JP4886294B2 - Optical element driving apparatus, exposure apparatus, and device manufacturing method - Google Patents

Description

The present invention precisely drives an optical element such as a lens in a desired direction using a driving means in a projection optical system constituting a semiconductor exposure apparatus such as a mask aligner or a stepper in order to obtain a more accurate imaging relationship. The present invention relates to an optical element driving device.
Furthermore, the present invention relates to an exposure apparatus having the optical element driving apparatus and a device manufacturing method using the exposure apparatus.

In general, a semiconductor exposure apparatus is an apparatus for transferring an original (reticle) having many different types of patterns onto a silicon wafer (substrate).
In order to create a highly integrated circuit, it is essential to improve not only the resolution performance of the projection optical system but also the overlay accuracy.
Overlay errors in a semiconductor exposure apparatus are classified into alignment errors, image distortions, and magnification errors.
The alignment error is reduced by adjusting the relative position between the original (reticle) and the substrate (wafer).
On the other hand, the magnification error can be adjusted by moving a part of the projection optical system in the optical axis direction.
When moving in the optical axis direction, it is necessary to prevent other components other than the moving direction, in particular parallel eccentricity and tilt error, from increasing.
The image distortion can be adjusted by intentionally decentering a part of the projection optical system in parallel or tilt.
Conventionally, the following techniques have been disclosed as drive elements for optical elements for semiconductor exposure apparatuses or general mechanical devices.

For example, Japanese Patent Laid-Open No. 2001-343575 (Patent Document 1) discloses a structure of an outer ring corresponding to a fixed lens barrel and an inner ring corresponding to a movable lens frame.
Three sets of optical element holding devices corresponding to the lens driving mechanism are disposed at a relative angle 120 on the outer ring, and a connecting arm which is a displacement output portion of the driving mechanism is coupled to the inner ring.
As a result, by controlling the output displacement of the three sets of driving mechanisms to a desired value, the movable lens can be driven to shift in the optical axis direction and can be tilt driven about two axes orthogonal to the optical axis. Has been.
Furthermore, the connecting arm unit coupled to the movable lens is driven in the optical axis direction of the lens by using a piezo actuator as a driving source and a flexure mechanism having a displacement expanding and guiding function including a rigid link and an elastic hinge.

Japanese Patent Application Laid-Open No. 2002-131605 (Patent Document 2) discloses a structure of a frame corresponding to a fixed lens barrel and a lens frame corresponding to a movable lens frame.
Three sets of flexure mechanisms corresponding to the lens driving mechanism are arranged at a relative angle of 120 on the frame body, and the displacement output portion of the flexure mechanism is coupled to the flexure joint portion which is a projection portion of the lens frame body.
Thus, by controlling the output displacement of the three sets of drive mechanisms to a desired value, the movable lens is driven to shift in the optical axis direction, and is also driven to shift in two directions orthogonal to the optical axis, and orthogonal to the optical axis. A structure capable of tilt driving around two axes is disclosed.
Further, the detailed structure of the flexure mechanism is disclosed, and the rotational displacement of the horizontal direction drive lever and the vertical direction drive lever is converted into the horizontal and vertical shift displacements of the displacement output part of the flexure mechanism.
JP 2001-343575 A JP 2002-131605 A

