JP2005203399A - Aligner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a twin reticle stage corresponding to double exposure without reducing the controllability of the stage. <P>SOLUTION: In an aligner for performing the transfer exposure of reticle (master) onto a wafer (substrate) successively, a reticle stage having a coarse positioning stage and a fine movement positioning stage has a plurality of fine movement stages on one coarse positioning stage. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a moving apparatus suitably used for high-precision processing such as a semiconductor lithography process, a stage including the moving apparatus, and an exposure apparatus including the stage.

  A conventional example is shown in FIG. FIG. 7 shows a conventional double exposure-compatible reticle stage. Reference numeral 101 denotes a stator of a reticle stage driving linear motor. Reference numeral 102 denotes a bar mirror serving as a stage measurement reference. Reference numeral 103 denotes a linear motor movable element for the stator, and reference numeral 104 denotes a reticle (master disk, mask). A plurality of reticles are mounted on one stage top plate 105. In the figure, two reticles are mounted to support high throughput during double exposure. Reference numeral 106 denotes a mechanism for chucking the reticle, and a plurality are mounted on the stage top plate. For an exposure apparatus in the atmosphere, vacuum suction is used, and for an exposure apparatus in a vacuum, an apparatus using an electrostatic chuck is used. An air static pressure bearing 107 is used on the stage running surface. Reference numeral 108 denotes a stage measurement reference interferometer corner cube. The stage position is measured and controlled with high accuracy by an interferometer (not shown).

In a stage where two or more reticles can be mounted on the same stage top plate, the rigidity is reduced by increasing the size and weight of the stage top plate, and the natural frequency of the mechanical system is reduced to control the stage. It has become a problem due to a decline in performance.
JP 2000-021715 A

  An object of the present invention is to provide a twin reticle stage that can handle double exposure without degrading the controllability of the stage.

  The present invention relates to a stage system having a coarse movement stage for positioning with a large stroke and a fine movement stage for fine final positioning of the stage position on the coarse movement stage, and independent actuators are provided on one coarse movement stage. It has been found that the above problems can be solved by mounting a plurality of fine movement stages.

  In an exposure apparatus that performs double exposure continuously and with high efficiency, exposure can be performed without sacrificing stage controllability.

(Example 1)
Examples of the present invention will be described below.

  FIG. 1 shows this embodiment.

  In FIG. 1, reference numeral 1 denotes a stator for a coarse motion stage driving linear motor. Reference numeral 2 denotes a bar mirror serving as a measurement reference for the coarse movement stage. 3 is a coarse stage linear motor movable element, and 4 is a reticle. A plurality of fine movement stage top plates 9 mounted on coarse movement stage top plate 5 are chucked. In the figure, two reticles are mounted on two fine movement stages to support double exposure. A mechanism 6 for chucking the reticle is mounted on the fine movement stage. Reference numeral 7 denotes a coarse movement stage running surface which uses an air static pressure bearing. Reference numeral 8 denotes a corner cube as a stage measurement standard. Reference numeral 10 denotes a fine movement stage actuator, and each fine movement stage is equipped with an independent actuator. By using a plurality of reticles, even if the size of the coarse movement stage is enlarged, the final positioning accuracy and controllability are not lowered by the fine movement stage mounted on the coarse movement stage.

(Other examples)
FIG. 2 shows a second embodiment. In the figure, the same reference numerals as those in FIG. 1 denote the same components. In the embodiment of FIG. 2, a mechanical chucking mechanism 12 is provided between the fine movement stage and the coarse movement stage. If only one stage is used for the exposure sequence, the unused stage can be held without being driven. The fine movement stage chucking mechanism may be a mechanism using a magnet or a mechanical clamping mechanism.

  FIG. 3 shows a third embodiment. In the figure, the same reference numerals as those in FIGS. 1 and 2 denote the same components. In the embodiment of FIG. 3, a position sensor 13 is provided between the fine movement stage and the reticle, and the displacement of the reticle with respect to the fine movement top plate that may occur during acceleration / deceleration is constantly monitored, and feedback or feed to both stage positions is performed. It is to forward.

