JP2006086427A - Substrate holding method and apparatus therefor, and exposure device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate holding method, in which a substrate will not be shifted in position when handed over and a contact point can be maintained always at a fixed position, even if the height of flatness is adjusted. <P>SOLUTION: Disclosed is the method of supporting three places of the substrate by a support member 10, wherein the member 10 is such that an O ring 11 is installed on a prop 13 rotatable for height adjustment so that an anchor ring is parallel to a perpendicular direction and the perpendicular direction top part of an outer peripheral part is arranged on the axis of rotation of the prop 13. Then the substrate is supported at the perpendicularly top part of the outer peripheral part of the O ring 11. The O ring 11 is arranged longitudinally, and then the outer peripheral surface of a rubber ring becomes convex upward, to make the substrate contact one point of the top part of the rubber ring, so that a space will not be formed between the substrate and rubber ring, and no suction phenomenon will occur. Consequently, the substrate will neither vibrate nor shift in position, when it is detached. Since the support points is always fixed, the substrate can be supported inside a narrow region. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is applicable to a vacuum treatment apparatus, a semiconductor manufacturing apparatus, an exposure apparatus, and the like. A substrate holding method and a substrate holding apparatus for holding a substrate such as a wafer and a reticle, and the substrate holding apparatus for holding a substrate. The present invention relates to an exposure apparatus that performs exposure processing.

In the manufacture of electronic devices such as semiconductor devices, liquid crystal display devices, CCD imaging devices, plasma display devices, or thin film magnetic heads (hereinafter collectively referred to as electronic devices), an exposure apparatus is used to manufacture a photomask or reticle (hereinafter referred to as an electronic device). The image of the fine pattern formed on the reticle) is projected and exposed on a semiconductor wafer or a substrate such as a glass plate (hereinafter collectively referred to as a wafer) coated with a photosensitive agent such as a photoresist.
In such a semiconductor manufacturing apparatus such as an exposure apparatus, a vacuum suction method using a flat table is generally used as a method for holding a substrate such as a wafer or a reticle. However, when the substrate is held in a vacuum environment, this vacuum suction method cannot be used. Therefore, a method of clamping the substrate mechanically from above or from the side or a method of dropping is used. However, this method causes problems such as generation of abrasion powder due to mechanical contact and friction, and damage to the substrate.

Therefore, conventionally, for example, as shown in FIGS. 7A and 7B, a small screw 62 holding the O-ring 61 vertically is fastened to the side surface of the column 63 and fastened, and the O-ring 61 is tightened. A method has been proposed in which the bottom surface of the wafer and the reticle is brought into contact with one uppermost point of the wafer and held (see, for example, Patent Document 1). Note that FIG. 7B is a top view of FIG.
JP 2004-1111685 A

For example, as shown in FIG. 8, there has been proposed a method in which a fluoro rubber pad 74 having a size of several millimeters is attached to the upper portion of a support 73 and a wafer or reticle is placed and held thereon. As for the support | pillar 73, the fixing | fixed part is a volt | bolt, and height adjustment is possible by rotating. In addition, the fluororubber pad 74 has a high friction coefficient of 0.2 to 0.3, and is extremely strong against disturbance vibrations that cause displacement, and is effective even in a vacuum.
Although there is a method in which the fluororubber pad 74 is made of ceramics, aluminum, or a resin material, the friction coefficient is as small as 0.1 or less, so that it is weak against disturbance vibration, and the rubber pad is more effective in that respect.

  However, in the method using the O-ring described above with reference to FIGS. 7A and 7B, the height of the support point of the substrate for adjusting the flatness is adjusted by rotating the support 63. I tried to do that. Therefore, the contact point on the bottom surface of the wafer and the reticle is within a circle having a radius R as shown in FIG. Therefore, even if a small O-ring is used to reduce the size of the component, the radius R of the contact point on the bottom surface is reduced to only a few millimeters (3 to 4 mm). As a result, for example, a reticle having a small contactable area of the loaded object, such as an EB exposure machine, may exceed the contactable area (depart from the contactable area) and is not appropriate.

