JPH08321463A - Device for exposing needless resist - Google Patents

Abstract

PURPOSE: To provide a device for exposing needless resist in the periphery of a substrate with equal quantity of light without causing unevenness in quantity of light for exposure. CONSTITUTION: The exit end 6b of a bundle of optical fibers 6 are introduced into the case 8a constituting a lens unit 8, and the light having entered into the entrance end 6a of a bundle of optical fibers 6 comes out of the exit end 6b. A converging lens 30 is arranged on the light path of light coming out of the exit end 6b of a bundle of optical fibers 6 within the casing 8a, and the light collected by the converging lens 30 passes the rectangular opening 34 made at a mask 32. The mask 32 is arranged in the relation of image nonpickup with the exit end 6b as to the converging lens 30. An image pickup lens 36 applies the light having passed the opening 34 of the mask 32 to a substrate 1. The mask 32 is arranged in the relation of image nonpickup with the exit end 6b as to the converging lens 30, and besides the mask 32 and the image pickup lens 36 are supported by the casing 8a and an arm 9 so that the mask 32 may be in the relation of image nonpickup with the surface of the substrate 1 as to the image pickup lens 36.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to, for example, IC, L
In the process of forming a fine pattern in the process of manufacturing electronic components such as SI and liquid crystal display devices, among the photoresist liquids applied to a semiconductor substrate typified by a silicon wafer or a substrate such as a dielectric, metal, or insulator, The present invention relates to an unnecessary resist exposure device for removing an unnecessary portion around a substrate in a developing process.

[0002]

2. Description of the Related Art In this type of unnecessary resist exposure apparatus, in order to completely remove an unnecessary photoresist liquid (hereinafter, simply referred to as an unnecessary resist) such as a peripheral portion of a substrate, the peripheral portion of the substrate where the unnecessary resist exists. It has been proposed to expose the substrate with light having a predetermined characteristic (such as ultraviolet rays). At this time, there is a demand for making the irradiation shape of the light on the substrate surface into a desired shape, for example, a rectangular shape. Therefore, as described in Japanese Utility Model Publication No. 5-30348, conventionally, a large number of optical fibers are cross-sectioned. Has been bundled into a rectangular shape and solidified, the emission end of the optical fiber bundle has a rectangular shape, and an image of the emission end surface is projected onto the surface of the substrate by a projection lens for exposure.

[0003]

However, in such an apparatus, the surface of the substrate is irradiated with the light emitted from each of the optical fibers constituting the optical fiber bundle, but a large number of light beams are emitted. Since it is practically difficult to bundle the fibers into a desired shape with no gaps between them, the method of projecting the image of the end face on the substrate surface in this way and exposing the light will result in a light amount distribution within the exposed surface. There is a problem that unevenness occurs and the exposure light amount becomes non-uniform. Further, even if the optical fibers can be bundled without any gap, the exposure light amount is also non-uniform because the light amount is uneven between the core part of each optical fiber and other parts. Furthermore, this type of optical fiber may be broken, but in the method described above, if even one of the bundled optical fibers has a broken line,
Since no light reaches the portion corresponding to the end face of the optical fiber, a very large unevenness of the light amount occurs. Therefore, it is necessary to keep the optical fiber completely free of disconnection, such as by immediately replacing the one that is broken during use, but such a bundle of many optical fibers that does not have any disconnection. Since the device itself is expensive, the entire device becomes expensive, and maintenance of the device is troublesome and maintenance costs are high.

The present invention has been made in view of the above circumstances, and it is possible to remarkably suppress the occurrence of unevenness in the distribution of the exposure light amount, to perform exposure with a uniform light amount distribution, and to manage the apparatus at low cost. An object is to provide an unnecessary resist exposure apparatus that is easy to maintain.

[0005]

According to another aspect of the invention, there is provided an unnecessary resist exposure apparatus, wherein a light source for emitting illumination light from an emission surface and an opening of a predetermined shape are formed on the optical path of the light source. Mask means arranged at a position separated from the emission surface of the light source, an imaging optical system for forming an image of the opening of the mask means, supporting means for supporting the substrate, the substrate supported by the supporting means, and the An image forming relationship maintaining unit for keeping the mask unit in an image forming relationship with each other with respect to the image forming optical system, and a light which passes through the opening of the mask unit and is irradiated onto the substrate surface by the image forming optical system. It is characterized by comprising scanning means for scanning the part.

