JP2002133730A - Optical axis adjusting device and exposing device provided with this device, and optical axis adjusting method and exposing method provided with this method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical axis adjusting device automatically adjusting an optical axis to prevent deviation of a processing point of a laser beam from a target point even when a state of a laser beam source changes. SOLUTION: This optical axis adjusting device has an optical axis automatic adjusting part having two mirrors perpendicularly refracting an optical path of an incident laser beam and a driver of the two mirrors, two position detecting sensors receiving the laser beam, and a control part having an estimation model of the optical axis automatic adjusting part and controlling the optical axis automatic adjusting part on the basis of output signals of the two position detecting sensors.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical axis adjusting apparatus, an exposure apparatus having the same, an optical axis adjusting method, and an exposure method having the same.

[0002]

2. Description of the Related Art CD or DVD (Digital Versatile Dis
Abbreviation of c. With the spread of optical disc playback devices such as registered trademarks, CDs and Ds that record content such as music or movies
Demand for VDs and the like is growing. An optical disk such as a CD or a DVD sold in the market is manufactured by stamping from a master on which a signal is recorded.

A master manufactured by an optical disk mastering device is manufactured by a known photoelectroforming method. Clean the glass disk and coat the cleaned disk with photoresist. Bake the photoresist coated disc,
The photoresist solvent is removed and the photoresist is cured. A signal is recorded on the baked disk using a laser beam.

[0004] The recorded disk is developed. By the development, a portion of the photoresist irradiated with the laser beam is removed. Because the glass disk is non-conductive, it is necessary to produce a conductive film in order to perform the next electroforming,
Sputter nickel on the developed disk. Electroforming (electroforming) is performed on the sputtered disk to generate a master on the disk. The back of the electroformed master is polished and peeled from the glass disk. Remove the hole in the center axis of the peeled master. The punched master is cleaned to remove photoresist and the like remaining on the surface. After that, a stamper is generated from the master, and stamping is performed by the stamper, thereby duplicating the optical disc. An optical disk master recording device (laser beam recorder) is used in the above-mentioned process of recording a signal on a resist-coated disk using a laser beam.

FIG. 3 shows a schematic configuration of an optical disk master recording apparatus. 101 is a laser oscillator, 102 is an air spindle, 103 is a slider, 104 is a focus actuator, 105 is a beam spot monitor, 1
06 is a moving optical system, 107 is a glass master, and 108 is a vibration isolation table. Ultraviolet laser light output from the laser oscillator 101 is modulated by a digital video signal or digital audio signal or the like, passes through a moving optical system, passes through a focus actuator 104, and irradiates a master 107 rotating by an air spindle 102. You. Spindle 10
By rotating the master in step 2 and slowly moving the slider 103 in the radial direction of the master 107, the laser light is transferred to the master while moving the moving optical system 106 including the focus actuator 104 mounted on the slider 103. The signal is recorded by irradiating 107.

The present invention is applicable to, for example, a master recording apparatus for manufacturing a master of an optical disk shown in FIG. In an optical disk master recording device or the like, the laser needs to be replaced due to the life of the laser or the like. When the laser is replaced, the optical axis of the laser is displaced, so that it is necessary to adjust the position of the optical component again, and a long time has been spent for the adjustment. In addition, pointing stability often changes due to a change in the state of the laser light source, and the optical axis needs to be adjusted each time.

Therefore, Japanese Patent Application Laid-Open No. 9-63079 discloses that two spots where the position detection sensor inputs laser light coincide with a fixed target spot (target position) even if the state of the light source changes. An optical axis adjusting device that adjusts the optical axis by using the driving mirror described above (referred to as Conventional Example 1). When the parallelism of the optical axis of the laser beam is kept constant, the laser beam can be accurately irradiated to the target processing point (target exposure point) on the master by the optical axis adjusting device of the first conventional example. However, since the angle detection and angle adjustment of the optical axis of the laser light cannot be performed by the optical axis adjusting device of the conventional example 1, when the emission angle of the laser light changes, the position detection sensor inputs the laser light. Even if the spot to be made coincides with the target spot, the actual processing point (exposure point) on the master to which the laser beam is irradiated is shifted from the target processing point.

Japanese Patent Application Laid-Open No. 11-179579 discloses a light for preventing an actual processing point (exposure point) on a master to be irradiated with a laser beam from deviating from a target processing point even when the emission angle of a laser beam changes. An axis adjusting device is described (referred to as Conventional Example 2). In the optical axis adjusting device of Conventional Example 2, laser light is branched at two points on the optical path of laser light from an output portion of a laser oscillator to an exposure point on a master, and each of the branched laser lights is divided into two PSDs. (Position Sensing Device) and adjusts the optical axis of the laser beam based on the detected signal.

