JP4487700B2 - Proximity exposure equipment - Google Patents

Description

  The present invention relates to a proximity exposure apparatus suitable for proximity exposure transfer of a mask pattern onto a substrate such as a large flat panel display such as a liquid crystal display or a plasma display.

  In proximity exposure, a translucent substrate (material to be exposed) coated with a photosensitive agent on the surface is held on the substrate stage of the proximity exposure apparatus, and the substrate is brought close to the mask held on the mask holding frame of the mask stage. Then, the gap between the two is set to several tens μm to several hundreds μm, for example, and then the exposure light is irradiated toward the mask by the irradiation device from the side away from the substrate of the mask. The pattern is exposed and transferred.

By the way, in proximity exposure, there is a method in which the mask is made the same size as the substrate and is exposed in a lump. However, in such a method, when the mask pattern is exposed and transferred onto a large substrate, the mask becomes large and the mask is exposed. This causes problems in terms of the influence on the pattern accuracy due to the bending of the pattern and the cost.
For these reasons, conventionally, when a mask pattern is exposed and transferred onto a large substrate, a mask smaller than the substrate is used, and the substrate stage is moved stepwise relative to the mask, for example, in the Y-axis direction. The so-called stepwise proximity exposure system that irradiates the pattern exposure light in a state in which the mask is placed close to the substrate at each step, thereby exposing and transferring a plurality of patterns drawn on the mask onto the substrate. Is often used.

  Specifically, for example, in the case of two-step exposure, first, the first substrate is transported onto the substrate stage and held at the exposure position, and then the lower surface of the mask and the substrate disposed opposite to each other above the substrate. The gap amount with the upper surface is measured by a gap sensor, and the substrate stage is finely moved up and down so that the gap amount becomes a predetermined target value based on the measured value, and then the gap amount becomes the target value. In this state, the exposure light of the first shot is irradiated from the irradiation means toward the mask, and the pattern of the mask is exposed and transferred to the substrate.

In the exposure for the second and subsequent layers, the alignment between the mask side alignment mark and the alignment mark exposed and transferred to the substrate is performed in a state where the gap amount has reached the target value. The exposure light of the first shot is irradiated from the irradiation means toward the mask, and the pattern of the mask is exposed and transferred to the substrate.
After the exposure, the substrate stage is slightly moved downward to increase the clearance between the lower surface of the mask and the upper surface of the substrate by a certain amount. In this state, the substrate stage is fed by one step relative to the mask, and the lower surface of the mask and the substrate The gap amount between the upper surface of the substrate and the upper surface of the substrate is measured by a gap sensor, and the substrate stage is finely moved up and down so that the gap amount becomes a predetermined target value based on the measured value.Then, the gap amount becomes the target value. In this state, the exposure light for the second shot is irradiated from the irradiation means toward the mask, and the mask pattern is exposed and transferred to the substrate.

In the exposure for the second and subsequent layers, the alignment between the mask side alignment mark and the alignment mark exposed and transferred to the substrate is performed in a state where the gap amount has reached the target value. The exposure light of the second shot is irradiated from the irradiation means toward the mask, and the pattern of the mask is exposed and transferred to the substrate.
After the exposure, the substrate stage is slightly moved downward to increase the gap between the lower surface of the mask and the upper surface of the substrate by a certain amount. In this state, the substrate is transported outside the apparatus to complete the exposure of the first substrate. .
After the exposure of the first substrate is completed, the second substrate is transported onto the substrate stage and held at the exposure position, and step exposure is performed in the same process as described above.

However, in the conventional proximity exposure apparatus described above, the gap amount between the lower surface of the mask and the upper surface of the substrate is measured by a gap sensor, and the substrate stage is finely moved up and down so that the gap amount becomes a target value based on the measured value. At the beginning, it is necessary to take a sufficient amount of clearance for safety, and to determine whether the sensor is in a position where measurement is possible. It takes time, and it takes time until the gap amount actually reaches the target value. For this reason, there is a problem that throughput is lowered when a mask pattern is step-exposed on a large number of large substrates.
The present invention has been made to solve such a problem, and an object thereof is to provide a proximity exposure apparatus capable of improving the throughput.

