JPH11144303A - Optical axis adjusting mechanism of allgner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the optical axis adjusting mechanism of an exposure device in which the optical axis of the laser beams made incident on a moving optical system is accurately adjusted by monitoring the laser beams by a fixed optical system and a moving optical system and surely detecting the laser beams for the monitoring purposes. SOLUTION: A first wedge substrate 10 is provided in a fixed optical system 11. The emitted laser beams from the substrate 19 are separated into first monitoring light A2 and laser beams A1 which are emitted to a moving optical system 12 for an exposure. A second wedge substrate 25 is provided in the system 12. The laser beams emitted from the substrate 25 are separated into second monitoring light A5 and exposure laser beams A4 to be emitted to an objective lens 26. Four PDs 22b and 28b detect the two beams of light A2 and A5 and the optical axes of the laser beams are detected of the systems 11 and 12.

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 mechanism for an exposure apparatus, and more particularly, to an exposure apparatus by condensing a laser beam on an object such as a resist plate in order to form a master such as a compact disk or an optical disk. The present invention relates to an optical axis adjusting mechanism for adjusting an optical axis of a laser beam in an exposure apparatus for performing the above.

[0002]

2. Description of the Related Art Generally, in a master disc exposure apparatus such as an optical disc, a large laser (Ar, He-cd, Kr, etc.) is used.
Is used to modulate the intensity of the laser light and condense it on a resist plate to form a spiral fine groove on the resist plate. When forming the fine grooves, a turntable moving method in which the resist plate is moved in the horizontal direction while rotating the resist plate by a turntable, and an optical system moving method in which the resist plate is rotated by the turntable and the objective lens is moved in the horizontal direction. There are two methods.

[0003] In recent years, optical disks have become even higher in density, and there has been a demand for higher precision of the pitch of the resist plate. It is becoming. In this optical system moving method, the optical system of the laser light to be exposed is separated into a fixed optical system and a moving optical system, and if the moving axis of the moving optical system does not coincide with the optical axis of the laser light, the moving optical system is moved. Since the optical axis of the laser beam shifts when the system moves and the axis of incidence on the objective lens shifts, the beam shape changes and the optical axis of the laser used as the light source also fluctuates. Various techniques have been devised to monitor the laser light and make the moving axis of the moving optics coincide with the optical axis of the laser light.

A conventional optical axis adjusting mechanism of this type is disclosed in Japanese Patent Publication No. 7-06066. This is provided with two light detecting means for detecting laser light in a fixed optical system of the exposure apparatus, and detecting a position change of the laser light from a detection signal of the light detecting means,
The optical axis is adjusted. In addition, there is another one described in JP-A-7-220287. In this device, a beam splitter for monitoring a laser beam is arranged between a fixed optical system and a moving optical system, and the return light of the laser beam by the objective lens is monitored and observed. To adjust.

[0005]

However, in the former optical axis adjusting mechanism, only the laser light of the fixed optical system is monitored, and the monitoring of the laser light of the movable optical system is not performed. There has been a problem that the deviation of the optical axis of the laser light incident on the system cannot be adjusted.

In the latter optical adjustment mechanism, a beam splitter is provided between the fixed optical system and the movable optical system. There was a problem that it was not possible to observe accurately. Specifically, as shown in FIG. 6, the beam splitter 1 is disposed at an angle of about 45 ° with respect to the optical axis of the laser light 2, and the beam splitter 1 is moved from the fixed optical system.
Is split into a laser beam 2a emitted to the moving optical system and a monitor laser beam 2b detected by a detecting means such as a CCD camera.

However, as a characteristic of the beam splitter 1, the incident laser light cannot be separated as it is into the laser light 2a and the monitor laser light 2b, and the ghost light is parallel to the regular laser lights 2a and 2b. A and B occur, so that only normal laser light cannot be emitted to the moving optical system and the CCD camera, and therefore, there is a problem that the laser light cannot be accurately monitored.