However, in this apparatus, the laser light is provided at two places on the optical path of the laser light from the output part of the laser oscillator to the exposure point on the master (or from the output part of the laser oscillator to the input part of the modulation element). Because the transmission mirror for branching is arranged,
The optical path of the laser beam before entering the modulation element becomes longer. Therefore, there is a problem that the laser beam is easily affected by fluctuation of air or the like, and pointing stability before entering the modulation element is deteriorated. Further, since the optical path length before entering the modulation element becomes long, there is a problem that the entire device becomes large. In addition, the optical axis adjusting device of Conventional Example 2 performs the optical axis adjustment in two steps of first performing angle correction and then performing position correction (translational movement), and it takes time to adjust the optical axis. There was a problem.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, such as the fact that laser light is easily affected by fluctuations of air or the like and the response is slow. According to the present invention, even if the optical axis of a laser beam is displaced when a laser or the like is installed, or even if the state of the laser light source changes after installation, the optical axis is adjusted so that the processing point of the laser light does not deviate from a target point. It is an object of the present invention to provide an optical axis adjustment device that automatically adjusts, an exposure apparatus including the same, an optical axis adjustment method, and an exposure method including the same. SUMMARY OF THE INVENTION It is an object of the present invention to provide a small optical axis adjustment device in which laser light is hardly affected by fluctuations of air or the like, an exposure apparatus including the same, an optical axis adjustment method, and an exposure method including the same. The present invention
An object of the present invention is to provide an optical axis adjustment device having a high response speed, an exposure apparatus including the same, an optical axis adjustment method, and an exposure method including the same. An object of the present invention is to provide a high-precision optical axis adjustment device, an exposure apparatus including the same, an optical axis adjustment method, and an exposure method including the same.

[0011]

According to the first aspect of the present invention, a laser beam incident in a direction of a first axis among three axes orthogonal to each other is reflected in a direction of a second axis. A first mirror; a second mirror that further reflects the laser light reflected in the direction of the second axis in a direction of a third axis;
An optical axis automatic adjustment unit having a mirror and a driving device for driving the second mirror; and a position having a first optical path long distance d1 from a second mirror of the optical axis automatic adjustment unit, A first position detection sensor for inputting a part of the laser beam output from the automatic optical axis adjustment unit, and a second optical path long distance d2 (d2> d1) from the second mirror of the automatic optical axis adjustment unit
A second position detection sensor which is located at a position having a position and inputs another part of the laser light output by the automatic optical axis adjustment section, and an estimation model of the automatic optical axis adjustment section,
And a control unit for controlling the optical axis automatic adjustment unit based on the output signal of the position detection sensor and the output signal of the second position detection sensor.

According to a seventh aspect of the present invention, a laser beam incident in a direction of a first axis among three axes orthogonal to each other is reflected in a direction of a second axis. The laser light reflected in the third direction is further reflected in the direction of the third axis, and the laser light reflected in the direction of the third axis is first reflected from the reflection position from the second axis to the third axis. A first position detecting step of detecting a position at a position having an optical path long distance d1, and a laser beam reflected in the direction of the third axis being transmitted to the second position.
A second position detecting step of detecting a position at a position having a second optical path long distance d2 (d2> d1) starting from a reflection position from an axis to the third axis, and an output signal in the first position detecting step And solving the state equation of the estimation model based on the target value and the output signal and the target value in the second position detecting step, and calculating the second equation from the first axis.
A drive amount determining step of determining a drive amount of a drive device that changes at least one of a reflection position and a reflection angle to an axis and a reflection position and / or a reflection angle from the second axis to the third axis; And a driving step of driving the driving device by the driving amount determined in the driving amount determining step.

In the optical axis adjusting device according to the first and fourth aspects of the present invention, all the actuators of the driving device (for example, the first mirror and the first mirror) are solved by solving the state equation of the estimation model of the automatic optical axis adjusting unit. The driving amounts of the four actuators for rotating and translating the second mirror are calculated, and all the actuators of the driving device are driven in one step, for example, as in the optical axis adjustment method according to claim 7, Adjust the optical axis. The present invention has an effect that an optical axis adjusting device and an optical axis adjusting method with a high response speed can be realized.