  FIG. 4 shows a fourth embodiment. In the drawing, a reticle stage on which a plurality of reticles can be mounted is not shown, but has the same configuration as FIG. In the 14 reticle supply / collection / alignment mechanisms, a plurality of 15 supply hands are provided, and a 17 reticle supply linear motion mechanism is configured to supply a plurality of supply reticles 16 onto the supply hands. When supplying and aligning the reticle to the stage, the reticle on the stage is first recovered in the 18 reticle recovery unit, and the supply reticle is aligned on the stage. Of course, the collection unit and the supply unit on the hand can be interchanged by the same mechanism. An alignment mechanism (not shown) is configured independently for a plurality of supply hands, and can simultaneously align a plurality of reticles.

  FIG. 5 shows an example of an exposure sequence in the present invention. By using two reticles with the same pattern, exposure step 1 and exposure step 2 in the figure can be performed continuously in one scan, and the number of acceleration / deceleration times and settling time can be reduced. Throughput can be increased. Although two different patterns can be used, it is desirable to use two identical patterns in consideration of subsequent process processing.

  FIG. 6 shows an example of an exposure sequence in double exposure according to the present invention. The control target values of the reticle stage and wafer stage at the time of the first exposure are the same as the stage drive profile when tracking control is not applied between both stages. Here, a memory for storing an error (drive deviation) from the stage drive profile of each stage during the first exposure is provided and stored in the control system. Thereafter, the previously stored memory deviation is added to the stage drive profile as a stage control parameter for the second exposure in which a double exposure trim mask or the like is superimposed on the same pattern. When taking into account, the memory may be added in the time domain as it is. You may add it. As described above, double exposure with high accuracy becomes possible.

Moving device shown in this embodiment Mobile device according to another embodiment Mobile device according to another embodiment Mobile device according to another embodiment Exposure sequence shown in other embodiments Position control sequence shown in another embodiment Moving device shown in conventional example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coarse motion LM stator 2 Coarse motion stage reference bar mirror 3 Coarse motion LM mover 4 Reticle 5 Coarse motion stage top plate 6 Reticle chuck 7 Stage traveling surface 8 Corner cube 9 Fine motion stage top plate 10 Fine motion stage actuator 11 Fine motion stage reference bar mirror DESCRIPTION OF SYMBOLS 12 Fine movement stage chucking mechanism 13 Reticle position sensor 14 Reticle supply, collection | recovery, alignment mechanism 15 Reticle supply hand 16 Reticle for supply 17 Reticle supply linear motion mechanism 101 Linear motor stator 102 Stage reference bar mirror 103 Linear motor movable element 104 Reticle 105 Stage Top plate 106 Reticle chuck 107 Stage running surface 108 Interferometer corner cube

Claims (7)

  In an exposure apparatus that sequentially transfers and exposes a reticle (master) to a wafer (substrate), a reticle stage having a coarse positioning stage and a fine positioning stage has a plurality of fine positioning stages on one coarse positioning stage. An exposure apparatus.   2. The exposure apparatus according to 1, wherein a fine movement stage that is not used for exposure is mechanically integrally supported with respect to the coarse movement stage.   The exposure apparatus according to 1-2, wherein each of the plurality of fine movement stages has an independent actuator.   The exposure apparatus according to any one of claims 1 to 3, wherein a plurality of reticles having the same pattern or different patterns are mounted on a plurality of fine movement stages, and a plurality of exposures are continuously performed in one scan.   5. An exposure apparatus according to any one of claims 1 to 4, wherein a sensor for measuring a reticle position is provided on each fine movement stage to detect a substrate shift and feed forward to the fine movement position.   6. The exposure apparatus according to any one of claims 1 to 5, wherein a plurality of reticle supply alignment apparatuses are provided, and reticles are supplied simultaneously to or close to a plurality of fine movement stages.   The exposure apparatus according to any one of claims 1 to 6, wherein when performing double exposure, the stage control deviation at the time of the first exposure is stored as a correction value for the stage drive target value at the time of the second exposure. .

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