JP3313609B2 - Wafer processing stage of wafer peripheral exposure system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer processing stage which moves and rotates a wafer while attracting and fixing the wafer in a wafer peripheral exposure apparatus applied to remove unnecessary resist on the wafer in a developing step. Things.

[0002]

2. Description of the Related Art For example, when manufacturing semiconductor devices such as ICs and LSIs, a photoresist (hereinafter referred to as a resist) is applied to the surface of a semiconductor wafer such as a silicon wafer.
Next, a circuit pattern is exposed and developed to form a resist pattern. Using this resist pattern as a mask, ion implantation, etching,
Processing such as lift-off is performed. The application of a resist to a semiconductor wafer (hereinafter referred to as a wafer) is usually performed in order to make the thickness of a resist film formed by the application uniform.
This is performed on the entire surface of the wafer by spin coating. Therefore, the resist is also applied to the peripheral portion of the wafer that is not often used as a pattern formation region.

When the resist is a positive resist, the peripheral portion is not exposed, so that the resist remains on the peripheral portion even after development. The resist remaining in the peripheral portion causes peeling or the like at the time of transporting and holding the wafer, and contaminates peripheral devices, eventually contaminating the wafer surface, leading to a reduction in yield. This is especially true for higher functionality integrated circuits,
As miniaturization is progressing, it has become a serious problem.

Therefore, it has been proposed to remove the unnecessary resist in the peripheral portion by a developing process. In order to realize this, a wafer for exposing the unnecessary resist in the peripheral portion is exposed separately from the step of exposing the circuit pattern in the pattern formation region. A peripheral exposure process is employed. When the wafer surface coated with the resist is sequentially exposed by a movable reduction projection exposure apparatus (stepper), the shape of a peripheral portion where a circuit pattern for one chip cannot be exposed has a step-like shape. When exposing such a stair-like unnecessary resist in the wafer peripheral exposure step, the wafer coated with the resist is placed on a processing stage and fixed by vacuum suction, and the processing stage is set in two directions orthogonal to each other (hereinafter referred to as two directions). (Referred to as an XY direction), and the exposure light guided by the light guide fiber is irradiated in a spot manner while moving along the stepwise pattern of the unnecessary resist on the wafer.

FIG. 6 shows a configuration example of a conventional wafer processing stage in a wafer peripheral exposure apparatus. Reference numeral 51 denotes a disk-shaped wafer fixing portion on which the wafer W is placed and fixed. The wafer fixing portion 51 is connected via a flange-shaped connecting member 52 to
The rotation motor is connected to a rotation shaft 58 connected to a rotation motor (not shown), and the rotation motor (not shown) is further mounted on an XY stage (not shown) movable in the XY directions. In addition, a concave portion 64 for reducing the contact area with the wafer W to reduce the amount of dust adhering to the wafer W on the surface of the wafer fixing portion 51, and a vacuum suction for fixing the wafer W by vacuum suction. A groove 71 is provided.

As described above, since the stepwise exposure is performed by moving the wafer processing stage in the XY directions, it is not always necessary to rotate the wafer fixing portion 51 for fixing the wafer W by vacuum suction. Absent. However, for example, the unnecessary resist area to be exposed is divided into four equal parts for each quadrant from the first quadrant to the fourth quadrant centered on the center of the wafer, and after exposing the first quadrant area, the wafer fixing part 51 is divided into 1 / If the exposure is performed in a procedure such as exposing the second quadrant region by rotating the wafer four times and then exposing the unnecessary resist regions without rotating the wafer, the wafer processing stage can be moved in the X-Y direction. Can be shortened, and the apparatus can be downsized.

The flange of the connecting member 52 has a plurality of holes 53 concentrically arranged at equal angular intervals.
A plurality of female screw holes 54 are provided on the lower surface of the wafer fixing portion 51 at positions corresponding to the above. The wafer fixing portion 51 penetrates these holes 53, and the female screw holes 54 of the wafer fixing portion 51
It is attached to the connecting member 52 by a plurality of screws 55 that are screwed together. Three or four female screw holes 56 are provided on the side of the connecting member 52, and are attached to the rotating shaft 58 inserted into the concave portion of the connecting member 52 by set screws 57 screwed into the female screw holes 56. Can be The portion 59 of the rotating shaft 58 that comes into contact with the set screw 57 is processed into a planar shape.