  Further, in the method of supporting the wafer or reticle by attaching the fluoro rubber pad 74 to the upper surface of the support column 73 as shown in FIG. 8, the upper surface of the fluoro rubber pad 74 is almost always small by bonding. Is curved into the recess. In this state, when a wafer or reticle is placed on a fluorine pad and picked up by a transfer device, an adhesive force is generated due to a sucker phenomenon. The adhesive strength is small in vacuum compared to the atmosphere and is not strong enough to be pulled away by the robot of the transfer device, but the adhesive strength is lost as soon as the fluororubber pad 74 and the wafer or reticle are separated. At that moment, that is, at the moment when the fluororubber pad 74 and the wafer or reticle are separated from each other, vibration may occur in the wafer or reticle, or the wafer or reticle may be slightly displaced due to the momentum. In the case of processing a substrate with high accuracy, it is necessary to further reduce the amount of positional deviation when the wafer or reticle is delivered. Such misalignment that occurs when the wafer or reticle is separated varies in the range of several μm to several hundred μm. However, in an apparatus that requires accuracy of several tens of μm, high-precision exposure processing, etc. Is a big problem because it can not be stable.

The present invention has been made in view of such a problem, and there is no positional deviation when the substrate is delivered, and the contact point is always maintained at a fixed position even when the flatness height is adjusted. Another object is to provide a substrate holding method and a substrate holding apparatus.
Another object of the present invention is to provide an exposure apparatus that can perform holding and height adjustment of a substrate with high accuracy without misalignment and can perform high-precision exposure processing.

  In order to solve the above problems, a substrate holding method according to the present invention is a substrate holding method for holding the substrate by supporting each of three or more desired locations of the substrate from below, and in each of the support locations, Is a pillar member that extends in the vertical direction and rotates with the vertical direction as the rotation axis direction. The vertical direction uppermost part is installed so that it may be arrange | positioned on the said rotating shaft of the said support | pillar member, The said board | substrate is supported in the said vertical direction uppermost part of the said outer peripheral part of the said annular member.

  Preferably, when the support member rotates, the annular member also rotates integrally with the support member, and the height of the uppermost portion in the vertical direction of the outer peripheral portion of the annular member that supports the substrate Is adjusted.

  The substrate holding device according to the present invention is a substrate holding device that holds the substrate by supporting each of three or more desired locations of the substrate from below, and extends in the vertical direction and rotates in the vertical direction. A column member that rotates as an axial direction, and an annular member, wherein an annular surface of the annular member is parallel to a vertical direction, and an uppermost vertical direction of an outer peripheral portion of the annular member is the A support member having an annular member disposed on the support member to be disposed on the rotation shaft is disposed at each support location, and the vertical direction of the outer peripheral portion of the annular member at each support location. The substrate is supported at the uppermost part.

Preferably, when the support member rotates, the annular member also rotates integrally with the support member, and the height of the uppermost portion in the vertical direction of the outer peripheral portion of the annular member that supports the substrate Is adjusted.
Preferably, the annular member is a rubber ring made of a soft and non-adhesive material.

  An exposure apparatus according to the present invention is an exposure apparatus that selectively irradiates energy rays onto a sensitive substrate to form a pattern, and includes any of the substrate holding apparatuses described above.

According to the present invention, there is provided a substrate holding method and a substrate holding apparatus that are capable of maintaining a contact point at a constant position without causing any positional deviation when delivering a substrate and adjusting the flatness height. Can be provided.
In addition, it is possible to provide an exposure apparatus that can hold the substrate and adjust the height with high accuracy without displacement and can perform exposure processing with higher accuracy.

An embodiment of the present invention will be described with reference to FIGS.
In the present embodiment, a basic configuration of a substrate holding device that holds a reticle, a wafer, or the like is shown, a reticle loader that applies the substrate holding device to holding a reticle, and the substrate holding device as a wafer or An exposure apparatus that can be used to hold a reticle will be described.

First, the substrate holding device of this embodiment will be described.
FIG. 1 is a plan view showing the configuration of the substrate holding device of the present embodiment.
2 to 4 are views showing the structure of the support member of the substrate holding apparatus of the present embodiment, FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1, and FIG. 3 is a view from the direction B in FIG. FIG. 4 is a top view seen from the direction C in FIG.

As shown in FIG. 1, the substrate holding device 1 has three support members 10 disposed on a holder base 3 at substantially the same central angle (120 °).
As shown in FIGS. 2 to 4, each support member 10 includes an O-ring 11, a machine screw 12, and a column 13.
The O-ring 11 is held by a small screw 12 and is fixed to the column 13 by screwing the small screw 12 into the column 13. In this embodiment, the O-ring 11 is made of soft and non-adhesive fluororubber, but may be made of nitrile rubber or silicon rubber. As clearly shown in FIGS. 2 and 3, the uppermost portion of the outer peripheral surface of the O-ring 11 is convex upward. Further, the uppermost portion is higher than the uppermost portions of the machine screw 12 and the support column 13.