Accordingly, the present invention monitors a laser beam with a fixed optical system and a moving optical system, and enables the laser beam for monitoring to be reliably detected so that the optical axis of the laser beam incident on the moving optical system can be adjusted. It is an object of the present invention to provide an optical axis adjustment mechanism of an exposure apparatus that can perform accurate adjustment.

[0009]

According to the first aspect of the present invention,
In order to solve the above problems, a fixed optical system having an optical member having a laser light source and adjusting the optical axis of laser light emitted from the laser light source, provided movably with respect to the fixed optical system, A moving optical system having an objective lens for converging the laser light emitted from the fixed optical system onto an object; and an optical axis adjusting mechanism of the exposure apparatus, the fixed optical system being emitted from the optical member. The laser light is disposed at an angle of about 45 ° with respect to the optical axis of the laser light, and most of the laser light is emitted to the moving optical system as exposure laser light, and the rest is polarized to the first monitor light. A wedge substrate, and a first detection member that receives the first monitor light and detects an optical axis of the laser light based on the first monitor light, wherein the movable optical system is provided from the fixed optical system. Emitted laser light A second wedge substrate which is disposed at an angle of about 45 ° with respect to the optical axis, emits most of the laser light to the objective lens as laser light for exposure, and polarizes the rest to second monitor light; And a second detection member that receives the second monitor light and detects the position of the optical axis of the laser light based on the second monitor light, and the first and second detection members are provided in the fixed optical system. And an adjusting unit for adjusting the position of the optical member based on the detection information from the optical member.

In this case, a first wedge substrate is provided in the fixed optical system, and laser light emitted from the first wedge substrate is separated into first monitor light and exposure laser light emitted to the movable optical system. I have. At this time, the ghost light emitted from the first wedge substrate can be emitted at a predetermined angle with respect to the normal laser light and the monitor light without being emitted in parallel with the normal laser light and the monitor light. In addition, only normal laser light and monitor light can be emitted to the first detection member and the moving optical system.

Further, a second wedge substrate is provided in the moving optical system, and laser light emitted from the second wedge substrate is separated into second monitor light and exposure laser light emitted to the objective lens. At this time, the ghost light emitted from the second wedge substrate can be emitted at a predetermined angle with respect to the normal laser light and the monitor light without being emitted in parallel with the normal laser light and the monitor light. Only normal laser light and monitor light can be emitted to the second detection member and the objective lens.

Further, by detecting normal monitor light by the first and second detection members, the optical axes of the laser light of the fixed optical system and the movable optical system can be detected. The displacement of the optical axis of the laser light can be adjusted based on the two monitor lights. In order to solve the above-mentioned problems, the invention according to claim 2 is based on claim 1.
In the invention described in the above, a parallel plane plate disposed between the first detection member and the first wedge substrate, and a CCD camera disposed on the opposite side of the first wedge substrate with respect to the parallel plane plate. Having the first monitor light from the parallel plane plate
It is characterized in that it is incident on a CCD camera through a wedge substrate.

In this case, since the laser light in the fixed optical system can be monitored by the CCD camera,
From the change in the state of the laser light monitored by the D camera, it is possible to grasp the deterioration of the members such as the laser light source and the optical member provided in the fixed optical system and changes in the characteristics. According to a third aspect of the present invention, in order to solve the above-mentioned problem, in the first or second aspect of the present invention, the second wedge substrate transmits a laser beam incident from an object via an objective lens to the first wedge. The laser light is reflected by the substrate, and the first wedge substrate causes the laser light to enter a CCD camera.

In this case, both the laser light incident from the object through the objective lens and the return light of the laser light emitted from the first wedge substrate to the moving optical system can be monitored by the CCD camera. The characteristics of the exposure laser light and the monitor light can be simultaneously grasped, and deterioration and changes in characteristics of members in the fixed optical system and the moving optical system can be grasped.