One end of the wafer fixing portion 51 has a vacuum suction groove 7.
1, a suction path 72 whose other end is open to the bottom surface of the wafer fixing portion 51, a through hole 73 in the connection member 52, and a rotary shaft 5
8 has one end open to the upper surface of the rotation shaft 58 and the other end
A suction path 74 is provided on each side of the suction pipe 8, and a vacuum suction system for vacuum-sucking a wafer through the vacuum suction groove 71, the suction path 72, the through hole 73, and the suction path 74 is formed. O-ring grooves 60 and 61 are provided on a contact surface between the connecting member 52 and the wafer fixing portion 51 and a contact surface between the connecting member 52 and the rotating shaft 53, and an O-ring 62 inserted into the O-ring grooves 60 and 61. , 63 prevent the vacuum suction system from leaking (hereinafter referred to as leak).

The supply of vacuum to the vacuum suction system is performed, for example, by
This is carried out as described in Japanese Utility Model Laid-Open No. 3-106728. That is, a housing (not shown) having a cavity therein is installed such that the cavity surrounds the opening at the other end of the suction passage 74 located on the side of the rotary shaft 58, and a vacuum (not shown) is provided through the housing. A vacuum is supplied from the pump to the vacuum suction system. With such a structure,
It is possible to always supply a vacuum regardless of the position of the opening when the rotation shaft 58 rotates.

[0010]

The exposure light guided by the light guide fiber is, for example, disclosed in Japanese Unexamined Patent Publication No. 8-317.
No. 30, JP-A-8-165593, and the like, the light is shaped by an aperture or the like (not shown) provided at the emission end 81 of the light guide fiber. By 82, an image is formed on the unnecessary resist in the peripheral portion of the wafer. This is because, as shown in FIG. 7, the change in illuminance at the boundary between the exposed portion and the non-exposed portion is sharpened on the unnecessary resist in the peripheral portion of the wafer W, so that the developed resist remains in a tapered shape. This is to prevent it. That is, if the resist after development remains in a tapered shape, the problem that the resist at the foot of the taper having a small resist film thickness is easily peeled off is avoided.

In such an image forming relationship, the wafer W is XY
It needs to be maintained during the exposure period moving in the direction.
That is, in FIG. 6, it is necessary to maintain the distance between the peripheral surface (resist surface) of the wafer W and the projection lens 82 within a predetermined range (within the depth of focus of the projection lens 82) during the exposure period. For example, when the wafer processing stage is moved in the X and Y directions to expose a stepwise unnecessary resist of the wafer W having a diameter of 200 mm in the circumferential portion, the predetermined range is ± 20 μm. In order to satisfy such a condition, as shown in FIG. 8, the entire surface of the wafer fixing portion 51 needs to fall within a region between virtual planes perpendicular to the optical axis and separated from each other by 20 μm. There is.

In the case of the wafer processing stage shown in FIG. 6, it is possible to process the surface of the surface of the wafer fixing portion 51, which is in direct contact with the wafer W, to within ± 1.5 μm. However, the wafer processing stage shown in FIG. 6 includes a connection between the wafer fixing portion 51 and the connection member 52, a connection between the connection member 52 and the rotation shaft 58, a connection between the rotation shaft 58 and a rotation motor (not shown), and the like. There are provided a plurality of mechanical connection portions that are integrally connected. Therefore, even if the processing accuracy of each connection portion is made high, when the wafer processing stage is assembled, the tolerance of the processing accuracy of the components constituting each connection portion is accumulated, and the wafer fixing portion 51 on which the wafer W is mounted is mounted. Surface is inclined by the cumulative tolerance,
As a result, it is difficult to fit the entire surface of the wafer fixing portion 51 in the space separated by 20 μm.

In view of the above problems, in order to fit the entire surface of the wafer fixing portion 51 in the space separated by 20 μm, it is necessary to adjust the inclination of the wafer fixing portion 51 after assembling the wafer processing stage. It is practical.
In the case of the wafer processing stage shown in FIG. 6, the above-described tilt adjustment is performed by adjusting the degree of screwing of three or four set screws 57. That is, the operation of loosening one of the two set screws 57 and tightening the other is repeated, so that the O-ring 63 does not leak.
The inclination of the wafer fixing portion 51 is adjusted within the range of the elastic deformation described above, and after the predetermined inclination is achieved, the two set screws 57 are tightened and fixed.

That is, the wafer processing stage does not have a mechanism for adjusting the inclination, and the elastic deformation of the O-ring 63, which is a member for realizing a seal for preventing a vacuum suction system from leaking, is provided. The tilt is adjusted for convenience using this function. Therefore, the following restrictions are imposed on the inclination adjustment.

