JP2006253469A - Stage device and exposure apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stage device for performing positional measurement using a laser interferometer which can reduce the influence of measurement error caused by deformation or the like. <P>SOLUTION: The stage device has a roughly-moving stage movable with a long stroke, a finely-moving stage movable with a short stroke relative to the roughly-moving stage, and a holding member fixed on the finely-moving stage for holding a substrate or a base plate. The stage device comprises an inteferometer system for performing positional measurement. The inteferometer system has an interferometer for irradiating measurement light and a reflector for reflecting the measurement light radiated from the interferometer. The reflector is provided to the holding member. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a stage apparatus that moves with an object mounted thereon, and relates to a stage apparatus that measures the position of the object using a laser interferometer. Furthermore, the present invention relates to an exposure apparatus provided with such a stage apparatus.

  The exposure apparatus includes a stage device for positioning a wafer or a reticle. In a stage apparatus, an interferometer is generally used to measure the position of a wafer or a reticle.

  FIG. 9 is a diagram showing a position measurement method using a laser interferometer in Patent Document 1. In FIG. In FIG. 9, in order to measure the position of the wafer held on the wafer chuck 40, the measurement light emitted from the laser interferometers 41 a to 41 c and 42 a to 42 b is reflected on the mirrors 43 and 44 provided on the fine movement stage 45. Let

  The fine movement stage 45 is provided on a coarse movement stage (not shown), and moves with the coarse movement stage in a long stroke. The laser interferometers 41a to 41c and 42a to 42b are fixed to a lens barrel support (not shown) that supports a projection lens (not shown) of the exposure apparatus.

  The mirror 43 for measuring the position of the fine movement stage 45 in the X direction is elongated along the Y direction. As a result, even if the fine movement stage 45 is moved in the Y direction with a long stroke, the measurement light from the laser interferometers 41a to 41c that measure the position in the X direction does not come off the mirror.

  Similarly, the mirror 44 for measuring the position of the fine movement stage 45 in the Y direction is elongated along the X direction. As a result, even if the fine movement stage 45 is moved in the X direction with a long stroke, the measurement light from the laser interferometers 41a to 41c that measure the position in the Y direction does not come off the mirror.

Further, by providing a plurality of laser interferometers, the position in the rotational direction of the fine movement stage can be measured.
JP 2002-319541 A Japanese Patent Laid-Open No. 03-010105

  As described above, in the method of measuring the position of the wafer by reflecting the measurement light emitted from the interferometer to the mirror provided on the fine movement stage, the distance between the position to be measured on the wafer and the mirror It is assumed that will not fluctuate.

  However, when the fine movement stage is deformed due to inertial force during stage acceleration / deceleration, the distance between the position to be measured and the mirror fluctuates. Such a variation in distance causes a measurement error and hinders highly accurate positioning.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to reduce the influence of measurement errors due to deformation of the stage body in a stage apparatus that performs position measurement using an interferometer.

  In order to achieve the above object, in the present invention, a coarse movement stage movable with a long stroke, a fine movement stage movable with a short stroke with respect to the coarse movement stage, and fixed on the fine movement stage, a substrate or A stage apparatus having a holding member for holding an original plate, wherein the stage apparatus includes an interferometer system for position measurement, and the interferometer system is irradiated with an interferometer that emits measurement light and the interferometer. And a reflection part that reflects the measurement light. The reflection part is provided on the holding member.

  In the present invention, the exposure apparatus is characterized in that the substrate and / or the original plate are positioned using such a stage apparatus.

  In the present invention, the device manufacturing method includes a step of exposing a wafer using such an exposure apparatus and a step of developing the wafer.

  ADVANTAGE OF THE INVENTION According to this invention, in the stage apparatus which measures a position using an interferometer, the influence of the measurement error by a deformation | transformation etc. of a stage main body can be reduced.

  The embodiment described below is an example as means for realizing the present invention, and should be appropriately modified or changed according to the configuration of the apparatus to which the present invention is applied and various conditions.

[Example 1]
FIG. 1 is a view showing an outline of an exposure apparatus in the first embodiment. The exposure apparatus includes an illumination unit 7, a reticle stage that moves a reticle having a pattern, a projection lens 9, and a wafer stage that moves a wafer. The illumination unit 7 illuminates the pattern, and the illuminated pattern is projected onto the wafer by the projection lens 9.

