JP6037019B2 - Exposure apparatus and exposure method - Google Patents

Description

  The present invention relates to an exposure apparatus and an exposure method used for manufacturing semiconductor devices, printed boards, LCDs, and the like. In particular, the present invention relates to an exposure apparatus and an exposure method that improve the quality of a finished product by correcting the deflection of the mask even when the mask size is increased.

  When manufacturing a semiconductor device, a printed circuit board, an LCD, or the like, a desired pattern is exposed on a workpiece through a glass mask having a predetermined pattern. When the size of the glass mask is increased, the mask holder supports the glass mask only at the peripheral edge portion, so that the glass mask is likely to be bent by its own weight. When the glass mask is bent, the exposure accuracy is greatly reduced.

  Therefore, for example, in Patent Document 1, an airtight space including a glass mask as a part is formed, and high-pressure air is introduced into the airtight space according to the bending direction of the glass mask, or an internal pressure (pressure) in the airtight space. An exposure apparatus is disclosed that can correct the deflection of the glass mask by lowering. Similarly, Patent Document 2 discloses a photomask contact method in which the mask and the metal thin plate are brought into close contact with each other by exhausting the air in the sealed space between the mask and the metal thin plate.

  Furthermore, Patent Document 3 discloses an exposure apparatus that adjusts the amount of deflection of the mask by adjusting the flow rate and flow velocity of the fluid passing between the mask and the optical plate. In Patent Document 3, the amount of deflection of the mask is detected by a detector, the valve is adjusted according to the amount of deflection, and the flow rate of the fluid passing between the mask and the optical plate is changed.

JP 2004-069692 A JP 2004-133302 A JP 2007-199569 A

  In patent documents 1 and 2, it is necessary to use an expensive regulator etc. for pressure control in an airtight space (sealed space). However, when the mask size is large, the mask area to be pressure controlled becomes large, so it is difficult to precisely adjust the amount of deflection over the entire mask surface by pressure control, and correction can be made according to the amount of mask deflection. There was a problem that it was difficult.

  Moreover, in patent document 3, it was necessary to perform an appropriate process with respect to an optical plate in order to make passage of a fluid easy, and there existed a problem that manufacturing cost increased.

  The present invention has been made in view of such circumstances, and provides an exposure apparatus and an exposure method that can appropriately correct the deflection of the mask even when the mask size is large and can perform exposure with high accuracy. The purpose is to provide.

  In order to achieve the above object, an exposure apparatus according to the present invention includes a light source, an optical plate provided with a mask pattern, and a mask holder that holds the optical plate and forms an airtight space on the light source side of the optical plate. An exposure apparatus that irradiates the optical plate with light from the light source and exposes the mask pattern onto a workpiece, a pressure adjustment mechanism for adjusting the pressure in the airtight space, and the mask holder An inclination mechanism for inclining at a predetermined angle, and after adjusting the pressure in the airtight space by the pressure adjustment mechanism in a state in which the mask holder is inclined at a predetermined angle by the inclination mechanism, the inclination mechanism Exposure is performed by returning the mask holder to the original angle.

  In the above configuration, the pressure adjusting mechanism for adjusting the pressure in the airtight space and the tilting mechanism for tilting the mask holder at a predetermined angle are provided, and the mask holder is tilted at the predetermined angle by the tilting mechanism. After adjusting the pressure in the airtight space by the pressure adjusting mechanism, the mask holder is returned to the original angle by the tilting mechanism and exposed. Thereby, in a state where the mask holder is inclined, for example, by adjusting the pressure in the airtight space so that the displacement of the shape of the mask holder at the time of exposure approaches 0, it is possible to correct the deflection due to the weight of the optical plate, The distance between the optical plate and the workpiece during exposure can be made constant. Therefore, the exposure accuracy of the mask pattern is increased and the quality of the finished product can be improved.

  The exposure apparatus according to the present invention further includes a displacement detector that detects a displacement of the shape of the optical plate, and detects the displacement of the shape of the optical plate at the time of exposure by the displacement detector, and the pressure adjustment Preferably, the mechanism adjusts the pressure in the airtight space so as to reduce the displacement of the shape of the optical plate detected by the displacement detector when the mask holder is tilted by the tilt mechanism.

  In the above configuration, when the mask holder is tilted, the pressure in the hermetic space is adjusted so as to reduce the displacement of the shape of the optical plate detected in advance, so that the displacement of the shape of the optical plate at the time of exposure is reduced. The distance between the optical plate and the workpiece during exposure can be made constant. Therefore, the exposure accuracy of the mask pattern is increased and the quality of the finished product can be improved.

