such as electrostatic printing and projection displays.
It is also considered to be used.

FIG. 19 is a schematic diagram showing the configuration of a conventional optical scanning device. In FIG. 19, light emitted from a laser light source 803 is scanned by a vibrating plane mirror 801.
The light from the vibrating plane mirror 801 is condensed by the lens 804, and the luminescent spot moves on the screen 805 in the direction of the arrow shown in the figure to perform scanning.

[0007]

In the structure of the conventional optical deflector, since the portion receiving the force and the portion reflecting the light are at the same place, they are susceptible to disturbance such as rotation. Similarly, since the portion receiving the force and the reflecting surface are the same, precise control of the angle is difficult. Further, the incident direction and the reflection direction are fixed and have no degree of freedom.
Furthermore, since the reflecting surface is a part of the movable metal electrode, there is a possibility that the deflection angle may change due to a change with time such as twisting or metal fatigue due to the use environment.

Similarly, in the conventional optical scanning device, since the size of the vibrating plane mirror or the rotating polygon mirror is relatively large, there is a disadvantage that the size of the device is increased. In addition, in order to perform accurate scanning, each element must be arranged in a strict positional relationship, and optical adjustment when assembling the apparatus is very complicated.

An object of the present invention is to provide an optical scanning device which solves the above-mentioned drawbacks of the conventional example and has a compact configuration and easy optical adjustment.

[0010]

An optical scanning device according to the present invention comprises:
A thin film-shaped cantilever has an optical waveguide and a first conductive region having conductivity, has an insulating region near the waveguide or in the cantilever, and has conductivity across the insulating region. A second conductive region is disposed, and an electrostatic force generated between the first conductive region and the second conductive region in the cantilever and an elastic force of the cantilever restoring from deformation cause a second conductive region. By moving a thin-film shaped cantilever along the shape of the structure including the conductive region, a light beam introduced from a light source disposed at the root of the cantilever into an optical waveguide disposed within the cantilever Is characterized by moving.

Some optical scanning devices of the present invention have two structures including the second conductive region, and they are opposed to each other with the cantilever interposed therebetween.

In the optical scanning device according to the present invention, the electrostatic force generated between the first conductive region and the second conductive region in the cantilever is gradually effective from the root of the cantilever. , A voltage generated by applying a voltage to the two electrodes, and a voltage applied to the second conductive region.

[0013] In the optical scanning device according to the present invention, a part or all of the first conductive region can be made of a semiconductor material.

[0014]

The actuator used in the optical scanning device of the present invention is an actuator manufactured using a thin film material / structure. In general, the form of the actuator is a cantilever (cantilever),
Various forms such as a membrane, a hinge, and a motor are conceivable. The driving method of each actuator is bimorph or unimorph using the piezoelectric effect, electrostatic driving using the counter electrode, bimetal / shape memory alloy using heat, one using volume change by electric field, gas pressure That are displaced by Among them, the electrostatic drive using the counter electrode is advantageous in that a thin cantilever-type optical waveguide is displaced to deflect light so that no excessive force is required.

[0015]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing an example of an actuator 10 that can be used in the optical scanning device of the present invention. The fixed electrode 11, the supporting plate 16, and the support beam 13, 13 ₁ are fixed on the same substrate (not shown) made of Si.
The movable electrode 12, driven parts 14 and 15, and support plate 16 are connected via joints 19, 18 and 17.

The fixed electrode 11 and the movable electrode 12 are the aforementioned comb-shaped linear microactuators manufactured by micromechanics technology.

The operation of the actuator 10 will be described with reference to FIG. By applying a voltage between the fixed electrode and the movable electrode 12, the movable electrode 12 repeatedly performs a parallel operation in parallel with the substrate due to electrostatic attraction (arrow B in FIG. 2A).
direction). Along with this, the driven parts 14 and 15 also repeatedly bend at the joint part (FIG. 2B).
(In the direction of arrow C), the force generated parallel to the substrate is converted to a direction perpendicular to the substrate.

