JPH0653121A - Positioning mechanism for light source lamp in light exposure device - Google Patents

Abstract

PURPOSE:To ensure illuminance uniformity in an exposing area without manual operation. CONSTITUTION:A mechanism is mounted on the top plane of an exposing stage 3. The mechanism is provided with an illumination meter 5 for providing luminance data of an exposing area on the exposing stage 3, an arithmetic circuit 6 which detects illuminance uniformity in the exposing area based on the luminance data from the illuminance meter 5 and calculates the deviation quantity of a light source lamp 1, and a driving part 7 which shifts the light source lamp 1 in the prescribed direction based on the deviation quantity calculated by the arithmetic circuit 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus for exposing a resist on a semiconductor substrate in a photolithography process for manufacturing a semiconductor, and more particularly to a light source lamp positioning mechanism for adjusting the illuminance uniformity of an exposure area. Is.

[0002]

2. Description of the Related Art FIG. 6 is a schematic block diagram showing a conventional exposure apparatus. In the figure, 51 is a light source lamp, 52 is a reflector, 53 is a lens, and 54 is an exposure stage. The light emitted from the light source lamp 51 is focused in one direction by the reflection plate 52, and further passes through the lens 53 to expose the exposure stage 5
4 is illuminated. Then, the resist on the semiconductor substrate (not shown) is exposed by the light with which the exposure stage 54 is irradiated.

In the exposure apparatus having such a structure, the so-called illuminance uniformity of the so-called exposure area projected on the semiconductor substrate (not shown) on the exposure stage 54 is determined by the light source lamp 5.
1 and the reflection plate 52 are arranged. In other words,
The illuminance uniformity in the exposure area can be adjusted by moving the light source lamp 51, and as a positioning mechanism for the light source lamp 51 for that purpose, the illuminance meter 55 in the conventional apparatus is used.
And an observation window 56 were provided.

The illuminance meter 55 is attached to the upper surface of the exposure stage 54, and the illuminance meter 55 can obtain the illuminance data of the exposure area on the exposure stage 54. The illuminance meter 55 is used in the exposure stage 54.
The illuminance data is measured by scanning the inside of the exposure area according to the movement of.

From the illuminance data obtained from the illuminance meter 55, illuminance distributions as shown in FIGS. 7A to 7C can be obtained depending on the positional relationship between the light source lamp 51 and the reflector 52. Here, V1 in the drawing is a region where light is uniformly irradiated on the exposure stage 55 (hereinafter referred to as a uniform region), V2 in the drawing.
Indicates an exposure area, and P1 in the figure indicates a uniform area V.
The center of 1 (optical axis point), P2 in the figure, indicates the center of the exposure region V2.

First, in the case of FIG. 7A, the illuminance uniformity is ensured in the exposure area V2, and in this state, the center P1 of the uniform area V1 and the center P2 of the exposure area V2 substantially coincide with each other. In addition, the intensity of the overall illuminance is secured above the allowable level.

In the case of FIG. 7B, the illuminance uniformity is not ensured in the exposure area V2, and in this state, the center P1 of the uniform area V1 and the center P2 of the exposure area V2.
There is a deviation between the two, and a difference in brightness appears in the exposure area V2. In such a case, the operator moves the light source lamps 51 in the horizontal direction (hereinafter, referred to as x and y directions) by an appropriate amount based on the previously recognized deviation, and finally each center P1,
It adjusted so that the position of P2 might correspond.

Also in the case of FIG. 7C, the illuminance uniformity is not ensured in the exposure area V2, and in this state, the center P1 of the uniform area V1 and the center P2 of the exposure area V2.
However, the overall illuminance is too weak and is below the acceptable level. In such a case, the operator moves the light source lamp 51 in the vertical direction (hereinafter, referred to as the z direction) by an appropriate amount based on the intensity of the illuminance in the exposure area, and finally an illuminance of an allowable level is obtained. Was adjusted.