In this embodiment, the starting point of the "first optical path length distance d1" is the reflection point of the second mirror of the automatic optical axis adjustment unit, and the ending point of the "first optical path length distance d1" is the first point. 1 is a light receiving unit of the position detection sensor. Also, “second optical path long distance d
The starting point of “2” is the reflection point of the second mirror of the automatic optical axis adjustment unit, and the ending point of “second optical path long distance d2” is the light receiving unit of the second position detection sensor. The “first optical path length distance d1” and the “second optical path length distance d2” mean the optical path length of the laser light from the start point to the end point. The “position detection sensor” includes an arbitrary sensor that detects a position on the sensor irradiated with the laser light. For example, a PSD (Position Sensing Dev) provided with electrodes on four sides of a photodiode formed in a square shape.
ice) or CCD (Charge Coupled Device).
The “state equation” refers to an arbitrary expression representing the relationship between the output signal of the first position detection sensor, the output signal of the second position detection sensor, and the driving amount of the automatic optical axis adjustment unit. Especially d2
By setting -d1 to a length of 20 mm or more, the optical axis of the laser beam can be adjusted with high angular accuracy (claim 2).

According to a third aspect of the present invention, there is provided a first mirror for reflecting a laser beam incident in a direction of a first axis among three axes orthogonal to each other in a direction of a second axis; An optical axis automatic having a second mirror for further reflecting the laser light reflected in the direction of the second axis in the direction of a third axis, and a driving device for driving the first mirror and the second mirror; An adjustment unit, a third transmission mirror that receives the laser light output by the optical axis automatic adjustment unit, transmits a part of the laser light, and reflects another part, and the third transmission mirror A first laser beam, which is one of a laser beam transmitted through the first mirror and a laser beam reflected by the third transmission mirror, and transmits a part of the first laser beam; A fourth transmission mirror that reflects a part of the light, and a second mirror of the optical axis automatic adjustment unit. And a second optical beam located at a position having a first optical path distance d1 from the laser beam, which is one of the laser beam transmitted through the fourth transmission mirror and the laser beam reflected by the fourth transmission mirror. A first position detection sensor for inputting the laser light of the second position, and a position having a second optical path long distance d2 (d2> d1) from the second mirror of the automatic optical axis adjustment section, and the fourth transmission A second position detection sensor for inputting a third laser beam which is another one of the laser beam transmitted through the mirror or the laser beam reflected by the fourth transmission mirror, and the first position detection An optical axis adjustment device comprising: a control unit that controls the automatic optical axis adjustment unit based on a sensor and an output signal of the second position detection sensor.

In the optical axis adjusting apparatus according to the present invention, the light is branched only at one position on the optical path of the laser light from the output of the laser oscillator to the exposure point (or from the output of the laser oscillator to the input of the modulation element). Since the transmission mirror is arranged, the optical path of the laser light before entering the modulation element is short. Therefore, the laser beam is less likely to be affected by fluctuations of air or the like, and pointing stability at the input section of the modulation element is improved. Further, since the optical path length before entering the modulation element is short, the entire device can be reduced in size. In particular, even when d2-d1 is lengthened, it is not necessary to lengthen the optical path of the laser light for irradiating the master, so that the influence of the fluctuation of air or the like received by the laser light does not increase. The present invention has an effect that a small and high-precision optical axis adjustment device in which laser light is hardly affected by fluctuations of air or the like and an exposure device including the same can be realized.

According to a fifth aspect of the present invention, the automatic optical axis adjusting section has a driving device for rotating and translating the first mirror and the second mirror, respectively. An optical axis adjustment device according to any one of claims 1 to 4.

According to the present invention, the processing point of the laser beam does not deviate from the target point even if the optical axis of the laser beam is displaced when the laser or the like is installed, or even if the state of the laser light source changes after the installation. This has the effect of realizing an optical axis adjusting device that automatically adjusts the optical axis.

The configuration of the actuator of the automatic optical axis adjustment unit for rotating and translating the first mirror and the second mirror respectively is arbitrary. Preferably, the optical axis automatic adjustment unit has four actuators (referred to as a first actuator, a second actuator, a third actuator, and a fourth actuator). For example, the first actuator of the optical axis automatic adjustment unit rotates the first mirror, the second actuator translates the first mirror,
A third actuator rotates the second mirror and a fourth
Actuator translates the second mirror.

For example, the first actuator of the automatic optical axis adjustment section rotates the first mirror, the second actuator translates the first mirror and the second mirror, and the third actuator moves the second mirror. The mirror is rotated, and the fourth actuator translates only the second mirror. For example,
A first actuator of the optical axis automatic adjustment unit rotates the first mirror about the first axis, and a second actuator rotates the first mirror about a second axis orthogonal to the first axis. Rotating, the third actuator translates the first mirror, and the fourth actuator translates the second mirror. As a result, it is sufficient if the first mirror and the second mirror can be rotated and translated, respectively. The actuator is an arbitrary driving device, such as a motor or a piezo element.