FIG. 3 is a perspective view of an optical deflector 86 using the actuator 10. The driven portion 14 of the actuator 10 shown in FIG. With respect to the incident light 32, the angle of the driven part 14 changes due to the difference in displacement of the movable electrode 12 due to the applied voltage, and the emitted light 33 is scanned within the range of the scanning angle θ.

In the optical deflector 86 configured as described above, since the driving section and the reflection surface are separated, the direction in which the force of the reflection surface is received is uniquely determined, and there is no disturbance effect such as rotation. For the same reason, precise control of the angle is also facilitated. Furthermore, since the joint does not contribute to the angle control by voltage application, the joint material can be freely selected, and an insulator such as a polymer film having a sufficiently small spring constant and excellent durability can be used.

Next, an example of a manufacturing process of the actuator and the optical deflector will be briefly described with reference to FIG. FIG. 4 shows FIG.
FIG. 4 is a sectional view taken along line AA of FIG. After phosphorus is ion-implanted into a substrate 41 made of silicon, a thermal oxide film 42 is formed as an insulating layer at a thickness of 5000.degree.
VD), a silicon nitride film 43 is formed at 1500 °. A part of this insulating layer is patterned by photolithography and etching to form a contact hole 44 (FIG. 4A). Dry etching was performed using CF ₄ as a reaction gas, but wet etching using buffered hydrofluoric acid or the like may be used. Next, after a first phosphorus-doped polysilicon layer was formed at 3000 ＬＰ by LPCVD, an electric shield portion 45 was formed by patterning (FIG. 4B). However, phosphorus may be implanted by ion implantation after the polysilicon is formed. A sacrificial silicon oxide film 46 is formed by a vacuum sputtering method (FIG. 4C), and after patterning, a phosphorus-doped polysilicon film 47 is formed by LPCVD.
To produce 2 μm. It goes without saying that phosphorus may be implanted by an ion implantation method. Patterning the phosphorus-doped polysilicon film 47 to form a fixed electrode,
A drive unit, a driven unit, a support plate, and a joint are formed (FIG. 4D). Here, polysilicon is used as the joint, but of course, another metal film or a polymer film may be formed as long as the spring constant is sufficiently small. The sacrificial layer silicon oxide film is removed by using a hydrofluoric acid aqueous solution to form the microactuator 10 shown in FIG.
Is formed (FIG. 4E). Further, before removing the sacrificial layer, a metal vapor-deposited film 48 is formed on a part of the driven portion, and the reflective surface is formed by patterning, thereby producing the optical deflector 86 shown in FIG. 4 (f)).

The microactuator and the optical deflector manufactured in this way can be made compact and lightweight, and can be arrayed. The beam length of the movable electrode is 200 μm. The number of combs of the comb-shaped fixed electrode is 11, the comb gap is 2 μm, and the length of the driven portion is 50 μm.
A displacement of μm / V was obtained. That is, 4 μm at an applied voltage of 40 V
m, and a displacement of about 20 μm was achieved in the vertical direction. Further, in the optical deflector manufactured using this actuator, the scanning angle θ = 90 ° to 4 ° in the direction shown in FIG.
A 4 ° scan was achieved.

Although a Si substrate is used here, a method of bonding a structure such as a driving unit and a fixed electrode on a glass substrate may be used.

FIG. 5 is a perspective view showing another example of the actuator. Movable electrode 52, the driven part 53, the fixed supporting plate 55 is connected by a joint 58,57,56, and movable electrode 52 is supported by support beam 59, 59 _1. The fixed electrode 51 is similar to the fixed electrode 11 of FIG. As in the case of the first actuator, the fixed electrode and the movable electrode were linear actuators using micromechanics technology.

The manufacturing method is the same as that of the first actuator. FIG. 6 is a diagram for explaining the operation of the actuator of this example. By applying a voltage to the fixed electrode 51 and the movable electrode 52 shown in FIG. 5, the movable electrode 52 is displaced in a direction parallel to a substrate (not shown) (the direction of arrow D in FIG. 6A). As a result, the driven parts 14 and 15 also receive a force, and are parallel to the substrate and perpendicular to the direction of displacement of the movable electrode 12 (FIG. 6).
(B) in the direction of arrow E).