In the present invention, the light emitted from the light source illuminates the surface on which the mask means is present. The opening of a predetermined shape formed in the mask means is illuminated by the irradiated light, while the substrate supported by the supporting means is in an image-forming relationship with the mask means by the image-forming optical system. The surface of the substrate is exposed in the shape of the formed opening. Even if there is some unevenness in the light amount distribution on the emission surface of the light source,
Since the mask means and the light source are separated from each other, such unevenness is not directly reflected in the light amount distribution of the surface on which the mask means exists, and unevenness on the surface of the mask means is reduced. The substrate is exposed in the shape of the openings formed in the mask means.

According to a second aspect of the present invention, in the unnecessary resist exposure apparatus according to the first aspect, a condensing optical system for condensing light from the light source is further provided between the emission surface of the light source and the mask means. The exit surface and the mask means are arranged in a non-imaging relationship. In the present invention, the light from the emission surface of the light source is collected by the condensing optical system and illuminates the surface on which the mask means exists, so that the light from the light source can be used efficiently. Since the mask means and the exit surface have a non-imaging relationship with respect to the condensing optical system, even if there is unevenness in the light quantity distribution on the exit surface, such unevenness is directly reflected in the light quantity distribution on the surface where the mask means exists. The surface of the mask means is uniformly illuminated by the light collected by the condensing optical system.

According to a third aspect of the invention, in the unnecessary resist exposure apparatus according to the second aspect, the arrangement position of the mask means substantially coincides with the position of the entrance pupil of the focusing optical system. In this invention, since the light emitted from each point on the emission surface of the light source illuminates the surface of the opening of the mask means, even if the light amount distribution of the emission surface is uneven, the opening surface of the mask means is uneven. Not evenly illuminated.

According to a fourth aspect of the present invention, in the unnecessary resist exposure apparatus according to the second or third aspect, the position of the entrance pupil of the imaging optical system is formed by the condensing optical system and the exit surface of the light source is formed. It almost coincides with the position of the image. In the present invention, since the position of the entrance pupil of the imaging optical system substantially coincides with the position of the image on the exit surface of the light source, the shape of the aperture of the imaging optical system affects the light quantity distribution on the exposure surface of the substrate. Without
The exposure light amount is determined by the aperture area of the imaging optical system.

According to a fifth aspect of the present invention, in the unnecessary resist exposure apparatus according to the first to fourth aspects, the light source is a light emitting element, a condensing unit for condensing light from the light emitting element, and the condensing unit. The light guide means for guiding the light condensed by the means. In the present invention, the light source is composed of the light emitting element, the condensing means for condensing the light from the light emitting element, and the light guiding means for guiding the light condensed by the condensing means.
Further, the degree of freedom in designing the apparatus configuration such as the arrangement of the light emitting elements when implementing the unnecessary resist exposure apparatus according to claim 4 is increased.

According to a sixth aspect of the present invention, in the unnecessary resist exposure apparatus according to the fifth aspect, the light guiding means is composed of an optical fiber. In the present invention, the light guide means is constituted by an optical fiber, whereby the invention of claim 5 can be easily implemented. According to a seventh aspect of the invention, in the unnecessary resist exposure apparatus according to the fifth aspect, the light guiding means is composed of a liquid fiber.

In the present invention, the light guide means is constituted by the liquid fiber, so that the invention of claim 5 can be implemented easily and at low cost.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An unnecessary resist exposure apparatus which is an embodiment of the present invention will be described below with reference to the drawings. Figure 2
FIG. 3 is a schematic diagram showing an embodiment of the present invention. Reference numeral 1 denotes a semiconductor wafer (hereinafter referred to as a substrate), on the surface of which a thin film 1a of photoresist (see FIG. 1) is formed, and the periphery thereof is irradiated with light for exposure. Two
Is a chuck that attracts the center of the substrate 1 and supports it in a horizontal posture, and 3 is a motor that drives the chuck 2 to rotate.

4 is a UV lamp which emits ultraviolet light, and 4a is U
The switch 5 that connects and disconnects the power supply to the V lamp 4 is U
A reflecting mirror that reflects the light from the V lamp 4 on the elliptical surface and collects it, and an optical fiber bundle 6 that guides the light collected by the reflecting mirror 5. The optical fiber bundle 6 is formed by bundling a plurality of optical fibers, and the incident end 6 a thereof is arranged at the condensing position of the reflecting mirror 5. Reference numeral 8 denotes a lens unit that is attached to the emitting end side of the optical fiber bundle 6 and irradiates the light guided through the optical fiber bundle 6 to the periphery of the substrate 1, 9 an arm that supports the lens unit 8, and 10 an arm 9. A drive source connected to the base. The drive source 10 rotationally drives the arm 9 in a horizontal plane to expose the lens unit 8 from a position above the substrate 1 supported by the chuck 2 to the periphery of the substrate 1 (shown by a solid line in FIG. 2) and a substrate. 1 to the standby position on the side of 1 (shown by a broken line in FIG. 2). 11 is a lens unit 8
Is an illuminance detector that receives the light emitted from the lens unit 8 and measures its illuminance when is in the standby position, for example, a photovoltaic element that generates an electromotive force according to the incident light, or an incident light. A resistor or the like whose resistance value changes in accordance with is used.

