APPARATUS FOR MEASUREMENT OF SUBSTRATES

摘要

The invention relates to an apparatus for measurement of substrates, comprising a carrier (2) for receiving the substrate to be measured; a measurement objective which images onto a detector a portion of the substrate held by the carrier (2); a measurement device by which the position of the carrier (2) is imaged onto a detector (12); a measurement device by which the position of the carrier (2) holding the substrate is determined relative to the measurement objective, with the measurement device comprising at least one laser interferometer (5) for position determination; a first flushing device which passes a first flushing medium in a laminar flow through the apparatus for generating a constant measurement atmosphere, as well as an adjustment device by which the carrier (2) can be moved relative to the measurement objective. In such an apparatus, a second flushing device is provided which passes a second flushing medium through the region of the measurement device in which the at least one laser interferometer (5) is located.