If a reflector is formed on the driven portion of the actuator, an optical deflector can be obtained as in the case of the first actuator.

FIG. 7 is a perspective view showing a third example of the actuator. The movable electrode 72 and the driven parts 74 and 75 are connected by joints 79, 78 and 77. The movable electrode 72 that rotates horizontally in the direction of arrow F is formed of an eight-spring rotor. A protrusion 72 ₁ is provided at one end of the movable electrode 72.
There are formed, the projections 72 ₁ are engaged with the slits 73 ₁ are formed on the driven portion 73. Thereby, the movable electrode 72
Is rotated in the direction of arrow F, the driven portion 73 is driven in the direction of arrow G, and the joint 78 connecting the driven portions 74 and 75 reciprocates in the direction of arrow H. The driving means shown here was the micromotor described above.

In the actuator of this embodiment, the driven portion performs the same movement as the first actuator in accordance with the rotation of the micromotor. With this configuration, the in-plane rotational driving force is converted into a displacement perpendicular to the substrate.

As a method of manufacturing the actuator of the present embodiment, a micromechanical technology for forming a micromotor is used, and a driven portion is simultaneously formed in the process of forming the micromotor, and a joint is formed in the same manner as in the first embodiment. To form an actuator.

In this embodiment, the rotor uses a micromotor having eight springs, but a four-spring, six-spring, or a polygonal or cylindrical micromotor may be used. When driving digitally instead of analogly, it goes without saying that a microstepping motor may be used.

The actuator thus manufactured has a rotating part radius of 100 μm, a gap of 1.5 μm, a length of the movable part of 80 μm, and starts to rotate by applying 70 V to each fixed electrode. A reciprocating operation of 80 μm was enabled. In accordance with this, the driven part also received a force, and achieved a displacement of 80 μm in a direction perpendicular to the substrate. Further, the optical deflector manufactured using the third actuator achieved a scan of θ = 87 ° to −90 °.

FIG. 8 is a perspective view showing a fourth example of the actuator. Movable electrode 81, driven parts 82, 83, 8
4. The fixed support plate 85 is connected by joints 78, 77, 76. Like the third actuator, the actuator of this example is a micromotor using micromechanics technology as the driving means.

In the operation of the actuator of this embodiment, the movable portion performs almost the same operation as the second actuator in accordance with the rotation of the micromotor. With this configuration, the rotational driving force in the substrate plane is converted in a direction parallel to the substrate plane and in a direction perpendicular to the driving plate.

The manufacturing method was similar to that of the second and third actuators.

As shown in FIG. 9, two or more actuators 10 ₁ and 10 ₂ can be formed together.

The optical deflector 86 can be used as, for example, a laser beam scanner for scanning a one-dimensional line at a high speed as shown in FIG. In addition, it can be used for applications such as an optical switch and an optical scanner in consideration of a driving method and an emission direction.

As described above, examples of actuators and examples of optical deflectors using several actuators have been described as reference examples of the present invention. However, optical deflectors using any actuator have similar effects. Needless to say. Depending on the purpose of use, the configuration of the actuator may be selected, and the direction of the outgoing light with respect to the incident light may be selected.
In addition, here, the one provided with the reflection plate in a part of the driven part adjacent to the fixed support plate is shown, but other driven parts or the optical deflector having the reflection plate on the whole driven part may be used. I don't care.

Hereinafter, the basic configuration of the optical scanning device of the present invention will be described with reference to the configuration of the actuator described above.

