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  Exposure apparatus, exposure method, and method for producing deviceUSPTO Application #: 20060274294Title: Exposure apparatus, exposure method, and method for producing device Abstract: A device manufacturing method includes the steps of providing an immersion liquid between a substrate and at least a portion of a projection system of a lithographic projection apparatus, wherein a non-radiation sensitive material is carried by the substrate, the non-radiation sensitive material being at least partially transparent to radiation and being of a different material than the immersion liquid, the non-radiation sensitive material being provided over at least a part of a radiation sensitive layer of the substrate; and projecting a patterned beam of radiation, through the immersion liquid, onto a target portion of the substrate using the projection system. (end of abstract)
Agent: Oliff & Berridge, PLC - Alexandria, VA, US Inventors: Hiroyuki Nagasaka, Nobutaka Magome Related Keywords: beam, exposure, radiation, substrate USPTO Applicaton #: 20060274294 - Class: 355053000 (USPTO) The Patent Description & Claims data below is from USPTO Patent Application 20060274294. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS-REFERENCE [0001] This is a Division of application Ser. No. 11/147,373 filed Jun. 8, 2005, which in turn is a Continuation of International Application No. PCT/JP03/015735 filed on Dec. 9, 2003 and that claims the conventional priority of Japanese patent Application No. 2002-357931 filed on Dec. 10, 2002. The disclosures of these applications are incorporated herein by reference in their entireties. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to an exposure apparatus and an exposure method for performing the exposure with an image of a pattern projected by a projection optical system in a state in which at least a part of a space between the projection optical system and a substrate is filled with a liquid. The present invention also relates to a method for producing a device. [0004] 2. Description of the Related Art [0005] Semiconductor devices and liquid crystal display devices are produced by the so-called photolithography technique in which a pattern formed on a mask is transferred onto a photosensitive substrate. The exposure apparatus, which is used in the photolithography step, includes a mask stage for supporting the mask and a substrate stage for supporting the substrate. The pattern on the mask is transferred onto the substrate via a projection optical system while successively moving the mask stage and the substrate stage. In recent years, it is demanded to realize the higher resolution of the projection optical system in order to respond to the further advance of the higher integration of the device pattern. As the exposure wavelength to be used is shorter, the resolution of the projection optical system becomes higher. As the numerical aperture of the projection optical system is larger, the resolution of the projection optical system becomes higher. Therefore, the exposure wavelength, which is used for the exposure apparatus, is shortened year by year, and the numerical aperture of the projection optical system is increased as well. The exposure wavelength, which is dominantly used at present, is 248 nm of the KrF excimer laser. However, the exposure wavelength of 193 nm of the ArF excimer laser, which is shorter than the above, is also practically used in some situations. When the exposure is performed, the depth of focus (DOF) is also important in the same manner as the resolution. The resolution R and the depth of focus 6 are represented by the following expressions respectively. R=k.sub.1.lamda./NA (1) .delta.=.+-.k.sub.2.pi./NA.sup.2 (2) [0006] In the expressions, .lamda. represents the exposure wavelength, NA represents the numerical aperture of the projection optical system, and k.sub.1 and k.sub.2 represent the process coefficients. According to the expressions (1) and (2), the following fact is appreciated. That is, when the exposure wavelength .lamda. is shortened and the numerical aperture NA is increased in order to enhance the resolution R, then the depth of focus .delta. is narrowed. [0007] If the depth of focus .delta. is too narrowed, it is difficult to match the substrate surface with respect to the image plane of the projection optical system. It is feared that the margin is insufficient during the exposure operation. Accordingly, the liquid immersion method has been suggested, which is disclosed, for example, in International Publication No. 99/49504 as a method for substantially shortening the exposure wavelength and widening the depth of focus. In this liquid immersion method, the space between the lower surface of the projection optical system and the substrate surface is filled with a liquid such as water or any organic solvent to utilize the fact that the wavelength of the exposure light beam in the liquid is 1/n as compared with that in the air (n represents the refractive index of the liquid, which is about 1.2 to 1.6 in ordinary cases) so that the resolution is improved and the depth of focus is magnified about n times. [0008] When the exposure is performed while making the liquid to flow through the space between the projection optical system and the substrate, or when the exposure is performed while moving the substrate with respect to the projection optical system in a state in which the space between the projection optical system and the substrate is filled with the liquid, then there is such a possibility that the liquid may be exfoliated from the projection optical system and/or the substrate. An inconvenience arises such that