JPH02297919A - Exposure device - Google Patents

Abstract

PURPOSE:To move a light radiating position circularly and to extend the lives of concave and convex mirrors by rotatably providing the mirrors around an optical axis. CONSTITUTION:Concave and convex mirrors 6, 7 are rotated at a constant speed around an optical axis 9 by a motor 19. A light 2 of an arcuate section 3 output from a light source 1 is transmitted perpendicularly to a mask 12 to the mirror 6, rereflected to be radiated perpendicularly to a board 13, and the arcuate pattern of the mask 12 is transferred to the board 13. However, the mirror 7 is disposed near the focus position of the mirror 6, and a movable body is movably disposed in a pane perpendicular to the optical axis. When a movable body motion controller 10 is started, a body 4a is moved in (+) Y-axis direction and a body 4b is moved in (-) Y-axis direction at an equal speed, the two-dimensional pattern of the mask 12 is transferred to the board 13. Since the radiated positions of the light 2 on the mirrors 6, 7 are moved at a constant speed circumferentially, the deterioration of the optical function at the specific position is not accelerated to extend their lives.

Description

[Detailed description of the invention] [L1 aspect of the invention] (Industrial application field) The present invention is a method for converting a central copy source pattern formed on a mask onto a substrate (wafer) using an optical system member such as a concave mirror or a convex mirror. The present invention relates to an exposure apparatus that is used for various purposes, and particularly relates to an exposure apparatus that can extend the life of concave mirrors, convex mirrors, and the like.

(Prior Art) An exposure apparatus that projects a predetermined pattern on a mask onto a substrate using a reflective optical system such as a concave mirror or a convex mirror and transfers the pattern onto the substrate is, for example, as shown in FIG. 4(a). It is configured. That is, the light output from the mercury lamp 31 is converted into a point with an arc-shaped cross section using a large number of optical members 32 such as surface mirrors and concave mirrors. Then, the light having an arcuate cross section is transmitted to a mask 34 mounted on the carrier 33.
The light transmitted through the mask 34 is reflected by the trapezoidal mirror 35, and the reflected light is transmitted to the concave mirror 36 and the convex mirror 3.
7 to re-reflect. The light re-reflected by the concave mirror 37 is again reflected downward by the trapezoidal mirror 35, and the optical path of this reflected light is passed through a substrate (wafer) 39 placed on a carrier 38. Each of the carriers 33, 38 is integrally constructed by a mechanism (not shown), and is movably supported within a city (in a horizontal plane) perpendicular to the optical axis by a moving mechanism (not shown).

In addition, an objective lens 40 is provided in front of the mask 34 so that it can be inserted and withdrawn freely, and the operator confirms the pattern drawn on the mask 34 through the eyepiece lens 43 via a plurality of reflections V141 and 42. The structure is such that it can be done.

In an exposure apparatus having such a structure, as shown in FIG. 4(b), the pattern 45 formed on the mask 34 is irradiated with light that extends /-J' across the arcuate cross section 44, and the light is applied to the substrate. 39, an arc-shaped pattern is projected onto the substrate 39. Therefore, when the carrier 33.38 is moved horizontally and linearly in one direction, the mask 34
The two-dimensional pattern 45 drawn on is sequentially copied onto the substrate 39.

However, the exposure apparatus configured as described above also has the following problems. That is, as described above, the light passes through the arcuate cross section 44 as f1, and the light that passes through the arcuate cross section 44 as H passes through the trapezoidal mirror 35. Concave mirror 36. Convex mirror 37. Concave f136, trapezoidal mirror 35
Teru and J are sent to the top of the ↓ board through . Moreover, the irradiation position of the light on each of the mirrors 35, 36, 37 is
Once the six mirrors 35.degree. 3b and 37 are assembled into this exposure apparatus, they are fixed. Therefore, during the actual operating period, the light always stays at a constant position on each mirror 35, 36, 37. As a result, the coating and the like deteriorate faster in the irradiated area than in other areas. In particular, in recent years, efforts have been made to shorten the exposure time by increasing the intensity of light (4), but increasing the intensity of light further increases the rate of deterioration of the irradiated area.

-h1 Since the concave VL 36 and the convex mirror 37 are generally formed in a disk shape, the portions that are not illuminated with light will not be illuminated permanently.