The basic structure of the actuator used in the optical scanning device of the present invention shown in FIG.
1a, two conductive regions 102a, 103a
Is applied. One conductive region 103a is incorporated in a thin-film cantilever 105 together with the optical waveguide 104. Optical waveguide 1
04 may be the entire region or a partial region of the film. The conductive region 102 includes a cantilever 105 and a base 106 on one side.
It has a phase structure that touches at a and becomes thinner as it goes further. Regarding the inclined shape up to the tip, it is only necessary that the phase is continuous and the tangent of the phase structure coincides with the surface of the cantilever 105, and any shape may be used as long as the shape of the phase is continuous. , A part of an ellipse, a parabola, or a hyperbola. In the present invention, as shown in FIG. 11, it is preferable to arrange another pair of conductive regions. That is,
The second conductive region 103b in the beam and the conductive region 102a
The conductive region 102b is provided on the opposite side of the beam 105 and the insulating layer 101b. This allows the displacement of the beam to occur symmetrically with respect to the beam. However, a sufficient function can be generated by arranging only one set of conductive regions. Light emitted from a light source (not shown) is introduced into the optical waveguide 104, travels in the direction indicated by the arrow (from left to right), and is emitted from the tip of the optical waveguide 104.

The actuator used in the optical scanning device according to the present invention shown in FIG. 11 applies strong voltage to the conductive region 102a and the conductive region 103a to first apply strong electrostatic attraction to the root 106a of the cantilever 105. Produces power. As a result, the gap between the conductive regions 102a and 103a becomes narrower, and the beam 104 gradually approaches the conductive region, so that the tip of the beam finally comes into contact with the conductive region in a shape similar to that of the conductive region. In this case, it may not always be the same because of the balance between the rigidity of the beam and the shape of the surface. Next, when the applied voltage is removed, the beam returns to its original position according to its rigidity. When returning to the original position, the voltage is applied to the conductive region 102.
When applied to the electrodes b and 103b, an electrostatic attractive force acts again, and then the conductive regions 103b and 102b attract each other and gradually approach to move so that the tip of the beam approaches 102b. The voltage can be applied and switched when the beam is at the center, or even when the beam is shifted, the voltage is applied according to the movement of the beam, and a smooth motion can be created. The type of voltage to be applied is selected from DC, AC, pulse, and the like. Ultimately, the voltage and its type are selected so that the movement becomes a desired movement according to the shape of the surface on which the light is projected. FIG.
In the example embodiment, the conductive regions 103a, 1a
03b is different in a symmetrical arrangement, but may be asymmetric or have conductive regions overlapped, that is, one conductive region. As a material constituting the conductive region used in the optical scanning device of the present invention, any material called a normal metal material is used. For example, aluminum, iron, SUS, copper, brass, gold, nickel, tungsten, chromium, and the like. A semiconductor can also be used. For example, S single crystal or non-single crystal
i, GaAs, ZnSe, and the like. Oxide conductors can also be used. For example, ITO, SnO ₂ , ZnO
₂ and so on.

As a material constituting the insulating region used in the optical scanning device of the present invention, for example, SiO ₂ , Si
₃ N ₄ , SiO _x , SiON _x , Si: N: H, glass and the like are used. Regarding the process for fabricating the structure of the optical scanning device of the present invention, a method of assembling a conventionally used component by miniaturizing it from the millimeter to the order of micrometer, and preferably a semiconductor process technology and a thin film deposition / etching technology are used. Used. In order to form a deep structure in the film thickness direction, lithography using X-rays can be used.

As the light source arranged in contact with the actuator in the optical scanning device of the present invention, a light emitting element such as a light emitting diode and a semiconductor laser, an electron beam, a white light source and the like can be considered. Among them, semiconductor lasers have a wide range of practical uses, such as application to measurement such as laser beam printers and interference measurement.
As a structure of a semiconductor laser having good luminous efficiency and temperature characteristics, there is one employing a multiple quantum well structure. Since laser light emitted from a semiconductor laser is generally diffused, it needs to be condensed.In particular, to condense the light of a semiconductor laser fabricated near a micro cantilever as in the present invention, a micro collimator is required. You need a lens. As an example of manufacturing such a microcollimator lens, there is one using photolithography technology ("Fabrication o").
f activeIntegrated Optical Micro-Encoder "1991 IEE
E Micro Electro Mechanical Systems Workshop, Procee
dings pp233-238).

