Radiation imagery chemistry: process – composition – or product th – Radiation modifying product or process of making – Radiation mask
Reexamination Certificate
1998-11-03
2001-01-09
Rosasco, S. (Department: 1756)
Radiation imagery chemistry: process, composition, or product th
Radiation modifying product or process of making
Radiation mask
Reexamination Certificate
active
06171730
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an exposure apparatus and an exposure method. Particularly, the present invention can be preferably applied to an evanescent light exposure apparatus used for fine processing having a size on the order of 100 nm or less.
2. Description of the Related Art
For a photolithographic apparatus having the limit of fine processing (at present, about 0.1 &mgr;m by using a near ultraviolet laser), which is limited by the wavelength of the light used, a fine processing apparatus has recently been proposed, which uses the construction of a near-field optical microscope (referred to as an “SNOM” hereinafter) as a means for permitting fine processing of a size smaller than that provided by the wavelength of the light used. An example of such an apparatus is an apparatus capable of locally exposing a resist by using evanescent light leaking from a fine aperture having a size on the order of 100 nm or less, beyond the processing limit, which is otherwise set by the wavelength of the light used. However, such a lithographic apparatus having the SNOM construction has a problem in that productivity is hardly improved because one processing probe is (or several processing proves are) used for fine processing.
As a method to solve this problem, a proposal has been made to provide a prism on an optical mask, with light being incident on the prism at an angle producing total reflection, to transfer a pattern of the optical mask to a resist at the same time by using evanescent light leaking from the total reflection surface (refer to Japanese Patent Laid-Open No. 8-179493).
In the batch exposure apparatus disclosed in Japanese Patent Laid-Open No. 8-179493, in which the prism is provided for exposure to evanescent light, the distance between the surfaces of the prism and the mask to the resist is thought to be preferably set to 100 nm or less. This is because the evanescent light leaking from the surfaces of the prism and the mask exponentially attenuates as the distance from the surfaces of the prism and the mask increases. However, since the surface precision or flatness of the surfaces of the prism and mask and the substrate, or the parallelism between the surfaces of the prism and mask and the substrate, etc., are limited, it is difficult to set the distance between the surfaces of the prism and mask and the resist surface to 100 nm or less over the entire surface of the prism and the mask. This produces a problem of nonuniformity in the exposed pattern, or causes a partial crushing of the resist by the surfaces of the prism and the mask.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide an exposure apparatus and an exposure method capable of easily performing batch exposure at the exposure light wavelength or less.
In a first aspect, the present invention provides an exposure apparatus for transferring a pattern to an object to be exposed by exposure using a mask having a width of 10 nm or less. The apparatus includes contact means for bringing a first surface of the mask into contact with the object to be exposed by elastically deforming the mask, and irradiation means for irradiating a second surface of the mask, which is brought into contact with the object to be exposed, the second surface being opposite to the first surface.
In another aspect, the present invention provides a mask for transferring a pattern to an object to be exposed by exposure. The mask includes a substrate having a thickness of about 0.1 to about 100 &mgr;m, a metal thin film provided on the substrate and having a thickness of about 10 to 100 nm, and an aperture pattern provided on the metal thin film and having a width of about 100 nm or less.
In still another aspect, the present invention provides an exposure method for transferring a pattern to an object to be exposed by exposure using a mask having an aperture pattern having a width of about 100 nm or less. The method includes the steps of bringing a first surface of the mask into contact with the object to be exposed by elastically deforming the mask, and irradiating a second surface of the mask, which is brought into contact with the object to be exposed, the second surface being opposite to the first surface.
In yet another aspect, the present invention provides a method of transferring a pattern to an object to be exposed by exposure. The method of the present invention includes the steps of providing a mask including (i) a substrate having a thickness of about 0.1 to about 100 nm, (ii) a metal thin film provided on the substrate and having a thickness of about 10 to 100 nm, and (iii) an aperture pattern provided on the metal thin film and having a width of about 100 nm or less, and transferring a pattern to the object by exposure using the mask, the object having a surface on which a resist film is formed by a Langmuir-Blodgett's method.
In still another aspect, the present invention provides a method of transferring a pattern to an object to be exposed by exposure. The method of the invention includes the steps of providing a mask including (i) a substrate having a thickness of about 0.1 to about 100 nm, (ii) a metal thin film provided on the substrate and having a thickness of about 10 to 100 nm, and (iii) an aperture pattern provided on the metal thin film and having a width of about 100 nm or less, and transferring a pattern to the object by exposure using the mask, the object having a surface on which a resist film is formed by a self-alignment single molecular film forming method.
In still another aspect, the present invention provides an exposure apparatus for exposing a pattern on a mask to an object by using evanescent light. The apparatus includes a pressure difference applying structure for generating a pressure difference between a first surface of the mask and a second surface of the mask, which is opposite to the first surface, a stage for supporting and arranging the object opposite to the first surface of the mask, with an interface therebetween, and a light source for emitting light to the second surface of the mask at an angle of total reflection in the interface between the first surface of the mask and the object to be exposed.
In yet a further aspect, the present invention provides a mask including a first surface, opposite to an object to be exposed, with an interface therebetween, a second surface, opposite to the first surface, which is irradiated with light to transfer a pattern to the object by exposure using evanescent light, a mother material, and an aperture pattern provided in the mother material. The mask is adhered to the object, and during adhesion, the refractive index of the mother material is higher than the refractive index of the constituent material of the object to be exposed, in the interface between the surface of the mask and the object.
In yet still another aspect, the present invention provides an exposure method for exposing a mask pattern to an object to be exposed by using evanescent light. The method includes the steps of arranging the mask opposite to the object, applying pressure to the mask, which is arranged opposite to the object, from the side of the mask, which is opposite to the side of the mask facing the object, generating evanescent light under the applied pressure, and transferring the pattern of the mask onto the object by exposure to the evanescent light.
Further objects, features and advantages of the present invention will become apparent from the following description of the preferred embodiments.
REFERENCES:
patent: 5737064 (1998-04-01), Inoue et al.
patent: 8-179493 (1996-07-01), None
Ikeda Tsutomu
Kuroda Ryo
Shimada Yasuhiro
Canon Kabushiki Kaisha
Fitzpatrick ,Cella, Harper & Scinto
Rosasco S.
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