According to a fourth aspect of the present invention, in order to solve the above-mentioned problems, in the first aspect of the present invention,
The moving optical system has a pinhole on the upstream side of the laser beam with respect to the second wedge substrate.
In that case, by providing the pinhole in the moving optical system, the distance between the pinhole and the objective lens can be always kept constant even when the moving optical system moves. For this reason, even if the beam diameter changes due to the diffusion rate of the laser itself, the beam diameter can be regulated by the pinhole, so that the characteristics of the laser light incident on the objective lens are kept constant. be able to.

According to a fifth aspect of the present invention, in order to solve the above-mentioned problem, in the fourth aspect of the present invention, an opening diameter of the pinhole is made variable. In this case, since the diameter of the beam emitted to the objective lens can be changed by the pinhole, a beam shape that matches the groove shape formed on the target object can be easily formed.

According to a sixth aspect of the present invention, in order to solve the above-mentioned problems, in the first aspect of the present invention,
The fixed optical system has a beam expander on the upstream side of the laser beam with respect to the first wedge substrate, and the beam expander enlarges the laser beam from an effective diameter of the objective lens. In this case, even if the optical axis of the laser beam fluctuates and the position of incidence on the objective lens shifts, the laser beam can be expanded by the beam expander beyond the effective diameter of the objective lens. The laser beam can be made incident on the objective lens at the largest position, and the deviation of the intensity distribution of the laser beam can be reduced, so that the fluctuation of the groove shape can be reduced.

According to a seventh aspect of the present invention, in order to solve the above-mentioned problems, in the first aspect of the present invention,
The optical member has an adjusting mirror for adjusting the angle of the laser beam. In this case, the optical axis of the laser beam can be adjusted by adjusting the angle of the optical member by the adjusting means.

According to an eighth aspect of the present invention, in order to solve the above-mentioned problems, in the first aspect of the present invention,
The optical member has a beam shifter that adjusts the laser light so as to translate the laser light in parallel. In this case, the optical axis of the laser beam can be adjusted by adjusting the position of the optical member by the adjusting unit.

[0020]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIGS. 1 to 5 are views showing an embodiment of an optical axis adjustment mechanism of an exposure apparatus according to the present invention, and show an exposure apparatus provided with an optical adjustment mechanism. First, the configuration will be described. In FIG. 1, reference numeral 11 denotes a fixed optical system, 12 denotes a moving optical system, and the moving optical system 12 is moved in one direction with respect to the moving optical system 11 by a moving means (not shown) (in FIG. 1, left and right directions).
To move to.

The fixed optical system 11 includes a laser light source 13, a light amount modulator 14, a pulse modulator 15, a beam shifter 16, and an adjustment mirror 1.
7, Beam expanders 18a, 18b, first wedge substrate 1
9, plane parallel plate 20, wedge substrate 21, PD22a, 4PD2
The moving optical system 12 includes a pinhole 24, a second wedge substrate 25, an objective lens 26, a wedge substrate 27, a PD 28a, and a 4PD 28.
b.

The laser light source 13 generates a laser beam made of Ar, and the light quantity modulator 14 modulates the light quantity of the laser light and emits it to the pulse modulator 15. The pulse modulator 15 is configured to pulse-modulate the light amount-modulated laser light and emit the pulsed light to a beam shifter (optical member) 16. The beam shifter 16 translates the incident laser light and emits it. The beam shifter 16 is driven in the X and Y directions by an actuator (not shown) to change the optical axis of the emitted laser light. ing.

The laser light emitted from the beam shifter 16 is changed by 90 ° by an adjusting mirror (optical member) 17, and the adjusting mirror 17 is driven in the XY directions by an actuator (not shown). Thus, the angle of the incident laser beam is adjusted and reflected by the beam expander 18a. The beam expanders 18a and 18b are disposed on the upstream side of the laser light with respect to the first wedge substrate 19, and as shown in FIG. It is becoming larger. In the beam expanders 18a and 18b, the effective diameter of the objective lens 26 is NA0.
If it is about 9, it is desirable that it be 3 mm or more.