As a material of the optical waveguide of the present invention, a dielectric layer transparent to guided light is used, for example, glass, quartz, SiO ₂ , SiO _x , SiO _x N _y , Si ₃
N ₄ , Si: N: H, ZnS, ZnO and the like are used. Regarding the diffusion of light in the optical waveguide, it is possible to confine and condense light by changing the refractive index of the material along the thickness direction and the in-plane direction in the waveguide. The light source and the actuator may be formed integrally on one substrate, or may be guided from an external light source to the actuator using an optical fiber or the like.

In the present invention, the size of the light spot on the screen is changed by forming a microcollimator lens at the tip of the beam and condensing or collimating the light emitted from the optical waveguide in the beam. Or reduce the distance from the screen. The method of manufacturing the lens may be a method of manufacturing the beam and then bonding the lens, or preferably, the same material is used when forming the optical waveguide. The cross section of the lens is selected from a semi-circle, a semi-ellipse, a semi-ellipse, and the like, and a focal length adjusting unit may be provided between the beam at the tip of the beam and the lens.

The substrate for forming the element including the actuator, the light source and the parts attached thereto may be any member as long as the element can be supported on the element, for example, a semiconductor represented by a Si wafer, The material is selected from an insulator such as a glass substrate and a conductor such as a metal substrate, and may be a single crystal or a non-single crystal. In some cases, an organic material such as a polymer may be used.

According to the present invention, a novel optical scanning device is provided by combining the above-mentioned actuator and the above-mentioned light source. Further, it is also possible to improve the scanning speed on the screen by manufacturing a plurality of optical scanning devices of the present invention on the same semiconductor substrate and operating them independently. Hereinafter, the optical scanning device of the present invention will be described in detail with reference to examples.

<Embodiment 1> FIGS. 12A to 12G show the present invention.
The method of manufacturing the optical scanning device according to the first embodiment
Show the structure. First, as shown in FIG.
Lower electrode 202 on a single crystal (100) wafer
After forming aluminum by 20μm evaporation,
Is applied and patterned. At that time resist
Adjust the bagging conditions of
Controls the adhesion of mi. Aluminum etchant phosphoric acid / nitrate
Side etch when etched with acid / acetic acid / water mixture
Proceeds faster than in the depth direction.
It is etched with a curved surface as shown in FIG.
The unit electrode 202 is formed. Its shape is 1/8 of an elliptical arc
And the lower electrode 202 is at a contact point with the substrate 201 at an angle of 30 degrees.
Make Next, a resist 204 is applied and dried from above.
Flattening by etching as shown in the structure of FIG.
Do. Then, at a substrate temperature of 100 ° C. by plasma CVD,
An SiNH film 205 is formed, followed by a first electrode 206
Then, aluminum is formed by vapor deposition, and then an optical waveguide layer 207 is formed.
T SiO_Two Is deposited by sputtering, and the second electrode 20 is again formed.
Aluminum is formed thereon as 8 and finally the SiNH film 2
09 is deposited at a substrate temperature of 100 ° C. (FIG. 12D).
The five layers of the film deposited in FIG.
Pattern using a strike mask. For etching
SiNH, SiO_Two Is CF _Four Dry etching of Al
The mixture used was a mixture of phosphoric acid / nitric acid / acetic acid / water. At that time
An extraction electrode is simultaneously produced (FIG. 12E). Next
Then, the Si of the substrate 201 is removed from the back by RIE of SF6.
After etching, the end 204f of the lower electrode 202 is
01 (FIG. 12F).