The support column 13 includes a head portion 13 a and a bolt portion 13 b, and the bolt portion 13 b is inserted into a screw hole 15 opened in the holder base 3 via a nut 14 fixed to the holder base 3. Thereby, the height is adjusted when the support | pillar 13 rotates. Further, the adjusted state is locked by the nut 14.
The head portion 13 a of the support column 13 is defined by a vertical surface 13 d parallel to the rotation axis direction (vertical direction) of the support column 13 and a bottom surface 13 e parallel to a direction (horizontal direction) perpendicular to the rotation axis direction of the support column 13. A notch 13c is provided. The vertical surface 13d of the notch 13c serves as a fixing surface for the machine screw 12 that holds the O-ring 11. The vertical surface 13d is positioned at the center of the O-ring 11 fixed by the machine screw 12 at the support column 13. It is formed at a position that becomes the center of rotation. In practice, as shown in FIG. 2, the distance L between the vertical surface 13 d of the support 13 and the center of the O-ring 11 is set so that the center of the O-ring 11 is the center of the support 13.

With the support member 10 having such a configuration, even when the support 13 is rotated in order to adjust the height of the O-ring 11, the center of the O-ring 11 is always the center of the support 13 and is in contact with the wafer or the reticle. The points are always the same point.
For example, the substrate holding apparatus 1 shown in FIGS. 1 to 4 holds a reticle 20 for an EB exposure machine, but the reticle 20 has a limited area in which a support member can come into contact (for example, FIG. 1). Areas shown with diagonal lines). However, as described above, in the case of the support member 10 of the present embodiment, the support point is always the same point, and thus it is possible to support within the narrow region.

In the support member 10, the O-ring 11 is arranged vertically, so that it contacts the lower surface of the wafer or reticle at one point on the outer periphery of the uppermost portion. Accordingly, the contact area is minimized, the contact surface is not recessed, and no adhesive force is generated due to the sucker action. As a result, when the wafer or reticle is lifted by the transfer device, a force other than the weight of the wafer or reticle does not act, and there is no possibility of causing a displacement.
On the other hand, the frictional force between the O-ring 11 and the silicon wafer or reticle is as high as 0.1 to 0.3, and the wafer or reticle can be stably held even when the O-ring 11 contacts at one point on the outer periphery.
That is, with such a support member 10, the positional deviation at the time of picking up the wafer or reticle can be stably limited to an extremely small amount.
Further, in the substrate holding apparatus 1, the support members 10 are arranged at three locations, and the wafer or reticle can be stably held without causing the wafer or reticle to float.

Next, a reticle loader configured to hold a reticle using such a substrate holding device will be described.
FIG. 5 is a plan view showing a reticle loader 30 including the substrate holding device 1 of FIG.
The reticle loader 30 includes an atmospheric loader unit 31 and a vacuum loader unit 32.
The atmospheric loader 31 includes an atmospheric robot 33, a pre-alignment 1 unit 34, an atmospheric reticle library unit 35, and a gantry unit 36 that supports them. The atmospheric robot 33 takes out the reticle 20 from the atmospheric reticle library unit 35 and conveys it to the pre-alignment 1 unit 34. The pre-alignment of the reticle 20 is performed in the pre-alignment 1 unit 34, and the reticle 20 subjected to the pre-alignment is conveyed again to the load lock chamber 41 via the gate valve 50 by the atmospheric robot 33.

The reticle 20 put in the load lock chamber 41 is evacuated by a vacuum pump 48 provided in the load lock chamber 41, and is then transported and stored in the vacuum reticle library 42 by the end effector 45 of the vacuum robot 44.
The load lock chamber 41 and the vacuum reticle library 42 are connected to a vacuum robot chamber 47 via gate valves 51 and 52, respectively. The vacuum robot chamber 47 is a chamber that houses the main part of the vacuum loader 32 and is evacuated by a vacuum pump 49 provided in the chamber.
As illustrated, the vacuum robot 44 includes a base 55, a first arm 56 fixed to the base 55 so as to be articulated and movable in the Z direction, a second arm 57 connected to the first arm 56 so as to be articulated, The end effector 44 is connected to the two arms 57 so as to articulate. The end effector 44 rotates in the XY plane and moves in the Z direction.

The reticle used for the exposure is taken out from the vacuum reticle library 42 by the vacuum robot 44, conveyed to the pre-alignment 2 unit 43, and a higher-definition alignment is executed than the pre-alignment 1 unit 34 in the atmosphere.
Thereafter, the vacuum robot 44 transports the wafer to the reticle stage unit 46 in the reticle stage chamber 53 in the exposure apparatus main body 54.

