Optical element fabrication method, optical element, exposure apparatus, device fabrication method

Abstract

There is to provide an optical element fabrication method including the steps of forming a thin film onto a substrate, and eliminating a color center produced in the forming step by giving energy to the substrate.

What is claimed is:  
     
         1 . An optical element fabrication method comprising the steps of: 
 forming a thin film onto a substrate; and    eliminating a color center produced in said forming step by irradiating light to the substrate.    
     
     
         2 . A fabrication method according to  claim 1 , wherein the substrate contains fluoride.  
     
     
         3 . A fabrication method according to  claim 1 , wherein the thin film contains fluoride.  
     
     
         4 . A fabrication method according to  claim 2 , wherein the fluoride is calcium fluoride.  
     
     
         5 . A fabrication method according to  claim 1 , wherein said irradiating step irradiates the light from a low-pressure mercury lamp.  
     
     
         6 . A fabrication method according to  claim 1 , wherein said irradiating step irradiates the light from a laser light source.  
     
     
         7 . A fabrication method according to  claim 1 , wherein said irradiating step sets light intensity of the light to be 0.02 mJ/cm 2  or higher.  
     
     
         8 . A fabrication method according to  claim 1 , wherein said irradiating step sets an irradiation time of the light to be five minutes or longer.  
     
     
         9 . A fabrication method according to  claim 1 , wherein said irradiating step sets a product between light intensity of the light and irradiation time of the light to be 0.1 mJ·minute/cm 2  or higher.  
     
     
         10 . A fabrication method according to  claim 1 , wherein said forming step forms the thin film in an atmosphere including plasma.  
     
     
         11 . A fabrication method according to  claim 1 , wherein said forming step uses electron beam heating to form the thin film.  
     
     
         12 . An optical element fabrication method comprising the steps of: 
 forming a thin film onto a substrate; and    eliminating a color center produced in said forming step by giving energy to the substrate.    
     
     
         13 . An optical element fabricated by a fabrication method comprising the steps of forming a thin film onto a substrate, and eliminating a color center produced in said forming step by irradiating light to the substrate.  
     
     
         14 . An optical element according to  claim 13 , wherein said optical element is a lens, a diffraction grating, and a complex thereof.  
     
     
         15 . An exposure apparatus that irradiates exposure light to an object to be exposed via an optical system including an optical element, and exposes the object, 
 wherein the optical element is fabricated by a fabrication method comprising the steps of forming a thin film onto a substrate, and eliminating a color center produced in said forming step by irradiating light to the substrate.    
     
     
         16 . An exposure apparatus according to  claim 15 , wherein the exposure light has a wavelength range of 300 nm or less.  
     
     
         17 . A device fabrication method comprising the steps of: 
 exposing the object to be exposed by using an exposure apparatus that irradiates exposure light to the object via an optical system including an optical element, and exposes the object, wherein the optical element is fabricated by a fabrication method comprising the steps of forming a thin film onto a substrate, and eliminating a color center produced in said forming step by irradiating light to the substrate; and    performing a predetermined process for the exposed object.