Reference numeral 12 is a shutter which is arranged in the optical path between the reflecting mirror 5 and the incident end 6a of the optical fiber bundle 6 to open and close the optical path, and 14 is a light quantity diaphragm also arranged in the optical path, 1
Reference numeral 5 is a rotary solenoid that drives the shutter 12 to open and close, and 17 is a motor that drives the light amount diaphragm 14. As shown in FIG. 3, the light quantity diaphragm 14 is formed by forming an opening 21 having a width that varies around the center of the disk 20. A pulse motor is used as the motor 17, and the size of the opening 21 of the light quantity diaphragm 14 placed in the optical path can be arbitrarily controlled.
The reflecting mirror 5 to the incident end 6a of the optical fiber bundle 6 are housed in a casing (not shown) and arranged at any place of the apparatus.

Reference numeral 22 is a so-called microcomputer (hereinafter referred to as a microcomputer), which comprises a CPU 22a and a memory 22b. The memory 22b is written and read by the CPU 22a, and stores a program of processing executed by the CPU 22a and information such as other necessary data. 23 is a CPU 22a of the microcomputer 22
A keyboard for inputting information such as numerical values and commands, and 24 is a display for displaying information such as the state of the device. The microcomputer 22 refers to the detection signal of the illuminance detector 11 and controls the operations of the motors 3, 17 and the drive source 10 and the rotary solenoid 15 and the opening / closing of the switch 4a based on a predetermined program.

FIG. 1 shows the UV lamp 4 to the lens unit 8
It is a schematic diagram which shows the detail of the optical system to the periphery. The emission end 6b of the optical fiber bundle 6 is guided into the casing 8a that constitutes the lens unit 8, and the light incident on the incidence end 6a of the optical fiber bundle 6 is emitted from the emission end 6b. Reference numeral 30 denotes a condenser lens disposed on the optical path of the light emitted from the emission end 6b of the optical fiber bundle 6 in the casing 8a, and 32 has a rectangular opening 34 through which the light collected by the condenser lens 30 passes. A mask, 36 is an imaging lens that irradiates the substrate 1 with the light that has passed through the opening 34 of the mask 32. Mask 32
Is arranged at the position of the entrance pupil of the condenser lens 30, and the imaging lens 36 is arranged at the position of the image of the exit end 6b by the condenser lens 30. That is, the mask 32 is the condenser lens 30.
Is placed in a non-imaging relationship with the exit end 6b. Also,
The mask 32 and the imaging lens 36 are arranged so that the mask 32 has an imaging relationship with the surface of the substrate 1 with respect to the imaging lens 36.
It is supported by the casing 8a and the arm 9. And
The lens unit 8 moves in a horizontal plane when the driving source 10 drives the arm 9, and moves while maintaining the above-described image forming relationship with the surface of the substrate 1 supported in a horizontal posture by the chuck 2. The shutter 12 and the light amount diaphragm 14 are not shown in FIG.

The operation of the apparatus of this embodiment will be described in detail below. The following operation of the apparatus is executed by the microcomputer 22 based on the operator's instruction input from the keyboard 23. When it is instructed to start the exposure processing on the substrate, the switch 4a
Is closed, the UV lamp 4 is turned on, and the shutter 12 is opened. Then, the light amount diaphragm 14 is driven so that the illuminance detected by the illuminance detector 11 becomes a desired value. When the substrate 1 is loaded into the chuck 2, the drive source 10 is driven,
The arm 9 is driven to a position where the light emitted from the lens unit 8 exposes a desired edge portion of the substrate 1. Then, in this state, the motor 3 is driven to rotate the substrate 1 once, the lens unit 8 scans the entire circumference of the edge of the substrate 1, and the entire circumference is exposed.

