| 摘要 |
PROBLEM TO BE SOLVED: To provide a cata-dioptric reduction system used as the projection optical system of a scanning type exposure device, provided with a beam splitter and a concave mirror of practical size and having resolution in quarter micron unit. SOLUTION: In this cata-dioptric reduction system; the image of a pattern on a 1st surface R is formed on a 2nd surface W and the 1st and the 2nd surfaces R and W are synchronously scanned, whereby the image of the pattern in a range enlarged in a scanning direction is formed on the 2nd surface W. The system is constituted of a 1st optical system G1 having positive refractive power, the beam splitter BS arranged so that the incident plane surface of a transmission reflection surface S may include a scanning direction, a 2nd optical system G2 arranged on the reflection optical path or the transmission optical path of the luminous flux made incident on the beam splitter BS and including one concave mirror Mc , a 3rd optical system G, arranged on the transmission optical path or the reflection optical path of the luminous flux returning to the beam splitter BS from the 2nd optical system G2 and having negative refractive power, a plane reflection surface Mp and a 4th optical system G4 having the positive refractive power in order from the 1st surface R. |