(Problem to be solved by the invention'XU) In this way, in conventional exposure equipment, light is concentrated on a certain part of the concave mirror or convex mirror, so the deterioration of that part is less than that of other parts. This shortens the life of the entire concave mirror or convex mirror, requiring frequent replacement of the concave mirror or convex mirror, and complicating inspection and repair work for the entire exposure apparatus.

Also, if concave mirrors and convex mirrors are replaced frequently, maintenance costs will increase.

The present invention was made in view of these circumstances, and
By providing a concave mirror or a convex mirror at a rotation angle around its optical axis, the light irradiation position can be moved straight on the circumference, and the deterioration of the concave ILl mirror or convex mirror can be uniformized by bearing it on the circumference. An object of the present invention is to provide an exposure apparatus that can extend the life of a convex mirror and reduce the maintenance cost of the entire apparatus.

[Structure of the invention]

(Means for Solving the Problems) In order to solve the above problems, the present invention includes a light source that outputs exposure light, and a light source that outputs light for exposure, and that the light outputted from this light source is incident on the optical axis in 11 rows. A concave mirror that reflects, and a convex mirror disposed near the % point position that reflects the light reflected by the concave mirror and causes it to enter the concave mirror,
A movable body is installed in the city perpendicular to the optical axis, and a complex mask formed on a mask is attached at a position inserted in the optical path from the light source to the concave mirror on the moving body. The original pattern is transferred by moving the movable body into the city orthogonal to the optical axis onto a substrate attached to a position inserted in the optical path of the light re-reflected by the concave mirror of the I'lJ moving body. The exposure apparatus is equipped with a rotation drive mechanism that rotates at least one of two curved mirrors, a concave mirror and a convex mirror, around an optical axis.

(Function) With an exposure apparatus configured in this way, the exposure light output from the light source passes through the pattern drawn on the mask attached to the movable body, enters the concave mirror, and is reflected by the concave mirror. is reflected by a convex mirror and then incident on a concave mirror again.
It is reflected again by this concave mirror. Then, the light is finally irradiated onto the substrate attached to the movable body. Therefore, the pattern drawn on the mask is projected onto the substrate, and the substrate is exposed. Then, when the mouth moving body is moved in a plane perpendicular to the optical axis by the movable body movement control section, the pattern drawn on the mask is transferred to the substrate.

In an exposure apparatus that transfers a pattern onto a substrate through such an operation, when at least one of the concave mirror and the convex mirror is rotated about the optical axis, the light irradiation position on the concave mirror moves in the circumferential direction. Note that even if these curved mirrors are rotated around the optical axis, their optical functions do not change at all. Therefore, by rotating these curved mirrors continuously or at regular intervals, the amount of light irradiation can be made uniform over the circumference. Therefore, it is possible to extend the life of concave mirrors and convex mirrors.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram showing a schematic configuration of an exposure apparatus according to an embodiment. 1 in the figure is a light source that outputs light for exposure, and inside this light source 1 is a mercury lamp as shown in FIG. 4(a), and the light emitted from this mercury lamp is An optical system member consisting of a plurality of reflecting mirrors that converts light into light is housed therein. The light 2 output from this light source 1 has an arcuate cross section 3 as shown.

The light 2 having an arcuate section 1j3 outputted from the light source 1 is transmitted through the mask attachment window 5 formed on one side of the first +'il moving body 4a, and is incident on one peripheral part of the concave surface vL6. The light 2 incident on one periphery of the concave mirror 6 is reflected by a convex mirror 7 disposed near the focal point of the concave mirror 6, and is again incident on the other periphery of the concave mirror 6. Concave mirror 6
The light 2 reflected again by the second movable body 4b is incident on the board mounting window 8 formed in the second movable body 4b.

The concave mirror 6 and the convex mirror 7 each having a circular disk shape are arranged so that their front axes 9 are parallel to the light 2 output from the light source 1. That is, the light 2 having an arcuate cross section 3 that enters the four surfaces fJ'A6 from the light source 1 and the light 2 that has an arcuate cross section 3 that is re-reflected from the concave mirror 6 and enters the board mounting window 8 of the movable body 4 are parallel. relationship, and are spaced from each other by an equal distance 1111d with respect to the optical axis 9.