  Further, the exposure apparatus according to the present invention stores in advance a relationship between the inclination angle of the mask holder and the pressure in the airtight space that brings the displacement of the shape of the optical plate at the time of exposure close to zero, It is preferable that the pressure adjusting mechanism adjusts the pressure in the airtight space so that the displacement of the shape of the optical plate at the time of exposure approaches 0 based on the stored relationship.

  In the above configuration, the relationship between the tilt angle of the mask holder and the pressure in the airtight space that brings the displacement of the shape of the optical plate at the time of exposure close to 0 is stored in advance, and the exposure time is based on the stored relationship. The pressure in the airtight space is adjusted so that the displacement of the shape of the optical plate approaches 0, so that the deflection due to its own weight can be automatically corrected, and the distance between the optical plate and the workpiece during exposure can be reduced. Can be constant. Therefore, the exposure accuracy of the mask pattern is increased and the quality of the finished product can be improved.

  The exposure apparatus according to the present invention preferably includes an angle sensor for detecting an inclination angle of the mask holder.

  In the said structure, since the angle sensor which detects the inclination angle of a mask holder is provided, the pressure in airtight space can be adjusted according to an inclination angle. Therefore, it is possible to maintain the exposure accuracy even when the mask is frequently exchanged.

  In the exposure apparatus according to the present invention, the pressure adjusting mechanism may readjust the pressure in the airtight space based on the displacement of the shape of the optical plate at the time of exposure detected by the displacement detector. preferable.

  In the above configuration, since the pressure in the airtight space is readjusted based on the detected displacement of the shape of the optical plate at the time of exposure, the exposure accuracy of the mask pattern can be increased, and the finished quality can be improved. Become.

  Next, in order to achieve the above object, an exposure method according to the present invention includes a light source, an optical plate provided with a mask pattern, and the optical plate, and forms an airtight space on the light source side of the optical plate. An exposure method for exposing the mask pattern of the optical plate to a work using a mask holder that performs a tilting step of tilting the mask holder with respect to the work by a predetermined angle, and the airtight space of the mask holder A pressure adjusting step for adjusting the internal pressure, a parallel arranging step for arranging the mask holder in parallel with the work, and an exposure step for exposing the light from the light source to the work through the optical plate. It is characterized by.

  In the above configuration, the mask holder is inclined at a predetermined angle with respect to the workpiece, and the pressure in the hermetic space of the mask holder is adjusted. The mask holder is rearranged parallel to the workpiece, and light from the light source is exposed to the workpiece via the optical plate. Thereby, in a state where the mask holder is inclined, for example, by adjusting the pressure in the airtight space so that the displacement of the shape of the mask holder at the time of exposure approaches 0, it is possible to correct the deflection due to the weight of the optical plate, The distance between the optical plate and the workpiece during exposure can be made constant. Therefore, the exposure accuracy of the mask pattern is increased and the quality of the finished product can be improved.

  According to the above configuration, in a state where the mask holder is inclined, for example, by adjusting the pressure in the airtight space so that the displacement of the shape of the mask holder at the time of exposure approaches 0, the deflection due to the weight of the optical plate is corrected. The distance between the optical plate and the workpiece during exposure can be made constant. Therefore, the exposure accuracy of the mask pattern is increased and the quality of the finished product can be improved.

It is a schematic diagram which shows the structure of the exposure apparatus which concerns on embodiment of this invention. It is a schematic diagram which shows the state which inclined the mask holder of the exposure apparatus which concerns on Embodiment 1 of this invention. It is a graph which shows the relationship between the inclination-angle of the mask holder of the exposure apparatus which concerns on Embodiment 1 of this invention, and the maximum deflection amount (maximum displacement) of the optical plate at the time of exposure. It is an illustration figure of the data structure memorize | stored in the control apparatus of the exposure apparatus which concerns on Embodiment 2 of this invention.

  Hereinafter, an exposure apparatus according to an embodiment of the present invention will be specifically described with reference to the drawings.

(Embodiment 1)
The exposure apparatus according to Embodiment 1 of the present invention adjusts the pressure (internal pressure) in the airtight space while tilting the mask holder that holds the optical plate in order to increase the exposure accuracy, and then returns the mask holder to the original position. The mask pattern is exposed to the workpiece 10 by returning to the angle. Therefore, the exposure apparatus according to the first embodiment includes an inclination mechanism that inclines the mask holder that holds the optical plate provided with the mask pattern at one end of the mask holder. FIG. 1 is a schematic diagram showing a configuration of an exposure apparatus according to an embodiment of the present invention. In FIG. 1, an imaging device, marks, and the like necessary for alignment with the workpiece are omitted, and only a configuration necessary for adjusting the distance between the optical plate and the workpiece is described.