  Here, the projection lens is an example of a projection optical system used in an exposure apparatus, and is an optical system including only a plurality of lens elements, and an optical system (catadioptric optics) including a plurality of lens elements and at least one concave mirror. System), an optical system having a plurality of lens elements and at least one diffractive optical element such as a kinoform, an all-mirror optical system, and the like can be used.

  The wafer stage is fixed on the fine movement stage 13, a coarse movement stage 13 that can be moved in the plane direction with a long stroke, a fine movement stage 2 that is mounted on the coarse movement stage and can be moved with a short stroke relative to the coarse movement stage, and A wafer chuck (holding member) 1 for holding the wafer is provided.

  As shown in FIG. 3, the coarse moving stage 13 includes an X guide 14 that is long in the X direction and a Y guide 15 that is long in the Y direction. The coarse movement stage is guided in the XY directions along these guides. Since the X guide 14 is moved in the Y direction by the linear motor 16 and the Y guide 15 is moved in the X direction by a linear motor (not shown), the coarse movement stage receives the force from each guide and moves in the XY direction.

  The fine movement stage 2 is rotated in the X, Y, Z direction, ωx (rotation direction around the X axis), ωy (rotation around the Y axis) with respect to the coarse movement stage by a linear motor 17 provided between the coarse movement stage and the fine movement stage. Direction), ωz (rotational direction around the Z axis) with a short stroke. As a result, highly accurate positioning can be performed on the fine movement stage.

  2 and 3 are diagrams for explaining the position measurement of the wafer stage.

  The wafer stage includes an interferometer system for position measurement. The interferometer system includes a light source that emits light for measurement, an interferometer that includes a splitter for dividing the light into reference light and measurement light, a mirror that reflects the divided reference light and measurement light, respectively And a detector for detecting interference light between the measurement light reflected by the mirror and the reference light.

  In this embodiment, the wafer stage includes a first interferometer system for measuring the position of the fine movement stage and a second interferometer system for measuring the position of the wafer chuck with respect to the fine movement stage.

  First, the first interferometer system will be described.

  The projection lens 9 is supported by a lens barrel support 10 independent of the coarse motion stage and the fine motion stage, and interferometers 5a to 5c and 6a to 6b (not shown in FIG. 1) are fixed to the lens barrel support 10. . Here, the interferometer includes a splitter (for example, a half mirror or a deflecting beam splitter) that splits light (for example, laser light) emitted from a light source (not shown) into reference light and measurement light.

  The divided measurement light is reflected by mirrors 3 and 4 provided on fine movement stage 2, and the divided reference light is reflected by a reference mirror (not shown) inside the interferometer. The reflected measurement light and reference light are guided to a detector (not shown). By detecting and calculating the interference light of the measurement light and the reference light by the detector, the relative position between the fine movement stage 2 and the lens barrel support 10 can be measured.

  Next, the second interferometer system will be described.

  Interferometers 19 and 20 for measuring the position of the wafer chuck 1 in the XY directions are provided on the fine movement stage 2 (FIG. 3). The configuration of the interferometers 19 and 20 is the same as that of the interferometers 5a to 5c and 6a to 6b described above. On the side surface of the wafer chuck 1, a mirror 29 having a reflecting surface perpendicular to the X direction and a mirror 30 having a reflecting surface perpendicular to the Y direction are provided. These mirrors are only required to have a size that corresponds to the measurement light irradiated from the interferometers 19 and 20.

  Light (for example, laser light) emitted from a light source (not shown) is guided to the interferometers 19 and 20 by the mirror 31 provided on the X guide of the coarse movement stage and the mirror 32 provided on the Y guide. . Interferometers 19 and 20 divide the light emitted from the light source into measurement light and reference light, the measurement light is reflected by mirrors 29 and 30 on the side surface of the wafer chuck, and the reference light is interferometer provided on fine movement stage 2. Reflected by reference mirrors 19 and 20 (not shown). The reflected measurement light and reference light are guided to a detector provided outside fine movement stage 2. The relative position between fine movement stage 2 and wafer chuck 1 can be measured by detecting and calculating the interference light of the measurement light and the reference light by the detector. Here, the detector can be provided in any of an X guide, a Y guide, and a coarse movement stage (stage movable portion).

  By controlling a linear motor or the like that drives the fine movement stage 2 using the above measurement result, high-accuracy positioning is possible.