Further, when the illuminance of the exposure area V2 becomes extremely weak due to the replacement work of the light source lamp 51 or the uniform illuminance area cannot be obtained in the exposure area V2, the operator uses the observation window 56. While confirming the position of the light source lamp 51, the light source lamp 5 is attached to the reference point carved in the observation window 56.
The light source lamp 51 is moved so that the center of 1 is located, and then the above adjustment work is performed.

[0010]

However, in the above-mentioned conventional exposure apparatus, the positioning work of the light source lamp 51 for ensuring the illuminance uniformity of the exposure area V2 requires the skill of the operator and is similar. Since this is a method of obtaining a predetermined positioning accuracy while repeating the work many times, the burden on the operator is great and more time is required until the adjustment is completed. There is also a problem in that there is a slight variation between operators in terms of the positioning accuracy of the light source lamp 51 and the time spent therefor.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a light source lamp positioning mechanism in an exposure apparatus that can ensure the illuminance uniformity of the exposure area without relying on human labor.

[0012]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and includes a light source lamp disposed in the vicinity of a reflection plate, and an exposure stage installed in a state of facing the light source lamp. In an exposure apparatus that includes a lens disposed between the light source lamp and the exposure stage, and the light emitted from the light source lamp is irradiated onto the exposure stage through the lens, the one mounted on the upper surface of the exposure stage, An illuminance meter for obtaining illuminance data of the exposure area on the exposure stage, and an arithmetic circuit for calculating the amount of positional deviation of the light source lamp by detecting the illuminance uniformity in the exposure area based on the illuminance data obtained by the illuminance meter. And the position determination of the light source lamp in the exposure apparatus, which includes a driving unit that moves the light source lamp in a predetermined direction based on the positional deviation amount calculated by the arithmetic circuit. It is a mechanism.

Further, by installing a pair of CCD cameras for observing the position of the light source lamp, and correcting the position of the light source lamp based on the observation data obtained by each CCD camera, at least the illuminance data obtained by the illuminometer. The position shift amount of the light source lamp can be calculated from the above.

[0014]

In the light source lamp positioning mechanism of the present invention, the arithmetic circuit detects the illuminance uniformity of the exposure area based on the illuminance data obtained from the illuminance meter, and calculates the positional deviation amount of the light source lamp. By the drive unit moving the light source lamp based on the amount of positional deviation, the light source lamp is positioned and the illuminance uniformity in the exposure area is secured. Also, if the position shift amount of the light source lamp is too large to calculate the position shift amount by the arithmetic circuit, CC
The position of the light source lamp is corrected on the basis of the observation data from the D camera, whereby the amount of positional deviation can be calculated.

[0015]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram of an exposure apparatus in the embodiment. In the figure, reference numeral 1 is a light source lamp, and the light source lamp 1 is arranged in the vicinity of the reflection plate 2. On the other hand, reference numeral 3 in the drawing is an exposure stage.
Is installed to face the above-mentioned light source lamp 1. Further, a lens 4 is arranged between the light source lamp 1 and the exposure stage 3.

Further, the exposure apparatus of this embodiment is provided with an illuminance meter 5, an arithmetic circuit 6, and a drive section 7 as a light source lamp positioning mechanism. The illuminance meter 5 is for obtaining illuminance data of the exposure area on the exposure stage 3, and is attached to the upper surface of the exposure stage 3. The illuminance meter 5 is connected to the arithmetic circuit 5, whereby the illuminance data from the illuminance meter 5 is sent to the arithmetic circuit 6.
Incidentally, the illuminance meter 5 uses a so-called photoelectric element whose current value changes depending on the intensity of light.

The arithmetic circuit 6 has a function of detecting the illuminance uniformity in the exposure area based on the illuminance data obtained by the illuminance meter 5 and calculating the positional deviation amount of the light source lamp 1. The arithmetic circuit 6 is connected to the control circuit 8 so that the positional deviation amount calculated by the arithmetic circuit 6 is sent to the control circuit 8.