Further, the radius of curvature of the arcuate cross section 3 of the light 2 is set so as to match the radius of curvature of the concave surface vL6 at the incident position when the light 2 is incident on the concave mirror 6. Therefore, even if the arc-shaped light 2 is reflected by the convex surface ff17 disposed near the focal point position and further reflected again by the concave mirror 6, the same arc-shaped cross section 3 is maintained.

Further, the first movable body 4a and the second movable body 4b are supported at the moving port (E) in the vertical direction (Y direction) in a plane perpendicular to the optical axis 9 and symmetrically with respect to the optical axis 9. Then, the movable body movement control unit 10 moves the first movable body 4a upward and the second movable body 4b at a constant speed in the Y direction in the figure.
are controlled to move downward, respectively.

A mask 12 on which a copy source pattern 11 is drawn, as shown in FIG. 2, is attached to the mask attachment window 5 of the first movable body 4a, and the board attachment window 8 of the second movable body 4b is attached to the mask attachment window 5 of the first movable body 4a. A substrate (wafer) 13 onto which a pattern is to be transferred is attached.

Note that the width (length) of the arcuate cross section 3 of the light 2 is set to a value wider than the width of the pattern 11 on the mask 12.

Further, driving rollers 14 and 15 are arranged so as to press against the concave mirror 6 and the convex mirror 7 (6) and J, respectively,
The drive roller 14 is directly attached to the drive shaft 16, and the drive roller 15 is connected to the drive shaft 16 via a belt 17 and a pulley 18. This drive shaft 16 is rotationally driven by a motor 19.

Therefore, when the motor 19 is rotationally driven, the drive shaft 16
rotates, the drive rollers 14 and 15 rotate, and the concave mirror 6 and convex mirror 7, whose outer peripheral surfaces are in contact with each of the drive rollers 14 and 15, rotate around the optical axis 9.

The ratio between the outer diameter of the drive roller 15 and the outer diameter of the pulley 18 is set such that when the concave mirror 6 rotates once, the convex surface i7 also rotates once. Therefore, the rotation angle of the concave surface m6 matches the rotation angle of the convex mirror 7. That is, each drive roller 14.15, belt 17. Drive shaft 1
6 and motor 19 constitute a rotational drive mechanism for concave mirror 6 and convex mirror 7.

In the exposure apparatus configured as described above, the exposure apparatus is started with the pivot motor 19 being started and the concave mirror 6 and the convex mirror 7 being rotated around the optical axis 9 at a constant speed. Then, the light 2 outputted from the light source 1 and having an arcuate cross section 3 perpendicularly passes through the mask 12, enters the concave mirror 6, is re-reflected by the concave mirror 6, and then passes through the substrate 13.
is irradiated perpendicularly to Therefore, the arcuate pattern of the mask 12 is projected onto the substrate 13 and transferred onto the substrate 13.

Then, the movable body movement control unit 10 is activated to move the first movable body 4a in the (+) Y-axis direction and move the second movable body 4b in the (-) direction.
) If they are moved at the same constant speed in the Y-axis direction,
The two-dimensional pattern 11 drawn on the mask 12 is the substrate 13
is transferred two-dimensionally.

In this way, when exposing while rotating the concave mirror 6 and the convex mirror 7, each curved surface f! 6.7 Since the irradiation position of light 2 on the top moves at a constant speed in the circumferential direction, it is irradiated uniformly over the circumference, and optical functions such as reflectance and coding will not deteriorate or accelerate only in a certain position. do not have. Therefore, since the mirror deteriorates uniformly over its entire circumference, the life of the mirror as a whole is significantly extended.

Incidentally, in the example, the lifespan could be extended by about three times or more compared to the case where the irradiation position was fixed.

Moreover, as another usage, it is also possible to rotate the six mirrors 6.7 at regular intervals.

That is, after driving the motor 19 to set the rotational angular position θ of the concave mirror 6 and the convex mirror 7 to an arbitrary angular position, the exposure apparatus is started.

After operating this exposure apparatus for a predetermined period of time, the motor 19 is driven to rotate the rotation angle position θ of the concave mirror 6 and the convex surface m7 by, for example, 80 degrees. Then, the exposure device is operated at this angular position. Then, the irradiation positions of the light 2 on the concave mirror 6 and the convex mirror 7 move to new positions.