According to an eighth aspect of the present invention, after the driving step is completed, the laser beam reflected in the direction of the third axis is moved from the reflection position from the second axis to the third axis in the first direction. Position detection at a position having an optical path long distance d1 of
The laser beam reflected in the direction of the third axis is
The second optical path long distance d from the reflection position from the axis to the third axis
A third position detection step for detecting a position at a position having a second position, an output signal in the first position detection step, an output signal in the second position detection step, and two output signals in the third position detection step. The optical axis adjustment according to claim 7, further comprising: an estimation model correcting step of correcting the estimation model based on the output signal and the determined driving amount or the actually driven driving amount. Is the way.

In the optical axis adjusting method according to the present invention, a more accurate estimation model is generated based on the output signal of the position detection sensor. The present invention has an effect that a highly accurate optical axis adjustment method can be realized.

According to a second aspect of the present invention, the difference between the first optical path length distance d1 and the second optical path length distance d2 is d2-d1 ≧ 20 mm. Item 2 is an optical axis adjusting device according to Item 1.

The present invention has the effect that a highly accurate optical axis adjustment device can be realized.

According to a sixth aspect of the present invention, there is provided an optical axis adjusting device according to any one of the first to fifth aspects, and a laser beam output by the automatic optical axis adjusting section. A condensing lens for irradiating the substrate coated with the resist with the input and condensed laser light.

According to a ninth aspect of the present invention, a laser beam adjusted by the optical axis adjusting method according to the seventh or eighth aspect is input to a condenser lens, and the laser light is adjusted by the condenser lens. This is an exposure method of irradiating a focused laser beam to a substrate coated with a resist to perform exposure.

The present invention has an effect that an exposure apparatus and an exposure method for performing high-precision exposure can be realized.

[0028]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; If the optical axis of the laser is adjusted during exposure by an exposure apparatus using an AO modulator (acoustic optical element), it is difficult to recognize the correct optical axis because the beam emission angle changes.

Therefore, in this embodiment, in order to shorten the optical path to the modulator, the laser beam (laser light) branched at one point on the optical path is further branched and the beam spot is detected by two position detecting sensors. Is detected, and the optical axis is corrected based on the output signal of the position detection sensor. By shortening the optical path from the output part of the laser oscillator to the condenser lens for exposing the master disk as compared with the second conventional example, it is less likely to be affected by disturbance, and the apparatus can be downsized.

FIG. 1 is a schematic structural view of an exposure apparatus equipped with an optical axis adjusting device according to an embodiment of the present invention. 1 is a laser oscillator, 2 is an automatic optical axis adjustment unit (including a first total reflection mirror and a second total reflection mirror), 3 is a third transmission mirror, 4 is a fourth transmission mirror, and 5 is a fourth transmission mirror. 1 is a position detection sensor, 6 is a second position detection sensor, 7 is a moving stage,
Reference numeral 8 denotes an objective lens (condensing lens), 9 denotes an optical disk master, 10 denotes a modulation element, and 11 denotes a semiconductor laser.

The laser light emitted from the laser oscillator 1 is incident on the third transmission mirror 3 through the automatic optical axis adjustment unit 2. Part of the incident laser light is transmitted through the third transmission mirror 3, and the other part of the incident laser light is reflected by the third transmission mirror 3. The laser light transmitted through the third transmission mirror 3 is incident on the fourth transmission mirror 4. A part of the laser light incident on the fourth transmission mirror 4 is reflected by the fourth transmission mirror 4, and the other part is reflected by the fourth transmission mirror 4.
Through the transmission mirror 4.

The laser light reflected by the fourth transmission mirror 4 is input to the first position detection sensor 5. The first position detection sensor 5 detects the position of the laser light irradiation spot on the light receiving surface, and outputs a signal corresponding to the detected position.
The laser light transmitted through the fourth transmission mirror 4 is input to the second position detection sensor 6. The second position detection sensor 6
The position of the irradiation spot of the laser beam on the light receiving surface is detected, and a signal corresponding to the detected position is output. The first position detection sensor 5 and the second position detection sensor 6 are PSDs in the embodiment.

The optical axis adjusting device of the embodiment drives the mirror of the automatic optical axis adjusting section based on the detection signals of the first position detecting sensor 5 and the second position detecting sensor 6, and controls the optical axis of the laser light. To adjust. The laser light reflected by the third transmission mirror 3 is input to the modulation element 10, modulated, and output.
The laser light output from the modulation element is reflected by a mirror, and is reflected by an objective lens 8 arranged on a moving stage 7.
It is input in the direction from the top to the bottom of the paper. The objective lens 8 focuses the input laser light and irradiates the resist layer on the master 9 of the optical disc. Semiconductor laser 11
Irradiates the master disk 9 with the laser light output by the controller, and detects the reflected light from the master disk 9 to execute the position control of the objective lens 8 in the focus direction.