However, in the drive mechanism disclosed in Japanese Patent Laid-Open No. 2001-343575 (Patent Document 1), an actuator and a flexure mechanism are arranged in parallel in the optical axis direction of the lens.
For this reason, the thickness of the outer ring corresponding to the fixed barrel increases in the optical axis direction, and it is difficult to store the mechanism in a lens unit that is thin in the optical axis direction.
Therefore, since the lens unit on which this mechanism is mounted is limited to a unit that is thick in the optical axis direction, the degree of freedom in optimizing aberration reduction in the entire projection optical system is limited.
Further, since the generated displacement of a small input source is enlarged and a large lens driving range is obtained, the natural frequency of the system is lowered, and external vibration applied to the lens barrel is easily transmitted to the lens.
For this reason, in order to obtain high image performance, there is a problem that it is difficult to apply to a lens having high sensitivity or a lens that requires high-speed driving.
Furthermore, there is a problem in that a desired position accuracy cannot be obtained because the force from the drive source deforms the lens barrel and the sensor mounting portion that measures the position of the movable portion is displaced.
The drive mechanism disclosed in Japanese Patent Laid-Open No. 2002-131605 (Patent Document 2) adjusts the tip displacement of the horizontal drive lever and the vertical drive lever with an adjustment washer and an adjustment button, and automatically controls the lens drive displacement. is not.
In addition, the adjustment washer and the adjustment button may be replaced with a piezo actuator or the like so that the structure can be automatically adjusted. However, the actuator protrudes in the optical axis direction, and the thickness in the optical axis direction is the same as in Patent Document 1. Becomes larger.
SUMMARY OF THE INVENTION An object of the present invention is to provide an optical element driving apparatus that has a highly reliable and thin configuration that prevents a bending moment from being applied to a linear actuator that is a driving means, and prevents damage to the linear actuator. .
A further object of the present invention is to provide an exposure apparatus having this optical element driving apparatus.
A further object of the present invention is to provide a device manufacturing method using this exposure apparatus.

In order to solve the above problems, an optical element driving apparatus for driving an optical element in the optical axis direction,
A plurality of linear actuators that are displaced in a direction perpendicular to the optical axis direction and in a tangential direction of a planar outer peripheral shape of the optical element;
A first member is provided at each end of each linear actuator in the tangential direction and includes a member that can rotate around a hinge, and takes out the displacement of the linear actuator to the side away from the linear actuator in the radial direction of the optical element. A link mechanism, a member connected to the first link mechanism, and a member disposed at a predetermined angle with respect to the tangential direction and rotatable in accordance with a displacement of the member connected to the first link mechanism. Including a second link mechanism that converts the displacement extracted by the first link mechanism in the optical axis direction, and a support mechanism provided between one end of the linear actuator and the first link mechanism, The support mechanism includes a spherical member and a conical recess that contacts the spherical member.

According to the optical element driving device of the present invention, the optical element driving device drives the optical element in the first direction,
A linear actuator that expands and contracts in a second direction perpendicular to the first direction;
A pair of displacement extraction links that are substantially parallel to the first direction and a third direction perpendicular to the second direction are connected to both ends of the connection portion, and one of the displacement extraction links is connected to one end of the linear actuator via a piezo receiving link. A first link mechanism that is supported on the other end of the linear actuator via a support mechanism and is displaced in the second direction;
A second link mechanism that is coupled to the first link mechanism and that converts the displacement in the second direction taken out by the first link mechanism into the first direction to be displaced.
For this reason, since it has a support mechanism, it becomes a highly reliable thin structure which prevents that a bending moment is applied to a linear actuator and prevents damage to a linear actuator.
Furthermore, according to the optical element driving device according to the present invention, the optical element driving device drives the optical element in the first direction,
A linear actuator that is displaced in a second direction perpendicular to the first direction;
First link mechanisms provided at both ends in the second direction of the linear actuator;
A second link mechanism connected to the first link mechanism and converting the displacement taken out by the first link mechanism into the first direction;
A support mechanism between the first link mechanism and the linear actuator;
The support mechanism includes a spherical member and a conical recess that contacts the spherical member.
For this reason, since it has a support mechanism, it becomes a highly reliable thin structure which prevents that a bending moment is applied to a linear actuator and prevents damage to a linear actuator.
Furthermore, according to the optical element driving device according to the present invention, the optical element driving device drives the optical element in the first direction,
A linear actuator that is displaced in a second direction perpendicular to the first direction;
A first link mechanism provided at both ends of the linear actuator in the second direction;
A second link mechanism connected to the first link mechanism and converting the displacement taken out by the first link mechanism into the first direction;
A support mechanism is provided between the first link mechanism and the linear actuator;
The support mechanism includes an elastic hinge.
For this reason, since it has a support mechanism, it becomes a highly reliable thin structure which prevents that a bending moment is applied to a linear actuator and prevents damage to a linear actuator.
Furthermore, according to the optical element driving device according to the present invention, the optical element driving device drives the optical element in the first direction,
A linear actuator that is displaced in a second direction perpendicular to the first;
A first link mechanism provided at both ends of the linear actuator in the second direction;
A second link mechanism connected to the first link mechanism and converting the displacement taken out by the first link mechanism into the first direction;
A support mechanism is provided between the first link mechanism and the linear actuator;
The support mechanism includes a spherical member, a conical recess that contacts the spherical member, and an elastic hinge.
For this reason, since it has a support mechanism, it becomes a highly reliable thin structure which prevents that a bending moment is applied to a linear actuator and prevents damage to a linear actuator.