  In this embodiment, by providing the wafer chuck 1 with a mirror for reflecting the measurement light of the interferometer, the relative position between the lens barrel support 10 and the wafer chuck 1 can be measured, and the fine movement stage 2 is deformed. Measurement error can be reduced.

  Further, in this embodiment, the relative position between the lens barrel support 10 and the wafer chuck 1 is measured by measuring the relative position between the lens barrel support 10 and the fine movement stage 2 and the relative position between the fine movement stage 2 and the wafer chuck 1. Measuring. According to this, the mirror provided in the wafer chuck 1 can be made small.

  In the present embodiment, only examples of the X direction and the Y direction are shown, but the present invention can also be applied to the ωz direction. An example applied to the Z direction, the ωx direction, and the ωy direction will be described in the second embodiment.

(Modification)
A modification of the first embodiment will be described with reference to FIG. Except for the points described below, it is the same as the above-described embodiment.

  In the above-described embodiment, the reference light divided by the dividers of the interferometers 19 and 20 is reflected by the mirror inside the interferometer, but in this modification, the reference light is fixed to the lens barrel support 10. Reflected by mirrors 24 and 25.

  The reference light reflected by the mirrors 24 and 25 is guided to the detector together with the measurement light reflected by the mirror on the side surface of the wafer chuck. The relative position between the lens barrel support 10 and the wafer chuck 1 can be measured by detecting and calculating the interference light of the measurement light and the reference light by the detector.

  According to this modification, since the mirrors 24 and 25 can be disposed outside, the fine movement stage 2 can be reduced in weight.

[Example 2]
Example 2 is an example in which the position of the wafer stage in the Z direction is measured. In FIG. 5, fine movement stage 2 is mounted on coarse movement stage 13, and wafer chuck 1 is mounted on fine movement stage 2.

  The fine movement stage 2 is provided with an interferometer 22 for measuring the position of the wafer chuck 1 in the XY directions. The configuration of the interferometer 22 is the same as that of the interferometers 5a to 5c and 6a to 6b in the first embodiment. A mirror 33 having a reflective surface perpendicular to the Z direction is provided on the back surface of the wafer chuck 1. The mirror 33 only needs to have a size within a range where the measurement light emitted from the interferometer 22 is incident.

  Light (for example, laser light) emitted from a light source (not shown) is guided to the interferometer 22 by a mirror provided on the X guide of the coarse movement stage. The interferometer 28 divides the light emitted from the light source into measurement light and reference light, the measurement light is reflected by a mirror on the back surface of the wafer chuck, and the reference light is a reference mirror (non-standard mirror) provided in the fine movement stage 2. Reflected). The reflected measurement light and reference light are guided to a detector provided outside fine movement stage 2. The relative position in the Z direction between fine movement stage 2 and wafer chuck 1 can be measured by detecting and calculating the interference light of the measurement light and the reference light by the detector. Here, the detector can be provided in any of an X guide, a Y guide, and a coarse movement stage (stage movable portion).

  Furthermore, by measuring the relative position in the Z direction between a lens barrel support (not shown) and the fine movement stage, as a result, the relative position in the Z direction between the lens barrel support and the wafer chuck can be measured.

  By controlling a linear motor or the like that drives the fine movement stage 2 using the above measurement result, high-accuracy positioning is possible.

(Modification)
A modification of the second embodiment will be described with reference to FIG. The second embodiment is the same as the second embodiment except for the points described below.

  In the above-described embodiment, the reference light emitted from the interferometer is reflected by the mirror inside the interferometer. However, in this modification, the reference light is reflected by the mirror 23 fixed to the lens barrel support 10. Yes. The interferometer can be provided on the fine movement stage, but is provided on the coarse movement stage in order to reduce the weight of the fine movement stage.

  Light (for example, laser light) emitted from a light source (not shown) is guided to the interferometer 22 by a mirror provided on the X guide of the coarse movement stage. The interferometer 22 divides the light emitted from the light source into measurement light and reference light, and the reference light reflected by the mirror 23 is guided to the detector together with the measurement light reflected by the mirror on the back surface of the wafer chuck. The relative position between the lens barrel support 10 and the wafer chuck 1 can be measured by detecting and calculating the interference light of the measurement light and the reference light by the detector.

  According to this modification, since the mirror 23 can be disposed outside the stage, the fine movement stage 2 can be reduced in weight.