[Description of Automatic Optical Axis Adjustment Unit] FIG. 2 shows a schematic configuration of the automatic optical axis adjustment unit 2. The laser light 20 emitted from the laser oscillator 1 changes the beam direction by 90 degrees by the first total reflection mirror 21 and the second total reflection mirror 22, respectively. A first rotary actuator 23 and a first translation actuator 25 are mounted on the first total reflection mirror 21. The first rotary actuator 23 rotates the first total reflection mirror 21 in the direction of 27, and the first translation actuator 25 translates the first total reflection mirror 21 in the direction of 29 (vertical direction in the embodiment). Let it.

A second rotary actuator 24 and a second translation actuator 26 are mounted on the second total reflection mirror 22. The second rotary actuator 24 is a second rotary actuator.
Is rotated in the direction of 28, and the second translation actuator 26 moves the second total reflection mirror 22 to 30.
(Horizontal direction in the embodiment). The automatic optical axis adjustment unit 2 adjusts the optical axis of the laser beam 20 by driving four actuators. FIG. 2 shows only the rotation axis of each actuator, and the illustration of the actuator attached to the rotation axis is omitted.

The automatic optical axis adjusting unit 2 of this embodiment is equipped with one rotary actuator and one translation actuator as a drive mechanism for each total reflection mirror. Instead of this, for example, the optical axis automatic adjustment unit mounts two rotary actuators and one translation actuator as a driving mechanism for one total reflection mirror, and drives another one total reflection mirror. May be mounted with one translation actuator. The automatic optical axis adjusting unit 2 of the present embodiment has two actuators for adjusting rotation (tilt angle) and two actuators for translation as actuators for adjusting the optical axis. Can be composed of any combination of four or more actuators.

The beam spot of the laser light (laser beam) output from the laser oscillator 1 is positioned on the light receiving surfaces of the first position detection sensor 5 (PSD) and the second position detection sensor 6 (PSD). The optical path is manually adjusted in advance (so that it is located within the detection range). When the condenser lens accurately irradiates the master disk with the laser light, the first position detection sensor 5 and the second position detection sensor 6 measure the positions where the beam spot of the laser light is input, and set the positions as target positions. To decide. The control unit stores target vectors e and f (two-dimensional position information of target positions on the light receiving surfaces of the first position detection sensor 5 and the second position detection sensor 6) obtained in advance by precision measurement. deep. Thereafter, based on the detection signals detected by the two PSDs, a control unit (not shown) drives the automatic optical axis adjustment unit 2 to control the two P axes.
The optical axis of the laser beam is adjusted so that the position where the SD enters the beam spot of the laser beam approaches the target position. Less than,
The adjustment method will be described.

The vector of the detection signal of the first position detection sensor 5 for detecting the laser beam reflected by the fourth transmission mirror 4 is represented by a (the position where the first position detection sensor 5 inputs the beam spot of the laser beam). Two-dimensional position information according to
And Similarly, the vector of the detection signal of the second position detection sensor 6 for detecting the laser beam transmitted through the fourth transmission mirror 4 is set to b (at the position where the second position detection sensor 6 inputs the beam spot of the laser beam). Corresponding two-dimensional position information). The vector a and the vector b are represented by the following equations (1) and (2). a = a ₁ · i ₁ + a ₂ · i ₂ (1) b = b ₁ · i ₁ + b ₂ · i ₂ (2) where i ₁ and i ₂ are unit vectors in the horizontal and vertical directions, respectively. . Let the center of each PSD be the origin.

The target vector of the detection signal of the first position detection sensor 5 is set to e (two-dimensional position information of the target position on the light receiving surface of the first position detection sensor 5), and the second position detection sensor 6 Is f (two-dimensional position information of the target position on the light receiving surface of the second position detection sensor 6). e = e ₁ · i ₁ + e ₂ · i ₂ (3) f = f ₁ · i ₁ + f ₂ · i ₂ (4) The vector of the detection signal of the first position detection sensor 5 is e−a.
Moving the detection spots of the first position detection sensor 5 and the second position detection sensor 6 to the target position by moving the detection signal vector of the second position detection sensor 6 by fb; Can be done.

The first rotation actuator 23 causes the first
Is rotated by θ, the first total reflection mirror 21 is translated x by the first translation actuator 25, the second total reflection mirror 22 is rotated γ by the second rotation actuator 24, and the second Translation actuator 2
It is assumed that the detection spots of the first position detection sensor 5 and the second position detection sensor 6 can be moved to the target positions by translating the second total reflection mirror 22 by y in accordance with FIG. The optical path length from the second total reflection mirror 22 to the first position detection sensor 5 is d ₁ , the optical path long distance from the second total reflection mirror 22 to the second position detection sensor 6 is d _{2 ,} The optical path long distance from the total reflection mirror 21 to the first position detection sensor 5 is d ₃ , and the first total reflection mirror 2
The optical path long distance from 1 to the second position detection sensor 6 is d ₄
(The optical path long distance is measured along the optical path.)

