JP4390466B2 - Exposure machine and exposure method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an exposure apparatus used for manufacturing a product such as a color filter, and more particularly to an exposure apparatus and an exposure method for performing exposure in a single wafer mode on a plurality of substrates with a photosensitive material.
[0002]
[Prior art]
In such an exposure machine, when exposing a substrate with a photosensitive material with a predetermined exposure pattern, first, (1) the substrate with the photosensitive material is supplied into the exposure machine by a robot arm or the like and placed on the exposure stage. After that, (2) the exposure stage is moved to position the substrate with the photosensitive material. Next, (3) the substrate with the photosensitive material is exposed with a predetermined exposure pattern by irradiating the substrate with the photosensitive material with exposure light through a mask by the irradiation optical system. Thereafter, (4) the exposure stage is moved to position the substrate with the photosensitive material at the discharge position, and (5) the exposed substrate is discharged out of the exposure apparatus by a robot arm or the like.
[0003]
By the way, in such an exposure machine, it is possible to perform exposure in a single wafer mode on a plurality of substrates with a photosensitive material, and the above steps (1) to (5) are repeated at a constant tact interval. By performing, a plurality of substrates on which the same exposure pattern is formed can be obtained.
[0004]
[Problems to be solved by the invention]
However, in the existing exposure machines, in the plurality of substrates obtained by repeatedly performing the steps (1) to (5), the exposure pattern is not actually the same, and the manufacture is started. In the initial stage until a certain period of time elapses, there has been a problem that unacceptable deviations (total pitch deviations, etc.) occur for each substrate.
[0005]
Conventionally, this cause has not been sufficiently investigated, but as a result of the diligent research by the present inventors, there is a main cause of the change over time in the dimensions of the mask used in the exposure machine, and the irradiation It has been found that the exposure pattern formed on the substrate is shifted as the mask temperature rises and changes its dimensions due to the influence of the exposure light irradiated from the optical system.
[0006]
The present invention has been made based on such knowledge, and minimizes the deviation of the exposure pattern for each substrate that occurs when exposure is performed in a single-wafer format on a plurality of substrates with a photosensitive material. An object of the present invention is to provide an exposure apparatus and an exposure method that can improve the yield.
[0007]
[Means for Solving the Problems]
The present invention provides, as a first solution, an exposure stage on which a substrate with a photosensitive material is placed, an irradiation optical system that irradiates exposure light toward the substrate with a photosensitive material placed on the exposure stage, and A mask stage disposed between an exposure stage and the irradiation optical system; a mask attached to the mask stage and shielding exposure light irradiated from the irradiation optical system with a predetermined pattern corresponding to an exposure pattern; A controller for controlling the exposure stage and the irradiation optical system, and the controller starts the exposure on the substrate with the photosensitive material in a state where the temperature of the mask has risen to a steady temperature during the exposure. An exposure apparatus characterized by controlling a stage and the irradiation optical system is provided.
[0008]
The first solving means described above further includes a detection device for detecting the temperature of the mask, and the control device heats the mask as a pretreatment of exposure by exposure light irradiated from the irradiation optical system. In addition, it is preferable to control the exposure stage and the irradiation optical system so that exposure to the substrate with the photosensitive material is started when the temperature of the mask detected by the detection device reaches a predetermined set temperature. . It is preferable that the apparatus further includes a mask loader for attaching the mask to the mask stage, and a temperature adjusting mechanism for adjusting the temperature of the mask held by the mask loader.
[0009]
Further, in the first solving means described above, a mask loader for attaching the mask to the mask stage, and a temperature adjusting mechanism for maintaining the temperature of the mask held by the mask loader at a predetermined set temperature. Further, it is preferable that the control device controls the exposure stage and the irradiation optical system so that exposure to the substrate with a photosensitive material is started when the mask is attached to the mask stage by the mask loader.
[0010]
As a second solution, the present invention irradiates a substrate with a photosensitive material placed on an exposure stage with exposure light through a mask by an irradiation optical system, and the substrate with the photosensitive material has a predetermined exposure pattern. In the exposure method for exposing, the step of irradiating the mask with exposure light from the irradiation optical system to heat the mask, and the irradiation optical system irradiates the mask when the temperature of the mask reaches a predetermined set temperature. And exposing the exposed exposure light to the substrate with the photosensitive material on the exposure stage through the mask and starting exposure to the substrate with the photosensitive material.