The first wedge substrate 19 is disposed at an angle of about 45 ° with respect to the optical axis of the laser light, and the laser light expanded by the beam expanders 18a and 18b is converted into the laser light as shown in FIG. Is emitted to the moving optical system 12 as laser light A1 for exposure, and the rest is polarized to first monitor light A2. The plane parallel plate 20 is P
D22a and 4PD22b are disposed between the first wedge substrate 19 and the parallel plane plate 20.
And is emitted to the wedge substrate 21.

The wedge substrate 21 is disposed at an angle of about 45 ° with respect to the optical axis of the first monitor light A2.
The first monitor light A2 transmitted through 20 is transmitted to PD22a and PD2a.
2b. The PD 22a is constituted by a light detecting element and detects the intensity of the laser beam A2. 4PD (first detection member) 22b is shown in FIG.
As shown in (1), it is constituted by a four-division type light detecting element, and detects the position of the optical axis of the laser light from the light incident on each of the detecting elements a, b, c, d.

Specifically, to detect the position in the X1 direction, X1 = (a + d)-(b + c) is executed. To detect the position in the Y1 direction, Y1 = (a + b)-(c + d) Is to be executed. The positions of the beam shifter 16 and the adjustment mirror 17 are adjusted by the actuator based on the result detected by the 4PD 22b, so that the areas of the laser beams incident on the elements a, b, c, and d become substantially equal. The optical axis of the laser beam is adjusted as described above.

The laser beam A2 reflected from the 4PD 22b passes through the parallel plane plate 20 and the first wedge substrate 19 from the wedge substrate 21 as shown in FIG.
23. The CCD camera 23 monitors this return light, and the return light incident on the CCD camera 23 is output as an image by a CRT monitor (not shown).

On the other hand, the pinhole 24 is formed in the second wedge substrate 25.
The pinhole 24 has a variable opening diameter 24a. As shown in FIG. 2, the pinhole 24 shields a part of the exposure laser beam A1 emitted from the fixed optical system 11 to block the laser beam A3.
The intensity distribution can be changed more finely by changing the aperture diameter 24a.

The laser beam A3 whose intensity distribution has been changed by the pinhole 24 is incident on the second wedge substrate 25. The second wedge substrate 25 has a laser beam A
The laser beam A3 is disposed at an angle of about 45 ° with respect to the optical axis 3, and most of the incident laser beam A3 is emitted to the objective lens 26 as exposure laser beam A4, and the rest is transmitted to the second monitor beam. A5 is polarized.

The objective lens 26 condenses the laser beam A4 emitted from the second wedge substrate 25 and irradiates it on a resist plate 29 as an object. The resist plate 29 is mounted on a turntable (not shown), and is rotated by the turntable. And
By irradiating the resist plate 29 with the laser beam A4 while rotating the resist plate 29 and moving the moving optical system 12 in one direction, a spiral groove is formed on the resist plate 29.

The second monitor light A5 is transmitted to the wedge substrate 2
The wedge substrate 27 is disposed at an angle of about 45 ° with respect to the optical axis of the second monitor light A5, and splits the second monitor light A5 into PD28a and PD28b. Has become. The PD 28a is formed of a light detecting element, and detects the intensity of the laser beam A5. 4PD (second detection member) 28b is 4P
Like D22b, it is composed of a four-division type photodetector, and detects the position of the optical axis of the laser beam from the light incident on each of the detectors a, b, c, d.

Specifically, to detect the position in the X2 direction, X2 = (a + d)-(b + c) is executed. To detect the position in the Y2 direction, Y2 = (a + b)-(c + d) Is to be executed. The positions of the beam shifter 16 and the adjustment mirror 17 are adjusted by the actuator based on the result detected by the 4PD 28b, so that the areas of the laser beams incident on the respective elements a, b, c, and d become substantially equal. The optical axis of the laser beam is adjusted as described above.

In the present embodiment, the positions of the beam shifter 16 and the adjusting mirror 17 are adjusted by actuators based on the detection results of the 4PDs 22b and 28b so that X1−X2 = 0 and Y1−Y2 = 0, so that the fixed optical The optical axis of the laser beam emitted from the system 11 to the moving optical system 12 is adjusted so that the resist plate 29 is accurately irradiated with the laser beam A4.