Assuming that the driving amount of each actuator is minute, the following state equations (5) and (6) are established. e−a = (e ₁ −a ₁ , e ₂ −a ₂ ) = (d ₃ θ + x, d ₁ γ + y) (5) f−b = (f ₁ −b ₁ , f ₂ −b ₂ ) = (D ₄ · θ + x, d ₂ · γ + y) (6) Equations (5) and (6) have four equations and four (θ, x, γ,
Since the unknowns of y) are included, they can be solved.

For example, the first rotary actuator 23 and the second rotary actuator 24 rotate by a rotation angle proportional to the number of drive pulses, and the first translation actuator 2
Assuming that the fifth and second translation actuators 26 translate by a distance proportional to the number of drive pulses, the following equations (7) to
Equation (10) holds (for example, each actuator is a piezoelectric element that performs a step operation according to the number of drive pulses). k ₁ , k ₂ , k ₃ , and k ₄ are proportional constants of each actuator, and n ₁ , n ₂ , n ₃ , and n ₄ are the number of drive pulses of each actuator. θ = k ₁ · n ₁ (7) x = k ₂ · n ₂ (8) γ = k ₃ · n ₃ (9) y = k ₄ · n ₄ (10)

The control unit of the embodiment uses a microcomputer.
Has an automatic optical axis adjustment unit in the memory of the microcomputer
Has an estimation model of The estimation model of the embodiment is
d₁, D ₂, D₃, D₄, K₁, K₂, K₃, K₄Etc.
These are constants and relational expressions such as Expressions (5) to (10). control
First, the first position detection sensor 5 and the second position
The output signal of the detection sensor 6 is input, and the above state equation is calculated.
By solving, the driving amount of each actuator (in the embodiment,
(The number of drive pulses) is calculated (drive amount determination step). Next
The control unit calculates the number of drive pulses n₁, N₂,
n₃, N₄Drive each actuator only (drive stage
Up).

If the accuracy of the estimation model is high, the detection spot of the laser beam of the first position detection sensor 5 and the second position detection sensor 6 can be moved to the target position in one step. When the detection spot of the laser light is located at the target position, the laser light is focused on an accurate position on the master disk 9 of the optical disk. In the conventional example 2, the rotary actuator is driven in the first step, and the detection spot of the laser beam is moved to the target position in two steps of driving the translation actuator in the next step. Solving to determine the drive amount of each actuator, simultaneously drive all actuators in one step to move the laser beam detection spot to the target position (only compare the number of actuator drive steps that occupy most of the control time. ing.).

If the estimation model is inaccurate, when each actuator is driven by the calculated number of drive pulses n ₁ , n ₂ , n ₃ , n ₄ (when the drive step is completed), the first The detection spots of the position detection sensor 5 and the second position detection sensor 6 are different from the target position. The control unit inputs the output signals of the first position detection sensor 5 and the second position detection sensor 6 when the driving step is completed, and outputs the signals of the first position detection sensor 5 and the second position detection sensor 6. The above equation of state is solved based on the output signal, and the drive amount (the number of drive pulses in the embodiment) of each actuator is calculated again (drive amount determination step again). Next, the control unit drives each actuator again by the calculated number of drive pulses (drive step again). This is repeated until the detection spot of each position detection sensor falls within the target position or within an allowable range centered on the target position.

Preferably, each time the driving of the actuator is completed (every time the driving step is completed), the constant of the estimation model is corrected based on the number of driving pulses and the resulting movement amount to increase the accuracy of the estimation model. . After completion of the driving step, the output signal of the first position detection sensor 5 and the output signal of the second position detection sensor are input (third position detection step). Next, the output signal of the first position detection sensor 5 and the output signal of the second position detection sensor 6 in the drive amount determination step, and the output signal of the first position detection sensor 5 and the third output signal in the third position detection step. 2 position detection sensor 6
The estimated model is corrected based on the output signal of (i) and the drive amount calculated in the drive amount determination step or the drive amount actually driven (drive step) (estimated model correction step).

Next, the control unit calculates the above state equation based on the output signals of the first position detection sensor 5 and the second position detection sensor 6 input in the third position detection step and the corrected estimation model. Then, the drive amount of each actuator (the number of drive pulses in the embodiment) is calculated again (drive amount determination step again). Next, the control unit drives each actuator again by the calculated number of drive pulses (drive step again). Repeat this. By increasing the estimation accuracy of the estimation model each time the actuator is driven once, the convergence of the laser beam spot to the target position can be accelerated.