In order to achieve the above object, an invention according to claim 1 includes a substrate stage that holds a substrate as an exposed material, and a mask stage that holds a mask having a pattern to be exposed while facing the substrate. A gap sensor for measuring a gap amount between the mask and the substrate, a gap amount adjusting means for relatively moving the mask stage and the substrate stage to adjust the gap amount, and the gap amount being a predetermined target value In the proximity exposure apparatus provided with irradiation means for irradiating light for exposure toward the mask so as to expose and transfer the pattern of the mask onto the substrate in a state adjusted to the gap amount, the gap amount adjusting means includes: when starting the exposure transfer for prior Symbol board pattern, a first goal the clearance amount based on the measurement values of the gap sensor is predetermined It causes relative movement between the substrate stage and the mask stage so that the height position of the movable one of said mask stage and said substrate stage when the amount of the gap is set to the first target value and stores the detected as the second target value, when exposing transferred before Symbol substrate a pattern of the mask after the second target value is stored, of said mask and said substrate stage the height position of the moving side is characterized by causing relative movement of said substrate stage and the mask stage so that the second target value.
According to a second aspect of the present invention, in the first aspect, the thickness of the substrate when the second target value is stored and the thickness of the substrate whose position is controlled based on the second target value A plate thickness difference calculating means for calculating a difference is provided, and a value of the plate thickness difference by the plate thickness difference calculating means is added to the second target value.

According to the first aspect of the present invention, feedback control is performed in which the difference between the measurement value of the gap sensor and the first target value is calculated and the mask and the substrate stage are finely moved up and down so that the difference becomes zero. When the exposure of the substrate W is performed after the moving height position of the mask stage and the substrate stage is stored as the second target value , the feedback control need not be performed, and the mask stage and the substrate stage since the height position of the movable out of need only perform control so as to have a second target value, it is possible to improve the throughput.
In the invention of claim 2, in addition to the invention of claim 1, when the thickness of the substrate when the second target value is stored is different from the thickness of the substrate to be positioned based on the second target value Can also be easily accommodated.

Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a partially broken explanatory view for explaining a proximity exposure apparatus as an example of an embodiment of the present invention, FIG. 2 is an explanatory view for explaining a measurement principle of a gap sensor, and FIG. FIG. 4 is a view for explaining the arrangement of the plate thickness measuring instrument.
As shown in FIG. 1, a proximity exposure apparatus as an example of an embodiment of the present invention uses a mask M smaller than a substrate W as a material to be exposed, and holds the mask M with a mask holding frame 25 of a mask stage 1. At the same time, the substrate W is held by the substrate stage 2, and in this state, the substrate stage 2 is moved stepwise relative to the mask M in the two axial directions of the X-axis direction and the Y-axis direction. The pattern of the mask M is exposed and transferred onto the substrate W by irradiating light for pattern exposure from the irradiating means 3 toward the mask M in a state of being opposed to each other.

  In FIG. 1, reference numeral 4 denotes an apparatus base 4. An X-axis stage feed mechanism 5 for moving the substrate stage 2 stepwise in the X-axis direction is installed on the apparatus base 4. A Y-axis stage feed mechanism 6 for moving the substrate stage 2 stepwise in the Y-axis direction is installed on the axis feed table 5a, and the substrate stage 2 is installed on the Y-axis feed table 6a of the Y-axis stage feed mechanism 6. Has been. The substrate W is held on the upper surface of the substrate stage 2 in a state of being vacuumed by a work chuck or the like.

  Between the Y-axis stage feed mechanism 6 and the substrate stage 2, there is a vertical coarse motion device 7 having a relatively coarse positioning resolution that performs a simple vertical movement of the substrate stage 2 but a large movement stroke and movement speed, and a vertical coarse motion A vertical fine movement device 8 that can be positioned with higher resolution than the apparatus 7 and finely adjusts the gap between the opposing surfaces of the mask M and the substrate W to a predetermined amount by finely moving the substrate stage 2 up and down is installed.

  The vertical coarse movement device 7 moves the substrate stage 2 up and down with respect to the fine movement stage 6b by an appropriate drive mechanism provided on the fine movement stage 6b described later. Reference numeral 14a denotes a coarse movement shaft fixed at four positions on the bottom surface of the substrate stage 2, which engages with a linear motion bearing 14 fixed to the fine movement stage 6b and is guided in the vertical direction with respect to the fine movement stage 6b. Note that it is desirable that the vertical coarse motion device 7 has high repeated positioning accuracy even if the resolution is low.

