Projection optical device

Abstract

Abstract PURPOSE:To adjust finely magnifications easily with a high precision without generating an asymmetrical magnification distribution by varying the pressure of an air chamber shut out from outside air to adjust the projection magnification of a projection object lens. CONSTITUTION:A projection object lens 1 reduces and projects the pattern of a reticle R, which is illuminated by an illuminating device 2, onto a wafer W on a table 3. Two independent air chambers 10 and 20 in the lens 1 are connected to pressure controllers 12 and 22 on the outside of the object lens by tubes 11 and 21. Constant-pressure air is supplied to controllers 12 and 22 from a pressurized air supplier 4 through filters 13 and 23, and magnification variations DELTAX1 and DELTAX2 per unit pressure in individual chambers 10 and 20, image-forming surface variations DELTAZ1 and DELTAZ2, and a magnification variation DELTAX and an image-forming surface variation DELTAZ per unit pressure of an air pressure are stored preliminarily by pressure sensors 14 and 24 and an operator 5. The operator 5 detects an air pressure variation DELTAP by the signal of a measuring instrument 6 and calculates pressure variations DELTAP1 and DELTAP2 and outputs signals to controllers 12 and 22 to give pressure variations DELTAP1 and DELTAP2 to individual chambers 10 and 22.

Inventors

• 👤 Akira Anzai
• 👤 安西　暁
• 👤 Koichi Ono
• 👤 大野　康一

Bibliographic Details