System for detecting a latent image using an alignment apparatus

摘要

PCT No. PCT/BE93/00046 Sec. 371 Date Jun. 27, 1994 Sec. 102(e) Date Jun. 27, 1994 PCT Filed Jul. 1, 1993 PCT Pub. No. WO94/01808 PCT Pub. Date Jan. 20, 1994.The system comprises a latent image detection device comprising an alignment device which uses non-actinic radiation (10) and which is intended for aligning the mask pattern with respect to the substrate (3) and is designed for detecting the measure of coincidence of a mask alignment feature and a substrate alignment feature (8). The alignment device is provided with a radiation-sensitive detection system (6) which is connected to an electronic signal circuit in which the amplitude of the radiation incident on the detection system is determined, which originates from a latent image, formed in the photosensitive layer, of a mask feature, in which a spatial frequency occurs which is approximately equal to the useful resolving power of the projection lens system and considerably greater than the resolving power of the alignment device.