  The vertical fine movement device 8 includes a fixed base 9 fixed to the Y-axis feed base 6a, and a linear guide guide rail 10 attached to the fixed base 9 with its inner end inclined obliquely downward. A ball screw nut (not shown) is connected to a slide body 12 that reciprocates along the guide rail 10 via a slider 11 straddling the guide rail 10. Is in contact with a flange 12a fixed to the fine movement stage 6b so as to be slidable in the horizontal direction.

Further, the flange 12a and the fixing base 9 are connected by a leaf spring 15 as shown in FIG. The leaf spring 15 has three tongue pieces 16 a, 16 b and 16 c, a central tongue piece 16 b is fixed to the flange 12 a, and both tongue pieces 16 a and 16 c are fixed to the fixing base 9.
Therefore, the flange 12a is restricted from moving in the horizontal plane (in the XY plane), and only fine movement in the vertical direction and a slight change in inclination are allowed. In addition, you may make it fix the tongue piece 16b of a center to the fixing stand 9, and the tongue pieces 16a and 16c of both sides to the flange 12a.

Then, when the screw shaft of the ball screw is rotationally driven by the motor 17 attached to the fixed base 9, the nut, the slider 11 and the slide body 12 are integrally moved along the guide rail 10 in an oblique direction. The flange 12a is finely moved up and down. At this time, the horizontal displacement of the flange 12 a is restricted by the action of the leaf spring 15.
The vertical fine movement device 8 is installed on one end side (left end side in FIG. 1) in the Y-axis direction of the Z-axis feed base 6a and two on the other end side, and a total of three are installed and controlled independently. It is like that. Thereby, the vertical fine movement device 8 finely adjusts the height of the flanges 12a at the three locations independently based on the measurement results of the gap amounts between the mask M and the substrate W at a plurality of locations by the gap sensor 31 described later. Since the height and inclination of the stage 2 can be finely adjusted, the gap between the mask M and the substrate W can be set to a target value with good parallelism.

On the Y-axis feed base 6a, a bar mirror 19 facing the Y-axis laser interferometer 18 that detects the position of the substrate stage 2 in the Y direction, and an X-axis laser that detects the position of the substrate stage 2 in the X-axis direction. A bar mirror (both not shown) facing the interferometer is installed.
The bar mirror 19 facing the Y-axis laser interferometer 18 extends along the X-axis direction on one side of the Y-axis feed base 6a, and the bar mirror facing the X-axis laser interferometer is on one end side of the Y-axis feed base 6a. It extends along the Y-axis direction.

The Y-axis laser interferometer and the X-axis laser interferometer are always arranged so as to face the corresponding bar mirrors and supported by the apparatus base 4. Two Y-axis laser interferometers 18 are installed apart from each other in the X-axis direction.
The two Y-axis laser interferometers 18 detect the position of the Y-axis feed base 6a and then the substrate stage 2 in the Y-axis direction and the yawing error via the bar mirror 19.

The X-axis laser interferometer detects the position of the X-axis feed base 5a and then the substrate stage 2 in the X-axis direction via the opposing bar mirror.
Two Y-axis direction position data and X-axis direction position data detection signals obtained during step feed are output to the control device, and the control device outputs this detection signal (actual position data) and commanded position data (to be positioned) A correction amount is calculated on the basis of the difference from the position data), and the calculation result is output to a driving circuit of a mask position adjusting means (and vertical fine movement device 8 as necessary), which will be described later. Accordingly, the mask position adjusting means and the like are controlled to correct the positional deviation and yawing error in the X-axis direction and the Y-axis direction, and the mask M is aligned so as to correctly face the position to be exposed on the substrate W. The control device is also used for gap adjustment and the like which will be described later.

The X-axis laser interferometer, the Y-axis laser interferometer, and the like are mainly used for exposure (first layer exposure) to the substrate W on which no pattern is formed yet. In the case of an exposure apparatus for exposure of the second and subsequent layers on the exposed substrate W, these may be omitted or used with an alignment camera.
The mask stage 1 can be moved in the X, Y, and θ directions (in the X, Y plane) by being inserted into a mask frame 24 formed of a substantially rectangular frame and a central opening of the mask frame 24 through a gap. The mask frame 24 is held in a fixed position above the substrate stage 2 by a support column 4 a protruding from the apparatus base 4.