The beam shifter 16 and the adjusting mirror 17
The actuator that adjusts the position of constitutes an adjusting unit. The second wedge substrate 25 reflects laser light incident from the resist plate 29 via the objective lens 26 to the first wedge substrate 19, and the first wedge substrate 19 converts the laser light into a CCD. The light is incident on the camera 23.

The CCD camera 23 outputs this return light to the 4PD 22b.
The return light from the resist plate 29 incident on the CCD camera 23 is output as an image by the CRT monitor together with the return light from the 4PD 22b together with the laser light reflected from the CCD camera 23. . Next, the operation will be described.

The laser light of Ar generated from the laser light source 13 is modulated in its light quantity by a light quantity modulator 14 and then pulse-modulated by a pulse modulator 15 to be beam-shifted by a beam shifter 16.
The laser light is translated by the beam shifter 16 and emitted to the adjustment mirror 17. This laser beam is incident on beam expanders 18a and 18b after the angle is adjusted by the adjusting mirror 17, and this laser beam is expanded beyond the effective diameter of the objective lens 26 by the beam expanders 18a and 18b. The light is emitted to the wedge substrate 19.

The laser beam incident on the first wedge substrate 19 is split into a laser beam A1 for exposure and a first monitor beam A2, and the first monitor beam A2 is transmitted through the plane parallel plate 20 to the PD22.
a and the spectrum is divided into PD22b. Further, when the laser beam A1 is emitted from the first wedge substrate 19, the laser beam A1 is emitted by a configuration unique to the wedge substrate 19 as shown in FIG.
At the same time, ghost light B1 is emitted. However, the ghost light B1 is not parallel to the laser light A1, but is emitted at a predetermined angle with respect to the laser light A1, and does not reach the second wedge substrate 25 via the pinhole 24.

When the first monitor light A2 is emitted from the first wedge substrate 19, a ghost light B2 is emitted together with the first monitor light A2 from the first wedge substrate 19 as shown in FIG. However, the ghost light B2 is not parallel to the first monitor light A2 but is emitted at a predetermined angle with respect to the first monitor light A2, and therefore does not reach the PD 28b.

Next, the intensity of the laser beam is detected by the PD 22a, the position of the optical axis of the laser beam is detected by the 4PD 22b, and the first monitor light A2 reflected from the 4PD 22b is transmitted from the wedge substrate 21 to the plane parallel plate. After being transmitted through 20 and the first wedge substrate 19 and being incident on the CCD camera 23, it is output as an image by a CRT monitor.

On the other hand, the laser beam A1 for exposure is
The laser light A3 emitted from the pinhole 24 is incident on the second wedge substrate 25 after a part thereof is shielded by 4 and the intensity distribution of the laser light is changed. Most of the laser light incident on the second wedge substrate 25 is emitted to the objective lens 26 as laser light A4 for exposure, and after being condensed by the objective lens 26, is irradiated on the resist plate 29, The resist plate 29 is exposed.

The laser light A from the first wedge substrate 25
When the laser beam A4 is emitted, ghost light is emitted together with the laser beam A4 due to the configuration specific to the wedge substrate 25 as in FIG. 3, but this ghost beam is not parallel to the laser beam A4 but Since the light is emitted at a predetermined angle, it does not reach the resist plate 29. On the other hand, the second monitor light A5 emitted from the second wedge substrate 25 is
After being split into PD28a and PD28b by 7
While the intensity of the laser beam is detected by D28a, 4
Depending on the PD 28b, the position of the optical axis of the laser beam is detected.

The laser light reflected from the resist plate 29 via the objective lens 26 is reflected on the first wedge substrate 19 via the second wedge substrate 25. CCD camera by wedge substrate 19
23. CCD camera 23 is C
The return light and the first monitor light A2 are simultaneously output as an image to the RT monitor.

