Patent ID: 6717896
Filing Date: 2004-04-06
Classification: B82Y,G03F,G11B

Abstract:
An exposure apparatus comprising:a convergent lens disposed opposite to an object and in a near-field of the object to condense an exposure laser light on the object, wherein the convergent lens includes a two-group lens of a condenser lens and a SIL, the SIL and condenser lens being supported together by a support member having a moving member fixed at an end thereof, and wherein the moving member moves the support member and thus moves the two-group lens of the condenser lens and SIL fixed to the support member towards and away from the object; an exposure light source to emit the exposure laser light; a gap length controlling light source to emit a gap length controlling laser light having a different wavelength from that of the exposure laser light and not in a range to which the object is sensitive, the gap length controlling laser light used only for gap length controlling; means for projecting the gap length controlling laser light to the convergent lens; means for detecting an intensity of a return part of the gap length controlling laser light reflected off an outgoing surface of the convergent lens opposite to the object, the convergent lens including a substantially hemispherical lens having a substantially flat surface facing the object as the outgoing surface; and means for moving the convergent lens for controlling the gap length between a substantially flat surface facing the object as the outgoing surface of the convergent lens and the object based on the light intensity detected by the light intensity detecting means.