For example, in a next-generation EB exposure apparatus, a pre-alignment mechanism cannot be installed on the reticle stage 46 due to a magnetic field problem or the like. Also, in the EUVL exposure apparatus, it is desirable that the pre-alignment mechanism unit is not installed near the reticle stage unit 46 because the environment is in a vacuum and the mechanism system of the stage table unit is simplified. Therefore, in these exposure apparatuses, a pre-alignment mechanism is installed on the vacuum loader side as shown in FIG.
After the pre-alignment is performed, the reticle 20 is transferred to the reticle stage 46 by the high-precision vacuum robot 8.

Next, an exposure apparatus configured to hold a wafer by the substrate holding apparatus 1 according to the present embodiment will be described.
FIG. 6 is a diagram for schematically explaining the configuration of the electron beam exposure apparatus 100.
An optical barrel 101 is disposed on the electron beam exposure apparatus 100. The optical barrel 101 is provided with a vacuum pump (not shown), and the optical barrel 101 is evacuated.

An electron gun 103 is disposed above the optical barrel 101, and emits an electron beam downward. Below the electron gun 103, an illumination optical system 104 including a condenser lens 104a, an electron beam deflector 104b, and the like is disposed in order. A reticle R is disposed below the lens barrel 104.
The electron beam emitted from the electron gun 103 is converged by the condenser lens 104a. Subsequently, the deflector 104b sequentially scans in the horizontal direction in the drawing, and illumination of each small region (subfield) of the reticle R in the field of view of the optical system is performed. In the figure, the condenser lens 104a has one stage, but an actual illumination optical system is provided with several stages of lenses, a beam shaping aperture, a blanking aperture, and the like.

  Reticle R is supported by holder 110 of reticle stage 111. The reticle stage 111 is placed on the surface plate 116.

  The reticle stage 111 is connected to a driving device 112 shown on the left side of the drawing. In practice, the driving device (linear motor) 112 is incorporated in the stage 111. The driving device 112 is connected to the control device 115 via the driver 114. Further, a laser interferometer 113 is installed on the side of the reticle stage 111 (right side in the figure). The laser interferometer 113 is also connected to the control device 115. Accurate position information of the reticle stage 111 measured by the laser interferometer 113 is input to the control device 115. In order to set the position of the reticle stage 111 as the target position, a command is sent from the control device 115 to the driver 114, and the driving device 112 is driven. As a result, the position of reticle stage 111 can be accurately feedback controlled in real time.

Below the surface plate 116, a wafer chamber (vacuum chamber) 121 is disposed. A vacuum pump (not shown) is connected to the side of the wafer chamber 121 (on the right side in the figure) to evacuate the wafer chamber 121.
A projection optical system 124 including a condenser lens (projection lens) 124a, a deflector 124b, and the like is disposed in the wafer chamber 121 (actually in an optical column in the chamber). A wafer (sensitive substrate) W is disposed in the lower part of the wafer chamber 121.

  The electron beam that has passed through the reticle R is converged by the condenser lens 124a. The electron beam that has passed through the condenser lens 124 a is deflected by the deflector 124 b, and an image of the reticle R is formed at a predetermined position on the wafer W. In the figure, the condenser lens 124a has one stage, but actually, a plurality of stages of lenses, aberration correction lenses, and coils are provided in the projection optical system.

  After the pre-alignment, the wafer W is transferred onto the stage 131 by the vacuum loader 30 in the vacuum robot chamber 31 and supported on the support member 10 (see FIG. 1) provided on the holder 130 on the wafer stage 131. ing. The wafer stage 131 is placed on the surface plate 136.

  A driving device 132 shown on the left side of the drawing is connected to the wafer stage 131. Actually, the driving device 132 is incorporated in the stage 131. The driving device 132 is connected to the control device 115 via the driver 134. A laser interferometer 133 is installed on the side of the wafer stage 131 (right side in the figure). The laser interferometer 133 is also connected to the control device 115. Accurate position information of the wafer stage 131 measured by the laser interferometer 133 is input to the control device 115. In order to target the position of the wafer stage 131, a command is sent from the control device 115 to the driver 134, and the driving device 132 is driven. As a result, the position of the wafer stage 131 can be accurately feedback controlled in real time.

  According to the substrate holding apparatus 1 of the present embodiment, the contact point of a reticle or wafer having a small contact area and a limit can always be set at a fixed position, and misalignment errors due to pick-up by a robot can be suppressed to a small level. In addition, a reticle or wafer can be stably held in a vacuum chamber and a load lock chamber that repeats vacuum and air, and a highly accurate vacuum transfer device can be realized.