The positions of the beam shifter 16 and the adjusting mirror 17 are adjusted by actuators based on the detection results of the 4PDs 22b and 28b so that X1−X2 = 0 and Y1−Y2 = 0. The optical axis of the laser beam emitted to the moving optical system 12 is adjusted so that the resist plate 29 is accurately irradiated with the laser beam A4. As described above, in the present embodiment, the first wedge substrate 19 is provided on the fixed optical system 11, and the laser light emitted from the first wedge substrate 19 is used for the first monitor light A2 and the exposure light emitted to the movable optical system 12. Laser light A2.

At this time, the ghost lights B1 and B2 emitted from the first wedge substrate 19 are not emitted in parallel with the normal laser light A1 and the monitor light A2, but are not emitted to the normal laser light A1 and the monitor light A2. Since the light can be emitted at a predetermined angle, the 4PD 22b and the moving optical system 11 can be used.
Only normal laser light A1 and monitor light A2 can be emitted.

Further, the second wedge substrate 25 is
To separate the laser light emitted from the second wedge substrate 25 into the second monitor light A5 and the exposure laser light A4 emitted to the objective lens 26. At this time, the second
The ghost light emitted from the wedge substrate 25 can be emitted at a predetermined angle with respect to the normal laser light A5 and the monitor light A3 without emitting the ghost light parallel to the normal laser light A5 and the monitor light A4. Only normal laser light A5 and monitor light A4 can be emitted to the 4PD 28b and the objective lens 26.

By detecting normal monitor lights A2 and A5 by the 4PDs 22b and 28b, the fixed optical system is detected.
Since the optical axis of the laser light of the movable optical system 11 and the movable optical system 12 can be detected, the displacement of the optical axis of the laser light can be adjusted based on the monitor lights A2 and A5. Also,
A parallel plane plate 21 is disposed between the 4bD 22b and the first wedge substrate 19, and a CCD camera 23 is disposed on the opposite side of the first wedge substrate 19 with respect to the parallel plane plate 21 to monitor light A2 in parallel. C from the face plate 21 through the first wedge substrate 19
Since the laser light is incident on the CD camera 23, the laser light in the fixed optical system 11 can be monitored by the CCD camera 23, and provided to the fixed optical system 11 based on a change in the state of the laser light monitored by the CCD camera 23. Laser light source 13, light intensity modulator 14, pulse modulator 15, beam shifter 16, adjustment mirror 17, beam expanders 18a and 18b,
A first wedge substrate 19, a plane parallel plate 20, a wedge substrate 21,
Deterioration and change in characteristics of the PD 22a and the PD 22b can be grasped.

Further, the second wedge substrate 25 is
The laser light incident from the camera through the objective lens 26 is reflected by the first wedge substrate 19, and the first wedge substrate
Since the laser light 19 is made to enter the CCD camera 23, the laser light incident from the resist plate 29 via the objective lens 26 and the laser light emitted from the first wedge substrate 19 to the moving optical system 12 CC both light return light
It can be monitored by the D camera 23. For this reason, the characteristics of the exposure laser light and the monitor laser light can be simultaneously grasped, and it is possible to grasp the deterioration and the change in the characteristics of the above-described members in the fixed optical system 11 and the moving optical system 12. it can.

The moving optical system 12 is connected to the second wedge substrate 25.
Since the pinhole 24 is provided on the upstream side of the laser beam, the pinhole 24 is provided in the moving optical system 12 so that the distance between the pinhole 24 and the objective lens 26 is always maintained even if the moving optical system 12 moves. Can be constant. For this reason, even when the beam diameter changes due to the diffusion rate of the laser itself, the beam diameter can be defined to be constant by the pinhole 24, so that the characteristics of the laser light incident on the objective lens 26 can be kept constant. Can be maintained.