[0011]
In the second solution described above, the mask is attached to a mask stage disposed between the exposure stage and the irradiation optical system, and the temperature of the mask before being attached to the mask stage. Preferably, the method further includes a step of adjusting the temperature, and a step of attaching the temperature-controlled mask to the mask stage.
[0012]
As a third solution, the present invention irradiates a substrate with a photosensitive material placed on an exposure stage with exposure light through a mask by an irradiation optical system, and the substrate with the photosensitive material has a predetermined exposure pattern. In an exposure method for exposure, a step of attaching a mask maintained at a predetermined set temperature to a mask stage disposed between an exposure stage and an irradiation optical system, and a time point when the mask is attached to the mask stage And irradiating the exposure light irradiated from the irradiation optical system to the substrate with the photosensitive material on the exposure stage through the mask, and starting exposure to the substrate with the photosensitive material. Provide a method.
[0013]
According to the present invention, since the exposure of the substrate with the photosensitive material is started in a state in which the temperature of the mask used in the exposure apparatus is raised to the steady temperature during the exposure, the exposure to the substrate with the photosensitive material is started. Subsequent mask dimensional changes can be minimized. For this reason, the shift | offset | difference for every board | substrate of the exposure pattern which arises when exposing with respect to several board | substrate with a photosensitive material in a single wafer form can be suppressed to the minimum, and the yield of a product can be improved.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0015]
First, the overall configuration of an exposure apparatus according to an embodiment of the present invention will be described with reference to FIG.
[0016]
As shown in FIG. 1, the exposure machine 1 includes an exposure machine body 10 and an irradiation optical system 20 that irradiates exposure light toward the exposure machine body 10.
[0017]
Among these, the exposure machine main body 10 has a base 11 and an exposure stage 12 installed on the base 11. Here, the exposure stage 12 mounts a substrate 31 with a photosensitive material to be exposed, a chuck stage 13 that holds the substrate 31 with a photosensitive material in a vacuum chuck system, and the chuck stage 13 in a vertical direction and a horizontal plane. And a drive stage 14 that can be moved in the interior.
[0018]
In such an exposure apparatus main body 10, a mask stage 15 to which a mask 16 is attached is provided above the exposure stage 12. Here, the mask 16 shields the exposure light irradiated from the irradiation optical system 20 toward the substrate 31 with the photosensitive material placed on the exposure stage 12 with a predetermined pattern corresponding to the exposure pattern.
[0019]
On the other hand, the irradiation optical system 20 includes an ultra-high pressure mercury lamp 21 and optical elements (parabolic mirror 22, cold mirror 23, integrator lens 24 and A spherical mirror 25), and can irradiate the exposure light (parallel light) toward the substrate 31 with the photosensitive material placed on the exposure stage 12 of the exposure machine main body 10. In such an irradiation optical system 20, a shutter 26 is provided between the cold mirror 23 and the integrator lens 24 so that the light emitted from the ultrahigh pressure mercury lamp 21 can be appropriately shielded and opened. It has become.
[0020]
A control device 29 is connected to the exposure stage 12 and the irradiation optical system 20 (extra-high pressure mercury lamp 21 and shutter 26) of the exposure apparatus main body 10 to supply a substrate 31 with a photosensitive material to the exposure stage 12. By controlling the exposure stage 12 and the irradiation optical system 20 of the exposure machine body 10 in conjunction with the operation of a robot arm (not shown) to be ejected, etc., the plurality of substrates 31 with photosensitive material are sequentially processed in a single wafer form. The exposure can be performed.
[0021]
Further, a mask loader 27 is installed adjacent to the exposure machine main body 10, and the mask 16 is detachably attached to the mask stage 15 of the exposure machine main body 10. A temperature adjusting mechanism 28 may be provided in the vicinity of the mask loader 27, and the mask 16 before the mask 16 is attached to the mask stage 15 by the mask loader 27 may be preheated to adjust the temperature.