  Note that the present embodiment can be applied not only in the Z direction but also in the ωx direction and the ωy direction, as in the first embodiment.

(Example of device manufacturing method using the above exposure apparatus)
Next, a semiconductor device manufacturing process using this exposure apparatus will be described. FIG. 7 is a diagram showing a flow of an entire manufacturing process of a semiconductor device. In step 1 (circuit design), a semiconductor device circuit is designed. In step 2 (mask fabrication), a mask is fabricated based on the designed circuit pattern.

  On the other hand, in step 3 (wafer manufacture), a wafer is manufactured using a material such as silicon. Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by using the above-described exposure apparatus and lithography technology using the above-described mask and wafer. The next step 5 (assembly) is called a post-process, and is a process for forming a semiconductor chip using the wafer produced in step 4, and is an assembly process (dicing, bonding), packaging process (chip encapsulation), etc. Process. In step 6 (inspection), the semiconductor device manufactured in step 5 undergoes inspections such as an operation confirmation test and a durability test. A semiconductor device is completed through these processes, and is shipped in Step 7.

  The wafer process in Step 4 has the following steps (FIG. 8). An oxidation step for oxidizing the surface of the wafer, a CVD step for forming an insulating film on the wafer surface, an electrode formation step for forming electrodes on the wafer by vapor deposition, an ion implantation step for implanting ions on the wafer, and applying a photosensitive agent to the wafer A resist processing step, an exposure step for transferring the circuit pattern to the wafer after the resist processing step by the above exposure apparatus, a development step for developing the wafer exposed in the exposure step, and an etching step for scraping off portions other than the resist image developed in the development step A resist stripping step that removes the resist that has become unnecessary after etching. By repeating these steps, multiple circuit patterns are formed on the wafer.

The figure which shows the outline of the exposure equipment The figure which shows the position measurement system concerning Example 1. FIG. Top view of the position measurement system according to the first embodiment. The figure which shows the modification of the modification 1 The figure which shows the position measurement system concerning Example 2. FIG. The figure which shows the modification of Example 2. Diagram showing device manufacturing method Diagram showing wafer process Diagram showing a conventional position measurement system

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wafer chuck 2 Fine movement stage 3 X mirror 4 Y mirror 5a-5c X interferometer 6a-6c Y interferometer 7 Illumination part 8 Reticle 9 Projection lens 10 Lens barrel support 11 Stage surface plate 12 Z displacement sensor 13 Coarse movement stage 14 X guide 15 Y guide 16 Y linear motor 17 Fine movement linear motor 18-20 Interferometer 22 Interferometer 23 Mirror 24, 25 Mirror fixed to the lens barrel support 29, 30 Mirror provided on the chuck 31, 32 Provided on the guide Mirror 33 Z mirror

Claims (10)

A stage apparatus having a coarse movement stage movable with a long stroke, a fine movement stage movable with a short stroke with respect to the coarse movement stage, and a holding member fixed on the fine movement stage and holding a substrate or an original plate. The stage apparatus includes an interferometer system for position measurement, and the interferometer system includes:
A stage apparatus comprising: an interferometer that irradiates measurement light; and a reflection portion that reflects measurement light emitted from the interferometer, wherein the reflection portion is provided on the holding member.   The stage apparatus according to claim 1, wherein the interferometer is mounted on the fine movement stage.   The stage apparatus according to claim 1, wherein the fine movement stage moves with six degrees of freedom with respect to the coarse movement stage. The interferometer system includes a light source that emits light for position measurement,
The stage apparatus according to claim 1, wherein the interferometer includes a splitter that divides the light into measurement light and reference light.   The stage apparatus according to claim 4, wherein the reference light is reflected by a second reflecting portion provided inside the interferometer.   The stage apparatus according to claim 4, wherein the reference light is reflected by a second reflecting portion fixed to a support independent of the coarse movement stage and the fine movement stage.   The stage apparatus according to claim 5, wherein the interferometer system includes a detector that detects the reference light reflected by the second reflection unit and the interference light of the measurement light.   The stage apparatus according to claim 1, wherein the interferometer system measures a position of the holding member in a vertical direction.   An exposure apparatus for positioning a substrate and / or an original plate using the stage apparatus according to claim 1. Exposing the wafer using the exposure apparatus according to claim 9;
And a step of developing the wafer.

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