Furthermore, according to the optical element driving device of the present invention, the optical element driving device has a guide that is fixed at one end to the fixed barrel on which the optical element driving device is mounted and that the other end presses the first link mechanism. The rigidity of the guide in the third direction is three times lower than that in the first and second directions.
For this reason, it becomes a thin structure which does not give a harmful deformation | transformation to the optical element mounted in a movable part, is provided with a high natural frequency, and satisfies a high disturbance vibration characteristic.
Furthermore, according to the optical element driving device of the present invention, the optical element driving device has a guide that is fixed at one end to the fixed barrel on which the optical element driving device is mounted and that the other end presses the first link mechanism. ,
The torsional rigidity of the guide around the second direction is at least three times lower than the torsional rigidity of the guide around the first direction and the guide around the third direction.
For this reason, it becomes a thin structure which does not give a harmful deformation | transformation to the optical element mounted in a movable part, is provided with a high natural frequency, and satisfies a high disturbance vibration characteristic.

Furthermore, according to the exposure apparatus of the present invention, since the optical element driving apparatus is provided, the structure is highly reliable.
Furthermore, according to the device manufacturing method of the present invention, since the exposure apparatus is used, the manufacturing method is highly reliable.

  Hereinafter, the present invention will be described with reference to the drawings based on the embodiments.

First, a schematic configuration of a semiconductor exposure apparatus to which an optical element driving apparatus according to a first embodiment of the present invention is applied will be described with reference to FIG.
This semiconductor exposure apparatus is a scanner type exposure apparatus that scans a reticle under slit illumination and performs an exposure operation while scanning the semiconductor wafer in synchronization with the reticle.
The projection optical system 1 is an optical system on which the optical element driving apparatus according to the first embodiment of the present invention is mounted.
Each lens unit includes a lens having a predetermined optical power, the optical element driving device according to the first embodiment that drives the lens, and a fixed barrel that stores them, and a plurality of lens units are stacked. Thus, one projection optical system 1 is configured.
The base frame 3 fixes the projection optical system 1 to the lens barrel surface plate 2.
The lens barrel surface plate 2 and the base frame 3 are fastened via a vibration isolation mechanism 3a so that the vibration of the floor on which the base frame 3 is installed is not transmitted to the projection optical system 1 and each lens in the projection optical system 1.
The illumination unit 4 is an apparatus that illuminates the reticle 5 serving as an original in various illumination modes.
The reticle stage 6 is a device that scans the reticle 5.
The reticle mount 7 is a mount for fixing the reticle stage 6 to the lens barrel mount 3.
The wafer 8 is a wafer coated with a photosensitive agent, and the wafer stage 9 is an apparatus that holds the wafer 8.
The wafer stage 9 adjusts the position of the wafer 8 in the optical axis direction and scans the wafer 8 in synchronization with the scanning operation of the reticle stage 6.
A lens control means 10 including a circuit and a CPU formed on the substrate controls the optical element driving device of the first embodiment according to a predetermined control flow.
The lens control unit 10 adjusts and drives a predetermined lens based on a result calculated based on various sensor information such as an atmospheric pressure sensor and a program stored in advance, and optimizes the optical performance of the projection optical system 1.
Details will be described with reference to FIGS.