In addition, this Embodiment was described in order to make an understanding of this invention easy, and does not limit this invention at all. Each element disclosed in the present embodiment includes all design changes and equivalents belonging to the technical scope of the present invention, and various suitable modifications are possible.
For example, in the present embodiment, the substrate holding device 1 according to the present invention is used as the reticle holder of the pre-alignment 2 part 43 of the vacuum loader part 32, but it is used as a reticle holder in the vacuum reticle library 42, the load lock chamber 41, and the like. May be.

It is a figure showing composition of a substrate holding device concerning one embodiment of the present invention. It is a side view which shows the structure of the supporting member of the board | substrate holding | maintenance apparatus shown in FIG. It is a front view which shows the structure of the supporting member of the board | substrate holding | maintenance apparatus shown in FIG. It is a top view which shows the structure of the supporting member of the board | substrate holding | maintenance apparatus shown in FIG. It is a figure which shows the structure of the reticle loader which has the board | substrate holding apparatus shown in FIG. It is a figure for demonstrating typically the structure of the exposure apparatus which can apply the board | substrate holding apparatus shown in FIG. It is a figure which shows the example of the conventional board | substrate holding apparatus. It is a figure which shows the other example of the conventional board | substrate holding | maintenance apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Substrate holding device 3 ... Holder base 10 ... Supporting member 11 ... O-ring 12 ... Small screw 13 ... Post 30 ... Reticle loader 31 ... Atmospheric loader part 32 ... Vacuum loader part 33 ... Atmospheric robot 34 ... Pre-alignment part 1 35 ... Atmospheric reticle library part 36 ... Fixing part 41 ... Load lock chamber 42 ... Vacuum reticle library 43 ... Pre-alignment part 2 44 ... Vacuum robot 45 ... 46 ... Reticle stage part 47 ... Vacuum robot chamber 48, 49 ... Vacuum pump 50-52 ... Gate valve 53 ... reticle stage chamber 54 ... exposure apparatus main body 55 ... base 56 ... first arm 57 ... second arm 100 ... electron beam exposure apparatus 101 ... optical barrel 103 ... electron gun 104 ... illumination optical system 111 ... reticle stage 112 ... Drive device (linear motor)
DESCRIPTION OF SYMBOLS 113 ... Laser interferometer 114 ... Driver 115 ... Control apparatus 116 ... Surface plate 121 ... Wafer chamber 124 ... Projection optical system 131 ... Wafer stage 132 ... Drive apparatus 133 ... Laser interferometer 134 ... Driver

Claims (7)

A substrate holding method for holding the substrate by supporting each of three or more desired locations on the substrate from below,
In each of the support portions, an annular member is attached to a support member that extends in the vertical direction and rotates about the vertical direction as the rotation axis direction, and the annular surface of the annular member is parallel to the vertical direction, The vertical outermost part of the outer peripheral part of the member is installed so as to be disposed on the rotation shaft of the support member, and the substrate is supported at the uppermost vertical part of the outer peripheral part of the annular member. A substrate holding method. As the support member rotates, the annular member also rotates integrally with the support member, and the height of the uppermost portion in the vertical direction of the outer peripheral portion of the annular member that supports the substrate is adjusted. The substrate holding method according to claim 1. A substrate holding apparatus for holding the substrate by supporting each of three or more desired locations on the substrate from below,
A strut member that extends in the vertical direction and rotates with the vertical direction as the rotation axis direction;
An annular member, wherein the annular surface of the annular member is parallel to the vertical direction, and the vertical uppermost portion of the outer peripheral portion of the annular member is disposed on the rotation axis of the support member. A support member having an annular member installed on the support member is disposed at each support location, and the substrate is supported at the uppermost portion in the vertical direction of the outer peripheral portion of the annular member at each support location. A substrate holding device. As the support member rotates, the annular member also rotates integrally with the support member, and the height of the uppermost portion in the vertical direction of the outer peripheral portion of the annular member that supports the substrate is adjusted. The substrate holding apparatus according to claim 3.   3. The substrate holding method according to claim 1, wherein the annular member is a rubber ring made of a soft / non-adhesive material.   5. The cloth substrate holding device according to claim 3, wherein the annular member is a rubber ring made of a soft and non-adhesive material. An exposure apparatus that forms a pattern by selectively irradiating energy rays onto a sensitive substrate,
An exposure apparatus comprising the substrate holding device according to claim 3, 4 or 6.

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