| 摘要 |
PURPOSE:To correct a reference position in case of revolution at theta deg. of a reticle automatically by detecting a reference mark on an X-Y stage, obtaining the quantity of revolution of the reticle through calculation from the waveform of the pattern and moving the quantity of revolution to a position reaching 0. CONSTITUTION:Beams from an illuminating light source 1 are condensed by a condenser lens 2, passed through the reticle 3 positioned by photoelectric microscopes 7A, 8B, reduced by a projection lens 4 and imaged onto a wafer 5. The wafer 5 is positioned onto a stage 6. The reference marks A, B are printed on the stage 6. A pattern detector 7 detects the reference marks through the projection lens. The X-Y stage is moved in parallel in the X or Y direction, and the reference mark B is pattern-detected and memorized similarly. An error DELTAtheta in case of the revolution of the reticle is calculated by two relative positional errors and the quantity of the X-Y stage moved. The reference positions of the photoelectric microscopes 7 are moved only by DELTAtheta. |