In this way, after operating at the same angle position for a certain period of time,
Since the rotational angle position θ is moved by Δθ, if the optical function such as reflectance or coating deteriorates due to the irradiation of the light 2 at the position above the MJ of one of the concave mirror 6 and the convex mirror 7, the irradiation position of the light will be changed. By moving to an adjacent position on the circumference,
Good optical function can be maintained for a long period of time. Therefore, the lifespan of the concave mirror 6 and the convex surface vL7 can be significantly extended compared to the concave mirror and convex mirror in conventional devices.

As a result, the replacement cycle of the concave mirror m6 and the convex mirror 7 can be extended, making inspection and repair of the entire exposure apparatus easier.
Moreover, maintenance costs can be significantly reduced.

Note that the present invention is not limited to the embodiments described above. In the embodiment, both the concave mirror 6 and the convex mirror 7 are rotated, but even if only the concave surface vL6 is rotated, the effectiveness of the present invention is sufficiently improved. Further, it is not necessarily necessary to rotate each concave mirror 687 in synchronization. Each may be rotated independently.

Furthermore, as shown in FIG.
15, but it is also possible to directly rotate the optical axis 9 common to the concave mirror 6 and the convex surface gf 17 using two motors, for example.

Furthermore, as shown in FIG. 3, the first 1 in FIG.
It is also possible to use a 111 moving body 4 in which the moving body 4a and the second l'lJ moving body 4b are integrally formed. In this case, the first reflecting mirror 20a is arranged in the optical path between the mask attachment window 5 to which the mask 12 is attached and the concave surface v16,
A second reflecting mirror 2 is provided in the optical path between the concave surface vL6 and the window 8 with a substrate.
0b and a third reflecting mirror 20c are inserted.

In this way, light 2 is placed on the optical path from the mask 12 to the substrate 13.
Three reflections Vt 20 a that reflect.

By inserting 20b and 20c, the mass 1
2 are formed as left and right images on the substrate 13, so the pattern of the mask 12 can be transferred to the substrate 13 while moving the mask 12 and the substrate 13 in the same direction.

[Effects of the Invention] As explained above, according to the exposure apparatus of the present invention, the concave mirror or the convex mirror is configured to be able to rotate around its optical axis by the rotation drive mechanism. Therefore, the irradiation position of the light on the concave mirror or the convex mirror can be moved by +1hi in the circumferential direction at a constant speed or every constant period, and the deterioration of the concave mirror or the convex 11LI'ft can be made uniform over the circumference. The lifespan of the convex mirror can be extended, and maintenance costs for the entire device can be reduced.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a schematic configuration of an exposure apparatus according to one embodiment of the present invention, FIG. 2 is a diagram showing a mask of the same embodiment, and FIG. 3 is a diagram showing another embodiment of the present invention.] FIG. 4(a) is a diagram showing a schematic configuration of a conventional exposure device, and FIG. 4(b) is a diagram showing a mask used in the conventional exposure device. ]...Light source, 2...Light, 3...Circular cross section, 4...
...1'l) Moving body, 4a...first moving body, 4b...
- Second movable body, 5... mask mounting window, 6... concave mirror, 7... convex mirror, 8... board mounting window, 9... optical axis, 1o... 11 moving body movement control Part, 11... Pattern, 12... Mask, 13... Substrate, 14.15.
... Drive roller, 19... Motor.

Claims (1)

[Scope of Claims] A light source that outputs light for exposure, a concave mirror that receives the light output from the light source parallel to the optical axis and reflects the incident light, and is disposed near the focal point of the concave mirror. It has a convex mirror that reflects the light reflected by the concave mirror and makes it enter the concave mirror again, and a movable body that is movable in a plane perpendicular to the optical axis, and the light source on the movable body. A copy source pattern formed on a mask attached to a position inserted in the optical path from the to the concave mirror to the concave mirror of the movable body is attached to a position inserted in the optical path of the light re-reflected by the concave mirror of the movable body. In an exposure apparatus that transfers images onto a substrate by moving the movable body in a plane orthogonal to the optical axis, at least one of the two curved mirrors, the concave mirror and the convex mirror, is rotated about the optical axis. Exposure equipment equipped with a rotational drive mechanism.