(1) The tilt adjustment using the elastic deformation of the O-ring 63 is controlled by the amount of movement of the two set screws 57 with the fulcrum as the O-ring 63 and the point of force as the tip of the set screw 57. Since the distance between the force point and the fulcrum is short, the change in the inclination of the wafer fixing portion 51 due to the movement of the set screw 57 per unit length is large. In the conventional wafer processing stage manufactured by the inventors, the pitch of the thread of the set screw 57 is 0.7 mm, and one of the set screws 57 is rotated by 15 degrees and loosened, and the other is rotated by 15 degrees and tightened. Thus, the inclination of the wafer fixing part 51 reached the maximum inclination angle of 0.4 degrees, and the peripheral part of the wafer fixing part 51 was raised or lowered by 350 μm. The minimum rotation angle of the set screw 57 that can be manually adjusted is empirically limited to 5 degrees. When the minimum rotation angle of the set screw 57 is 5 degrees, the peripheral portion of the wafer fixing portion 51 rises or falls by about 117 μm. Resulting in. Therefore, it is impossible to perform delicate tilt adjustment.
It is very difficult to fit in a space separated by 0 μm.

The present invention has been made in view of the above circumstances, and by adding a tilt adjusting mechanism,
An object of the present invention is to provide a wafer processing stage that can easily perform fine tilt adjustment.

According to the first aspect of the present invention, the dew around the wafer is provided.
The wafer processing stage of the optical device uses unnecessary resist on the wafer.
The wafer is exposed in a wafer peripheral exposure device that exposes the wafer.
A wafer processing stage for holding by suction,
Two directions that are connected and are orthogonal to each other by the driving means;
A shaft driven in the rotation direction and having a vacuum suction path therein;
Flange-shaped base material attached to a shaft and having a hole in the center
And a vacuum suction part on the surface to hold the wafer by suction.
For holding the wafer by suction that communicates with the vacuum suction part inside
A disk-shaped wafer fixing part with a passage
The wafer fixing portion and the shaft are formed of the flange-shaped base material.
Through the hole and the wafer suction fixing passage of the wafer fixing part
By connecting pipe to connect the vacuum suction path of the shaft
Are connected, and three V
A groove body is provided, and the base material has a direction perpendicular to the base material surface.
Are provided with three displaceable support shafts, and the three V-grooves are provided.
The above three support shafts respectively facing the body,
The angle of inclination of the fixing part with respect to the base material can be adjusted.
And the three V-grooves are mounted on the disk-shaped wafer.
C. Concentric with respect to the center of the fixing part,
Arrange so that the imaginary lines that match the direction of the V-groove cross at one point.
It is characterized by being placed.

A wafer according to claim 2 of the present invention.
The wafer processing stage of the peripheral exposure apparatus
A point substantially coincides with the center of the disk-shaped wafer fixing portion.
It is characterized by:

Further, according to a third aspect of the present invention, the wafer processing stage of the wafer peripheral exposure apparatus further comprises:
And three female screw holes are provided on the lower surface of the wafer fixing member, and three spring washers, three male screws passing through the three through holes, and the female screw are formed. The three male screws screwed to each other and screwed to the three female screws are concentric with the center of the disk-shaped wafer fixing portion, are positioned on the imaginary line, and The suction portion is provided around the periphery of the surface of the wafer fixing portion in a circumferential shape.

[0020]

[0021]

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a wafer processing stage of a wafer peripheral exposure apparatus according to the present invention will be described below in detail with reference to embodiments shown in the drawings.

FIGS. 1 and 2 are views for explaining the arrangement of a wafer processing stage of a wafer peripheral exposure apparatus according to the present invention. Here, FIG. 1 is a sectional view taken along the line AA in FIG. FIG. 2 is a view of the wafer processing stage shown in FIG. 1 as viewed from an arrow B, and a part thereof is a cross-sectional view taken along line CC in FIG.

Reference numeral 1 denotes a disk-shaped wafer fixing portion on which the wafer W is mounted and fixed by vacuum suction. As in the configuration example of the conventional wafer processing stage shown in FIG. 6, the wafer fixing part 1 is connected to a cylindrical rotary shaft 3 connected to a rotary motor (not shown) via a flange-shaped connecting member 2, The wafer W fixed to the wafer fixing unit 1 is rotated by the rotation motor (not shown). A rotation motor (not shown) is further mounted on an XY stage (not shown) movable in the XY directions, and the wafer W is fixed by controlling the drive of the XY stage (not shown). Is moved in the XY directions.