Further, since the opening diameter 24a of the pinhole 24 is made variable, the diameter of the beam emitted to the objective lens 26 by the pinhole 24 can be changed, and the resist plate 29
It is possible to easily form a beam shape that matches the groove shape formed on the substrate. Also, beam expanders 18a and 18b are provided on the upstream side of the laser beam with respect to the first wedge substrate 19, and the laser beam is expanded by the beam expanders 18a and 18b beyond the effective diameter of the objective lens 26. Even if the optical axis of the optical axis fluctuates and the position of incidence on the objective lens 26 shifts, the beam expanders 18a and 18b
Thereby, the laser beam can be expanded beyond the effective diameter of the objective lens 26.

For this reason, the laser beam can be made incident on the objective lens 26 at the position where the intensity distribution is the largest, and the deviation of the intensity distribution of the laser beam can be reduced and the fluctuation of the groove shape can be reduced. Further, since the adjusting mirror 17 for adjusting the angle of the laser light is provided as an optical member, the optical axis of the laser light can be adjusted by adjusting the angle of the adjusting mirror 17 with the actuator.

Furthermore, since the beam shifter 16 for adjusting the laser light so as to move in parallel is provided as an optical member, the optical axis of the laser light can be adjusted by adjusting the position of the beam shifter 16 by the actuator.

[0052]

According to the first aspect of the present invention, the first wedge substrate is provided in the fixed optical system, and the laser light emitted from the first wedge substrate is emitted to the first monitor light and the moving optical system. It is separated into laser light for exposure. At this time, the ghost light emitted from the first wedge substrate can be emitted at a predetermined angle with respect to the normal laser light and the monitor light without being emitted in parallel with the normal laser light and the monitor light. In addition, only normal laser light and monitor light can be emitted to the first detection member and the moving optical system.

Further, a second wedge substrate is provided in the moving optical system, and the laser light emitted from the second wedge substrate is separated into the second monitor light and the exposure laser light emitted to the objective lens. At this time, the ghost light emitted from the second wedge substrate can be emitted at a predetermined angle with respect to the normal laser light and the monitor light without being emitted in parallel with the normal laser light and the monitor light. Only normal laser light and monitor light can be emitted to the second detection member and the objective lens.

Also, by detecting normal monitor light by the first and second detection members, the optical axes of the laser light of the fixed optical system and the movable optical system can be detected. The displacement of the optical axis of the laser light can be adjusted based on the two monitor lights. According to the second aspect of the present invention, the laser light in the moving optical system can be monitored by the CCD camera.
From the change in the state of the laser light monitored by the D camera, it is possible to ascertain the deterioration of the equipment such as the laser light source and the optical members provided in the fixed optical system and changes in the characteristics.

According to the third aspect of the present invention, both the laser light incident from the object via the objective lens and the return light of the laser light emitted from the first wedge substrate to the moving optical system are converted by the CCD camera. Because it is possible to monitor, the characteristics of the laser light for exposure and the laser light for monitoring can be grasped at the same time, and it is possible to grasp the deterioration and the change of the characteristics of the devices in the fixed optical system and the moving optical system. .

According to the fourth aspect of the invention, by providing the pinhole in the moving optical system, the distance between the pinhole and the objective lens can always be kept constant even when the optical system moves. For this reason, even if the beam diameter changes due to the diffusion rate of the laser itself, the beam diameter can be regulated by the pinhole, so that the characteristics of the laser light incident on the objective lens are kept constant. be able to.

According to the fifth aspect of the present invention, since the diameter of the beam emitted to the objective lens can be changed by the pinhole, a beam shape that matches the groove shape formed on the object can be easily formed. can do. According to the invention described in claim 6, even when the optical axis of the laser light fluctuates and the position of incidence on the objective lens shifts, the laser beam is expanded by the beam expander beyond the effective diameter of the objective lens. Therefore, the laser beam can be made incident on the objective lens at the position where the intensity distribution is the largest, so that the deviation of the intensity distribution of the laser beam can be reduced and the fluctuation of the groove shape can be reduced.

According to the seventh aspect of the present invention, by adjusting the angle of the optical member by the adjusting means, the optical axis of the laser beam can be adjusted. According to the eighth aspect of the present invention, by adjusting the position of the optical member by the adjusting means, the optical axis of the laser beam can be adjusted.

