Stage drive method and stage unit, exposure apparatus, and device manufacturing method

#The present invention relates to stage drive methods and stage units, exposure apparatus, and device manufacturing methods, and more particularly to a stage drive method in which two stages movable in an area including a first area within a two-dimensional plane where a liquid is locally supplied are driven and a stage unit suitable for implementing the stage drive method, an exposure apparatus that supplies liquid in a space between a projection optical system and a substrate and exposes the substrate via the projection optical system and the liquid, and a device manufacturing method that uses the exposure apparatus.

#Conventionally, in a lithography process for manufacturing electronic devices such as a semiconductor device (such as an integrated circuit), a liquid crystal display device or the like, a reduction projection exposure apparatus by the step-and-repeat method that transfers an image of a pattern of a mask or a reticle (hereinafter generally referred to as a ‘reticle’) onto each of a plurality of shot areas on a photosensitive substrate such as a wafer coated with a resist (photosensitive agent), a glass plate, or the like (hereinafter generally referred to as a ‘substrate’ or a ‘wafer’) via a projection optical system, or a projection exposure apparatus by the step-and-scan method (the so-called scanning stepper (also referred to as a scanner)) are mainly used.

#Resolution R of the projection optical system that the projection exposure apparatus has can be expressed as in equation (1) below by Rayleigh's formula. R=k1·λ/NA  (1)

#FIG. 1 is a schematic view showing a configuration of an exposure apparatus related to a first embodiment;

#FIG. 2 is a planar view showing a wafer stage unit related to the first embodiment;

#FIG. 3 is a perspective view showing a wafer stage WST1 in FIG. 2;

#A first embodiment of the present invention will be described below, referring to FIGS. 1 to 10.

#FIG. 1 schematically shows the entire configuration of an exposure apparatus 100 related to the first embodiment. Exposure apparatus 100 is a projection exposure apparatus by the step-and-scan method, that is, the so-called scanning stepper (also called a scanner). Exposure apparatus 100 is equipped with illumination system 10, a reticle stage RST that holds a reticle R serving as a mask, a projection unit PU, a wafer stage unit 50 that has wafer stages WST1 and WST2, off-axis alignment systems ALG1 and ALG2, a control system for these components or assemblies, and the like. On wafer stages WST1 and WST2, substrates serving as wafers are to be mounted. In FIG. 1, a wafer W1 is mounted on wafer stage WST1, and a wafer W2 is mounted on wafer stage WST2.

#As is disclosed in, for example, Kokai (Japanese Unexamined Patent Application Publication) No. 2001-313250 and its corresponding U.S. Patent Application Publication No. 2003/0025890 description or the like, illumination system 10 is configured including a light source and an illuminance uniformity optical system, which includes an optical integrator, and the like. Illumination system 10 also includes a beam splitter, a relay lens, a variable ND filter, a reticle blind, and the like (all of which are not shown). In illumination system 10, an illumination light (exposure light) IL illuminates a slit-shaped illumination area set by the reticle blind on reticle R with a substantially uniform illuminance. In this case, for example, an ArF excimer laser beam (wavelength: 193 nm) is used as illumination light IL. Further, as the optical integrator, a fly-eye lens, a rod integrator (an internal reflection type integrator), a diffractive optical element or the like can be used. As illumination system 10, besides the system described above, a system having the arrangement disclosed in, for example, Kokai (Japanese Unexamined Patent Application Publication) No. 6-349701, and the corresponding U.S. Pat. No. 5,534,970, may also be employed. As long as the national laws in designated states or elected states, to which this international application is applied, permit, the above disclosures of the Kokai publications, the U.S. patent application publication description, and the U.S. patent are incorporated herein by reference.