An inwardly extending flange 26 is provided on the lower surface of the central opening of the mask holding frame 25 along the entire circumference of the opening. A mask M on which a pattern to be exposed is drawn on the lower surface of the flange 26 is detachably held via a vacuum suction device (not shown) or the like.
Further, above the flange 26, a gap sensor 31 as a means for measuring a gap amount between the opposing surfaces of the lower surface of the mask M and the upper surface of the substrate W, and an alignment mark (in the exposure region R of the mask M) (Not shown) and an alignment mark (not shown: used for alignment of the second and subsequent layers) provided on the substrate W side or an alignment mark (not shown) provided on the substrate stage 2 Alignment cameras 30 as means for capturing the images are movably arranged.

  As shown in FIG. 2, the gap sensor 31 applies laser light from the light projecting unit 31a to the lower surface of the mask M and the upper surface of the substrate W, and receives the reflected light on each surface by the light receiving unit (line sensor) 31b. The amount of clearance between the lower surface of M and the upper surface of the substrate W is detected, and is arranged at two locations in the Y-axis direction, two locations apart from each other on the inner side of the two sides along the Y-axis direction of the flange 26. ing.

  Based on the measurement results of these four gap sensors 31, an arithmetic process is performed by a control device (not shown) to detect the amount of deviation in parallelism between the opposing surfaces of the mask M and the substrate W. This detection The gap between the opposing surfaces of the mask M and the substrate W is set to a predetermined value by the three vertical fine movement devices 8 that can be driven independently of each other according to the amount of deviation.

  In this embodiment, the vertical fine movement device 8 and the control device constitute the gap amount adjusting means of the present invention, and the gap amount adjusting means exposes the pattern of the mask M onto the first substrate W. At the time of transfer, the control device controls the vertical fine movement device 8 to finely move the substrate stage 2 up and down so that the gap amount becomes a predetermined first target value based on the measurement value of the gap sensor 31. At the same time, the height of the substrate stage 2 when the gap amount is set to the first target value is detected (detected by, for example, an encoder or the like from the rotation number of the motor 17 of the vertical fine movement device 8), and this is detected. Is stored in a predetermined storage area, and when the pattern of the mask M is exposed and transferred to the second and subsequent substrates W, control is performed so that the height of the substrate stage 2 becomes the second target value. The device is a vertical fine motion device 8 Controlled to be vertical fine substrate stage 2.

  The alignment camera 30 is arranged at two locations, one on each of the upper sides of the two sides of the flange 26 along the Y-axis direction, approximately in the center of the Y-axis direction, and the image data of these two alignment cameras 30 is included. On the basis of this, the amount of plane deviation between the mask M and the substrate W can be detected by performing arithmetic processing with a control device (not shown), and the mask position adjusting means sets the mask holding frame 25 to X, X according to this detected plane deviation amount. The direction of the mask M held by the mask holding frame 25 with respect to the substrate W is adjusted by moving in the Y and θ directions.

  The mask position adjusting means is spaced apart from each other in the Y-axis direction on one side along the Y-axis direction of the mask holding frame 25 and a Y-axis direction driving device (not shown) attached to one side along the X-axis direction of the mask frame 24. And two X-axis direction drive devices (not shown) mounted in the X-axis direction, and the Y-axis direction drive device adjusts the mask holding frame 25 in the Y-axis direction. Thus, the X-axis direction and the θ-axis direction (swinging around the Z-axis) of the mask holding frame 25 are adjusted.

In FIG. 1, reference numeral 28 denotes a masking aperture mechanism having a light shielding blade that limits the exposure range by shielding exposure light in an arbitrary range on the mask M held by the mask holding frame 25 as necessary. .
In order to perform step exposure using the proximity exposure apparatus having the above configuration, first, the alignment mark on the substrate stage 2 imaged by the alignment camera 30 and the exposure area of the mask M held by the mask holding frame 25 are provided. The mask position adjusting means moves the mask holding frame 25 in a predetermined direction in accordance with the amount of deviation from the alignment mark to adjust the orientation of the mask M so that the initial position of the mask M with respect to the substrate stage 2 is adjusted. The posture (position) of M is stored in a storage area of a control device (not shown).