[Brief description of the drawings]

FIG. 1 is a view showing one embodiment of an optical axis adjustment mechanism of an exposure apparatus according to the present invention, and is a configuration diagram of an exposure apparatus having the optical axis adjustment mechanism.

FIG. 2 is a diagram illustrating a positional relationship between a beam expander and a pinhole according to an embodiment and a change in laser light thereof.

FIG. 3 is a diagram illustrating laser light incident on a first wedge substrate, emitted laser light, and return light according to one embodiment.

FIG. 4 is a diagram illustrating a 4PD according to an embodiment.

FIG. 5 is a diagram illustrating a state in which monitor light is emitted to a 4PD according to an embodiment.

FIG. 6 is a diagram showing a laser beam that enters and exits a conventional beam splitter.

[Explanation of symbols]

 11 Fixed optical system 12 Moving optical system 13 Laser light source 16 Beam shifter (optical member) 17 Adjustment mirror (optical member) 18a, 18b Beam expander 19 First wedge substrate 20 Planar parallel plate 22b 4PD (first detection member) 23 CCD Camera 24 Pinhole 24a Aperture diameter 25 Second wedge substrate 26 Objective lens 28b 4PD (second detection member) 29 Resist plate (object)

Claims (8)

[Claims] A fixed optical system having a laser light source and an optical member for adjusting an optical axis of laser light emitted from the laser light source; and a fixed optical system movably provided with respect to the fixed optical system. A moving optical system having an objective lens for converging the laser light emitted from the system on an object; and an optical axis adjusting mechanism of the exposure apparatus, the fixed optical system comprising: a laser light emitted from the optical member. A first wedge substrate which is disposed at an angle of about 45 ° with respect to the optical axis of the first wedge substrate and emits most of the laser light to a moving optical system as laser light for exposure, and polarizes the rest to first monitor light. And a first detection member that receives the first monitor light and detects an optical axis of the laser light based on the first monitor light, wherein the movable optical system is emitted from the fixed optical system. With respect to the optical axis of the laser beam A second wedge substrate that is disposed at an angle of about 45 ° and emits most of the laser light to the objective lens as laser light for exposure, and polarizes the remainder to second monitor light; And a second detection member for detecting the position of the optical axis of the laser beam based on the second monitor light. The fixed optical system receives the detection information from the first and second detection members. An optical axis adjusting mechanism for an exposure apparatus, further comprising adjusting means for adjusting the position of the optical member based on the adjusting means. 2. A parallel flat plate disposed between the first detecting member and the first wedge substrate, and a first flat plate with respect to the parallel flat plate.
2. The exposure apparatus according to claim 1, further comprising: a CCD camera disposed on a side opposite to the wedge substrate, wherein the first monitor light is incident on the CCD camera from the plane parallel plate through the first wedge substrate. Optical axis adjustment mechanism. 3. The second wedge substrate reflects a laser beam incident from an object via an objective lens to a first wedge substrate, and the first wedge substrate causes the laser beam to enter a CCD camera. 3. An optical axis adjusting mechanism for an exposure apparatus according to claim 1, wherein: 4. An optical axis adjusting mechanism for an exposure apparatus according to claim 1, wherein said movable optical system has a pinhole on the upstream side of the laser beam with respect to the second wedge substrate. . 5. An optical axis adjusting mechanism for an exposure apparatus according to claim 4, wherein an opening diameter of said pinhole is made variable. 6. The fixed optical system has a beam expander upstream of the laser beam with respect to the first wedge substrate, and the beam expander enlarges the laser beam beyond the effective diameter of the objective lens. The optical axis adjustment mechanism of the exposure apparatus according to claim 1. 7. The optical member according to claim 1, wherein said optical member has an adjusting mirror for adjusting an angle of the laser beam.
An optical axis adjusting mechanism for the exposure apparatus according to any one of the above. 8. An optical axis adjusting mechanism for an exposure apparatus according to claim 1, wherein said optical member has a beam shifter for adjusting a laser beam so as to translate.