With respect to the upper electrode 211, a part of the upper electrode 211 of the substrate 210 separately manufactured up to FIG. A part of the substrate 210 is processed by removing a part by etching (FIG. 12).
(G)). This is so that the lead wire can be connected to the beam 215. After that, the upper part of the insulating layer SiNH and the lower part of the upper electrode 211 are joined. Regarding the bonding, the upper electrode 211 and the lower electrode 202 are externally connected by using a jig.
Is fixed at a position where the tip of the end has a configuration as shown in FIG. 12 (g). Unnecessary portions of the substrate 210 are removed by cutting to complete the structure as shown in FIG. The beam 215 of the cantilever optical scanning device manufactured by the above method has a length of 20 mm, a thickness of 5 μm, and a width of 5 mm. The distance between the tip of the beam 215 and the lower electrode 202 was 5 mm. A voltage of 5 is applied between the first electrode 206 and the lower electrode 202.
When 0V was applied, the beam 2 was shaped into a shape along the lower electrode 202.
15 was deformed. Next, the voltage was changed to a pulse, and the pulse height was 8
When a voltage of 0 V, a duty of 50, and a frequency of 200 Hz were applied, the beam 215 was perpendicular to the substrate 201 with a maximum deflection angle of 4 °.
Vibrated at 5 °.

<Embodiment 2> In the device structure of Embodiment 1, the voltage was alternately applied between the first electrode and the lower electrode, and between the second electrode and the upper electrode. First, the first electrode and the second electrode were dropped to ground, and a pulse height of ± 50 V, a duty of 50, and a frequency of 200 Hz were applied between the upper electrode and the lower electrode. ± 40 degrees. Light emitted from a semiconductor laser was introduced from the end 215 of the optical waveguide portion of the device having this structure using an optical fiber. When the beam was vibrated under the above conditions, the introduced light was emitted from the tip of the beam, and the bright spot generated on the screen could be scanned. When the distance between the light source and the screen was 250 mm, the scan length on the screen was 250 mm.

<Embodiment 3> FIG. 13 shows an example of an optical scanning device of a type in which a beam 315 is vibrated in parallel to a substrate.
The structure is such that aluminum electrodes 302 and 303 are formed on a glass substrate 301.
Are formed, electrodes 306 and 307 are sandwiched by an optical waveguide 308 in contact therewith, and insulating layers 304 and 3 are sandwiched by the electrodes 306 and 307.
05 is partially floating from the substrate 301.

FIGS. 14A to 14H show the fabrication process (at the XY section in FIG. 13). First, a resist 300 having a thickness of 2 μm is formed on the substrate 301 in a pattern shape of a movable portion of a beam as a sacrificial layer (FIG. 14A).
A 0 μm aluminum layer 310 is deposited (FIG. 14B). Next, an electrode shape is formed by photolithography using a resist to form aluminum electrodes 302 and 303 and electrodes 306 and 307 (FIG. 14C). Dry etching of CCI4 was used for the electrode etching. Next, resist 311 for lift-off
Was applied by 20 μm (FIG. 14D). Next, the electrode 30
The resist 311 other than the resist 311 on 2, 303, 306, and 307 was removed by patterning by photolithography (FIG. 14E). Then plasma CV
D, an insulating film is deposited. First, in order to provide a refractive index gradient in the film thickness direction, first, an SiO ₂ film 3 is mixed with a mixed gas of SiH ₄ / O _2.
12 is deposited at 5 μm, and nitrogen gas is introduced to form SiON.
After depositing the film 313 at 10 μm, the nitrogen gas was stopped to deposit a 5 μm SiO ₂ film 314 (FIG. 14).
(F)). The SiON film 313 will later become the optical waveguide 308 shown in FIG. Next, after removing the insulating film on the aluminum electrodes 302 and 303 by lift-off, the resist film is again covered with a resist, and an unnecessary insulating film is removed by dry etching (FIG. 14 (g)), thereby forming an element shape as shown in FIG. did. Finally, the resist 300, which is a sacrificial layer between the substrate and the beam, was dissolved with a solvent to complete the displaceable beam 315 having the optical waveguide 308 (FIG. 14 (h)). Next, a lead terminal was attached to each electrode by bonding. The length of the beam was 10 mm, the height of the beam was 20 μm, and the thickness was 20 μm. The electrodes 306 and 307 of this element are grounded, and the electrodes 303 and 302 are set to 200 Hz and 100 Hz.
When a sine wave of V was applied, the beam vibrated at a maximum deflection angle of 75 degrees in a direction parallel to the substrate surface.