Here, the reason why the wafer fixing part 1 of the wafer processing stage is not only movable in the XY directions but also rotatable is that exposure is performed by the procedure described in the prior art.
This is because the moving distance of the wafer processing stage in the X-Y direction is shortened to reduce the size of the apparatus. Note that, instead of moving the wafer fixing unit 1, the emission end of the light guide fiber that emits the exposure light may be moved in the X-Y direction. Also in this case, if the wafer fixing unit 1 is rotatable, the light guide is performed by combining the exposure in the 1/4 of the exposure area and the 1/4 rotation / stop similarly to the procedure described in the background art. The apparatus can be miniaturized by shortening the moving distance of the emission end of the fiber in the X-Y direction.

As shown in FIG. 3 showing the bottom surface of the connecting member 2, on the lower surface side of the connecting member 2, a step portion 10 into which the cylindrical rotary shaft 3 is inserted, and further surrounds the rotary shaft 3 by a half circumference. A protrusion 11 is provided. The connecting member 2 is attached to the rotating shaft 3 by sandwiching the rotating shaft 3 between the fixing member 24 surrounding the remaining half circumference of the rotating shaft 3 and the protrusion 11 and screwing the protrusion 11 and the fixing member 24 together. Can be

Returning to FIGS. 1 and 2, on the surface of the wafer fixing portion 1, as in the configuration example of the conventional wafer processing stage shown in FIG. The concave portion 12 is provided to reduce the amount of adherence. A circumferential vacuum suction groove 13 for fixing the wafer W by vacuum suction is provided at a peripheral portion of the surface of the wafer fixing portion 1, and one end of the vacuum fixing groove 13 is provided inside the wafer fixing portion 1. A suction path 14 is provided, the other end of which communicates with the connection pipe insertion hole 15 provided on the bottom surface of the wafer fixing part 1. On the other hand, a suction hole having a through hole 16 in the connection member 2, one end of the rotation shaft 3 communicating with a connection pipe insertion hole 17 provided on the upper surface of the rotation shaft 3, and the other end opening in a side portion of the rotation shaft 3. 18 are provided.

The suction path 14 and the suction path 18 are connected by inserting one end of the connection pipe 19 into the connection pipe insertion hole 15 and the other end into the connection pipe insertion hole 17. That is, a vacuum suction system for vacuum-sucking the wafer from the vacuum suction groove 13, the suction path 14, the connection pipe 19, and the suction path 18 is formed. O-ring grooves 20 and 21 are provided on a contact surface between the connection pipe insertion hole 15 and the connection pipe 19 and a contact surface between the connection pipe insertion hole 17 and the connection pipe 19, and are inserted into the O-ring grooves 20 and 21. O-rings 22 and 23 prevent leakage of the vacuum suction system.

The vacuum is supplied to the vacuum suction system by, similarly to the configuration example of the conventional wafer processing stage, a housing (not shown) having a cavity therein, and a suction passage having the cavity located on the side of the rotary shaft 3. A vacuum pump (not shown) supplies the vacuum to the vacuum suction system through the housing. With such a structure, it is possible to always supply a vacuum regardless of the position of the opening where the rotating shaft 3 rotates.

The tilt adjusting mechanism of the wafer fixing part 1 of the wafer processing stage of the wafer peripheral exposure apparatus according to the present invention is configured as follows. As shown in FIG. 4 showing the bottom surface of the wafer fixing portion 1, on the back surface of the wafer fixing portion 1, V-groove bodies 4a, 4b, 4c are attached concentrically at equal angular intervals, and imaginary lines a, b, and c corresponding to the respective V-grooves.
Intersect at one point, and this intersection substantially coincides with the center of the wafer fixing portion 1. On the other hand, the connection member 2 is threaded with three ball point screws 5 each having a movable ball embedded at the tip. Then, as shown in FIGS. 1 and 2, the V-groove portions of the three V-groove bodies 4 and the balls of the three ball-point screws 5 are paired with each other, and the wafer fixing portion 1 is provided with respect to the connection member 2. It is held at intervals. Since the ball at the tip of the ball screw 5 fits into the V-groove of the V-groove body 4, the wafer fixing portion 1 is prevented from rotating with respect to the connecting member 2, and the stable connection between the wafer fixing portion 1 and the connecting member 2 is prevented. An even number is realized.

