The present invention relates to a stage apparatus, an exposure apparatus, and a semiconductor device manufacturing method.
In recent years, the semiconductor industry has been changing and progressing very fast. Accordingly, a semiconductor manufacturing apparatus that can further shrink the feature size and improve the throughput of elements has been sought. To meet the demand for a smaller element feature size, the numerical aperture (NA) of the projection lens has been increased. To manufacture high-performance elements with high productivity, an increase in the diameter of the substrate and the like have been performed.
For example, currently, an exposure system having two stages has been proposed to improve the throughput and alignment accuracy. This is an exposure system that transports and transfers a whole substrate holding unit between two stages as it holds a substrate. More specifically, according to this exposure system, alignment is performed at the first stage, and exposure is preformed at the second stage different from the first stage during alignment. This makes it possible to ensure high-accuracy alignment time and improve the throughput.
To ensure the superiority of this system, first, the reproducibility of the surface of the substrate holding unit on different stages must be ensured reliably. More specifically, the substrate holding unit must be held between the first stage (alignment stage) and second stage (exposure stage) without changing the surface state of the substrate holding unit, e.g., the surface accuracy, distortion, or the like. Furthermore, the substrate holding unit must be moved between the stages quickly and must be stationarily held on or removed from a support surface for the substrate holding unit instantaneously.
In general, however, when the substrate holding unit and a support surface for it are to be brought into total contact with each other, it is difficult to stationarily hold the substrate holding unit on the support surface or to remove it from the support surface instantaneously. The substrate holding unit is highly likely to conform to the shape of the support surface for it. To reliably, stationarily hold the substrate holding unit, after it has moved from a stage, on the support surface for it, the substrate holding unit needs a stationary fixing force that can withstand stage driving. To ensure reproducibility of the surface of the substrate holding unit at the second stage different from the first stage, when the substrate holding unit is to be moved between the stages or is to be stationarily held on or removed from the support surface for it, a power that changes the surface of the substrate holding unit should not be applied to the substrate holding unit. In a conventional exposure system, however, when the substrate holding unit is to be moved between the stages or is to be stationarily held on or removed from the support surface for it instantaneously, it is difficult to ensure the reproducibility of the surface of the substrate holding unit on different stages without changing the surface of the substrate holding unit.
The present invention has been made in view of the above problems, and has as its object to improve the throughput.
The first aspect of the present invention relates to a stage apparatus, having a substrate holding unit which chucks and holds a substrate, comprising a flat surface having a recess where the substrate holding unit is to be mounted, and a fixing member which fixes a projection support provided to the substrate holding unit onto the flat surface, wherein the substrate holding unit is supported by the fixing member while a distal end of the projection support is in contact with the recess of the flat surface and a remaining portion of the substrate holding unit is not in contact with the flat surface.
According to a preferred embodiment of the present invention, the fixing member preferably has a mechanism which applies no moment force to the projection support.
According to a preferred embodiment of the present invention, the recess is preferably a V-shaped groove, and the projection support preferably comes into point contact with the V-shaped groove at a distal end thereof.
According to a preferred embodiment of the present invention, the projection support preferably comprises at least three projection supports and the fixing member fixing the projection supports, respectively.
According to a preferred embodiment of the present invention, the projection support and the fixing member preferably form one component.
According to a preferred embodiment of the present invention, the fixing member is preferably fixed to the projection support.
According to a preferred embodiment of the present invention, the fixing member can preferably tilt freely at a contact portion with the projection support in an axial direction of the projection support and in a planar direction.
According to a preferred embodiment of the present invention, a small gap is preferably present between the projection support and the fixing member, and the projection support can preferably tilt freely in an axial direction of the projection support and in a planar direction because of the gap.
According to a preferred embodiment of the present invention, the fixing member preferably has one of a circular shape, an elliptical shape, a shape similar to an ellipse, or a polygonal shape.
According to a preferred embodiment of the present invention, the fixing member can preferably elastically deform.
According to a preferred embodiment of the present invention, the fixing member preferably has an outer seal portion on an outer surface thereof, and the outer seal portion preferably comes into contact with the flat surface to define a closed space.
According to a preferred embodiment of the present invention, a seal number is preferably arranged between the projection support and the fixing member.
According to a preferred embodiment of the present invention, the V-shaped groove is preferably formed to extend in three directions on the flat surface at an angular interval of about 120°.
According to a preferred embodiment of the present invention, the stage apparatus preferably has a chucking/holding mechanism which chucks and holds the projection support onto the flat surface.
According to a preferred embodiment of the present invention, the stage apparatus preferably has a chucking/holding mechanism which chucks and holds the projection support onto the substrate holding unit.
According to a preferred embodiment of the present invention, the projection support can preferably be removed from the flat surface by canceling a chucking/holding force from the chucking/holding mechanism.
According to a preferred embodiment of the present invention, the projection support can preferably be removed from the substrate holding unit by canceling a chucking/holding force from the chucking/holding mechanism.
