Photocopying – Projection printing and copying cameras – Step and repeat
Reexamination Certificate
1999-05-11
2001-07-24
Adams, Russell (Department: 2851)
Photocopying
Projection printing and copying cameras
Step and repeat
C355S067000, C355S077000, C355S075000
Reexamination Certificate
active
06266131
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to a scanning-type exposure apparatus suitably used for the manufacture of various electronic devices such as a liquid crystal display device and a semiconductor chip.
In one such conventional scanning-type exposure apparatus as disclosed in Japanese Patent Unexamined Publication No. 61-188933, a mask, serving as a master plate, and a light-sensitive substrate, serving as a member to be exposed (hereinafter referred to as “exposure member”), are positioned or registered with respect to each other, and then the mask and the light-sensitive substrate are moved (that is, subjected to a scanning operation) in unison relative to an optical projection system, so that an image of the mask is transferred to the light-sensitive substrate. In this exposure apparatus, the mask is supported horizontally, and a stage movable in directions X, Y and e is provided for the light-sensitive substrate. This stage requires a large stroke for stepping movement in a direction (direction X) perpendicular to the scanning direction.
In this conventional exposure apparatus, the mask and the light-sensitive substrate are placed on a carriage, and are scanningly moved relative to the optical projection system through the carriage, thereby exposing the whole of a pattern area. Recently, however, a pattern area has been increased in size, and there has now been increasingly used a method in which a plurality of liquid crystal panels are taken or formed from a single light-sensitive substrate. Under the circumstances, it has been necessary to increase the extent of exposure and to increase the scanning length. This has invited a problem that the size of the exposure apparatus itself has been increased. To overcome this problem, there has been proposed a so-called step-and-scan exposure method in which the pattern area is divided into a plurality of sections, and the scanning exposure is effected for each section in a separate manner. This method has been used in the manufacture of a device having a large single effective pattern area such as a liquid crystal device.
In the step-and-scan exposure method, however, the mask and the optical system must be steppingly moved relative to each other not only in the scanning direction but also in a direction perpendicular to the scanning direction (In some scanning methods, the light-sensitive substrate must also be moved relative to the mask). This not only makes the construction of the exposure apparatus complicated but also requires the mask and the light-sensitive substrate to be aligned with each other for each stepping motion so that highly precisely-adjoining exposure areas can be joined together. This adversely affects the throughput.
Furthermore, when the large mask corresponding to the large pattern area is supported horizontally, the mask is flexed or deflected due to its own weight, and because of this deflection the pattern image of the mask is shifted laterally, thus causing a shift error. This shift error adversely affects the precision of the exposure as described later.
SUMMARY OF THE INVENTION
It is an object of this invention to provide an exposure apparatus which overcomes the above problems of the prior art.
According to one aspect of the present invention, there is provided a scanning-type exposure apparatus comprising:
a support structure for substantially vertically holding an original plate and an exposure member in opposed relation to each other;
an optical projection system comprising a plurality of optical elements arranged in a predetermined direction for projecting an equal-size, erected image of the original plate onto the exposure member; and
a scanning device for scanningly moving the original plate and the exposure member in synchronism with each other relative to the optical projection system in a direction which is perpendicular to both of the predetermined direction and an optical axis of the optical projection system.
The scanning device can comprise an air bearing, and a guide. In this case, the guide has a first travel region for supporting the original plate and the exposure member during the movement of the master plate and the exposure member for effecting the exposure, and a second travel region extending continuously from the first travel region. With this arrangement, the guide needs to be worked with high precision only at the first travel region, and despite this the support structure can be moved over a wide range throughout the guide. With this construction, the original plate and the exposure member can be exchanged easily, and the maintenance of the support structure can be effected easily.
According to another aspect of the invention, there is provided an exposure apparatus which comprises a conveyance device for conveying a light-sensitive substrate in such a manner that the light-sensitive substrate is disposed vertically at an exposure position, the conveyance device occupying a less installation space in a horizontal direction.
According to a further aspect of the invention, there is provided an exposure apparatus for exposing a light sensitive substrate, comprising:
a substrate stage having a vertically-disposed holder surface for holding the light-sensitive substrate;
an erecting stage for erecting the light-sensitive substrate, fed from the exterior of the apparatus, in such a manner that a plane of the light-sensitive substrate is disposed substantially vertically; and
a conveyance device for conveying the erected light-sensitive substrate to the holder surface of said substrate stage.
REFERENCES:
patent: 3494695 (1970-02-01), Sollima et al.
patent: 3819265 (1974-06-01), Feldman et al.
patent: 4011011 (1977-03-01), Hemstreet et al.
patent: 4391494 (1983-07-01), Hershel
patent: 4737823 (1988-04-01), Bouwer et al.
patent: 4760429 (1988-07-01), O'Conner
patent: 4899195 (1990-02-01), Gotoh
patent: 5298939 (1994-03-01), Swanson et al.
patent: 5498118 (1996-03-01), Nakahara
patent: 5530516 (1996-06-01), Sheets
patent: 5568225 (1996-10-01), Tazawa et al.
patent: 5579147 (1996-11-01), Mori et al.
patent: 5798822 (1998-08-01), Miyazaki et al.
Expanding the Horizons of Optical Projection Lithography, pp. 77-82, Solid State Technology/May 1982.
Hamada Tomohide
Shirasu Hiroshi
Adams Russell
Armstrong Westerman Hattori McLeland & Naughton LLP
Nguyen Hung Henry
Nikon Corporation
LandOfFree
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 Exposure apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Exposure apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2534180