The drive unit 7 moves the light source lamp 1 in a predetermined direction based on the amount of positional deviation calculated by the arithmetic circuit 6, and is connected to the control circuit 8. In this example, the drive unit 7 operates according to a command from the control circuit 8, but the operation of the drive unit 7 can be directly controlled by the arithmetic circuit 6 depending on the circuit configuration.

Here, a specific example of the drive unit 7 will be described with reference to FIG. As shown in the figure, the driving unit 7 is x, y, z.
Direction moving screws 9, 10, 11 and supporting members 12, 1 screwed to the moving screws 9, 10, 11 respectively.
3 and 14 and motors 15 and 16 (not shown) for rotating the respective moving screws 9, 10 and 11, and each motor 15, 16 and (not shown) is the above-mentioned control circuit. 8 is connected. The light source lamp 1 includes a support member 12
Attached to the bottom of each motor 15, 16,
It can move in the x, y, and z directions in response to rotation (not shown).

Further, in the exposure apparatus of this embodiment, the pair of CCD cameras 17 for observing the position of the light source lamp 1 is used.
a and 17b are installed. Each CCD camera 17a,
17b is installed horizontally at a right angle to the light source lamp 1, and the center of the camera and the center of the light source are arranged with the light source lamp 1 in a regular arrangement state (where the illuminance uniformity in the exposure area is secured). Are positioned so that and match. With this configuration, the light source lamp 1 in the xyz directions
Will be observed by the CCD cameras 17a and 17b.

In addition, each CCD camera 17a, 17b is connected to the second arithmetic circuit 18, whereby each C
The observation data from the CD cameras 17a and 17b are sent to the second arithmetic circuit 18. The second arithmetic circuit 18 has a function of calculating the positional deviation amount of the light source lamp 1 based on the observation data obtained from the CCD cameras 17a and 17b. Further, the second arithmetic circuit 18 is connected to the control circuit 8 for controlling the operation of the drive unit 7, whereby the position of the light source lamp 1 is corrected based on the observation data obtained from the CCD cameras 17a and 17b. It is configured to.

Next, the operation of the light source lamp positioning mechanism will be described with reference to the flow chart of FIG. First, turn on the power of the exposure apparatus to expose stage 1
Light is radiated on the top (S1). Next, the illuminance meter 5 is scanned to obtain illuminance data of the exposure area (S2). Then, a data map as shown in FIG. 4 is created based on the illuminance data obtained from the illuminance meter 5 (S3). In the data map of FIG. 4, the exposure area V2 is finely divided into, for example, a grid, and the illuminance data in each of the divisions W is measured by the illuminance meter 5.

Subsequently, the illuminance uniformity of the exposure area is detected by the arithmetic circuit 6 based on the data map of FIG. 4 (S
4). In this embodiment, the illuminance uniformity of the exposure area is detected as follows. First, the maximum value and the minimum value are extracted from the illuminance data in each section W of the data map, and a numerical value obtained by applying each of these values to a predetermined mathematical expression is compared with a preset reference value. Detected by.
At the same time, it is also detected depending on whether or not the illuminance of the entire exposure area is secured at an allowable level. Here, when the illuminance uniformity of the exposure area is detected as (good), the light source lamp 1 is in the regular arrangement state, and thus the operation is ended (S5). To step (S6).

Further, the arithmetic circuit 6 calculates the amount of positional deviation of the light source lamp 1 in the xy directions based on the illuminance data obtained from the illuminance meter 5 (S6). Here, when calculating the amount of positional deviation of the light source lamp 1, for example, the illuminance data of the hatched section W in the data map shown in FIG. 4 is extracted, and the illuminance data below the allowable level is extracted from the extracted illuminance data. The section W is calculated, and the size area thereof is calculated. This size region is calculated as the positional deviation amounts L1 and L2 of the light source lamp 1 in the x and y directions as shown in FIG.

Subsequently, the arithmetic circuit 6 determines whether or not the amount of positional deviation in the xy directions calculated in step S6 is 0 (zero) (S7). When it is determined in step S7 that the amount of positional deviation in the xy directions is not 0 (zero), the control circuit 8 operates the drive unit 7 based on the amount of positional deviation, whereby the light source lamp 1 in the xy directions is operated. The position is corrected (S8).

