Photocopying – Projection printing and copying cameras – Detailed holder for photosensitive paper
Reexamination Certificate
2002-12-09
2004-04-13
Nguyen, Henry Hung (Department: 2851)
Photocopying
Projection printing and copying cameras
Detailed holder for photosensitive paper
C355S053000
Reexamination Certificate
active
06721041
ABSTRACT:
INCORPORATION BY REFERENCE
The disclosure of the following priority application is incorporated herein by reference in its entirety: Japanese Patent Application No. 11-341844 filed Dec. 1, 1999.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a stage device and an exposure apparatus, and more particularly to a stage device provided with a plurality of stages and an exposure apparatus provided with the stage device.
2. Description of Related Art
Conventionally, various exposure apparatus are used to fabricate a semiconductor device (integrated circuit), a liquid crystal display device, or the like by a photolithographic process. Recently, as semiconductor devices have become highly integrated, reduction projection exposure apparatus such as a step•and•repeat type projection exposure apparatus (a so-called stepper) and a step•and•scan type scanning projection exposure apparatus (a so-called scanning•stepper), that improves upon the stepper, have been widely used.
These types of projection exposure apparatus are predominantly used for the production of semiconductor devices. Therefore, processing capability as to how many wafers can be exposure-processed within a predetermined time, that is, throughput needs to be improved.
The following shows the main processes performed in these types of projection exposure apparatus.
(a) First, a wafer loading process is performed that loads a wafer onto a wafer holder of a wafer (substrate) stage by using a wafer loader.
(b) Next, a search alignment process is performed that performs position detection of the wafer by a search alignment mechanism. Specifically, the search alignment process is performed by, for example, using the image of the wafer as a reference or by detecting a search alignment mark on the wafer.
(c) Subsequently, a fine alignment process is performed that accurately obtains the position of each shot region on the wafer (each shot region corresponds to an area where a circuit pattern will be formed). This fine alignment process typically uses an EGA (Enhanced•Global•Alignment) method. In this method, arrangement data for all shot regions on the entire wafer can be obtained (see U.S. Pat. No. 4,780,617) by selecting a plurality of sample shot regions on the wafer, measuring the position of an alignment mark (wafer mark) arranged in the sample shots, and by performing statistical calculation by a so-called least squares method or the like based on this measurement result and a designed value of shot arrangement. Then, a coordinate position of each shot region can be obtained with high throughput and with relatively high accuracy.
(d) Next, an exposure process is performed in which an image of a pattern of a reticle (mask) is transferred onto the wafer (substrate) via a projection optical system as each shot region on the wafer is sequentially positioned at an exposure position based on a base alignment amount that was measured in advance and a coordinate position of each shot region obtained by the above-mentioned EGA method or the like.
(e) Next, a wafer unloading process is performed that unloads the wafer that has been exposure-processed from the wafer stage by using a wafer unloader. This wafer unloading process is simultaneously performed with the above-mentioned (a) wafer loading process for the next wafer to be exposure-processed. That is, a wafer replacement process is constituted by steps (a) and (e).
Thus, in a conventional projection exposure apparatus, three significant operations, such as: (1) wafer replacement; (2) alignment (search alignment, fine alignment); (3) exposure; and (4) wafer replacement, or the like, are repeated by using one wafer stage.
Even if some of the plurality of operations within the above-mentioned three operations, that is, wafer replacement, alignment, and exposure operation, can be performed simultaneously, throughput can be improved compared to the case when these operations are sequentially performed. Exposure of a wafer is not performed during wafer replacement and alignment, and thus in order to improve shortening of process time, that is, throughput, for example, a method can be considered that simultaneously independently controls a first stage in which wafer replacement and alignment are performed and a second stage in which exposure is performed.
With respect to this concept, for example, International Publication No. WO98/40791 discloses a stage device (positioning device) that independently drives two stages in parallel in a two-dimensional X-Y plane. This device provides a pair of driving mechanisms that are symmetrically arranged. Each driving mechanism has a stationary member of an X driving linear motor, opposite ends of which are attached to a respective one of two moving elements of a Y-axis linear motor of that driving mechanism. The moving elements of each Y-driving linear motor drive its stage in the Y-axis direction by a driving force of this Y driving linear motor. The stage device also has rigid connection mechanisms (coupling mechanisms) that couple a side of a stage (object holder) that faces the moving member of the X driving linear motor to that moving member. Thus, the two stages are coupled to the respective driving mechanisms by the respective connection mechanisms.
However, in the positioning device described in the above-mentioned WO98/40791, a rigid connection mechanism is used to couple respective stages to respective driving mechanisms. This rigid connection mechanism includes movable parts that are moved along with the stages, and therefore the weight of the movable parts becomes heavy. As a result, positioning control is not sufficiently assured with respect to the stages. Furthermore, in this positioning device, as described. above, a rigid connection mechanism is used, and therefore a shock force generated during connection (during coupling) may cause a positional shift of a semiconductor substrate (wafer) on the stage. Additionally, as clarified from FIG. 2 or the like of the above-mentioned International Publication, a point of application of thrust of the stages is displaced from the center of gravity, so that rotational moment is generated.
SUMMARY OF THE INVENTION
This invention has been made in view of the above circumstances. One object of this invention is to provide a stage device that prevents a shock force from acting on a movable body when the movable body is positioned with respect to two stationary side members and that prevents an object that is to be mounted on the movable body from being positionally shifted.
Another object of this invention is to provide a stage device that can prevent a shock force from acting on the stages when the two stages are replaced and can simultaneously separately process objects mounted on the stages.
Another object of this invention is to provide an exposure apparatus that improves the ability to control the position of a substrate on a stage and simultaneously improves throughput.
The stage device according to one aspect of the invention includes a first stationary member, a second stationary member, a moving member and positioning devices. The first stationary member extends in a first direction. The second stationary member extends in the first direction and is spaced apart from the first stationary member in a second direction perpendicular to the first direction. The moving member can cooperate with the first stationary member and with the second stationary member. The positioning devices selectively position the moving member into cooperation with one of the first and second stationary members without physically contacting the moving member with the first and second stationary members.
In this specification, “cooperation” means any type of mutual interaction, for example, electromagnetic mutual interaction (including both electromagnetic mutual interaction and magnetic mutual interaction) that is performed between a stationary member and a moving member so that a driving force (thrust) that relatively drives the stationary member
Nguyen Henry Hung
Nikon Corporation
Oliff & Berridg,e PLC
LandOfFree
Stage device and exposure apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Stage device and exposure apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Stage device and exposure apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3203596