Scanning stage

Abstract

Provided is a small-sized scanning stage for scanning a device on the surface of a scan target having a large diameter.　A scanning stage 10 comprises: an X-Y stage (21); a device (17) that is fixed to an X-Y-Z coordinate system common to the X-Y stage (21); a rotating stage (22) provided on the X-Y stage (21) and holding and rotating a scan target (15); a first drive unit (11) that drives the X-Y stage (21) so that an input / output axis (18) of the device (17) scans a scan region (R) which is one region that is set from among a plurality of regions (A, B, C, D) into which the scan target (15) is equally divided with respect to a rotation center O of the rotating stage (22); and a second drive unit (12) that drives the rotating stage (22) so that a region (A, B, C, D) yet to be scanned is positioned in the scan region (R).

Description

Scanning stage

[0001] The present invention relates to a scanning stage for scanning the surface of a scanning object.

[0002] In semiconductor manufacturing, there is a process for inspecting the patterns formed on wafers. This inspection process detects abnormalities and defects in highly integrated semiconductor integrated circuits. To inspect all patterns on the wafer, the wafer is placed on an XY stage and scanned from one end to the other by a detector.

[0003] Japanese Patent Application Laid-Open No. 2000-156392

[0004] Incidentally, in order to increase the number of elements per wafer and improve productivity, wafers have become larger in diameter, with 12 inches (approximately 300 mm) being the mainstream at present. As mentioned above, if the entire surface of a substrate such as a wafer is to be scanned by simply moving the XY stage, there is an unavoidable problem of increasing the size of the XY stage.

[0005] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a compact scanning stage that allows an apparatus to scan the surface of a scanning target having a large diameter.

[0006] 1 is a perspective view showing the appearance of a scanning stage according to a first embodiment of the present invention. (A), (B), (C), and (D) are top perspective views of the scanning stage explaining the operation of the XY stage in the first embodiment. (A), (B), (C), and (D) are top views explaining the operation of a rotation stage in the scanning stage. 2 is a perspective view showing the appearance of a scanning stage according to a second embodiment of the present invention. (A), (B), (C), and (D) are top perspective views of the scanning stage explaining the operation of the XY stage in the second embodiment. (A) is an explanatory diagram of the effect of a scanning region showing an example of a scanning stage of the present invention, and (B) is an explanatory diagram of a scanning region showing a comparative example.

[0007] First Embodiment A first embodiment of the present invention will now be described with reference to the accompanying drawings. Figure 1 is a perspective view showing the exterior of a scanning stage 10A (10) according to the first embodiment. As described above, the scanning stage 10A (10) comprises an XY stage 21, a device 17 fixed to a common coordinate system (X-Y-Z) with the XY stage 21, and a rotating stage 22 that is mounted on the XY stage 21 and that holds and rotates a scanning target 15.

[0008] Furthermore, the scanning stage 10 is equipped with a first drive unit 11 that drives the X-Y stage 21 so that the input / output axis 18 of the device 17 scans a scanning region R, one of which is set as a scanning region R by equally dividing the scanning object 15 into a plurality of regions (A, B, C, D) relative to the rotation center point O of the rotating stage 22, and a second drive unit 12 that drives the rotating stage 22 so that the unscanned region (A, B, C, D) is positioned in the scanning region R.

[0009] In the embodiment, the scanning object 15 is exemplified as a wafer for semiconductor manufacturing, but is not limited to this and may also include a liquid crystal substrate, an electronic circuit board, and other panels or sheets on which patterns are formed. The shape is also not limited to a circle and may include a rectangle.

[0010] The X-Y stage 21 is composed of a base body 25 that defines the X-Y-Z coordinate system, an X-axis rail 26 that is provided on the base body 25 along the X-axis of this coordinate system, an X-axis table 27 that moves along the X-axis rail 26, a Y-axis rail 28 that is provided on the X-axis table 27 along the Y-axis of this coordinate system, and a Y-axis table 29 that moves along the Y-axis rail 28.

[0011] This allows the XY stage 21 to arbitrarily horizontally displace the Y-axis table 29 in the XY plane coordinate system. Although not shown, the linear displacement of each of the X-axis table 27 and the Y-axis table 29 can be achieved by converting the rotational angular displacement of a rotary motor using a mechanical element such as a ball screw, or by a linear motor.

[0012] The device 17 is mechanically and structurally integrated with the base body 25 of the XY stage 21, and is fixed to the XYZ coordinate system together with the XY stage 21. In this embodiment, the device 17 is exemplified as an optical camera that observes the surface of the scanning object 15. This optical camera observes the pattern on the scanning object 15 (wafer) from a direction along the input / output axis 18. Note that the observation light source (not shown) may irradiate light in a direction along the input / output axis 18, or may irradiate light from an oblique direction relative to the input / output axis 18.

[0013] The optical sensor detects the light reflected from the surface of the scanned object 15 along the input / output axis 18. Light sources for observation include visible light, ultraviolet light, deep ultraviolet light, vacuum ultraviolet light, X-rays, and electron beams. The device 17 is not limited to an optical camera for surface observation, but also includes electrical testing testers, electron guns, ion guns, foreign material detectors, exposure machines, and other inspection and pattern projection devices. When the device 17 is a transfer system using an exposure machine, the portion of the device 17 corresponding to the reticle (precise light-dark pattern) is fixed to the coordinate system (X-Y-Z).