  Next, the first substrate W is transported onto the substrate stage 2 and held at the exposure position. In this state, the gap amount between the lower surface of the mask M and the upper surface of the substrate W, which are opposed to each other above the substrate W, is set. Based on the measurement value measured by the gap sensor 31, the control device controls the vertical fine movement device 8 so that the gap amount becomes a first target value set in advance to finely move the substrate stage 2 up and down. The height of the substrate stage 2 when the gap amount is set to the first target value is detected and stored as a second target value for the first shot in a predetermined storage area. In the state where the first target value is reached, the exposure light of the first shot (first position) is irradiated from the irradiation means 3 toward the mask M, and the pattern of the mask M is exposed and transferred to the substrate W.

  In the exposure for the second and subsequent layers, the alignment (alignment) between the alignment mark on the mask M side and the alignment mark exposed and transferred to the substrate W is performed in a state where the gap amount has reached the first target value. After the alignment, the exposure light for the first shot is irradiated from the irradiation means 3 toward the mask M, and the pattern of the mask M is exposed and transferred to the substrate W.

  After the exposure, the control device may use the vertical fine motion device 8 (however, if it is desired to increase the speed or to provide a clearance with a margin, the vertical coarse motion device 7 is used instead of the vertical fine motion device 8. This is the same in the lowering process of all the substrate stages 2 described below.) The substrate stage 2 is lowered to increase the gap between the lower surface of the mask M and the upper surface of the substrate W by a certain amount. The X-axis stage feed mechanism 5 or the Y-axis stage feed mechanism 6 feeds the substrate stage 2 to the mask M by a predetermined step amount in the X-axis direction or Y-axis direction, and the exposure position for the second shot (second place). Position to.

  At this time, based on position data in the X-axis direction and the Y-axis direction of the substrate stage 2 by the X-axis laser interferometer and the two Y-axis laser interferometers 18, positioning errors and yawing errors in the X-axis direction and the Y-axis direction ( Step feed error), the controller calculates a correction amount of the orientation of the mask M according to the step feed error based on the step feed error and the initial posture information of the mask M stored in the storage area, By outputting this calculation result to the driving circuit of the mask position adjusting means (and the vertical fine movement device 8 as necessary), the mask position adjusting means and the like are controlled according to the correction amount, and the mask is held via the mask holding frame 25. The direction of M is adjusted.

  Next, the gap amount between the lower surface of the mask M and the upper surface of the substrate W is measured by the gap sensor 31, and based on the measured value, the control device sets the gap amount to a predetermined first target value. The vertical fine movement device 8 is controlled to finely move the substrate stage 2 up and down, and the height of the substrate stage 2 is detected when the gap amount is set to the first target value, and this is detected at the second shot position. 2 is stored in a predetermined storage area, and then the exposure light for the second shot is irradiated from the irradiation means 3 toward the mask M in a state where the gap amount becomes the first target value. Then, the pattern of the mask M is exposed and transferred to the substrate W. When the vertical coarse movement device 7 is used when the substrate stage 2 is lowered, the vertical movement device 7 brings the substrate stage 2 closer to the mask M by a predetermined amount prior to the clearance adjustment by the vertical fine movement device 8. You may do it. The same applies to the adjustment of all gap amounts described below.

In the exposure for the second and subsequent layers, the alignment (alignment) between the alignment mark on the mask M side and the alignment mark exposed and transferred to the substrate W is performed in a state where the gap amount has reached the first target value. After the alignment is completed, the exposure light for the second shot is irradiated from the irradiation unit 3 toward the mask M, and the pattern of the mask M is exposed and transferred to the substrate W. Thereafter, similarly, predetermined step exposure is repeated.
After the exposure of all the regions is completed, the control device lowers the substrate stage 2 by the vertical movement device 7 to increase the gap amount between the lower surface of the mask M and the upper surface of the substrate W by a certain amount. The step exposure of the 1st board | substrate W is complete | finished by conveying out of an apparatus.