At this time, according to the above configuration, the mask 3
The plane where 2 exists is illuminated by the light emitted from the emission end 6b of the optical fiber bundle 6 and collected by the condenser lens 30. Since the mask 32 and the surface of the substrate 1 are in an image-forming relationship by the imaging lens 36, the surface of the substrate 1 is exposed in the shape of the opening 34 formed in the mask 32. Further, even if there is some unevenness in the light amount distribution at the emitting end 6b due to the characteristics of the optical fibers forming the optical fiber bundle 6 or the disconnection of a part thereof, the mask 32
And the emission end 6b of the optical fiber bundle 6 are separated from each other, and the two are not in an image forming relationship, so such unevenness is not directly reflected on the light quantity distribution on the surface of the mask 32. . Further, the mask 32 is arranged at the entrance pupil position of the condenser lens 30, and each of the lights emitted from each point of the exit end 6 b illuminates the surface of the opening 34 of the mask 32. The surface is uniformly illuminated without unevenness, and in combination, the unevenness of the light amount distribution on the surface of the mask 32 is remarkably reduced and evenly illuminated.

Therefore, the light quantity distribution of the exposure light applied to the substrate 1 in the shape of the opening 34 is also uniform. Further, since the UV lamp 4 is arranged at a position separated from the lens unit 8 and the light from the UV lamp 4 is guided to the lens unit 8 by the optical fiber bundle 6, the lens unit 8 can be downsized. The arm 9 and the motor 10 can also be downsized.

In the above structure, the UV lamp 4 corresponds to the light emitting element, the reflecting mirror 5 corresponds to the condensing means, the optical fiber bundle 6 corresponds to the light guiding means, and the emitting end 6b corresponds to the emitting surface. A light source is constructed. Further, the condenser lens 30 serves as a condenser optical system, the imaging lens 36 serves as an imaging optical system, and the aperture 3
The mask 32 on which the mask 4 is formed is used as the mask means and the chuck 2
Is a supporting means, the casing 8a and the arm 9 are image forming relationship maintaining means, and the motor 3 is a scanning means.

In the above embodiment, the optical fibers are bundled and used as the light guiding means, but liquid fibers may be used. In this case, the device can be constructed relatively inexpensively as compared with the case of using the optical fiber. Further, in the above-described embodiment, the light emitting element is arranged at a position separated from the lens unit 8 and the light from the light emitting element is guided to the lens unit 8 by the optical fiber bundle 6. A light source may be built in the unit 8. Even in this case, by disposing the mask means at a position apart from the emission surface of the light source, it is possible to make the distribution of the amount of light exposed on the substrate uniform. Further, if the amount of light from the light source or the light emitting element is sufficient, one or both of the condenser lens 30 and the reflecting mirror 5 may not be used.

Further, in the above embodiment, the image formation relationship between the substrate 1 and the mask 32 is maintained by fixing the distance between the lens unit 8 and the substrate 1, but the lens unit 8 is fixed to the substrate 1. A so-called autofocus mechanism that moves up and down to maintain this imaging relationship may be provided.
Even if there is a slight warp or the like on the substrate 1, the imaging relationship can be maintained without being affected by it. If an image-side telecentric lens is used as the imaging lens 36,
The accuracy required to maintain the above-mentioned image formation relationship can be relaxed.

Further, as the mask 32, a mask having a rectangular opening 34 is used, but for example, when it is desired to expose only the target portion in a specific shape so that the carrier means of the substrate holds it, or When it is desired to expose a desired pattern on the substrate, a mask having an opening corresponding to the shape or pattern may be used. In the above embodiment, since the position of the entrance pupil of the imaging lens 36 matches the position of the image of the exit end 6b formed by the condenser lens 30, the shape of the opening of the imaging lens 36 exposes the substrate. It does not affect the light intensity distribution on the surface. Therefore, for example, instead of the illustrated light quantity diaphragm 14, by disposing a variable light quantity diaphragm in the opening near the entrance pupil position of the imaging lens 36,
The illuminance of the irradiation light may be adjusted without causing unevenness in the light amount distribution. An iris diaphragm or the like may be used as the light quantity diaphragm. Further, although the above-described embodiment is a so-called peripheral exposure apparatus that exposes and removes the unnecessary resist in the peripheral portion of the substrate, if the unnecessary resist to be removed is present in a portion other than the peripheral portion of the substrate, it is desired to remove it. Scanning may be performed so as to expose a portion.

[Other Embodiments of Mask] The mask 40 shown in FIG. 4 is used in place of the mask 32 in the above embodiment. This mask 40 has an arc-shaped opening 4
One. The arc-shaped opening 41 has a predetermined width D, and its radius of curvature is set to be substantially the same as the radius of the substrate 1. The width D is determined by the width of the substrate 1 to be exposed and the magnification of the optical system. In addition, in this embodiment, the magnification of the optical system is increased, and the illumination area P (shown by the alternate long and short dash line) is secured to be larger than that in the above embodiment. Then, the arc length of the opening 41 is set to be as long as possible within the illumination region P. The arc length is changed in relation to other exposure conditions.

