Photocopying – Projection printing and copying cameras – Step and repeat
Reexamination Certificate
2001-06-29
2003-05-20
Niebling, John F. (Department: 2812)
Photocopying
Projection printing and copying cameras
Step and repeat
Reexamination Certificate
active
06567154
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a scan projection exposure apparatus and, more particularly, to a step & scan projection exposure apparatus for synchronously driving a mask for forming a semiconductor element and a substrate such as a semiconductor wafer, and sequentially exposing a plurality of exposure regions on the semiconductor wafer to a circuit pattern on the mask.
The present invention further relates to a method of maintaining the exposure apparatus by using a network, and a semiconductor device manufacturing method and semiconductor manufacturing factory using the network and exposure apparatus.
BACKGROUND OF THE INVENTION
A step & scan projection exposure apparatus synchronously drives a reticle stage which supports a mask (to be referred to as a “reticle” hereinafter) and a wafer stage which supports a semiconductor wafer, and projects a circuit pattern on a reticle to each exposure region (shot region) on a semiconductor wafer. After one shot region is exposed, the wafer and reticle stages must move (to be referred to as “step driving” hereinafter) to the next shot region to be exposed.
In exposure by scan driving, the synchronization error between the reticle and wafer stages must fall within a predetermined allowable range. Step driving increases a synchronization error, which must fall within the allowable range by the start of exposure after the start of scan driving. To meet this condition, the parameters of a step driving profile, such as the accelerations and speeds of the two stages in step driving and a time (to be referred to as a “settling time” hereinafter) taken from the end of step driving to the start of scan driving must be set in a controller for controlling the step & scan projection exposure apparatus. Conventionally in an apparatus of this type, parameters which make the scan synchronization error at a shot exhibiting the largest scan synchronization error be equal to or smaller than an allowance a are determined, and the determined parameters are set to the same values in all step driving operations.
In the prior art, as described above, the parameters of the step driving profile are set to the same values in all step driving operations.
In practice, however, the convergence of the synchronization error after step driving changes depending on conditions such as the shot region layout, shot (position on the wafer stage), step direction, step driving acceleration, speed, and settling time. If the parameters of the step driving profile are set to the same values, like the prior art, they must be set based on an estimated worst case value. In general, the synchronization error is reduced by setting a low acceleration, low speed, and long settling time in step driving, which results in a long step driving time and low throughput (productivity) of the exposure apparatus. Conventional setting of the step driving profile based on the worst case value excessively decreases the throughput.
SUMMARY OF THE INVENTION
The present invention has been made to overcome the conventional drawbacks, and has as its object to increase the throughput of a step and scan exposure apparatus by optimizing the parameters of a step driving profile for every step driving without increasing the scan synchronization error between reticle and wafer stages during exposure.
According to the present invention, the foregoing object is attained by providing a step & scan projection exposure apparatus comprising: a master stage which can move while supporting a master; a substrate stage which can move in synchronism with the master stage while supporting a substrate; and a controller for controlling synchronous scan driving of the master stage and substrate stage, and setting for each step driving a step driving profile used to perform step driving on the basis of a synchronization error between the master stage and the substrate stage.
According to another aspect of the present invention, the foregoing object is attained by providing a semiconductor device manufacturing method comprising the steps of: installing, in a semiconductor manufacturing factory, manufacturing apparatuses for performing various processes including an exposure apparatus for exposing a substrate to a pattern; and manufacturing a semiconductor device by using the manufacturing apparatuses in a plurality of processes, the exposure apparatus having a master stage which can move while supporting a master, a substrate stage which can move in synchronism with the master stage while supporting a substrate, and a controller for controlling synchronous scan driving of the master stage and substrate stage, and setting for each step driving a step driving profile used to perform step driving on the basis of a synchronization error between the master stage and the substrate stage.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.
REFERENCES:
patent: 6331885 (2001-12-01), Nishi
Canon Kabushiki Kaisha
Fitzpatrick ,Cella, Harper & Scinto
Niebling John F.
Stevenson Andre′ C
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