  After the step exposure of the first substrate W is completed, the initial alignment of the mask M is completed in the same procedure as the first substrate, and then the second substrate W is transferred onto the substrate stage 2 to the exposure position. In this state, the control device controls the vertical fine movement device 8 so that the height of the substrate stage 2 becomes the second target value of the first shot of the first substrate W, and the substrate stage 2 is moved. Then, the exposure light for the first shot is masked from the irradiation means 3 in a state where the height of the substrate stage 2 becomes the second target value for the first shot stored in the storage area. The pattern of the mask M is exposed and transferred onto the substrate W by irradiation toward M.

In the second and subsequent exposures, the alignment mark on the mask M side and the alignment mark exposed and transferred to the substrate W in a state where the height of the substrate stage 2 becomes the second target value of the first shot, After the alignment is completed, the exposure light for the first shot is irradiated from the irradiation unit 3 toward the mask M, and the pattern of the mask M is exposed and transferred to the substrate W.
After the exposure, the control device lowers the substrate stage 2 by the vertical fine movement device 8 to increase the gap amount between the lower surface of the mask M and the upper surface of the substrate W by a certain amount, and in this state, the X-axis stage feed mechanism 5 or the Y-axis stage The feed mechanism 6 feeds the substrate stage 2 to the mask M by a predetermined step amount in the X-axis direction or the Y-axis direction.

  At this time, based on position data in the X-axis direction and the Y-axis direction of the substrate stage 2 by the X-axis laser interferometer and the two Y-axis laser interferometers 18, positioning errors and yawing errors in the X-axis direction and the Y-axis direction ( Step feed error), the controller calculates a correction amount of the orientation of the mask M according to the step feed error based on the step feed error and the initial posture information of the mask M stored in the storage area, By outputting this calculation result to the driving circuit of the mask position adjusting means (and the vertical fine movement device 8 as necessary), the mask position adjusting means and the like are controlled according to the correction amount, and the mask is held via the mask holding frame 25. The direction of M is adjusted.

  Next, the control device controls the vertical fine movement device 8 so that the height of the substrate stage 2 becomes the second target value of the second shot stored in the storage area of the first substrate W. The stage 2 is finely moved up and down, and then the exposure light for the second shot from the irradiation unit 3 is applied to the mask M in a state where the height of the substrate stage 2 becomes the second target value at the position of the second shot. The pattern of the mask M is exposed and transferred onto the substrate W.

  In the exposure of the second and subsequent layers, the alignment of the alignment mark on the mask M side and the alignment mark exposed and transferred to the substrate W with the height of the substrate stage 2 set to the second target value ( Alignment) is performed, and after the alignment is completed, the exposure light of the second shot is irradiated from the irradiation unit 3 toward the mask M, and the pattern of the mask M is exposed and transferred to the substrate W. Thereafter, similarly, predetermined step exposure is repeated.

After the exposure of all regions is completed, the control device lowers the substrate stage 2 by the vertical fine movement device 8 to increase the gap amount between the lower surface of the mask M and the upper surface of the substrate W by a certain amount. Then, the step exposure of the second substrate W is completed.
As described above, in this embodiment, when the second and subsequent substrates W are exposed, the difference between the measurement value of the gap sensor 31 and the first target value is calculated so that the difference becomes zero. In addition, it is not necessary to perform feedback control for finely moving the substrate stage 2 with the vertical fine movement device 8, and it is only necessary to control the vertical fine movement device 8 so that the height of the substrate stage 2 becomes the second target value. Can be improved.

  Further, the substrate stage 2 is moved stepwise in the X-axis direction and the Y-axis direction with respect to the mask M and irradiated with light for pattern exposure at each step, whereby a plurality of patterns of the mask M are formed on the substrate. Since exposure transfer is performed on W, exposure to a large substrate W can be performed with a smaller mask M to reduce cost and increase pattern accuracy. A variety of patterns can be created.

In addition, this invention is not limited to the said embodiment, In the range which does not deviate from the summary of this invention, it can change suitably.
For example, in the above embodiment, the case where the thickness of the first substrate W is the same as the thickness of the second and subsequent substrates W has been described. As a coping method when the thickness of the subsequent substrate W is different, for example, before the first substrate W and the second and subsequent substrates W are respectively transferred onto the substrate stage 2, for example, as shown in FIG. As shown in the figure, one or more (three in the figure) thickness measuring instruments are positioned above the substrate W placement portion in the substrate pre-alignment apparatus 50 for pre-alignment of the substrate W installed outside the apparatus. 40, the thickness of the substrate W (or the height of the upper surface of the substrate W from a certain reference surface) is measured by the plate thickness measuring device 40, and when the second and subsequent substrates W are exposed, The measured value of the thickness of the first substrate W (or the height of the upper surface of the substrate W from a certain reference plane) and the second substrate The control device calculates a relative difference from the measured value of the thickness of the descending substrate W (or the height of the upper surface of the substrate W from a certain reference surface), and calculates the relative difference value of the plate thickness for each shot position. By adding to the target value of 2, it is possible to easily cope with the case where the thickness of the first substrate W is different from the thickness of the second and subsequent substrates W.