As described above, the tilt adjusting mechanism of the wafer fixing section 1 of the wafer processing stage according to the present invention penetrates the V-grooves 4a, 4b, 4c provided on the back surface of the wafer fixing section 1 and the connecting member 2. The configuration is such that the three ball point screws 5 to be screwed with each other are paired with each other. The inclination adjustment is performed by appropriately adjusting the degree of screwing of the three ball point screws 5 to change the inclination angle of the wafer fixing portion 1 with respect to the connection member 2. For example, when the degree of screwing of the ball point screw 5 that is paired with the V-groove body 4a is changed, the inclination angle of the wafer fixing portion 1 with respect to the connecting member 2 changes around the Vb-Vc line. Similarly, when the degree of screwing of the ball screw 5 opposite to the V-groove body 4b is changed, the inclination angle changes around the Vc-Va line, and the degree of screwing of the ball screw 5 opposite to the V-groove body 4c is changed. When the angle is changed, the inclination angle changes around the Va-Vb line. In FIG. 5, the adjustment range of the inclination angle is the gap d between the connection pipe insertion hole 15 provided on the lower surface of the wafer fixing part 1 and the connection pipe 19 and the connection pipe provided on the upper surface of the rotating shaft 3. It is defined by a gap d between the insertion hole 17 and the connection pipe 19.

The actual tilt adjustment is performed in the following procedure. A dial gauge is fixed to a base on which an XY stage (not shown) for moving the wafer fixing unit 1 in the XY direction is fixed, and the measuring unit of the dial gauge is attached to an arbitrary part of the surface of the wafer fixing unit 1. Contact is made and this point is determined as a reference point, and the dial gauge is set to zero. The wafer fixing unit 1 is moved in the X-Y direction, and displacements in the optical axis direction at a plurality of points at appropriate distances from the reference point are measured with a dial gauge. Whether the displacement amounts of the plurality of points are within a width of ± 10 μm around the reference point, that is, the entire surface of the wafer fixing unit 1 is perpendicular to the optical axis and separated from the virtual plane by 20 μm. If the condition is not satisfied, the inclination of the wafer fixing part 1 is adjusted by the inclination adjusting mechanism, and the state of the surface of the wafer fixing part 1 is measured again by the dial gauge. . The procedure described above is repeated until the entire surface of the wafer fixing unit 1 fits in the space separated by 20 μm.

Incidentally, the wafer fixing portion 1 and the connecting member 2 having the above-described inclination adjusting mechanism pass through the through hole 6 of the connecting member 2 and are provided with female screw holes 8 provided on the back surface of the wafer fixing portion 1. It is fixed by three fixing screws 7 screwed together. Here, the fixing screw 7 penetrates the spring washer 9, and the elastic force of the spring washer 9 presses the wafer fixing portion 1 against the connecting member 2.
Due to this pressing force, each V of the V-grooves 4a, 4b, 4c
The pair of the groove and the ball of the three ball-point screws 5 is firmly held, and the three ball-point screws 5 are not loosened even if the wafer processing stage moves many times in the XY directions. A slope of 1 is maintained.

As described above, since the wafer processing stage according to the present invention has the mechanism for adjusting the inclination of the wafer fixing portion 1, the following advantages are obtained as compared with the conventional wafer processing stage as shown in FIG. is there.

(1) As is apparent from FIG. 4, the fulcrum at the time of tilt adjustment is on the line Va-Vb, on the line Vb-Vc,
It is on the Vc-Va line, and the point of force is the tip of the ball point screw 5. On the other hand, in the conventional wafer processing stage, the fulcrum is the O-ring 63 and the point of force is the tip of the set screw 57. Accordingly, since the distance between the fulcrum and the fulcrum is longer in the wafer processing stage of the present invention, the change in the inclination of the wafer fixing portion 1 due to the movement of the ball point screw 5 per unit length is shown in FIG.
Set screw 5 in the conventional wafer processing stage shown in FIG.
7 is smaller than the change in the inclination of the wafer fixing portion 51 due to the movement per unit length of 7. That is, as compared with the conventional wafer processing stage, finer tilt adjustment can be performed, and the adjustment can be performed in a short time.

(2) The pressing force of the three fixing screws 7 penetrating the spring washer 9 causes the V-groove body 4
The pairs of the V-grooves a, 4b, and 4c and the balls of the three ball-point screws 5 are firmly held, and even if the wafer processing stage moves many times in the XY directions, three ball-point screws are used. The inclination of the wafer fixing part 1 is maintained without the slackening of the wafer 5.