Next, an optical element constituting a part of the projection optical system 1 and an optical element driving apparatus according to the first embodiment of the present invention for driving the optical element will be described with reference to FIG.
A plurality of optical elements and a plurality of optical element driving devices of the first embodiment are mounted, and a lens is used as the optical element.
2A is a plan view in which the lens and the lens frame are removed, FIG. 2B is a plan view in which the lens and the lens frame are mounted, and FIG. 2C is a cross-sectional view.
As shown in FIG. 2C, the flat portion 101a of the fixed barrel 101 fixes the optical element driving device 110 and the lens position detecting means 102 of the first embodiment.
The side wall cylindrical portion 101b of the fixed barrel 101 is a portion that is coupled to other lens units adjacent in the vertical direction.
Three optical element driving devices 110 according to the first embodiment are installed on the bottom flat portion 101a of the fixed barrel 101 at equal intervals.
The lens position detection means 102 is a means for detecting the displacement in the optical axis direction of the lens frame and the radial displacement perpendicular to the optical axis.
The lens position detection unit 102 includes an interference length measuring device using a semiconductor laser, a capacitance displacement meter, a linear encoder, a differential transformer displacement meter, and the like, and is used according to required accuracy.

Next, a state where the lens 103 is mounted on the lens frame 104 will be described with reference to FIG.
The lens frame 104 on which the lens 103 is mounted and accommodated is provided with flange-like projections at six locations on the upper surface, and three of the flange portions are provided with lens frame mounting screws 105 at the displacement output portion of the optical element driving device 110. Used to fasten.
Note that the heights of the three optical element driving devices 110 are made relatively equal by a spacer (not shown) provided between the optical element driving device 110 and the lens frame 104.
This prevents unnecessary deformation of the lens frame 104 and the lens 103.
With reference to FIG. 2C, a state where the other three portions of the flange portion are used as targets for detecting the displacement of the lens frame 104 will be described.
When the lens position detection unit 102 is formed of, for example, a laser interference type displacement sensor, the lens position detection unit 102 projects a detection laser beam in the optical axis direction and the radial direction of the lens 103.
A reflection surface is provided on the bottom surface of the lens frame 104. From the interference information of the laser beam reflected by the reflection surface, the optical axis direction (Z direction) and radial direction of three positions (near the flange portion) of the lens frame 104 are measured. Detect displacement.
In the above configuration, when the three sets of optical element driving devices 110 are driven by an equal amount, the lens 103 can be translated in the optical axis direction, that is, the Z-axis direction shown in FIG.
Further, by providing a predetermined difference in the driving amounts of the three optical element driving devices 110, tilt driving in the θa and θb directions shown in FIG. 2B is possible.
At this time, the translation and tilt drive amount of the lens 103 can be accurately controlled by feeding back the output of the lens position detection unit 102 in the optical axis direction.
Further, by monitoring the output in the radial direction of the lens position detecting means 102, the shift amount of the image accompanying the parallel decentering in the plane orthogonal to the optical axis of the lens 103 is calculated.
Therefore, by adding this calculation result to the driving amount of the wafer stage 9 shown in FIG. 1, the alignment error of the reticle image due to the lens eccentricity is eliminated.

Next, the optical element driving device 110 according to the first embodiment of the present invention will be described with reference to a detailed view of FIG.
FIG. 5B is a plan view seen from above the lens in the optical axis direction, and FIG. 5D is a side view seen from the center of the lens. The X axis, Y axis, and Z axis are defined as shown.
A flat portion 101a of the fixed barrel 101 shown in FIG. 2 is shown.
The linear actuator 512 is a device that expands and contracts in a direction (X direction) perpendicular to the optical axis direction (Z direction).
In the first link mechanism 511, displacement extraction links 511a and 511b are connected to both ends of the connecting portion 511h.
The displacement extraction link 511a is brought into contact with one end 512a of the linear actuator 512 via a piezo receiving link 511q.
The displacement extraction link 511b is supported by the other end 512b of the linear actuator 512 via a support mechanism, and is displaced in the X direction perpendicular to the optical axis direction.
The second link mechanism 515 is connected to the first link mechanism 511, and is a mechanism that converts the displacement in the X direction perpendicular to the optical axis direction taken out by the first link mechanism 511 into the optical axis direction and displaces it.
The 1st link mechanism 511 comprises the drive mechanism main body of the optical element drive device 110, consists of a single metal block, is formed by wire electric discharge machining and cutting, and comprises a link mechanism.
The laminated piezo actuator 512 is configured such that a drive source in which electrostrictive elements and electrodes are alternately laminated is enclosed in an expandable sealed cylindrical container, and the total length in the X-axis direction increases substantially in proportion to the applied voltage. To do.
The piezo adjustment screw 513 corrects a dimensional error of the piezo actuator 512 and applies pressure, and is interposed between the first link mechanism 511 and the piezo actuator 512.
The piezo adjustment screw 513 is fixed by a nut (not shown).

