ALIGNER, ALIGNING METHOD AND METHOD FOR FABRICATING DEVICE

摘要

In an aligner (100), a detection light flux from an irradiation system (20a) is reflected off the surface and rear of a light transmitting protective member for protecting the pattern face of a mask (R), first and second reflected light beams thus produced are received by a light receiving system (20b), and a main controller (50) calculates the thickness of the protective member based on the detection signals. Exposure is enabled where variation in the focus state of the pattern image is taken into account depending on the calculated thickness of the protective member. Irrespective of difference in the thickness of the protective member for protecting the pattern face of a mask, highly accurate exposure can be effected. Setting of detection offset of the light receiving system or resetting of the origin is eliminated by optimizing the incident angle of the detection light flux.