Although the automatic optical axis adjusting section 2 of the embodiment has an actuator for driving each mirror by a moving amount proportional to the number of pulses, an actuator of, for example, a normal DC motor may be used instead. The control unit stores a state equation (estimated model) including a speed component and an acceleration component of the DC motor, and determines the control amount of each actuator by solving the state equation. By performing appropriate control, it is possible to realize a faster response than in the embodiment.

In order to maintain the parallelism of the optical axis of the laser light with high accuracy (to maintain the state where the optical axis tilt of the laser light is sufficiently small), the tilt of the optical axis of the laser light is adjusted with high sensitivity. It is important to be able to detect. As can be seen from Equations (5) and (6), by increasing the values of d ₂ -d ₁ and d ₄ -d ₃ , the accuracy of discrimination between θ and x and the accuracy of discrimination between γ and y are improved. (The inclination of the optical axis of the laser beam can be detected with high sensitivity.) | D ₃ −d ₁ | =
Since the optical path length of | d ₄ −d ₂ | (the optical path length between the first mirror and the second mirror) is a substantially constant value determined by the structure of the automatic optical axis adjustment unit, d ₂ −d ₁ = d ₄ −d ₃
Holds.

When processing a disk (master disk of an optical disk) on which a resist is applied by using a laser beam, it is assumed that a deviation of a processing point of the disk is allowed by Δa. Assuming that the focal length of the focus actuator 104 is f and the inclination of the optical axis at that time is θ, the following relational expression holds. Δa = f · θ (11)

The resolution of the position detecting sensor for detecting the spot is r, and the optical path length from the second mirror to the first position detecting sensor 5 (referred to as "first detecting distance") is d.
_{1 (d1} in the description of the claims), a second mirror (referred to as "second detection distance".) Optical path long distance to the second position detecting sensor 6 in the description of d _{2 (claims} d
Assuming 2), the following relational expression holds. θ = r / (| d ₂ −d ₁ |)) (12) Therefore, | d ₂ −d ₁ | can be expressed by the following equation (13). | D ₂ −d ₁ | = r / θ = rf · (Δa) (13)

Therefore, in order to adjust the parallelism of the optical axis with high accuracy, the detection distance of the two beam position detection sensors needs to satisfy the following expression (14). | D ₂ −d ₁ | ≧ r / θ = rf · (Δa) (14) If Δa = 0.01 μm, f = 2 mm, and r = 0.1 μm, D = d ₄ −d ₂ = 20 mm. . By setting the optical path length distance between the two beam detection units to be equal to or more than 20 mm, it is possible to reduce the deviation of the processing point of the disc to the allowable amount Δa or less.

[0053]

According to the present invention, there is obtained an advantageous effect that an optical axis adjusting device having a high response speed and an optical axis adjusting method having a high response speed can be realized. According to the present invention, there is obtained an advantageous effect that a small and high-precision optical axis adjustment device and an exposure device including the same can be realized, in which laser light is not easily affected by fluctuations of air or the like.

According to the present invention, even if the optical axis of the laser beam is displaced when the laser or the like is installed, or the state of the laser light source changes after the installation, the processing point of the laser light does not deviate from the target point. Thus, the advantageous effect that the optical axis adjusting device and the optical axis adjusting method for automatically adjusting the optical axis can be realized is obtained. According to the present invention, an advantageous effect that a highly accurate optical axis adjusting device and an optical axis adjusting method can be realized is obtained. According to the present invention, there is obtained an advantageous effect that an exposure apparatus and an exposure method for performing high-precision exposure can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an exposure apparatus (including an optical axis adjustment apparatus) according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of an automatic optical axis adjustment unit according to an embodiment of the present invention.

FIG. 3 is a schematic configuration diagram of an optical disk master recording apparatus;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Laser oscillator 2 Optical axis automatic adjustment part 3 3rd transmission mirror 4 4th transmission mirror 5 1st position detection sensor 6 2nd position detection sensor 7 Moving stage 8 Objective lens 9 Optical disk master 10 Modulation element 21st 1 total reflection mirror 22 second total reflection mirror 23 first rotation actuator 24 second rotation actuator 25 first translation actuator 26 second translation actuator 101 laser oscillator 102 air spindle 103 slider 104 focus actuator 105 beam spot Monitor 106 Moving optical system 107 Glass master 108 Vibration isolation table

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hitoshi Miyakita 1006 Kazuma Kadoma, Osaka Pref. Matsushita Electric Industrial Co., Ltd. Term (reference) 2H097 CA17 LA20 5D121 BB21 BB38

Claims (9)