On the other hand, when it is determined in step S7 that the amount of positional deviation in the xy directions is 0 (zero), the positional deviation of the light source lamp 1 in the z direction is based on the illuminance data obtained from the illuminance meter 5. The amount is calculated (S9), and the control circuit 8 operates the drive unit 7 based on the calculated amount of positional deviation to correct the position of the light source lamp 1 in the z direction (S8).

Thus, the light source lamp 1 in the xyz directions
When the position correction is completed, the process returns to step S2 again, the illuminance meter 5 is scanned, the illuminance uniformity of the exposure area is confirmed in the same manner as before, and if OK, the positioning operation is ended (S).
5).

In step S6 described above, if the positional deviation amount cannot be calculated because the degree of positional deviation of the light source lamp 1 is too large, the calculation becomes impossible and the process proceeds to step S10. In step S10, the position of the light source lamp 1 is confirmed by the CCD cameras 17a and 17b installed on the side of the light source lamp 1. The observation data confirmed here is sent to the second arithmetic circuit 18. The second arithmetic circuit 18 calculates the positional deviation amount of the light source lamp 1 in the xyz directions based on the observation data obtained from the CCD cameras 17a and 17b (S11). After that, the position of the light source lamp 1 is corrected based on the position shift amount (S8),
Then, the process returns to step S2 to restart the operation. By performing the operations of steps S10, S11, and S8 described here, at least the positional deviation amount of the light source lamp 1 can be calculated in step S6 in the next operation flow.

In the exposure apparatus of this embodiment, the light source lamp 1 is positioned in accordance with such an operation, and the positioning operation ensures the illuminance uniformity of the exposure area.

[0030]

As described above, according to the present invention,
Since the adjustment of the illuminance uniformity in the exposure area can be automatically performed without relying on human hands, the skill level of the operator and the work load required for the adjustment, which have been conventionally required, can be eliminated. In addition, since it is not necessary to repeat the same work many times as in the conventional case, the time for the adjustment work is significantly shortened. Further, the automation of the adjustment work eliminates the variations in the adjustment accuracy among the workers and the variations in the time required for the adjustment work.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an exposure apparatus in an embodiment.

FIG. 2 is a diagram illustrating an example of a drive unit.

FIG. 3 is an operation flowchart in the embodiment.

FIG. 4 is a diagram illustrating a data map.

FIG. 5 is a diagram illustrating an example of a layout state of exposure areas.

FIG. 6 is a schematic configuration diagram showing a conventional exposure apparatus.

FIG. 7 is a diagram illustrating an illuminance distribution.

[Explanation of symbols]

1 Light Source Lamp 2 Reflector 3 Exposure Stage 4 Lens 5 Illuminance Meter 6 Arithmetic Circuit 7 Drive Unit 17a, 1
7b CCD camera

Claims (2)

[Claims] 1. A light source lamp disposed in the vicinity of a reflector, an exposure stage disposed opposite to the light source lamp, and a lens disposed between the light source lamp and the exposure stage. An exposure apparatus in which light emitted from the light source lamp is irradiated onto the exposure stage through the lens, which is mounted on an upper surface of the exposure stage to obtain illuminance data of an exposure area on the exposure stage. Illuminance meter, an arithmetic circuit that detects the illuminance uniformity in the exposure area based on the illuminance data obtained by the illuminance meter, and calculates the positional deviation amount of the light source lamp, and the positional deviation calculated by the arithmetic circuit. A light source lamp positioning mechanism in an exposure apparatus, comprising: a drive unit that moves the light source lamp in a predetermined direction based on an amount. 2. A pair of CCD cameras for observing the position of the light source lamp is installed, and the position of the light source lamp is corrected based on the observation data obtained by each CCD camera, so that at least the illuminance meter 2. The light source lamp positioning mechanism in an exposure apparatus according to claim 1, wherein the positional deviation amount of the light source lamp can be calculated from the obtained illuminance data.