According to a preferred embodiment of the present invention, the chucking/holding mechanism preferably uses one of a negative pressure, a Coulomb force, and a magnetic force.
The second aspect of the present invention relates to a stage apparatus, having a substrate holding unit which chucks and holds a substrate, comprising a flat surface having a projection support where the substrate holding unit is to be mounted, and a fixing member which fixes the projection support provided to the flat surface with a recess formed in the substrate holding unit, wherein the substrate holding unit is supported by the fixing member while the recess of the substrate holding unit is in contact with a distal end of the projection support and a remaining portion of the substrate holding unit is not in contact with the flat surface.
The third aspect of the present invention relates to an exposure apparatus comprising an optical system which projects exposure light irradiating a master having a pattern onto a substrate, and a stage apparatus having a substrate holding unit which holds the substrate or master, wherein the stage apparatus includes a stage, a flat surface which drives the substrate holding unit within a predetermined plane, and a fixing member which fixes a projection support formed on the substrate holding unit onto the flat surface, and the substrate holding unit is supported while a distal end of the projection support is in contact with the flat surface and the substrate holding unit is not in contact with the flat surface.
The fourth aspect of the present invention relates to a semiconductor device manufacturing method comprising an applying step of applying a photosensitive material on a substrate, an exposure step of transferring a pattern onto the substrate, applied with the photosensitive material in the applying step, by utilizing the exposure apparatus, and a developing step of developing the photosensitive material on the substrate where the pattern has been transferred in the exposure step.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts through the figures thereof.
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
The preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
A stage apparatus according to the first preferred embodiment of the present invention will be described in detail.
The wafer chuck 9 has a pin-shaped projection (not shown) interspersed on its support surface where a wafer 8 (see
The stage apparatus, according to the preferred embodiment of the present invention, is characterized in the following respects. Namely, as shown in
Although the V-groove 12 of this embodiment has a V shape, the present invention is not limited to this. For example, any V-groove 12 will do as long as it is formed of two surfaces including an inclined surface and the projection support 11 slides on it by the weight of the wafer chuck 9 so that the position of the projection support 11 is determined. The open angle formed by the two surfaces may be 90°, or more than that, or less than that. The projection support 11, which comes into contact with the V-groove 12 of the wafer chuck support surface 13, preferably has a shape (e.g., a spherical shape) with which the contact portion of projection support 11 and the V-groove 12 of the wafer chuck support surface 13 forms point contact. If the moment force is small, the projection support 11 and wafer chuck support surface 13 may be formed to come into linear contact or surface contact with each other.
In this embodiment, the wafer chuck 9 has the projection support 11, and the V-groove 12 is formed on a stage 10. However, the present invention is not limited to this. For example, the relationship between the projection support 11 on the lower surface of the wafer chuck 9 and the V-groove 12 can be reversed. More specifically, the projection support 11 may be formed on the wafer chuck support surface 13, and the V-groove 12 may be formed in the lower surface of the wafer chuck 9. In this case, the projection support 11 for supporting the wafer chuck 9 is fixed to the wafer chuck 9. When the chucking/holding force is canceled, the projection support 11 can be released from the wafer chuck support surface 13. The projection support 11 for supporting the wafer chuck 9 may be fixed to the wafer chuck support surface 13. When the chucking/holding force is canceled, the projection support 11 can be released from the wafer chuck 9.
A stage apparatus according to the second preferred embodiment of the present invention is characterized in the following respects. Namely, as shown in
The wafer chuck 9 has three projection supports 11. As shown in
As described above, that the V-grooves 12 are arranged in three directions at an angular interval of about 120° and that the projection supports 11 and the V-grooves 12 of the wafer chuck support surface 13 come into point contact with each other are very effective to stably support the wafer chuck 9.
A fixing member 14, which holds the projection support 11 against the wafer chuck support surface 13 with a force that chucks and holds the wafer chuck 9 can define a closed space, when an outer seal portion present on its outer surface comes into contact with the wafer chuck support surface 13 with no gap. The fixing member 14 preferably has one of a circular shape, an elliptical shape, a shape similar to an ellipse, or a polygonal shape. The chucking/holding force acting on the fixing member 14 is preferably one of a negative pressure, a Coulomb force, and a magnetic force. When the chucking/holding force is a negative pressure, a closed space is needed. The suction force is obtained by vacuum (e.g., evacuation with a vacuum pump) from a vacuum hole (not shown) in the closed space defined by the fixing member 14 and wafer chuck support surface 13.
When leakage is prevented in the above manner, the projection support 11 can be chucked reliably to the wafer chuck support surface 13. The outer seal portion present on the outer surface of the projection support 11 can be incorporated in the following embodiments as well.
A stage apparatus according to the third preferred embodiment of the present invention includes a wafer chuck 9, which chucks and holds a wafer 8 with suction caused by a negative pressure or the Coulomb force, as shown in
A stage apparatus according to the fourth preferred embodiment of the present invention has a wafer chuck 9, which chucks and holds a wafer 8 by suction caused by a negative pressure or a Coulomb force. To prevent deformation of the surface of the wafer chuck 9, which is caused by the shape of a wafer chuck support surface 13, in this stage apparatus, a projection support 11 for supporting the wafer chuck 9 has an arrangement for absorbing or avoiding deformation.