As described above, in the wafer processing stage according to the present invention, the inclination of the wafer fixing part 1 can be easily adjusted without skill by the inclination adjusting mechanism of the wafer fixing part 1, and the inclination adjustment can be performed. Even if the post-wafer processing stage moves many times in the X and Y directions, the inclination of the wafer fixing portion 1 is maintained. The distance between the front surface) and the projection lens disposed on the emission end side of the light guide fiber is maintained within a predetermined range, and the boundary between the exposed portion and the non-exposed portion of the unnecessary resist over the entire periphery of the wafer. , The change in illuminance can be sharpened, and the resist after development can be prevented from remaining in a tapered shape.

As described above, the V-groove members 4a, 4b, 4c having the V-groove portions are concentrically arranged on the back surface of the wafer fixing portion 1 at equal angular intervals, and (1) coincide with each V-groove portion. Virtual lines a, b, and c intersect at one point,
(2) The intersection point substantially coincides with the center of the wafer fixing portion 1, but the arrangement of the V-grooves 4a, 4b, 4c is not limited to this. However, it is considered that the above configuration is preferable for the following reasons.

(1) When the imaginary lines a, b, and c intersect at one point, the thermal expansion and contraction of the wafer fixing part 1 due to the change in the ambient temperature becomes expansion and contraction based on the intersection, and the wafer fixing part 1 itself does not move. On the other hand, when the imaginary lines a, b, and c do not intersect at one point, the thermal expansion and contraction of the wafer fixing unit 1 due to the change in the ambient temperature does not take place at the above-mentioned certain point, but as a result of the thermal expansion and contraction, The fixed part 1 moves in the rotation direction.

In the case of exposing a step-like unnecessary resist composed of two sides facing in two directions perpendicular to each other, the wafer W mounted on the wafer fixing part 1 or the light emitting end of a light guide fiber for emitting exposure light is exposed. Are moved in the X-Y directions (two directions perpendicular to each other) that match the above two directions, so that if the wafer fixing unit 1 moves during the exposure to rotate the wafer W, the desired exposure is achieved. Can not. As circuit pattern miniaturization advances, the exposure position accuracy of unnecessary resist near the boundary with the circuit pattern improves, and as the wafer diameter increases, the time required for unnecessary resist exposure tends to increase, In the future, the problem of the movement of the wafer fixing unit 1 due to the thermal expansion and contraction may not be overlooked.
Therefore, it is desirable that the imaginary lines a, b, and c that coincide with the V-groove portion intersect at one point.

(2) In the wafer periphery exposure step, the resist around the wafer may be annularly exposed at a constant width from the edge of the wafer in addition to the case where the unnecessary resist in the step shape is exposed. In this case, the wafer processing stage on which the wafer is fixed is rotated while controlling the position of the exit end of the light guide fiber from which the exposure light is emitted so as to irradiate a region of a fixed width from the edge of the wafer.

As described above, when the wafer is rotated on the processing stage during exposure, if the intersection of the virtual lines a, b, and c at one point does not coincide with the center of the wafer fixing unit 1, the wafer fixing unit 1 Eccentricity occurs between the center of the wafer fixing portion 1 and the center of rotation during the thermal expansion and contraction, and is affected by the moment of inertia. If they match, there is no eccentricity between the center of the wafer fixing part 1 and the center of rotation during thermal expansion and contraction, so that stable rotation can be realized without being affected by the moment of inertia. Therefore, if the intersection is made substantially coincident with the center of the wafer fixing unit 1, the wafer processing stage according to the present invention is common to both a device for exposing the peripheral portion of the wafer in a stepwise manner and a device for circularly exposing the periphery. Can be used.

FIG. 4 shows an example in which the three fixing screws 7 are concentrically arranged on the imaginary lines a, b, and c, respectively. However, the present invention is not limited to this. is not. However, it is considered that the above configuration is preferable for the following reasons.