[0022]
FIG. 2 is a view showing a state where the mask 16 is attached to the mask stage 15. As shown in FIG. 2, a vacuum suction hole 19 is formed in a portion of the lower surface of the mask stage 15 corresponding to the outer periphery of the mask 16 so that the mask 16 can be held by a vacuum chuck method. Yes. A thermocouple (detection device) 18 is attached to the mask stage 15 via a support member 17 so that the temperature of the mask 16 can be detected by a contact method. Here, the thermocouple 18 is installed in such a positional relationship as to be able to detect the temperature of the outer peripheral portion of the mask 16 outside the exposure area where the exposure light is not irradiated. The detection device that detects the temperature of the mask 16 is not limited to the thermocouple 18 that detects the temperature of the mask 16 in a contact manner, and a radiation thermometer that detects the temperature of the mask 16 in a non-contact manner can also be used. .
[0023]
Note that such a thermocouple 18 is connected to a control device 29, and the control device 29 heats the mask 16 as a pre-exposure process with exposure light emitted from the irradiation optical system 20, and the thermocouple 18. The exposure stage 12 and the irradiation optical system 20 of the exposure apparatus main body 10 can be controlled so that the exposure of the substrate 31 with the photosensitive material is started when the temperature of the mask 16 detected by the above reaches a predetermined set temperature. It has become.
[0024]
That is, in the exposure machine 1 shown in FIGS. 1 and 2, the temperature of the mask 16 irradiated with the exposure light by the irradiation optical system 20 is as shown in FIG. 4 for a certain period of time after the start of exposure. It rises and changes at a substantially constant temperature after the fixed time has elapsed. For this reason, using such a temperature change characteristic of the mask 16, the temperature of the mask 16 reaches a set temperature (a steady temperature during exposure (symbol Ts in FIG. 4) that becomes constant after a certain time elapses). Until the mask 16 is heated by the exposure light irradiated from the irradiation optical system 20 (empty exposure), and the temperature of the mask 16 reaches a predetermined set temperature (symbol Ts in FIG. 4), the substrate 31 with the photosensitive material is exposed. Start exposure.
[0025]
Next, the operation of the exposure apparatus 1 shown in FIGS. 1 and 2 will be described with reference to the flowchart shown in FIG.
[0026]
First, the mask 16 is attached to the mask stage 15 of the exposure apparatus main body 10 by the mask loader 27 (step 101).
[0027]
In this state, the control device 29 determines whether or not the temperature of the mask 16 detected by the thermocouple 18 is normal (whether or not it is in the vicinity of the set temperature) (step 102).
[0028]
If it is determined in step 102 that the temperature of the mask 16 is normal, the process proceeds to step 106 where the production line is operated under the control of the control device 29 and the production process ( Exposure of a plurality of substrates 31 with photosensitive materials in a single wafer mode) is started. Details of this production process will be described later.
[0029]
On the other hand, when the temperature of the mask 16 is not normal (when it is higher or lower than the allowable temperature from the set temperature), the process proceeds to step 103, and it is determined whether or not the temperature of the mask 16 is higher than the set temperature.
[0030]
If the temperature of the mask 16 is higher than the set temperature, the temperature of the mask 16 is cooled to the vicinity of the set temperature (step 104), and the process proceeds to step 102 again. On the other hand, when the temperature of the mask 16 is lower than the set temperature, the control device 29 controls the irradiation optical system 20 to heat (empty exposure) the mask 16 with the exposure light irradiated from the irradiation optical system 20. (Step 105). At this time, the substrate 31 with the photosensitive material is not placed on the exposure stage 12 of the exposure apparatus main body 10.
[0031]
As described above, when the process of heating the mask 16 by irradiating the exposure light with the photosensitive material substrate 31 not being placed on the exposure stage 12 is continued (steps 102, 103, and 105), The temperature rises according to a temperature curve as shown in FIG. 4 and reaches a predetermined set temperature (reference symbol Ts in FIG. 4).
[0032]
At this time, the control device 29 determines that the temperature of the mask 16 is normal (step 102), proceeds to step 106, operates the production line under the control of the control device 29, and uses the exposure machine 1. The production process (exposure in a single wafer format for the plurality of substrates 31 with photosensitive material) is started.
[0033]
Specifically, first, a substrate 31 with a photosensitive material is supplied into the exposure machine 1 using a robot arm (not shown) or the like and placed on the exposure stage 12 (chuck stage 13) of the exposure machine body 10. .