The piezo adjustment screw 513 shown in FIG. 5 pushes and adjusts the piezo actuator 512 via the steel ball 518.
However, as shown in FIG. 7B, the piezo receiving link 511r and the elastic hinge H56 may be separate parts and the parts may be pushed by the piezo adjustment screw 513.
The one end 512a of the piezo actuator 512 and the piezo receiving link 511q come into contact with each other.
The other end (512b) of the piezo actuator 512 is in contact with a piezo receiving link 511r having a spherical member 518 made of a steel ball as a support mechanism and a cone-shaped recess 519 in contact with the spherical member 518.
By this support mechanism, damage due to a bending moment applied to the piezoelectric actuator 512 is prevented.
The second link mechanism 515 is a direction changing member, and converts the output displacement transmitted from the piezoelectric actuator 512 to the first link mechanism 511 in the Z-axis direction.
The conversion member coupling screw 516 couples the connection links 511e and 511f that are displacement output portions of the first link mechanism 511 and the horizontal links 515a and 515b that are displacement input portions of the second link mechanism 515.
The conversion member mounting screw 517 is screwed to the fixed barrel 101 from the upper surface side of the second link mechanism 515.
In order to further shorten the length of the second link mechanism 515 in the X-axis direction, the conversion member attaching screw 517 may be attached from the back surface (lower part) of the fixed barrel 101.
In FIG. 5D, the conversion member mounting screw 517 is attached to the fixed barrel 101 at a part of the lower surface of the second link mechanism 515.
For this reason, the driving force by the piezo actuator 512 is transmitted to the fixed barrel 101 to reduce the occurrence of unnecessary deformation, and further reduce the erroneous output of the position detecting means 102.

Next, the manufacturing method of the 1st link mechanism 511 which is a drive mechanism main body of the optical element drive device 110, and the 2nd link mechanism 515 which is a direction change member is demonstrated.
The first link mechanism 511 includes a plate-shaped metal block having a predetermined thickness as a base material, and forms an outer portion by wire electric discharge machining.
Next, using a drilling machine, after machining a central screw round hole, a mounting screw hole pilot hole and a screw relief hole are machined from the side surfaces of the arms.
Finally, the adjustment screw hole 511m for loading the piezo adjustment screw 513 is threaded to complete the processing.
Next, the 2nd link mechanism 515 which is a direction change member consists of a plate-shaped metal block of the predetermined thickness used as a base material, and forms an external part and a slit part by wire electric discharge machining.
Next, using a drilling machine, the pilot holes for the lens frame attachment screw holes 515j are machined, and then the pilot holes for the attachment screw holes and the screw escape holes are machined from both side surfaces.
Finally, the lens frame mounting screw hole 515j and the prepared holes of the horizontal links 515a and 515b are threaded to complete the processing.

Next, an assembly procedure of the optical element driving device 110 according to the first embodiment of the present invention will be described.
The both side arms of the first link mechanism 511 that is the drive mechanism main body are inserted into the two window portions of the second link mechanism 515 that is the direction changing member.
Further, the first link mechanism 511 and the second link mechanism 515 are coupled by the conversion member coupling screw 516 as shown in FIG.
Next, the piezo actuator 512 is loaded in the central space of the first link mechanism 511 that is the drive mechanism main body.
Further, the piezo adjustment screw 513 is screwed in from the right side of the piezo adjustment screw hole 511m.
Next, the bottom 512b of the piezo actuator 512 is pushed leftward so that the output end 512a of the piezo actuator 512 is brought into pressure contact with the right end surface of the piezo receiving link 511q of the link mechanism, and the mounting of the piezo actuator 512 is completed.
Finally, the drive mechanism mounting screw 514 and the conversion member mounting screw 517 are used to screw the first link mechanism 511 and the second link mechanism 515 to the fixed barrel 101, and the assembly is completed.