  In FIG. 1, an exposure apparatus 1 according to an embodiment of the present invention includes a light source 100, an optical plate 11 provided with a mask pattern, and a mask holder 13 that holds the optical plate 11 and forms an airtight space 12. I have. The optical plate 11 is provided on the mask holder 13 on the side facing the workpiece 10. The airtight space 12 is formed on the light source 100 side of the optical plate 11. A transmission glass 14 capable of transmitting light from the light source 100 is provided on the opposite side of the mask holder 13 from the side facing the workpiece 10.

  One end of the mask holder 13 is provided with a gas pipe 28 for supplying or discharging gas in order to adjust the pressure in the hermetic space 12. It is provided with a valve 26 capable of controlling the above. By controlling the operation of the valve 26, it is possible to control whether the inside of the hermetic space 12 is hermetically sealed or opened to a room pressure (atmospheric pressure).

  The other end of the mask holder 13 is provided with a tilting mechanism 21 that can tilt the mask holder 13, for example, a hinge that can rotate. The tilt mechanism 21 is preferably provided with, for example, an electric motor. This is because the mask holder 13 can be inclined at a desired angle by controlling the operation by the control device 30.

  A high-pressure air source 22 that supplies high-pressure air that increases the pressure in the hermetic space 12 and a vacuum pump 23 that lowers the pressure in the hermetic space 12 are connected to the gas pipe 28 via regulators 24 and 25, respectively. ing. The pressure in the hermetic space 12 is detected by a pressure sensor 29 provided in the middle of the gas pipe 28. A signal indicating the pressure value in the hermetic space 12 detected by the pressure sensor 29 is transmitted to the control device 30, and the control device 30 controls the operation of the regulators 24, 25 and the valve 26 so that the inside of the hermetic space 12 is desired. The pressure is adjusted (pressure adjusting mechanism 20).

  The optical plate 11 is bent by its own weight. Such a bending amount is detected as a displacement of the bending shape of the optical plate 11 by a detector (displacement detector) 15. In general, when the optical plate 11 is disposed horizontally (inclination angle 0 degree), the amount of deflection (displacement) of the shape of the optical plate 11 is 0 at both ends and the maximum value near the center. However, when the optical plate 11 is tilted, the balance of its own weight fluctuates, so that the position where the maximum value is reached fluctuates, that is, the bending shape of the optical plate 11 changes. The present invention is characterized in that a state with a small amount of bending is created by adjusting the pressure in the airtight space 12 by utilizing the change in the bending shape caused by tilting the optical plate 11. .

  FIG. 2 is a schematic diagram showing a state in which the mask holder 13 of the exposure apparatus 1 according to Embodiment 1 of the present invention is tilted. FIG. 2A to FIG. 2E show the states of inclination angles of 0 degree, 30 degrees, 60 degrees, 90 degrees, and 180 degrees in order.

  As shown in FIG. 2 (a), when the inclination angle of the mask holder 13 is 0 degree, the optical plate 11 is in a state of being horizontally disposed. Therefore, the bending amount of the optical plate 11 is 0 at both ends and near the center. Maximum value. As the inclination angle of the mask holder 13 and FIG. 2 (b) and FIG. 2 (c) increases, the change of the bending shape due to the weight of the optical plate 11, that is, the position where the bending amount (displacement) becomes the maximum value is It moves from the vicinity of the center to the tilt mechanism 21 side.

  With the mask holder 13 tilted, the valve 26 is closed and the regulator 24 or the regulator 25 is operated to adjust the pressure in the hermetic space 12. After adjusting the pressure in the airtight space 12, the mask holder 13 is returned to the original angle to expose the mask pattern onto the workpiece 10. That is, exposure is performed after the mask holder 13 is rearranged so as to be parallel to the workpiece 10. Thereby, the amount of deflection (displacement) of the optical plate 11 can be easily adjusted so as to be approximately uniform on the surface of the optical plate 11. FIG. 3 is a graph showing the relationship between the tilt angle of the mask holder 13 of the exposure apparatus 1 according to Embodiment 1 of the present invention and the maximum amount of deflection (maximum displacement) of the optical plate 11 during exposure.