For reference, FIG. 5 shows the opening 34 and the illumination area R of the mask 32 in the above-described embodiment in comparison with the opening 41 and the illumination area P of the mask 40 in this embodiment. The operation is basically the same as that of the above embodiment. That is, when the start of the exposure process is instructed, the shutter 12 is opened and the substrate 1 carried into the chuck 2 is rotated to sequentially expose the entire circumference of the edge of the substrate 1. Board 1 to 3
After rotating by 60 °, the shutter 12 is closed. Exposure conditions in this case, for example, the arc length of the opening 41, the illuminance, the substrate 1
The rotation speed of is subjected to a test in advance and is set to such an extent that the photoresist liquid on the substrate 1 does not foam during exposure.

In such an embodiment, a small exposure energy can be applied to a relatively large exposure area. Therefore, it is possible to avoid a problem when a large exposure energy is applied to the photoresist solution in a short time, that is, a problem of bubbling of the photoresist solution, without prolonging the entire processing time for exposing the entire circumference of the substrate.

[0028]

According to the first aspect of the present invention, even if there is some unevenness in the light amount distribution on the emission surface of the light source, it does not directly affect the exposed light amount distribution, and the unevenness of the exposure light amount distribution. Can be reduced. In addition, the device configuration is simple and inexpensive, and the device management is easy.

According to the invention of claim 2, further, the light from the light source can be efficiently used. According to the invention of claim 3, even if the light amount distribution on the emission surface of the light source is uneven,
It is possible to perform uniform exposure without unevenness in the light amount distribution. According to the invention of claim 4, the shape of the aperture of the imaging optical system does not affect the light quantity distribution on the exposure surface of the substrate.

According to the fifth aspect of the invention, the degree of freedom in designing the apparatus configuration such as the arrangement of the light emitting elements when implementing the unnecessary resist exposure apparatus of the first to fourth aspects is further increased. According to the invention of claim 6, the invention of claim 5 can be easily implemented. According to the invention of claim 7, the invention of claim 5 can be implemented easily and inexpensively.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a configuration of a main part of an unnecessary resist exposure apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a configuration of an unnecessary resist exposure apparatus according to an embodiment of the present invention.

FIG. 3 is a front view of a light amount diaphragm.

FIG. 4 is a front view showing another embodiment of the mask.

5 is a diagram showing the size of the opening of the mask of FIG. 4 in comparison with other embodiments.

[Explanation of symbols]

 1 substrate 2 chuck 3 motor 4 UV lamp 5 reflecting mirror 6 optical fiber bundle 6b emitting end 8 lens unit 8a casing 9 arm 10 drive source 30 condenser lens 32, 40 mask 34, 41 aperture 36 imaging lens

Claims (7)

[Claims] 1. A light source that emits illumination light from an emission surface, a mask means that has an opening of a predetermined shape, and is arranged at a position on the optical path of the light source and away from the emission surface of the light source, An image forming optical system that forms an image of the opening of the mask unit, a supporting unit that supports the substrate, and a substrate that is supported by the supporting unit and the mask unit keep the image forming optical system in an image forming relationship with each other. Unnecessary resist exposure, characterized by comprising image relationship maintaining means and scanning means for scanning a desired portion of the substrate with light that passes through the opening of the mask means and is irradiated onto the surface of the substrate by the imaging optical system. apparatus. 2. A condensing optical system for condensing light from the light source is further provided between the emission surface of the light source and the mask means, and the emission surface and the mask means are arranged in a non-imaging relationship. The unnecessary resist exposure apparatus according to claim 1. 3. The unnecessary resist exposure apparatus according to claim 2, wherein the arrangement position of the mask means substantially coincides with the position of the entrance pupil of the focusing optical system. 4. The unnecessary resist according to claim 2, wherein the position of the entrance pupil of the imaging optical system substantially coincides with the position of the image of the exit surface of the light source formed by the condensing optical system. Exposure equipment. 5. The light source comprises a light emitting element, a condensing means for condensing light from the light emitting element, and a light guiding means for guiding the light condensed by the condensing means. 5. The unnecessary resist exposure apparatus according to claim 4. 6. The unnecessary resist exposure apparatus according to claim 5, wherein said light guiding means is constituted by an optical fiber. 7. The unnecessary resist exposure apparatus according to claim 5, wherein the light guiding means is constituted by a liquid fiber.