[0034]
Next, after the chuck stage 13 is moved by the drive stage 14 of the exposure stage 12 to perform alignment between the substrate 31 with the photosensitive material and the mask 16, the mask is applied by the irradiation optical system 20 toward the substrate 31 with the photosensitive material. By irradiating exposure light through 16, the substrate 31 with the photosensitive material is exposed with a predetermined exposure pattern.
[0035]
Then, after exposing the substrate 31 with the photosensitive material in this manner, the exposure stage 12 is moved to position the substrate 31 with the photosensitive material at the discharge position, and then the substrate is exposed using a robot arm (not shown) or the like. The substrate 31 is discharged out of the exposure machine 1.
[0036]
Then, by repeating the above steps at a constant tact interval for the number of photosensitive material-provided substrates 31 to be exposed, a plurality of substrates on which the same exposure pattern is formed are obtained.
[0037]
During the production process as described above, it is advisable to separately monitor whether or not the production line is stopped (step 107), and the production process of step 106 is continued while the production line is not stopped.
[0038]
Here, when the production line is stopped, it is determined whether or not the operation is resumed (step 108). When the operation is resumed, the process returns to step 102, and the processes of steps 102 to 104 are performed. Then, the process of step 106 is performed. In step 108, if the operation is not finally resumed, the entire process is terminated.
[0039]
As described above, according to the present embodiment, the irradiation optical system 20 starts until the temperature of the mask 16 used in the exposure apparatus 1 reaches a set temperature (a constant temperature during exposure that becomes constant after a certain time has elapsed). Since the mask 16 is heated by the irradiated exposure light and the exposure to the substrate 31 with the photosensitive material is started when the temperature of the mask 16 reaches a predetermined set temperature, the exposure to the substrate 31 with the photosensitive material is performed. The dimensional change of the mask 16 after being started can be minimized. For this reason, the shift | offset | difference for every board | substrate of the exposure pattern which arises when exposing with respect to the some board | substrate 31 with a photosensitive material in a single wafer format can be suppressed to the minimum, and the yield of a product can be improved.
[0040]
In the embodiment described above, the temperature of the mask 16 has reached a predetermined set temperature when the operation of the exposure apparatus 1 is started and when the exposure apparatus 1 is temporarily stopped and then restarted. However, the present invention is not limited to this. Whether or not the temperature of the mask 16 has reached a predetermined set temperature before the exposure of the plurality of substrates 31 with photosensitive materials is started in the exposure apparatus 1. It may be determined whether or not.
[0041]
In the above-described embodiment, the controller 29 controls the exposure of the substrate 31 with the photosensitive material to start when the temperature of the mask 16 detected by the thermocouple 18 reaches a predetermined set temperature. However, any other method can be used as long as the exposure can be performed on the substrate 31 with the photosensitive material in a state where the temperature of the mask 16 is raised to a steady temperature during the exposure. Specifically, for example, the time required for the temperature of the mask 16 to reach a predetermined set temperature after the exposure of the exposure light to the mask 16 is predicted in advance, and the exposure to the mask 16 is performed by the control device 29. You may control to start the exposure with respect to the board | substrate 31 with a photosensitive material, when the irradiation time of light reaches a predetermined value. At this time, the substrate 31 with the photosensitive material is not placed on the exposure stage 12 of the exposure apparatus main body 10 until the irradiation time of the exposure light on the mask 16 reaches a predetermined value.
[0042]
Further, in the above-described embodiment, the mask 16 is heated by the exposure light irradiated from the irradiation optical system 20 in order to raise the temperature of the mask 16 to a predetermined set temperature. The temperature of the mask 16 before being attached to the stage 15 is kept at a predetermined set temperature by a temperature adjusting mechanism 28 provided in the vicinity of the mask stage 27, and thus the mask 16 kept at the predetermined set temperature in this way. May be attached to the mask stage 15 by a mask loader 27. In this case, the control device 29 controls the mask loader 27 to start exposure of the photosensitive material-provided substrate 31 when the mask 16 is attached to the mask stage 15.