Next, with reference to FIG. 6, the link operation | movement of the 1st link mechanism 511 which is a drive mechanism main body, and the 2nd link mechanism 515 which is a direction change member is demonstrated.
The first link mechanism 511 that is a drive mechanism main body is a schematic plan view, and the second link mechanism 515 that is a direction changing member is a schematic side view.
Hereinafter, the operation principle of the optical element driving apparatus 110 according to the first embodiment of the present invention will be described with reference to FIGS.
When a predetermined voltage is applied to the two electrode terminals provided at the bottom right end of the piezo actuator 512, the entire length L of the piezo actuator 512 extends by dL in the X-axis direction.
At this time, as shown in FIG. 6A, one piezo receiving link 511q is displaced left by dX1 = dL / 2, and the other piezo receiving link 511r is displaced right by dX2 = dL / 2.
At this time, the displacement take-out links 511a and 511b that are configured to be rotatable about the hinges H52 and H57 and extend in the Y-axis direction are rotated by a predetermined minute angle around the Z-axis.
Therefore, the connecting link 511e is displaced by dX3, and the connecting link 511f is displaced by dX4.
Here, the lengths of the links 511a and 511b are defined as shown in FIG.
For this reason, the displacement amounts of the connecting links 511e and 511f are each expanded by about b / a times the displacement amounts dx1 and dx2 given to the piezoelectric receiving links 511q and 511r by the piezoelectric actuator 512.
Here, this magnification is called a geometric magnification of the first link mechanism 511 which is the drive mechanism body, and is defined as α.
In addition, since the magnification is reduced due to deformation such as bending of the displacement extraction links 511a and 511b, which leads to driving loss, it is necessary to pay sufficient attention to the design.

The displacement in the X-axis direction of the connecting links 511e and 511f is transmitted to the horizontal links 515a and 515b of the second link mechanism 515 that is a direction changing member, as shown in FIG. 6B.
At this time, the direction conversion links 515c and 515d arranged at an angle θ with respect to the X axis rotate to raise the lens frame drive link 515g by dZ5 in the Z axis direction.
The Z-axis direction displacement dZ5 is approximately cot θ times the average value of the displacements of the horizontal links 515a and 515b.
Here, this magnification is called a geometric magnification of the second link mechanism 515 which is a direction changing member, and is defined as β.
The geometric magnification γ of the entire optical element driving apparatus 110 that combines the first link mechanism 511 and the second link mechanism 515 that is a direction changing member is the product of the geometric magnifications of the first link mechanism 511 and the second link mechanism 515 (γ = α × β).
In order to extract a large displacement from the slight generated displacement dL of the piezo actuator 512 and realize a driving amount of a wide range of optical elements, it is desirable to increase α and / or β.
To increase α, a shown in FIG. 6A needs to be reduced and b needs to be increased. To increase β, θ should be reduced.
However, if b is increased, the fixed barrel 101 becomes larger and has a larger diameter, so there is a design limitation.
Further, when the enlargement ratio is increased, the natural frequency of the optical element driving device 110 is reduced, and for example, vibration from the outside of the fixed barrel 101 is transmitted to the lens, image performance is deteriorated, and driving speed is reduced. Consideration is necessary.
In the case of the optical element driving device 110 for driving the lens, the combined geometric magnification γ is particularly preferably not less than 0.7 and not more than 2 in terms of vibration characteristics.
Further, from the viewpoint of the space in the Z-axis direction, the angle θ formed with the X-axis of the direction change links 515c and 515d of the second link mechanism 515 that is a direction change member is preferably between 30 and 60 degrees.
In this case, the geometric magnification β is approximately between 0.57 and 1.72.