The wafer fixing portion 1 has V-grooves 4a, 4b, 4c
The upward force is urged by the three ball-point screws 5 that are paired with the respective V-grooves, while the wafer fixing part 1 is lowered by the elastic force of the spring washer 9 that the three fixing screws 7 penetrate. The directional force is urged and pressed against the connection member 2. Here, as shown in FIG. 4, the angles intersecting at the center of the wafer fixing portion 1 and forming mutually are on imaginary lines a, b, and c which are equal to each other, and are concentrically formed by the ball screw 5. When the point of application of the force in the direction and the point of application of the force in the downward direction by the spring washer 9 through which the fixing screw 7 penetrates are arranged, the wafer fixing portion 1 is
Is generated symmetrically with respect to the center of the wafer fixing portion 1. Therefore, the wafer fixing unit 1
Is symmetrical with respect to the center of the wafer fixing portion 1 even in the peripheral portion of the wafer W. Therefore, even if the distortion occurs, the circumferential vacuum suction groove 13 on the surface of the wafer fixing portion 1 and the wafer W are in uniform contact. Therefore, it is considered that the influence on the vacuum adsorption is small.

On the other hand, the positional relationship between the positions of the three ball-point screws 5 that match the respective V-grooves of the V-grooves 4a, 4b, and 4c and the positions of the three fixing screws 7 that pass through the spring washer 9 is as follows. If the relationship is not as shown in FIG. 4, even if the distortion of the wafer fixing portion 1 occurs, the distortion does not occur symmetrically with respect to the center of the wafer fixing portion 1. Therefore, when the distortion occurs, the contact between the circumferential vacuum suction groove 13 on the surface of the wafer fixing portion 1 and the wafer W is not uniform, and it is considered that a leak may occur in some cases. Therefore, the configuration shown in FIG. 4 is considered to be preferable.

[0046]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the wafer processing stage of the present invention will be described, but the present invention is not limited to these embodiments.

According to the configuration shown in FIGS. 1 to 5, a wafer processing stage according to the present invention was prepared under the following conditions. The diameter of the wafer fixing portion 1: 100 mm The position of the center of each V groove of the V-grooves 4 a, 4 b, 4 c: the distance from the center of the wafer fixing portion 1 38 mm The 120 ° interval from the center of the wafer fixing portion 1. Lead screw 5: Fine screw with a screw pitch of 0.5mm ・ Gap d: 0.2mm

In the wafer processing stage satisfying the above conditions, the adjustment range of the tilt angle of the wafer fixing part 1 with respect to the connecting member 2 was ± 4 °. Here, when one of the three ball tip screws 5 was rotated by 5 degrees, which is the minimum rotation angle that can be manually adjusted, the peripheral portion of the wafer fixing portion 1 was raised or lowered by about 4.6 μm. That is, in the conventional wafer processing stage, the rising distance or the falling distance of the peripheral portion of the wafer fixing portion is about 117 μm,
It has become possible to perform a fine adjustment of the tilt more than 5 times.

[0049]

According to the wafer processing stage of the present invention,
Three V-grooves are provided on the lower surface of the wafer fixing part, and three support shafts displaceable in a direction perpendicular to the surface of the substrate are provided on the substrate,
Since the wafer fixing portion is supported by the three support shafts facing the three V-groove bodies so that the tilt angle with respect to the base material can be adjusted, the distance between the fulcrum points at the time of tilt adjustment is reduced. The length can be increased to some extent, and more delicate tilt adjustment of the wafer fixing portion can be performed as compared with the conventional wafer processing stage, and this adjustment can be performed in a short time.

Further, three through holes are provided in the base material, and three female screw holes are provided in the lower surface of the wafer fixing member, and three spring washers and three through holes are provided through the three through holes. If the male screw and the female screw are screwed respectively,
Due to the pressing force of the three male screws penetrating the spring washer, the pairs of the three V-grooves and the three support shafts are firmly held, and the wafer processing stages are orthogonal to each other many times. Even if the wafer is moved or rotated in two directions, the inclination of the wafer fixing portion is stably maintained.

Also, the three V-grooves are concentric with the center of the disk-shaped wafer fixing portion so that imaginary lines corresponding to the directions of the three V-grooves intersect at one point. In this case, the thermal expansion and contraction of the wafer fixing portion due to the change in the ambient temperature becomes expansion and contraction based on the intersection, and the wafer fixing portion itself does not move. Therefore, even if the exposure position accuracy is improved and the time required for exposing the unnecessary resist due to the increase in the diameter of the wafer is increased, the direction of the two sides of the step-like unnecessary resist which are orthogonal to each other and the exposure light are reflected on the wafer. The desired exposure can be achieved without deviation from two directions perpendicular to each other, which move relatively to.

If the intersection of the imaginary line is made substantially coincident with the center of the disk-shaped wafer fixing portion, the resist around the wafer can be removed from the edge of the wafer by a predetermined width while rotating the wafer processing stage. In the case of annular exposure, thermal expansion and contraction of the wafer fixing portion occurs around the center of rotation, so that stable rotation can be realized.