the pattern image, which is to be transferred to the substrate, is deteriorated. In other cases, the pattern image is deteriorated as well when any turbulence appears in the liquid flow when the exposure is performed while making the liquid to flow through the space between the projection optical system and the substrate. SUMMARY OF THE INVENTION [0009] The present invention has been made taking the foregoing circumstances into consideration, an object of which is to provide an exposure apparatus, an exposure method, and a method for producing a device, in which a pattern can be transferred accurately by arranging a liquid in a desired state when an exposure process is performed while filling a space between a projection optical system and a substrate with the liquid. It is noted that parenthesized numerals or symbols affixed to respective elements merely exemplify the elements by way of example, with which it is not intended to limit the respective elements. [0010] In order to achieve the object as described above, the present invention adopts the following constructions corresponding to FIGS. 1 to 9 as illustrated in embodiments. [0011] According to a first aspect of the present invention, there is provided an exposure apparatus (EX) which exposes a substrate (P) by transferring an image of a pattern through a liquid (50) onto the substrate, the exposure apparatus comprising: [0012] a projection optical system (PL) which projects the image of the pattern onto the substrate, wherein: [0013] a portion (60, PK) of the projection optical system (PL), which makes contact with the liquid (50), is surface-treated to adjust affinity for the liquid (50). [0014] In the exposure apparatus of the present invention, the surface treatment is applied to the portion of the projection optical system (hereinafter appropriately referred to as "liquid contact portion") which makes contact with the liquid in order to adjust the affinity for the liquid. Therefore, the liquid is maintained in a desired state between the projection optical system and the substrate. For example, if the affinity of the liquid contact portion for the liquid is too low, any phenomenon, in which any harmful influence is exerted on the liquid immersion exposure, arises, for example, such that the liquid is exfoliated from the contact portion, and/or any bubble is generated. On the other hand, if the affinity of the liquid contact portion for the liquid is too high, any inconvenience arises in some cases, for example, such that the liquid is spread while causing excessive wetting with respect to the contact portion and the liquid outflows from the space between the projection optical system and the substrate. On the contrary, in the case of the exposure apparatus of the present invention, the affinity is adjusted with respect to the liquid disposed at the liquid contact portion of the projection optical system. Therefore, the liquid immersion state is reliably maintained between the substrate and the projection optical system even in the case of the full field exposure in which the substrate stands still with respect to the exposure light beam during the exposure as well as in the case of the scanning type exposure apparatus in which the substrate is moved by a movable stage during the exposure. [0015] According to a second aspect of the present invention, there is provided an exposure apparatus (EX) which exposes a substrate (P) by transferring an image of a pattern through a liquid (50) onto the substrate, the exposure apparatus comprising: [0016] a projection optical system (PL) which projects the image of the pattern onto the substrate, wherein: [0017] the projection optical system (PL) has a first surface area (AR1) which includes a surface of an optical element (60) disposed at a tip of the projection optical system, and a second surface area (AR2) which is disposed around the first surface area (AR1); and [0018] affinity of the first surface area (AR1) for the liquid (50) is higher than affinity of the second surface area (AR2) for the liquid (50). [0019] According to the present invention, the affinity for the liquid of the first surface area including the optical element disposed at the tip of the projection optical system is made higher than that of the second surface area disposed therearound. Accordingly, the liquid is stably arranged on the optical path for the exposure light beam owing to the first surface area. Further, the liquid is not spread with the wetting to the surroundings owing to the second surface area, and thus does not outflow to the outside. Therefore, the liquid can be stably arranged on the optical path for the exposure light beam even in the case of the full field exposure in which the substrate stands still with respect to the exposure light beam during the exposure as well as in the case of the scanning type exposure in which the substrate is moved with respect to the exposure light beam during the exposure. [0020] According to a third aspect of the present invention, there is provided an exposure apparatus (EX) which exposes a substrate (P) by illuminating a pattern with an exposure beam (EL) and transferring an image of the pattern through a liquid (50) onto the substrate (P), the exposure apparatus comprising: [0021] a projection optical system (PL) which projects the image of the pattern onto the substrate; and Continue reading... Full patent description for Exposure apparatus, exposure method, and method for producing device Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Exposure apparatus, exposure method, and method for producing device patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. 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