In the case of the optical element driving apparatus 110 according to the present embodiment, when the displacement is applied to the first link mechanism 511 by the piezo actuator 512, the displacement take-out links 511a and 511b rotate about the elastic hinges H52 and H57.
For this reason, the piezoelectric actuator 512 slightly moves in the Y-axis direction.
As shown in FIG. 5, the fixed link 511 h of the first link mechanism 511 is screwed to the fixed barrel 101 at the center of the lower surface.
In this case, along with the generated displacement of the piezo actuator 512, the connecting links 511e and 511f are translated in the Y-axis direction.
As a result, the lens frame drive link 515g of the second link mechanism 515, which is a direction changing member, translates in the Y-axis direction.
As shown in FIG. 2, three optical element driving devices 110 are connected to the lens frame 104 approximately equally.
For this reason, the translational movement in the Y-axis direction described above distorts the lens frame, resulting in deformation of the lens. Further, when the Y-axis direction displacement components of the three optical element driving devices 110 are different from each other, the parallel decentering of the lens is caused, which is not preferable as a highly accurate lens driving mechanism.
In order to reduce the harmful translational movement of the lens frame drive link 515g in the Y direction, it is not preferable to unfix the fixed link of the first link mechanism 511 that is the drive mechanism body. This is because the first link mechanism 511, which is a drive mechanism body, has a degree of freedom around the X axis around the direction changing member 515 and has a low natural frequency, which makes it difficult to suppress disturbance vibration. is there.
Considering the above points, the fixed link of the first link mechanism 511, which is a drive mechanism body, is given a degree of freedom in the Y, θX, and axial directions, and is supported with a high spring constant in the X, Z, θy, and θz axis directions Install the guide 511V.
The guide 511V is provided so that one end is fixed to the fixed barrel 101 on which the optical element is mounted, and the other end presses the first link mechanism 511.
The rigidity of the guide 511V in the direction perpendicular to both the optical axis direction and the displacement direction of the guide 511V is configured to be three times lower than the rigidity of the guide 511V in both directions.
In the optical element driving device 110 according to the first embodiment, in particular, the translational rigidity in the Y-axis direction is configured to be at least three times lower than the other translational rigidity (X-axis direction and Z-axis direction).
In addition, the torsional rigidity around the X-axis is configured to be at least three times lower than the torsional rigidity around the other two axes (Y-axis and Z-axis).
As a result, the movable part (lens and lens frame) is driven without generating a harmful force against the lens deformation and without generating a low natural frequency of the harmful local mode of the optical element driving device 110. can do.
The guide 511V may be provided with a slit or the like for further reducing the influence on the deformation of the lens to further reduce the rigidity in the other axial directions, but should not exceed the range of the rigidity ratio.

As described above, the lens frame drive link 515g is displaced in the Z direction as the piezo actuator 512 is extended, but the lens frame drive link 515g is displaced only in the Z direction and not in the X direction and the Y direction. It is desirable.
Therefore, in order to realize such characteristics, the following auxiliary links are provided.
First, in order to restrict the movement of the lens frame drive link 515g in the X-axis direction, support links 515e and 515f are connected to the left and right sides thereof.
With this link, the lens frame drive link 515g has a degree of freedom of displacement in the Z-axis direction, but restricts the degree of freedom in the X-axis direction.
Further, other support links 515s and 515t are provided to restrict the movement of the lens frame drive link 515g in the Y-axis direction.
The support links 515s and 515t are arranged near the center of the horizontal links 515a and 515b, and restrict the degree of freedom in the Y-axis direction while maintaining the degree of freedom of the horizontal link in the X-axis direction.
Therefore, the restriction effect in the Y-axis direction of the horizontal links 515a and 515b is transmitted to the lens frame drive link 515g via the direction conversion links 515c and 515d.
With the above configuration, the area of the screw hole 515j on the lens frame attachment link 515g is displaced only in the Z direction, and the degree of freedom in the X direction and the Y direction is restricted, so the lens frame 104 is accurately driven in the Z direction. can do.

Next, with reference to FIG. 9 and FIG. 10, an embodiment of a device manufacturing method using an exposure apparatus having the optical element driving apparatus of Embodiment 1 of the present invention will be described.
FIG. 9 is a flowchart for explaining how to fabricate devices (ie, semiconductor chips such as IC and LSI, LCDs, CCDs, and the like).
Here, the manufacture of a semiconductor chip will be described as an example.
In step 1 (circuit design), a device circuit is designed.
In step 2 (mask production), a mask on which the designed circuit pattern is formed is produced.
In step 3 (wafer manufacture), a wafer is manufactured using a material such as silicon.
Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by lithography using the mask and the wafer.
Step 5 (assembly) is called a post-process, and is a process for forming a semiconductor chip using the wafer created in step 4. The assembly process (dicing, bonding), packaging process (chip encapsulation), and the like are performed. Including.
In step 6 (inspection), inspections such as an operation confirmation test and a durability test of the semiconductor device created in step 5 are performed.
Through these steps, a semiconductor device is completed and shipped (step 7).