Example 4 In order to perform optical scanning by introducing a light source, a jig shown in FIG. 15 was prepared and an optical fiber 520 was connected. The jig 522 has a height of 20 μm and a width of 15 μm.
The electrodes 502 and 503 are made at the same time as the electrodes 502 and 503 made of aluminum having a length of 5 mm and a length of 5 mm. Then, the fiber 522
For positioning, a V-groove 524 is formed on the jig according to the height and position of the optical waveguide, and the fiber is adhered to the V-groove 524. A microcollimator lens 525 is formed at the tip of the beam. In this embodiment, the shape of the lens is a semi-cylindrical column. The lens was manufactured simultaneously with the optical waveguide 508. Light introduced by an optical fiber using a halogen lamp as the light source, when the distance between the light source and the screen is 200 mm,
The scan length on the screen was 250 mm.

<Embodiment 5> FIG. 16 shows an embodiment in which the beams of the optical scanning device are different from those of the third embodiment. The difference from the third embodiment is that the insulating layer 604 is provided on the side surface of the electrode 602 in the insulating layer.
The insulating layer 605 was disposed on the side surface of the electrode 603. As a material of the insulating layer, SiO ₂ is used, and is patterned and manufactured in a desired shape at the same process stage as the optical waveguide.
In this structure, since there was no insulating layer in the beam portion, the beam was light and easily moved, so that the driving voltage was lowered by 20 V as compared with the third embodiment.

<Embodiment 6> This embodiment is an example of an optical scanning device in which a semiconductor laser as a light source and an optical scanning section are monolithically formed on one substrate, and is schematically shown in FIG. The manufacturing method is as follows. First, an n-type GaAs of 1 μm as a buffer layer 702 and a cladding layer 70 are sequentially formed on an n-type GaAs substrate 701.
3 as n-type AlGaAs 2 μm, n-type Al0.4G
a0.6As 2 μm, non-doped GaAs100 #, Al0.2, Ga0.8As30 as active region 704
Å was repeated four times and finally GaAs100Å was laminated to form an active region 704 having a multiple quantum well structure. Next, as the cladding layer 705, P-type Al0.4Ga0.8As
5 μm, GaAs 0.5 μm as cap layer 706
It was formed by molecular beam epitaxy. Subsequently, as shown in order to limit the current injection area, after etching to about 0.4 μm before the active layer 704, polyimide 707 was formed by spin coating, and only the top part of the edge was etched to form an injection area. Next, Cr-
An Au ohmic electrode was formed. After performing a heat treatment for diffusion, the GaAs substrate is etched to form a resonance surface. Etching is performed using R ₂ using Cl ₂ gas.
Performed by the IBE method. Here, the cavity length is 300 μm. A semiconductor laser was manufactured by the above method. Next, a beam, a driving electrode, and a microcollimator lens were formed on the same substrate in the same manner as in Example 4. A voltage was applied to the electrodes in the beam and the driving electrodes to displace the beam, and the light emitted from the semiconductor laser was scanned one-dimensionally to scan the starting point on the screen 200 mm away from the screen by 250 mm.

A similar result could be obtained by bonding the above-mentioned semiconductor laser to the substrate on which the optical scanning portion was formed with an adhesive or the like.

[0056]

According to the optical scanning device of the present invention, a light beam introduced from a light source produced on the same substrate as the optical scanning device produced on the substrate or a light source placed outside is used for the optical scanning device. By displacing the optical waveguide in the beam, it is possible to provide an optical scanning device having a compact configuration and easy optical adjustment.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a first actuator that can be used in an optical scanning device according to the present invention.

FIGS. 2A and 2B are perspective views illustrating the operation of a first actuator.

FIG. 3 is a perspective view illustrating an optical deflector using a first actuator.

FIGS. 4 (a) to (f) are schematic manufacturing process diagrams of a first actuator.

