| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a last lens of immersion exposure device formed of a crystal represented by formula BaLiF<SB>3</SB>. <P>SOLUTION: A last lens for immersion exposure device is formed of a crystal represented by formula BaLiF<SB>3</SB>. The crystal is preferably a single crystal represented by formula BaLiF<SB>3</SB>. The immersion exposure device is preferably provided with a light source of a wavelength of 200 nm or less, more specifically, an ArF excimer laser oscillator or an F<SB>2</SB>excimer laser oscillator. By virtue of the last lens of the immersion exposure device, it is possible to attain a high refractivity, a high transmissivity, and low SBR at the wavelength, preferably 200 nm or less, of the light used in the light source, and to facilitate improving the resolution of the exposure device. <P>COPYRIGHT: (C)2007,JPO&INPIT |