  In FIG. 3, the maximum deflection amount (maximum displacement) indicates a state where a positive value indicates that the shape of the optical plate 11 is convex upward, and a negative value indicates a state where the optical plate 11 is convex downward. Further, Δ marks indicate a state where no pressure is applied to the airtight space 12, that is, a natural state. In this case, the valve 26 is open.

  A mark ◯ shows a state in which a pressure of −0.1 kPa is applied in the airtight space 12, that is, a state in which pressure is applied so that the shape of the optical plate 11 is convex upward. Further, □ marks are pressures smaller than the pressure in the state where a pressure of −0.07 kPa is applied in the airtight space 12, that is, the state indicated by the marks ◯ so that the shape of the optical plate 11 is convex upward. It shows the state when. In either case, the valve 26 is closed.

  As is clear from FIG. 3, the maximum deflection amount (maximum displacement) of the optical plate 11 increases as the mask holder 13 increases in inclination angle (the shape of the optical plate 11 is convex downward). From the state to the convex state). However, depending on the pressure applied in the airtight space 12, there is an inclination angle at which the maximum deflection amount becomes zero. For example, when the inclination angle of the mask holder 13 is 60 degrees, the maximum deflection amount becomes substantially 0 when a pressure of −0.07 kPa is applied in the airtight space 12. Therefore, the deflection of the optical plate 11 can be corrected by adjusting the pressure in the airtight space 12 so that the maximum deflection amount of the optical plate 11 becomes zero according to the inclination angle of the mask holder 13.

  As described above, according to the first embodiment, in a state where the mask holder 13 is inclined, for example, the airtight space in which the bending amount (displacement) of the bending shape of the optical plate 11 of the mask holder 13 at the time of exposure is brought close to zero. By adjusting the pressure in 12, the deflection due to the weight of the optical plate 11 can be corrected, and the distance (exposure gap) between the optical plate 11 and the workpiece 10 during exposure can be made constant. Therefore, the exposure accuracy of the mask pattern is increased and the quality of the finished product can be improved.

  Of course, the displacement of the bending shape of the optical plate 11 at the time of exposure is detected by the detector 15, and the pressure in the airtight space 12 is readjusted by the pressure adjustment mechanism 20 based on the detected displacement of the bending shape. Also good. As a result, the mask pattern can be exposed to the workpiece 10 with high accuracy.

  Further, by detecting in advance the deflection amount (displacement) of the bending shape of the optical plate 11 at the time of exposure by the detector 15, the airtight space 12 that reduces the detected deflection amount (displacement) when tilting by the tilt mechanism 21. This is because it is possible to grasp in advance whether the pressure applied to the inside is positive or negative, and it is possible to easily identify which of the regulator 24 and the regulator 25 should be operated.

  In addition, when the shape of the workpiece 10 itself is warped and there is a bend or the like, the inclination angle of the mask holder 13 and the pressure applied to the airtight space 12 so that the shape of the optical plate 11 matches the shape of the workpiece 10. May be adjusted. For example, the control device 30 controls the operations of the regulators 24 and 25 and the valve 26 so that when the shape of the workpiece 10 is convex downward, the optical plate 11 is airtight so that the maximum deflection amount becomes a negative value. By adjusting the pressure applied in the space 12, the shape of the optical plate 11 is made convex downward. Similarly, when the shape of the workpiece 10 is convex upward, the pressure applied to the airtight space 12 is adjusted so that the maximum deflection amount of the optical plate 11 becomes a positive value. Thus, the shape of the optical plate 11 can be changed according to the shape of the workpiece 10, and the exposure accuracy of the mask pattern can be increased.

(Embodiment 2)
Since the configuration of the exposure apparatus according to the second embodiment of the present invention is the same as that of the first embodiment, detailed description thereof will be omitted by attaching the same reference numerals. The exposure apparatus 1 according to the second embodiment of the present invention determines in advance each tilt angle of the mask holder 13 from the relationship between the tilt angle of the mask holder 13 and the maximum deflection amount of the optical plate 11 during exposure shown in FIG. The second embodiment is different from the first embodiment in that the pressure to be applied in the airtight space 12 is obtained and stored in order to make the maximum deflection amount of the optical plate 11 at the time of exposure zero.

  That is, the exposure apparatus 1 according to Embodiment 2 of the present invention applies pressure to the hermetic space 12 in order to make the maximum deflection amount of the optical plate 11 during exposure zero for each inclination angle of the mask holder 13. Is obtained in advance and stored in a memory, a storage device, or the like of the control device 30. FIG. 4 is a view showing an example of the data structure stored in the control device 30 of the exposure apparatus 1 according to Embodiment 2 of the present invention.