As the plate thickness measuring device 40, various types such as a non-contact type such as an optical type and a type having a contact such as an electric micrometer can be used. Here, in this example, the plate thickness measuring device 40 and the control device constitute the plate thickness difference detecting means of the present invention.
In the above embodiment, a combination of a linear guide and a ball screw is used as the feeding means of each stage feeding mechanism. However, the present invention is not necessarily limited to this. For example, a linear motor or the like is used as the feeding means. May be used.

  Further, in the above embodiment, the substrate stage 2 is configured to be movable in the Z-axis direction (vertical direction), but instead, the mask stage 1 may be configured to be movable in the Z-axis direction. In this case, when the pattern of the mask M is exposed and transferred to the first substrate W, the gap amount adjusting means is a first target value in which the gap amount is determined in advance based on the measured value of the gap sensor 31. The control device controls the vertical fine movement device 8 so as to finely move the mask stage 1 and detects the height of the mask stage 1 when the gap amount is set to the first target value. Is stored in a predetermined storage area as a second target value, and when the pattern of the mask M is exposed and transferred to the second and subsequent substrates W, the height of the mask stage 1 becomes the second target value. Thus, the control device controls the device for finely moving the mask stage 1 up and down.

  Furthermore, in the above-described embodiment, the case where the substrate stage 2 is stepped in the biaxial direction with respect to the mask M and the pattern exposure light is irradiated for each step is taken as an example, but the present invention is not limited to this. The present invention is also applied to the case where the substrate stage 2 is moved stepwise in the uniaxial direction with respect to the mask M and light for pattern exposure is irradiated for each step, or in the case of a batch exposure method that does not involve a step operation. Needless to say, you can.

It is explanatory drawing which fractured | ruptured one part for demonstrating the proximity exposure apparatus which is an example of embodiment of this invention. It is explanatory drawing for demonstrating the measurement principle of a gap sensor. It is the figure seen from the arrow A direction of FIG. It is a figure for demonstrating arrangement | positioning of a plate | board thickness measuring device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mask stage 2 Substrate stage 3 Irradiation means 8 Vertical fine movement device (gap amount adjustment means)
W Substrate M Mask 25 Mask holding frame 31 Gap sensor 40 Plate thickness measuring device (plate thickness difference calculating means)

Claims (2)

A substrate stage for holding a substrate as a material to be exposed; a mask stage for holding a mask having a pattern to be exposed facing the substrate; and a gap sensor for measuring a gap amount between the mask and the substrate; A gap amount adjusting means for relatively moving the mask stage and the substrate stage to adjust the gap amount, and exposing and transferring the mask pattern to the substrate in a state where the gap amount is adjusted to a predetermined target value. In a proximity exposure apparatus provided with irradiation means for irradiating light for exposure toward the mask as much as possible,
The clearance amount adjusting means, when starting the exposure transfer for the pattern of the mask before Symbol substrate, a first target value the clearance amount based on the measurement values of the gap sensor is predetermined together with the cause of the mask stage and said substrate stage relatively moving so that the height position of the movable one of said mask stage and said substrate stage when the amount of the gap is set to the first target value detects and stores it as the second target value, when exposing transferred before Symbol substrate a pattern of the mask after the second target value is stored, of said mask stage and said substrate stage proximity exposure apparatus, characterized in that the height position of the movable side relatively moves with the mask stage so that the second target value and the substrate stage. Wherein the thickness of the substrate of the second time that stores the target value, a plate thickness difference calculating means for calculating the thickness difference between the thickness of the second of said substrate to position control based on the target value, the 2. The proximity exposure apparatus according to claim 1, wherein a value of the plate thickness difference by the plate thickness difference calculating means is added to the second target value.

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