FIG. 10 is a detailed flowchart of the wafer process in Step 4.
In step 11 (oxidation), the surface of the wafer is oxidized.
In step 12 (CVD), an insulating film is formed on the surface of the wafer.
In step 13, an electrode is formed on the wafer.
Step 14 (ion implantation) implants ions into the wafer.
In step 15 (resist process), a photosensitive agent is applied to the wafer.
Step 16 (exposure) uses the exposure apparatus to expose a circuit pattern on the mask onto the wafer.
In step 17 (development), the exposed wafer is developed.
In step 18 (etching), portions other than the developed resist image are removed.
In step 19 (resist stripping), the resist that has become unnecessary after the etching is removed.
By repeatedly performing these steps, multiple circuit patterns are formed on the wafer.

BRIEF DESCRIPTION OF THE DRAWINGS It is a whole block diagram of the semiconductor exposure apparatus which mounts the optical element drive device of Example 1 of this invention. It is a block diagram which applied the optical element drive device of Example 1 of this invention to the lens drive device. It is a control block diagram of the optical element drive device of Example 1 of the present invention. It is a control flowchart of the optical element drive device of Example 1 of the present invention. 1 is a structural diagram of an optical element driving device according to Embodiment 1 of the present invention. FIG. It is operation | movement explanatory drawing of the optical element drive device of Example 1 of this invention. It is a partial detail drawing of the optical element drive device of Example 1 of this invention. It is a figure which shows the manufacturing process of a semiconductor device. It is a figure which shows the detail of the wafer process of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Projection lens 10 Lens control means 11 Lens CPU
DESCRIPTION OF SYMBOLS 12 Piezo driver 21 Main body CPU 101 Fixed lens tube 102 Lens position detection means 103 Lens 104 Lens frame 110 Drive mechanism 511 Drive mechanism main body 512 Piezo actuator 513 Piezo adjustment screw 511a, 511b Displacement extraction link 515c, 515d Direction conversion link 515g Lens frame drive Link 511q, 511r Displacement extraction link

Claims (7)

An optical element driving apparatus for driving an optical element in the optical axis direction,
A plurality of linear actuators that are displaced in a direction perpendicular to the optical axis direction and in a tangential direction of a planar outer peripheral shape of the optical element;
A first member is provided at each end of each linear actuator in the tangential direction and includes a member that can rotate around a hinge, and takes out the displacement of the linear actuator to the side away from the linear actuator in the radial direction of the optical element. A link mechanism;
A member connected to the first link mechanism; and a member disposed at a predetermined angle with respect to the tangential direction and rotatable in accordance with a displacement of the member connected to the first link mechanism, A second link mechanism that converts the displacement extracted by the one link mechanism in the optical axis direction;
A support mechanism provided between one end of the linear actuator and the first link mechanism;
The support mechanism includes a spherical member and a conical recess that contacts the spherical member.   The optical element driving apparatus according to claim 1, wherein one end of the linear actuator and the first link mechanism are connected via the support mechanism and an elastic hinge.   The optical element driving apparatus according to claim 1, further comprising a connecting portion that connects first link mechanisms provided at both ends of the linear actuator. A guide for connecting the fixed barrel on which the optical element driving device is mounted and the connecting portion;
The optical element driving device according to claim 3, wherein rigidity in the radial direction of the guide is three times or more lower than that in the optical axis direction and the tangential direction. A guide for connecting the fixed barrel on which the optical element driving device is mounted and the connecting portion;
The torsional rigidity of the guide around the tangential direction is three times or more lower than the torsional rigidity of the guide around the optical axis direction and the guide around the radial direction. Optical element driving device.   An exposure apparatus comprising the optical element driving device according to claim 1.   A device manufacturing method comprising: a step of exposing an exposure target using the exposure apparatus according to claim 6; and a step of developing the exposed exposure target.

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