[0014] The rotary stage 22 is composed of a rotary motor 23 whose housing is fixed to the upper surface of the Y-axis table 29 of the XY stage 21, and a rotary table 24 that is supported by the rotation shaft of the rotary motor 23 and holds the scanning object 15 on its upper surface. This allows the rotary stage 22 to rotate and displace the rotary table 24 in a θ rotation coordinate system defined by the Y-axis table 29.

[0015] The scanning object 15 is divided into a plurality of equal areas (A, B, C, D) symmetrically about the rotation center point O. One of the areas is set as the scanning area R, and the input / output axis 18 of the device 17 is scanned. Note that in the embodiment, the scanning object 15 is shown as being divided into four equal areas (A, B, C, D), but is not limited to this, and an object divided into two or more equal areas is also applicable.

[0016] 2A, 2B, 2C, and 2D are top perspective views of the scanning stage 10, illustrating the operation of the XY stage 21. The first driving unit 11 (FIG. 1) drives the Y-axis table 29 of the XY stage 21 so that the input / output shaft 18 of the device 17 scans the scanning region R. Note that while the XY stage 21 is operating, the rotating stage 22 is stationary.

[0017] 3A, 3B, 3C, and 3D are top views illustrating the operation of the rotating stage 22 in the scanning stage 10. The second drive unit 12 (FIG. 1) drives the rotating stage 22 so that the unscanned areas (A, B, C, and D) of the scanning object 15 are positioned in the scanning region R. Note that while the rotating stage 22 is operating, the XY stage 21 (FIG. 2) is stationary.

[0018] Second Embodiment A second embodiment of the present invention will now be described with reference to the accompanying drawings. Figure 4 is a perspective view showing the appearance of a scanning stage 10B (10) according to the second embodiment. Figures 5(A), (B), (C), and (D) are top perspective views of the scanning stage 10B illustrating the operation of the XY stage 21 in the second embodiment.

[0019] Thus, the scanning stage 10B (10) comprises an XY stage 21, equipment 17 provided on the XY stage 21, and a rotating stage 22 that is fixed to a coordinate system (X-Y-Z) common to the XY stage 21 and that holds and rotates the scanning object 15. Note that in Figure 4, the scanning object 15 and areas (A, B, C, D) cannot be seen from the angle shown in the figure, but are shown as seen through from the back of the rotating stage 22.

[0020] Furthermore, the scanning stage 10 is equipped with a first drive unit 11 that drives the X-Y stage 21 so that the input / output axis 18 of the device 17 scans a scanning region R, one of which is set as a scanning region R by equally dividing the scanning object 15 into a plurality of regions (A, B, C, D) relative to the rotation center point O of the rotating stage 22, and a second drive unit 12 that drives the rotating stage 22 so that the unscanned region (A, B, C, D) is positioned in the scanning region R.

[0021] In the second embodiment, the device 17 is fixed to the upper surface of the Y-axis table 29 of the XY stage 21. Also in the second embodiment, the housing of the rotating stage 22 is mechanically integrated with the base body 25 of the XY stage 21, and thus the rotating stage 22 is fixed to the XYZ coordinate system together with the XY stage 21. The rotating table 24, which is rotatably supported by the housing of the rotating stage 22, holds the scanning object 15 on its upper surface. As a result, the rotating stage 22 can rotate and displace the rotating table 24 in the θ rotating coordinate system defined by the XYZ coordinate system.

[0022] The explanation of the first embodiment based on FIG. 3 is also applicable to the explanation of the second embodiment.

[0023] 6A is an explanatory diagram of the effect of the scanning region R showing an embodiment of the scanning stage 10 of the present invention. FIG. 6B is an explanatory diagram of the scanning region R' showing a comparative example. In this way, in the scanning stage 10, by rotating the rotary stage 22, one of a plurality of regions (four shown) into which the scanning object 15 is equally divided is positioned in the fixed scanning region R. This has the effect of making it possible to provide a compact scanning stage 10 that can scan the surface of a scanning object 15, such as a substrate with a large diameter, with the input / output shaft 18 of the device 17.

[0024] 10...scanning stage, 11...first drive unit, 12...second drive unit, 15...scanning object, 17...equipment, 18...input / output axis, 21...X-Y stage, 22...rotating stage, 23...rotation motor, 24...rotating table, 25...base body, 26...X-axis rail, 27...X-axis table, 28...Y-axis rail, 29...Y-axis table, R...scanning area.

Claims

1. A scanning stage comprising: an X-Y stage; equipment fixed to a coordinate system common to said X-Y stage; a rotation stage mounted on said X-Y stage to hold and rotate an object to be scanned; one of a plurality of areas obtained by equally dividing said object to be scanned around the rotation center point of said rotation stage is set as a scanning area, a first drive unit that drives said X-Y stage so that the input / output axis of said equipment scans this scanning area; and a second drive unit that drives said rotation stage so that the area that has not yet been scanned is positioned within said scanning area.

2. A scanning stage comprising: an XY stage; equipment mounted on the XY stage; a rotating stage fixed to a coordinate system common to the XY stage and for holding and rotating an object to be scanned; a first drive unit that drives the XY stage so that the input / output axis of the equipment scans one of a plurality of areas obtained by equally dividing the object to be scanned around the rotation center point of the rotating stage, the scanning area being set as one of the areas; and a second drive unit that drives the rotating stage so that the unscanned area is positioned within the scanning area.

3. A scanning stage according to claim 1 or 2, wherein the object to be scanned is a wafer for semiconductor manufacturing.

4. A scanning stage according to claim 1 or claim 2, wherein the device is an optical camera that observes the surface of the object to be scanned.

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