  In the example of FIG. 4, for each inclination angle of the mask holder 13, the pressure to be applied in the hermetic space 12 in order to make the maximum deflection amount of the optical plate 11 during exposure zero is obtained and stored. By storing in advance, it is possible to control so that an optimum pressure corresponding to the tilt angle is automatically applied.

  Conversely, the angle at which the mask holder 13 should be inclined can also be obtained from the pressure applied in the airtight space 12. In this case, the control device 30 controls the operation of the tilt mechanism 21 so that the tilt angle of the mask holder 13 is automatically adjusted. The inclination angle of the mask holder 13 may be detected by the angle sensor 27 shown in FIG. The type of the angle sensor 27 is not particularly limited, and may be a rotary encoder provided on the rotating shaft of the tilt mechanism 21, for example.

  As described above, according to the second embodiment, the pressure in the airtight space 12 can be automatically adjusted according to the inclination angle of the mask holder 13, so that the bending due to the weight of the optical plate 11 is automatically performed. Correction can be made, and the distance (exposure gap) between the optical plate 11 and the workpiece 10 during exposure can be made constant. Therefore, the exposure accuracy of the mask pattern is increased and the quality of the finished product can be improved.

  In addition, it cannot be overemphasized that embodiment mentioned above can be changed in the range which does not deviate from the meaning of this invention. For example, the relationship between the inclination angle of the mask holder 13 stored in advance and the pressure to be applied in the airtight space 12 is not limited to storing in a tabular data configuration as shown in FIG. Instead, the pressure for a predetermined inclination angle may be stored as a function or the like.

  In the embodiment described above, the mask holder 13 is tilted in the exposure apparatus 1 to adjust the pressure, and then the exposure is returned to the original angle. However, it goes without saying that the same effect can be obtained even if the mask holder 13 is tilted by another apparatus to adjust the pressure and then the mask holder 13 is attached to the exposure apparatus 1 and exposed.

DESCRIPTION OF SYMBOLS 1 Exposure apparatus 10 Workpiece 11 Optical plate 12 Airtight space 13 Mask holder 15 Detector (displacement detector)
20 Pressure adjustment mechanism 21 Inclination mechanism 24, 25 Regulator 26 Valve 27 Angle sensor 30 Control device

Claims (6)

A light source;
An optical plate provided with a mask pattern;
An exposure apparatus that holds the optical plate and forms a hermetic space on the light source side of the optical plate, and irradiates the optical plate with light from the light source to expose the mask pattern onto a workpiece. There,
A pressure adjusting mechanism for adjusting the pressure in the airtight space;
An inclination mechanism for inclining the mask holder at a predetermined angle,
After adjusting the pressure in the airtight space by the pressure adjusting mechanism in a state where the mask holder is tilted by a predetermined angle by the tilt mechanism, the mask holder is returned to the original angle by the tilt mechanism and exposed. An exposure apparatus characterized by the above. A displacement detector for detecting displacement of the shape of the optical plate;
The displacement detector detects the displacement of the shape of the optical plate at the time of exposure,
The pressure adjusting mechanism adjusts the pressure in the hermetic space so as to reduce the displacement of the shape of the optical plate detected by the displacement detector when the mask holder is tilted by the tilt mechanism. The exposure apparatus according to claim 1. The relationship between the inclination angle of the mask holder and the pressure in the airtight space that brings the displacement of the shape of the optical plate during exposure closer to 0 is stored in advance.
3. The pressure adjustment mechanism according to claim 2, wherein the pressure adjustment mechanism adjusts the pressure in the airtight space so that the displacement of the shape of the optical plate at the time of exposure approaches 0 based on the stored relationship. Exposure device.   The exposure apparatus according to claim 1, further comprising an angle sensor that detects an inclination angle of the mask holder.   5. The pressure adjustment mechanism re-adjusts the pressure in the airtight space based on the displacement of the shape of the optical plate at the time of exposure detected by the displacement detector. 6. An exposure apparatus according to claim 1. A light source;
An optical plate provided with a mask pattern;
An exposure method for exposing the mask pattern of the optical plate to a work using a mask holder that holds the optical plate and forms an airtight space on the light source side of the optical plate,
An inclining step of inclining the mask holder with respect to the workpiece by a predetermined angle;
A pressure adjusting step of adjusting the pressure in the hermetic space of the mask holder, and a parallel arranging step of arranging the mask holder in parallel with the workpiece,
And an exposure step of exposing the work to light from the light source via the optical plate.

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