The wafer fixing part 1 is provided with three V
While the upward force is urged by the three support shafts that are paired with the groove, the downward force is urged by the elastic force of the spring washer that the three male threads penetrate and is pressed against the base material. . The three male screws, which are screwed with the three female screws, are concentric with the center of the disk-shaped wafer fixing portion, are positioned on the imaginary line, and the vacuum suction portion is mounted on the wafer. If it is provided circumferentially on the periphery of the surface of the fixed part, even if these upward and downward forces cause the distortion of the wafer fixed part, this distortion will be relative to the center of the wafer fixed part. Since it occurs symmetrically and is distorted symmetrically with respect to the center also in the peripheral portion of the wafer fixing portion, the circumferential vacuum suction portion on the surface of the wafer fixing portion uniformly contacts the wafer, and The effect on adsorption is reduced.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a wafer processing stage of a wafer peripheral exposure apparatus according to the present invention.

FIG. 2 is a diagram illustrating a configuration of a wafer processing stage of the wafer peripheral exposure apparatus according to the present invention.

FIG. 3 is a diagram illustrating a bottom surface of a connection member 2;

FIG. 4 is a view showing a wafer fixing unit 1;

FIG. 5 is a diagram illustrating a gap d.

FIG. 6 is a diagram showing a configuration example of a conventional wafer processing stage in a wafer peripheral exposure apparatus.

FIG. 7 is a diagram showing a change in illuminance at a boundary portion between an exposed portion and a non-exposed portion on an unnecessary resist and a shape of the resist after development.

FIG. 8 is a diagram illustrating a relationship between a surface of a wafer fixing portion and a region between virtual planes perpendicular to the optical axis and separated from each other by 20 μm.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wafer fixing part 2 Connection member 3 Rotating shaft 4a, 4b, 4c V-groove body 5 Ball tip screw 6 Through hole 7 Fixing screw 8 Female screw hole 9 Spring washer 10 Step 11 Projection 12 Depression 13 Vacuum suction groove 14 Suction path Reference Signs List 15 connection pipe insertion hole 16 through hole 17 connection pipe insertion hole 18 suction path 19 connection pipe 20 O-ring groove 21 O-ring groove 22 O-ring 23 O-ring 24 fixing member a, b, c virtual line W wafer

Claims (3)

(57) [Claims] 1. A wafer processing stage for adsorbing and holding a wafer in a wafer peripheral exposure apparatus for exposing an unnecessary resist on the wafer, wherein the wafer processing stage is connected to a driving means and is driven in two directions and a rotation direction orthogonal to each other by the driving means. A shaft having a vacuum suction passage therein, a flange-shaped base material attached to the shaft and having a hole in the center, and a vacuum suction portion for suction-fixing a wafer on the surface and provided inside the vacuum suction portion. A disc-shaped wafer fixing portion provided with a wafer suction fixing passage communicating with the wafer, the wafer fixing portion and the shaft penetrate through the hole of the flange-shaped base material, and the wafer of the wafer fixing portion The suction fixing passage is connected to a vacuum suction passage of the shaft by a connection pipe, and three V-grooves are provided on a lower surface of the wafer fixing portion. Three support shafts displaceable in a direction perpendicular to the surface are provided, and the tilt angle of the wafer fixing portion with respect to the base material is adjusted by the three support shafts respectively facing the three V-groove bodies. Supported as possible, the three V-grooves are located at the center of the disk-shaped wafer fixing portion.
Concentric with each other, one direction in the direction of the three V-grooves.
A wafer processing stage of a wafer peripheral exposure apparatus, wherein the matching virtual lines are arranged so as to intersect at one point . 2. The method according to claim 1, wherein the intersection of the imaginary line is a solid of the disk-shaped wafer.
The center of the fixed portion substantially coincides with the center of the fixed portion.
4. A wafer processing stage of the wafer peripheral exposure apparatus according to 4. 3. The base member is provided with three through holes , and the lower surface of the wafer fixing member is provided with three female screw holes.
Through the three spring washers and the three through holes
The three male screws to be screwed are respectively screwed with the female screw, and the three male screws to be screwed to the three female screws are the circles described above.
Concentric with the center of the plate-shaped wafer fixing portion ,
The vacuum suction part is located on the imaginary line,
That it is provided circumferentially around the periphery of the fixed part
The wafer peripheral exposure apparatus according to claim 1 or 2,
Wafer processing stage.