In the stage apparatus according to this embodiment, a fixing member 14 can tilt freely at its contact portion in the axial direction of the projection support 11 and in the planar direction. When the fixing member 14 has the above degrees of freedom at its contact portion, a small gap is present at the contact portion of the projection support 11 and fixing member 14. This small gap allows the fixing member 14 to move freely.
When the projection support 11 has a fixing member 14 with a shape that ensures a wide surface area parallel to the wafer chuck support surface 13, the fixing member 14 can move freely at the contact portion with respect to the projection support 11.
As an example of the above arrangement, for example, in the stage apparatus according to this embodiment, as shown in
A stage apparatus according to the fifth embodiment of the present invention has a fixing member 14 which holds only a projection support 11 for a wafer chuck 9 with respect to a wafer chuck support surface 13. As shown in
A stage apparatus according to the sixth preferred embodiment of the present invention is characterized in that, as shown in
A stage apparatus according to the seventh preferred embodiment of the present invention is characterized in that, as shown in
A stage apparatus according to the eighth preferred embodiment of the present invention is characterized in that, as shown in
A stage apparatus according to the ninth preferred embodiment of the present invention is characterized in that, as shown in
A stage apparatus according to the tenth preferred embodiment of the present invention is characterized in that, as shown in
A stage apparatus according to the eleventh preferred embodiment of the present invention includes a wafer chuck 9 which chucks and holds a wafer 8 by suction caused by a negative pressure or the Coulomb force. The wafer chuck 9 is placed on a wafer chuck support surface 13 through a projection support 11 which comes into contact with the wafer chuck support surface 13, and is chucked and placed by a negative pressure, the Coulomb force, or a magnetic force.
Since the wafer chuck 9 must be fixed on the wafer chuck support surface 13, not only is the wafer chuck 9 placed on the wafer chuck support surface 13, but also a force is applied to the projection support 11, which comes into contact with the wafer chuck support surface 13, thereby fixing the wafer chuck 9. As this force, a vacuum force, a Coulomb force, a magnetic force, or the like, is used. A mechanism that generates such a force is incorporated in the wafer chuck support surface 13 or the projection support 11. The mechanism which generates the force includes a mechanism such as a pump for generating a vacuum force, an electrode for generating the Coulomb force, an electromagnet for generating a magnetic force, and the like.
As described above, according to the present invention, a large integrated device can be manufactured stably with high productivity. With the stage apparatus according to the preferred embodiment of the present invention and the wafer chuck incorporated in it, the wafer chuck can be stationarily held on and removed from the support surface of the wafer chuck instantaneously. Thus, only the projection support can be held and fixed without applying any forces to the wafer chuck. The reproducibility of the surface of the wafer chuck on different stages can thus be obtained.
As described above, with the stage apparatus according to the preferred embodiment of the present invention, problems accompanying the increase in diameter of the wafer, high-speed movement of the wafer chuck, and the like, are solved, so that the throughput can be improved.
[Exposure Apparatus]
An example will be described wherein a stage apparatus according to a preferred embodiment of the present invention is applied to a reduction projection exposure apparatus.
[Exposure Sequence]
The exposure sequence of the exposure apparatus will be described. After the wafer 8 as the exposure target is set in the exposure apparatus automatically or manually, the exposure apparatus starts operation upon reception of an exposure start command. First, the wafer 8 is transported onto the wafer chuck 9 placed on the stage 10 by a transport system. Subsequently, a plurality of alignment marks on the wafer 8 are detected and measured by an off-axis scope 7 mounted on the stage 10. The magnification, rotation, and X-Y error amounts of the wafer 8 are determined, and the position of the wafer 8 is corrected. The stage 10 moves so as so to set the first shot position of the wafer 8 chucked and held by the wafer chuck 9 to coincide with the exposure position. After the first shot position is focused by a surface measuring means 6, it is exposed for about 0.2 sec. The off-axis scope 7 steps to the second shot position on the wafer 8, and exposure is sequentially repeated. This sequence is performed repeatedly. When the final shot process is ended, an exposure process for one wafer 8 is completed. The wafer 8 is transferred from the wafer chuck to a recovery transport band, and is returned to the wafer carrier.
[Semiconductor Device Manufacturing Process]
A semiconductor device manufacturing process utilizing the above exposure apparatus will be described.
As described above, according to the present invention, the throughput can be improved.
As many apparently widely different embodiments of the present invention can be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the claims.
Number | Date | Country | Kind |
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2002-329701 | Nov 2002 | JP | national |
This application is a continuation application of copending U.S. patent application Ser. No. 10/704,638, filed Nov. 12, 2003.
Number | Date | Country | |
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Parent | 10704638 | Nov 2003 | US |
Child | 11210883 | Aug 2005 | US |