Patent ID: 6356616
Filing Date: 2002-03-12
Classification: G03F

Abstract:
A projection-exposure apparatus comprising:(a) an X-ray source; (b) an illumination-optical system operable to irradiate a surface of a reticle defining a pattern with X-rays emitted from the X-ray source; (c) a projection-optical system operable to receive X-rays reflected by the surface of the reticle and to project and focus an image of the irradiated pattern onto a surface of a substrate; (d) a reticle stage operable to secure the reticle; (e) a substrate stage operable to secure the substrate; (f) a vacuum chamber enclosing the projection-optical system, the reticle stage, and the substrate stage; (g) an axial-position detection system operable to optically detect the position of the substrate in the direction of an optical axis of the projection-optical system, wherein the axial-position detection system comprises (i) a light source, (ii) a first slit, (iii) a light-transmitting system operable to illuminate the first slit, (iv) a first optical assembly operable to project an image of the first slit onto the surface of the substrate, (v) a second slit, (vi) a second optical assembly operable to project the projected image of the first slit formed on the surface of the substrate onto the second slit, and (vii) a detector operable to receive light that passes through the second slit; and (h) wherein at least the first slit, first optical assembly, second slit, and second optical assembly are disposed within the vacuum chamber.