FIG. 5 is a perspective view illustrating a second actuator that can be used in the optical scanning device of the present invention.

FIGS. 6A and 6B are top views illustrating the operation of a second actuator.

FIG. 7 is a perspective view illustrating a third actuator that can be used in the optical scanning device of the present invention.

FIG. 8 is a perspective view illustrating a fourth actuator that can be used in the optical scanning device of the present invention.

FIG. 9 is a perspective view illustrating a fifth actuator that can be used in the optical scanning device of the present invention.

FIG. 10 is a perspective view illustrating another example of the optical deflector.

FIG. 11 is a perspective view of a basic configuration of an optical scanning device according to the present invention.

12 (a) to (g) show Examples 1 and 2 of the present invention.
FIG. 4 is a cross-sectional view showing a process of the optical scanning device according to the first embodiment.

FIG. 13 is a perspective view of an optical scanning device according to a third embodiment of the present invention.

FIGS. 14A to 14H are diagrams showing a process of the optical scanning device according to the third embodiment of the present invention.

FIG. 15 is a perspective view of an optical scanning device according to Embodiment 4 of the present invention.

FIG. 16 is a perspective view of an optical scanning device according to Embodiment 5 of the present invention.

FIG. 17 is a perspective view of an optical scanning device according to Embodiment 6 of the present invention.

FIG. 18 is a perspective view of a conventional optical deflector.

FIG. 19 is a schematic diagram showing a configuration of a conventional optical scanning device.

[Explanation of symbols]

11 and 41 fixed electrode 12,22,42,55,62,72 movable electrodes 13 _1, 49 ₁ support beams 63,71 drive plate 14,15,43,44, 64,65,73,74, 81 Driven plate 16, 45, 66, 75 Support plate 17, 18, 19, 46, 47, 48, 67, 68, 69, 76, 77, 78 Joint 31 Silicon substrate 32 Thermal oxide film 33 Silicon nitride film 34 Contact Hole 35 polysilicon film (electric shield layer) 36 silicon oxide film (sacrifice layer) 37 polysilicon film 82 reflector 83 incident light 102, 103, 202, 211, 206, 208, 302, 303, 306, 307 electrode 101, 205, 209, 304, 305 Insulating layer 104, 207, 308 Optical waveguide 105 Cantilever 215, 315 Beam 201 210,301 board

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazuo Isaka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Masahiro Fushimi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inside (72) Inventor Hiroshi Takagi 3-30-2 Shimomaruko, Ota-ku, Tokyo Within Canon Inc. (72) Inventor Tomoko Murakami 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc.

Claims (6)

[Claims] 1. A thin-film cantilever having an optical waveguide and a first conductive region having conductivity, having an insulating region near the waveguide or in the cantilever, and sandwiching the insulating region. A second conductive region having conductivity is disposed, and an electrostatic force generated between the first conductive region and the second conductive region in the cantilever and an elastic force that restores the cantilever from deformation By moving the thin-film-shaped cantilever along the shape of the structure including the second conductive region, a light source disposed at the root of the cantilever is moved to an optical waveguide disposed in the cantilever. An optical scanning device characterized by moving an introduced light beam. 2. The optical scanning device according to claim 1, further comprising two structures including the second conductive region, which are opposed to each other with the cantilever interposed therebetween. 3. A first conductive region in the cantilever and a second conductive region in the cantilever.
2. An electrostatic force generated between the cantilever and the conductive region gradually works effectively from a root portion of the cantilever.
The optical scanning device according to claim 1. 4. A first conductive region in the cantilever and a second conductive region in the cantilever.
2. The optical scanning device according to claim 1, wherein the electrostatic force generated between the first and second conductive regions is generated by applying a voltage to two electrodes. 5. The optical scanning device according to claim 1, wherein a part or the whole of the first conductive region is made of a semiconductor material. 6. A first conductive region in the cantilever and a second conductive region in the cantilever.
2. The optical scanning device according to claim 1, wherein an electrostatic force generated between the first and second conductive regions applies a voltage to the second conductive region.