[0043]
In the embodiment described above, when the mask 16 is heated (empty exposure) by exposure light irradiation, the chuck stage 13 is moved by the drive stage 14 so that the exposure light is not irradiated onto the chuck stage 13 of the exposure stage 12. Evacuate it. Thus, the temperature of the chuck stage 13 is prevented from rising when the mask 16 is heated (empty exposure), and the dimensional change of the substrate 31 with the photosensitive material due to the temperature rise of the chuck stage 13 is minimized. Can be suppressed.
[0044]
【The invention's effect】
As described above, according to the present invention, it is possible to minimize the deviation of the exposure pattern for each substrate that occurs when a plurality of substrates with photosensitive materials are exposed in a single wafer format, and to improve the product yield. Can be improved.
[Brief description of the drawings]
FIG. 1 is a view showing the overall configuration of an exposure apparatus according to an embodiment of the present invention.
FIG. 2 is an enlarged view showing details of a part II in FIG.
FIG. 3 is a flowchart for explaining the operation of the exposure apparatus shown in FIGS. 1 and 2;
4 is a conceptual diagram showing a change in temperature of a mask in the exposure apparatus shown in FIGS. 1 and 2. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Exposure machine 10 Exposure machine body 11 Base 12 Exposure stage 13 Chuck stage 14 Drive stage 15 Mask stage 16 Mask 17 Support member 18 Thermocouple 19 Vacuum suction hole 20 Irradiation optical system 21 Super high pressure mercury lamp 22 Parabolic mirror 23 Cold mirror 24 Integrator Lens 25 Spherical mirror 26 Shutter 27 Mask loader 28 Temperature adjustment mechanism 29 Control device 31 Substrate with photosensitive material

Claims (4)

An exposure stage on which a substrate with a photosensitive material is placed;
An irradiation optical system for irradiating exposure light toward the substrate with the photosensitive material placed on the exposure stage;
A mask stage disposed between the exposure stage and the irradiation optical system;
A mask attached to the mask stage and shielding exposure light irradiated from the irradiation optical system with a predetermined pattern corresponding to an exposure pattern;
A control device for controlling the exposure stage and the irradiation optical system;
A thermocouple that contacts the mask and detects the temperature of the mask , and
The controller heats the mask as a pre-exposure process with exposure light irradiated from the irradiation optical system in a state where the substrate with a photosensitive material is not placed on an exposure stage, and detects by the thermocouple The exposure stage and the irradiation optical system are configured to start exposure of the substrate with the photosensitive material after the substrate with the photosensitive material is placed on the exposure stage when the temperature of the mask thus obtained reaches a predetermined set temperature. Control
The thermocouple is an outer peripheral portion of the mask outside the exposure area where the exposure light is not irradiated and is installed in the opening of the mask stage, and a portion of the thermocouple that is spaced from the mask stage to the exposure area side exposure machine, wherein the Turkey can detect the temperature in contact with the mask. A mask loader for attaching the mask to the mask stage;
The exposure apparatus according to claim 1, further comprising a temperature adjustment mechanism that adjusts a temperature of the mask held by the mask loader. In an exposure method in which exposure light is irradiated through a mask by an irradiation optical system toward a substrate with a photosensitive material placed on an exposure stage, and the substrate with the photosensitive material is exposed with a predetermined exposure pattern.
Irradiating exposure light from the irradiation optical system to the mask so as to heat the mask in a state where the substrate with photosensitive material is not placed on the exposure stage;
When the temperature of the mask reaches a predetermined set temperature, after placing the substrate with the photosensitive material on the exposure stage, the exposure light irradiated from the irradiation optical system is exposed to light on the exposure stage through the mask. Irradiating the substrate with the material, and starting the exposure to the substrate with the photosensitive material,
The mask is attached to a mask stage disposed between the exposure stage and the irradiation optical system,
A thermocouple for detecting the temperature of the mask in contact with the mask is installed in the outer periphery of the mask outside the exposure area where the exposure light is not irradiated and in the opening of the mask stage. spaced portions from the mask stage to the exposure region side in contact with the mask Ki out to detect the temperature, the temperature of the mask is detected in contact with the mask by the thermocouple in the step of irradiating the exposure light An exposure method. Adjusting the temperature of the mask before being attached to the mask stage;
The exposure method according to claim 3, further comprising: attaching the mask whose temperature is adjusted to the mask stage.

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