[Claims] 1. A first mirror that reflects laser light incident in a direction of a first axis among three axes orthogonal to each other in a direction of a second axis, and a laser beam that is reflected in a direction of the second axis. An automatic optical axis adjustment unit including a second mirror that further reflects the laser light in the direction of the third axis, and a driving device that drives the first mirror and the second mirror; and the automatic optical axis adjustment unit. A first position detection sensor which is located at a position having a first optical path long distance d1 from the second mirror, and which receives a part of the laser light output by the automatic optical axis adjustment unit; Second position detection that is located at a position having a second optical path long distance d2 (d2> d1) from the second mirror of the unit, and receives another part of the laser light output by the automatic optical axis adjustment unit. A first position detection sensor, comprising: a sensor; and an estimation model of the optical axis automatic adjustment unit. A control unit for controlling the automatic optical axis adjustment unit based on the output signal of the second position detection sensor and the output signal of the second position detection sensor. 2. The optical axis adjusting device according to claim 1, wherein a difference between the first optical path length distance d1 and the second optical path length distance d2 is d2-d1 ≧ 20 mm. 3. A first mirror for reflecting a laser beam incident in a direction of a first axis in three mutually orthogonal spatial axes in a direction of a second axis, and a laser beam reflected in a direction of the second axis. An automatic optical axis adjustment unit including a second mirror that further reflects the laser light in the direction of the third axis, and a driving device that drives the first mirror and the second mirror; and the automatic optical axis adjustment unit. Input the laser light output,
A third part that transmits a part of the laser light and reflects another part;
And the laser light transmitted through the third transmission mirror or the third transmission mirror.
A first laser beam, which is one of the laser beams reflected by the transmission mirror, is input, and a fourth laser beam transmits a part of the first laser beam and reflects another part. A transmission mirror, located at a position having a first optical path long distance d1 from the second mirror of the optical axis automatic adjustment unit, and reflected by the laser light transmitted through the fourth transmission mirror or by the fourth transmission mirror; A first position detection sensor for inputting a second laser beam, which is one of the laser beams, and a second optical path long distance d2 (d2) from a second mirror of the optical axis automatic adjustment unit. > D1), the fourth
A second position detection sensor for inputting a third laser beam which is another one of the laser beam transmitted through the transmission mirror or the other laser beam reflected by the fourth transmission mirror; An optical axis adjustment device, comprising: a control unit that controls the optical axis automatic adjustment unit based on output signals from a position detection sensor and the second position detection sensor. 4. The optical axis adjustment device according to claim 3, wherein the control unit has an estimation model of the optical axis automatic adjustment unit. 5. The apparatus according to claim 1, wherein the optical axis automatic adjustment unit has a driving device for rotating and translating the first mirror and the second mirror, respectively. An optical axis adjusting device according to claim 1. 6. The optical axis adjusting device according to claim 1, wherein the laser light output from the optical axis automatic adjusting unit is input, and the collected laser light is registered. An exposure apparatus, comprising: a condensing lens that irradiates a substrate on which is coated. 7. A laser beam incident in a direction of a first axis in three spatial axes orthogonal to each other is reflected in a direction of a second axis, and the laser beam reflected in the direction of the second axis is further reflected in a third direction. The laser light reflected in the directions of the three axes and reflected in the direction of the third axis is first reflected from the reflection position from the second axis to the third axis.
A first position detection step of detecting a position at a position having an optical path long distance d1, and a laser beam reflected in the direction of the third axis starting from a reflection position from the second axis to the third axis. Optical path long distance d of 2
2 (d2> d1), based on the output signal and target value in the first position detection step and the output signal and target value in the second position detection step. Solve the equation of state of the estimation model
At least one of a reflection position and a reflection angle from the first axis to the second axis and the third axis from the second axis.
A drive amount determining step of determining a drive amount of a drive device that changes at least one of a reflection position and a reflection angle on an axis; and a drive step of driving the drive device by the drive amount determined in the drive amount determination step. An optical axis adjustment method, comprising: 8. The laser beam reflected in the direction of the third axis after completion of the driving step is transmitted from the second axis to the third axis.
The position is detected at a position having a first optical path long distance d1 from the reflection position on the axis, and the laser light reflected in the direction of the third axis is reflected from the reflection position from the second axis to the third axis. A third position detection step of detecting a position at a position having an optical path length distance d2 of 2, an output signal of the first position detection step, an output signal of the second position detection step,
An estimation model modification step of modifying the estimation model based on the two output signals in the position detection step and the determined drive amount or the actually driven drive amount. Item 7. The optical axis adjustment method according to Item 7. 9. A laser beam adjusted by the optical axis adjustment method according to claim 7 or 8 is input to a condenser lens, and the laser light focused by the condenser lens is coated with a resist. Exposure method for irradiating exposed substrate.